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  • 1.
    Adolfsson, Emelie
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Alm Carlsson, Gudrun
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Grindborg, Jan-Erik
    Statens Strålskyddsinstitut, Stockholm.
    Gustafsson, Håkan
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Carlsson Tedgren, Åsa
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Response of Lithium Formate EPR Dosimeters at Photon Energies Relelvant to Brachytherapy2009Ingår i: IFMBE Proceedings, Heidelberg: Springer Berlin Heidelberg , 2009, s. 236-239Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    After development of sensitive dosimeter materials Electron Paramagnetic Resonance EPR dosimetry has been successfully used also in radiation therapy. The intensity of the EPR-signal is a measure of the amount of free radicals created by ionizing radiation which is proportional to the absorbed dose in the dosimeter. Lithium formate monohydrate is a dosimeter material with 2-6 times higher sensitivity than alanine, a linear dose response over a wide dose range and mass-energy absorption properties similar to water. These properties make lithium formate promising for verification of absorbed doses around high dose rate brachytherapy sources where the dose gradient is steep and the photon energy distribution changing with distance from the source. Calibration of the dosimeters is performed in 60Co or MV photon beams where high dosimetric accuracy is feasible. The use in brachytherapy field relies on the assumption that the production of free radicals per mean absorbed dose in the dosimeter is similar at the lower photon energies present there. The aim of this work was to test that assumption. The response of the dosimeters as a function of photon energy was determined by irradiations with four x-ray qualities in the range 100-250 kV and 137Cs, relative to the response when irradiated with 60Co, all photon beams with well-known air kerma rates at the Swedish Secondary Standards Dosimetry Laboratory. Monte Carlo simulations were used to convert air kerma free in air to mean absorbed dose to the dosimeter. The measured response relative 60Co as a function of photon energy was below unity for all qualities. The maximum deviation from unity was 2.5% (100 kV, 135 kV) with a relative standard deviation of 1.5% (k = 1).

  • 2.
    Adolfsson, Emelie
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Alm Carlsson, Gudrun
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Grindborg, Jan-Erik
    Swedish Radiation Safety Authority, Stockholm, Sweden .
    Gustafsson, Håkan
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Carlsson Tedgren, Åsa
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen. Swedish Radiation Safety Authority, Stockholm, Sweden .
    Response of lithium formate EPR dosimeters at photon energies relevant to the dosimetry of brachytherapy2010Ingår i: Medical physics (Lancaster), ISSN 0094-2405, Vol. 37, nr 9, s. 4946-4959Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE:

    To investigate experimentally the energy dependence of the detector response of lithium formate EPR dosimeters for photon energies below 1 MeV relative to that at 60Co energies. High energy photon beams are used in calibrating dosimeters for use in brachytherapy since the absorbed dose to water can be determined with high accuracy in such beams using calibrated ion chambers and standard dosimetry protocols. In addition to any differences in mass-energy absorption properties between water and detector, variations in radiation yield (detector response) with radiation quality, caused by differences in the density of ionization in the energy imparted (LET), may exist. Knowledge of an eventual deviation in detector response with photon energy is important for attaining high accuracy in measured brachytherapy dose distributions.

    METHODS:

    Lithium formate EPR dosimeters were irradiated to known levels of air kerma in 25-250 kV x-ray beams and in 137Cs and 60Co beams at the Swedish Secondary Standards Dosimetry Laboratory. Conversions from air kerma free in air into values of mean absorbed dose to the detectors were made using EGSnrc MC simulations and x-ray energy spectra measured or calculated for the actual beams. The signals from the detectors were measured using EPR spectrometry. Detector response (the EPR signal per mean absorbed dose to the detector) relative to that for 60Co was determined for each beam quality.

    RESULTS:

    Significant decreases in the relative response ranging from 5% to 6% were seen for x-ray beams at tube voltages < or = 180 kV. No significant reduction in the relative response was seen for 137Cs and 250 kV x rays.

    CONCLUSIONS:

    When calibrated in 60Co or MV photon beams, corrections for the photon energy dependence of detector response are needed to achieve the highest accuracy when using lithium formate EPR dosimeters for measuring absorbed doses around brachytherapy sources emitting photons in the energy range of 20-150 keV such as 169Yb and electronic sources.

  • 3.
    Adolfsson, Emelie
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet.
    Carlsson Tedgren, Åsa
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US.
    Alm Carlsson, Gudrun
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US.
    Gustafsson, Håkan
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Medicinsk teknik i Östergötland.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet.
    Optimisation of an EPR dosimetry system for robust and high precision dosimetry2014Ingår i: Radiation Measurements, ISSN 1350-4487, E-ISSN 1879-0925, Vol. 70, s. 21-28Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Clinical applications of electron paramagnetic resonance (EPR) dosimetry systems demand high accuracy causing time consuming analysis. The need for high spatial resolution dose measurements in regions with steep dose gradients demands small sized dosimeters. An optimization of the analysis was therefore needed to limit the time consumption. The aim of this work was to introduce a new smaller lithium formate dosimeter model (diameter reduced from standard diameter 4.5 mm to 3 mm and height from 4.8 mm to 3 mm). To compensate for reduced homogeneity in a batch of the smaller dosimeters, a method for individual sensitivity correction suitable for EPR dosimetry was tested. Sensitivity and repeatability was also tested for a standard EPR resonator and a super high Q (SHQE) one. The aim was also to optimize the performance of the dosimetry system for better efficiency regarding measurement time and precision. A systematic investigation of the relationship between measurement uncertainty and number of readouts per dosimeter was performed. The conclusions drawn from this work were that it is possible to decrease the dosimeter size with maintained measurement precision by using the SHQE resonator and introducing individual calibration factors for dosimeter batches. It was also shown that it is possible reduce the number of readouts per dosimeter without significantly decreasing the accuracy in measurements.

  • 4.
    Adolfsson, Emelie
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet.
    Gustafsson, Håkan
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Medicinsk teknik i Östergötland.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet.
    Alm Carlsson, Gudrun
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US.
    Olsson, Sara
    Medical Physics and Technology, Växjö Central Hospital, Växjö, Sweden.
    Carlsson Tedgren, Åsa
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US.
    A system for remote dosimetry audit of 3D-CRT, IMRT and VMAT based on lithium formate dosimetry2014Ingår i: Radiotherapy and Oncology, ISSN 0167-8140, E-ISSN 1879-0887, Vol. 113, nr 2, s. 279-282Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this work was to develop and test a remote end-to-end audit system using lithium formate EPR dosimeters. Four clinics were included in a pilot study, absorbed doses determined in the PTV agreed with TPS calculated doses within ±5% for 3D-CRT and ±7% (k=1) for IMRT/VMAT dose plans.

  • 5.
    Adolfsson, Emelie
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Karlsson, Mattias
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet.
    Alm Carlsson, Gudrun
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US.
    Carlsson Tedgren, Åsa
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US. Swedish Radiation Safety Authority, Stockholm, Sweden .
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Olsson, Sara
    Central Hospital Växjö, Sweden.
    Gustafsson, Håkan
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Investigation of signal fading in lithium formate EPR dosimeters using a new sensitive method2012Ingår i: Physics in Medicine and Biology, ISSN 0031-9155, E-ISSN 1361-6560, Vol. 57, nr 8, s. 2209-2217Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this study was to investigate signal fading in lithium formate electron paramagnetic resonance (EPR) dosimeters used for clinical applications in radiotherapy. A new experimental method for determination of signal fading, designed to resolve small changes in signal from slowly decaying unstable radicals, was used. Possible signal fading in lithium formate due to different storage temperatures was also tested. Air humidity was kept at a constant level of 33% throughout the experiments. The conclusion drawn from the investigations was that the EPR signal from lithium formate is stable during at least 1 month after irradiation and is not sensitive to variations in storage temperature andlt;40 degrees C when kept at a relative air humidity of 33%. This makes lithium formate a suitable dosimeter for transfer dosimetry in clinical audits.

  • 6.
    Adolfsson, Emelie
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet.
    White, Shane
    Department of Radiation Oncology (MAASTRO), GROW – School for Oncology and Developmental Biology, Maastricht University Medical Center, The Netherlands.
    Landry, Guillaume
    Department of Radiation Oncology (MAASTRO), GROW – School for Oncology and Developmental Biology, Maastricht University Medical Center, The Netherlands.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet.
    Gustafsson, Håkan
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Medicinsk teknik i Östergötland.
    Verhaegen, Frank
    Department of Radiation Oncology (MAASTRO), GROW – School for Oncology and Developmental Biology, Maastricht University Medical Center, The Netherlands.
    Reniers, Brigitte
    Department of Radiation Oncology (MAASTRO), GROW – School for Oncology and Developmental Biology, Maastricht University Medical Center, The Netherlands.
    Carlsson Tedgren, Åsa
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US.
    Alm Carlsson, Gudrun
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US.
    Measurement of absorbed dose to water around an electronic brachytherapy source: Comparison of two dosimetry systems: lithium formate EPR dosimeters and radiochromic EBT2 film2015Ingår i: Physics in Medicine and Biology, ISSN 0031-9155, E-ISSN 1361-6560, Vol. 60, nr 9, s. 3869-3882Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Interest in high dose rate (HDR) electronic brachytherapy operating at 50 kV is increasing. For quality assurance it is important to identify dosimetry systems that can measure the absorbed doses in absolute terms which is difficult in this energy region. In this work a comparison is made between two dosimetry systems, EPR lithium formate dosimeters and radiochromic EBT2 film.

    Both types of dosimeters were irradiated simultaneously in a PMMA phantom using the Axxent EBS. Absorbed dose to water was determined at distances of 10 mm, 30 mm and 50 mm from the EBS. Results were traceable to different primary standards as regards to absorbed dose to water (EPR) and air kerma (EBT2). Monte Carlo simulations were used in absolute terms as a third estimate of absorbed dose to water.

    Agreement within the estimated expanded (k = 2) uncertainties (5% (EPR), 7% (EBT2)) was found between the results at 30 mm and 50 mm from the x-ray source. The same result was obtained in 4 repetitions of irradiation, indicating high precision in the measurements with both systems. At all distances, agreement between EPR and Monte Carlo simulations was shown as was also the case for the film measurements at 30mm and 50mm. At 10mm the geometry for the film measurements caused too large uncertainty in measured values depending on the exact position (within sub-mm distances) of the EBS and the 10 mm film results were exculded from comparison.

    This work has demonstrated good performance of the lithium formate EPR dosimetry system in accordance with earlier experiments at higher photon energies (192Ir HDR brachytherapy). It was also highlighted that there might be issues regarding the energy dependence and intrinsic efficiency of the EBT2 film that need to be considered for measurements using low energy sources.

  • 7.
    Alm Carlsson, Gudrun
    et al.
    Linköpings universitet, Institutionen för medicin och vård, Radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Ekberg, Stefan
    Linköpings universitet, Institutionen för medicin och vård, Radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Helmrot, Ebba
    Linköpings universitet, Institutionen för medicin och vård, Radiofysik. Linköpings universitet, Hälsouniversitetet.
    Lindström, Jan
    Linköpings universitet, Institutionen för medicin och vård, Radiofysik. Linköpings universitet, Hälsouniversitetet.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och vård, Radiofysik. Linköpings universitet, Hälsouniversitetet.
    Matscheko, Georg
    Linköpings universitet, Institutionen för medicin och vård, Radiofysik. Linköpings universitet, Hälsouniversitetet.
    Nilsson, Håkan
    Linköpings universitet, Institutionen för medicin och vård, Radiofysik. Linköpings universitet, Hälsouniversitetet.
    Persliden, Jan
    Linköpings universitet, Institutionen för medicin och vård, Radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Sandborg, Michael
    Linköpings universitet, Institutionen för medicin och vård, Radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Stenström, Mats
    Linköpings universitet, Institutionen för medicin och vård, Radiofysik. Linköpings universitet, Hälsouniversitetet.
    Monte Carlo metoden: ett verktyg inom strålningsfysiken1995Rapport (Övrigt vetenskapligt)
    Abstract [sv]

    Detta kompendium är tänkt att användas som ett propedeutiskt kursmaterial för kursdeltagare i kursen "Monte Carlo simulering av foton- och elektrontransport vid diagnostiska och radioterapeutiska strålkvaliteter".

    Först följer en kort repetition av den grundläggande statistik som utnyt1jas i beräkningarna. Därefter följer en beskrivning av slumptal. det fundament som metoden bygger på. Vidare beskrivs val ur olika frekvensfunktioner. Valet kan även göras ur så kallade falska fördelningar för att reducera variansen i den skattade storheten. Metoderna belyses i ett avsnitt om problemlösningsmetodik. först i allmänna termer för att sen gå in på ett specifikt problem (Buffons nålproblem) där en analys och strukturering av problemet görs varefter flödesschema och kodning exemplifieras. Så följer två moment där en beskrivning görs av färderna av fotoner respektive elektroner genom materia. För elektronfärderna gör man en indelning i klass 1- och klass II-färder. Vad detta innebär och hur deltapartiklar tas om hand beskrivs i ett kapitel. Till sist kommer en kort introduktion till de tre laborationerna med laborationshandledningar. Speciell vikt har lagts vid att initiera laboranten att fundera på fysiken i de simulerade experimenten.

    Detta kompendium har tillkommit som examinationsarbete vid en kurs i "Monte Carlo simulering av foton- och elektrontransport vid diagnostiska och radioterapeutiska strålkvaliteter", med andra ord den kurs du själv nu ämnar studera. Författarna önskar dig lycka till med kursen och hoppas att du kommer att få glädje av den. Speciellt hoppas vi att denna skrift ska underlätta för dig att tillgodogöra dig informationen vid föreläsningarna och under laborationerna.

  • 8.
    Brandejsky, Vaclav
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US. Linköpings universitet, Hälsouniversitetet.
    Dahlqvist Leinhard, Olof
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Lundberg, Peter
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US. Östergötlands Läns Landsting, Diagnostikcentrum, Röntgenkliniken i Linköping. Linköpings universitet, Hälsouniversitetet.
    A novel method for RF coil magnetic field mapping2008Konferensbidrag (Övrigt vetenskapligt)
  • 9.
    Brandejsky, Vaclav
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US. Linköpings universitet, Hälsouniversitetet.
    Dahlqvist Leinhard, Olof
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Lundberg, Peter
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US. Östergötlands Läns Landsting, Diagnostikcentrum, Röntgenkliniken i Linköping. Linköpings universitet, Hälsouniversitetet.
    New MR-scanner independent B1 field mapping technique2009Konferensbidrag (Övrigt vetenskapligt)
  • 10.
    Carlsson, C.A.
    et al.
    Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Alm Carlsson, Gudrun
    Linköpings universitet, Institutionen för medicin och vård, Radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Pettersson, Håkan
    Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen. Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Matscheko, G.
    Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    An instrument for measuring ambient dose equivalent, H*(10)1996Ingår i: Radiation Protection Dosimetry, ISSN 0144-8420, E-ISSN 1742-3406, Vol. 67, nr 1, s. 33-39Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The design and calibration of a small and simple instrument for measuring the ambient dose equivalent, H*(10), in photon fields is described. Comprising a thermoluminescence LiF dosemeter inside a 20 mm diameter PMMA sphere, it is capable of measuring the ambient dose equivalent with a nearly isotropic response. In the interval 0.1-100 mSv and for the energy range 30 keV to 1.25 MeV the energy response is within -31% and +15% relative to that of 137Cs gamma radiation (662 keV). In practical use, it is therefore sufficient to calibrate the instrument in a 137Cs gamma field using the corresponding conversion coefficient H*(10)/Kair taken from tabulations. The possibility of using the instrument to monitor the ambient dose equivalent for energies above 1.25 MeV is discussed and indicates that the range of applicability can be extended to 4.4 MeV with an energy response within -10% relative to 662 keV.

  • 11.
    Dahlqvist Leinhard, Olof
    et al.
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Cohen, L
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Lundberg, Peter
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US. Östergötlands Läns Landsting, Diagnostikcentrum, Röntgenkliniken i Linköping. Linköpings universitet, Hälsouniversitetet.
    Absolute quantification of 31P muscle MRS using B1-field mapping2005Konferensbidrag (Övrigt vetenskapligt)
  • 12.
    Danilczuk, M.
    et al.
    nstitute of Nuclear Chemistry and Technology, Warsaw, Poland.
    Gustafsson, Håkan
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Sastry, M. D.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Development of nickel-doped lithium formate as potential EPR dosimeter for low dose determination2007Ingår i: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, ISSN 1386-1425, Vol. 67, nr 5, s. 1370-1373Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    EPR dosimetry employing l-α-alanine has been in vogue during the past few years, due to its tissue equivalence and linear dose response. However, l-α-alanine dosimetry has been improved during the past years, the sensitivity of this material is still too low for clinical applications. Polycrystalline lithium formate doped with NiCl2 was therefore examined for radiation response in the dose range of clinical interest (<5 Gy) using CW EPR and pulse EPR techniques. At equal and moderate settings of microwave power and modulation amplitude lithium formate doped with 1.6 wt% of NiCl2 was almost four times more sensitive compared to l-α-alanine, which is the most common EPR dosimeter standard. It was shown that the nickel-doped lithium formate has an excellent radiation response with a low limit of the measurable dose, and a linear dose response in the range 1–5 Gy. The relaxation and power saturation studies showed that high microwave power can be applied during measurements to improve the sensitivity of this material as an EPR dosimeter. These results show that lithium formate doped with Ni(II) exhibits promising properties required for further development of an EPR dosimeter in the dose range typical for clinical dosimetry.

  • 13. Danilczuk, M.
    et al.
    Gustafsson, Håkan
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Sastry, M.D.
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Lund, Anders
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemisk Fysik. Linköpings universitet, Tekniska högskolan.
    Ammonium Dithionate – a New Material for Highly Sensitive EPR Dosimetry2008Ingår i: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy, ISSN 1386-1425, E-ISSN 1873-3557, Vol. 69, nr 1, s. 18-21Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Polycrystalline ammonium dithionate has been examined for its radiation response in the low dose range (< 5 Gy) using EPR technique. The •SO3- radical ion was detected as a single EPR line with a peak-to-peak derivative width of ca. 0.44 mT in irradiated samples and its intensity was found to vary linearly with dose. At equal and moderate settings of microwave power and modulation amplitude ammonium dithionate was at least 7 times more sensitive than L-alanine which is the most common EPR dosimeter standard. Pulse experiments were performed on the powder samples to obtain the longitudinal relaxation time. These and microwave saturation experiments served to indicate the optimal microwave power to be applied during measurements as an EPR dosimeter for best sensitivity of this material. It is thus claimed that ammonium dithionate has excellent potential to become an EPR dosimeter with a low limit of the measurable dose for cases where tissue equivalence is not required or can be corrected for.

  • 14.
    Fattibene, P
    et al.
    Ist Super Sanita.
    Wieser, A
    Helmholtz Zentrum Muenchen.
    Adolfsson, Emelie
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Benevides, L A
    USN.
    Brai, M
    University of Palermo.
    Callens, F
    University of Ghent.
    Chumak, V
    Research Centre Radiat Medical AMS.
    Ciesielski, B
    Medical University of Gdansk.
    Della Monaca, S
    Ist Super Sanita.
    Emerich, K
    Department Paediat Dentistry.
    Gustafsson, Håkan
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet.
    Hirai, Y
    Radiat Effects Research Fdn.
    Hoshi, M
    Hiroshima University.
    Israelsson, Axel
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Ivannikov, A
    Medical Radiol Research Centre.
    Ivanov, D
    Institute Met Phys.
    Kaminska, J
    Medical University of Gdansk.
    Ke, Wu
    Beijing Institute Radiat Med.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Marrale, M
    University of Palermo.
    Martens, L
    University of Ghent.
    Miyazawa, C
    Ohu University.
    Nakamura, N
    Radiat Effects Research Fdn.
    Panzer, W
    Helmholtz Zentrum Muenchen.
    Pivovarov, S
    Institute Nucl Phys.
    A Reyes, R
    Uniformed Serv University of Health Science.
    Rodzi, M
    Hiroshima University.
    Romanyukha, A A
    USN.
    Rukhin, A
    Institute Nucl Phys.
    Sholom, S
    Research Centre Radiat Medical AMS.
    Skvortsov, V
    Medical Radiol Research Centre.
    Stepanenko, V
    Medical Radiol Research Centre.
    A Tarpan, M
    University of Ghent.
    Thierens, H
    University of Ghent.
    Toyoda, S
    Okayama University of Science.
    Trompier, F
    Institute Radioprotect and Surete Nucl.
    Verdi, E
    Helmholtz Zentrum Muenchen.
    Zhumadilov, K
    Hiroshima University.
    The 4th international comparison on EPR dosimetry with tooth enamel Part 1: Report on the results2011Ingår i: Radiation Measurements, ISSN 1350-4487, E-ISSN 1879-0925, Vol. 46, nr 9, s. 765-771Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents the results of the 4th International Comparison of in vitro electron paramagnetic resonance dosimetry with tooth enamel, where the performance parameters of tooth enamel dosimetry methods were compared among sixteen laboratories from all over the world. The participating laboratories were asked to determine a calibration curve with a set of tooth enamel powder samples provided by the organizers. Nine molar teeth extracted following medical indication from German donors and collected between 1997 and 2007 were prepared and irradiated at the Helmholtz Zentrum Munchen. Five out of six samples were irradiated at 0.1, 0.2, 0.5, 1.0 and 1.5 Gy air kerma; and one unirradiated sample was kept as control. The doses delivered to the individual samples were unknown to the participants, who were asked to measure each sample nine times, and to report the EPR signal response, the mass of aliquots measured, and the parameters of EPR signal acquisition and signal evaluation. Critical dose and detection limit were calculated by the organizers on the basis of the calibration-curve parameters obtained at every laboratory. For calibration curves obtained by measuring every calibration sample three times, the mean value of the detection limit was 205 mGy, ranging from 56 to 649 mGy. The participants were also invited to provide the signal response and the nominal dose of their current dose calibration curve (wherever available), the critical dose and detection limit of which were also calculated by the organizers.

  • 15.
    Fattibene, Paola
    et al.
    Istituto Superiore di Sanità, Rome, Italy.
    Trompier, Francois
    Institut de Radioprotection et de Sûreté Nucléaire, Fontenay-aux-Roses, France.
    Wieser, Albrecht
    Institute of Radiation Protection, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany.
    Brai, Maria
    Dipartimento di Fisica e Chimica, Università di Palermo, Viale Delle Scienze, Palermo, Italy.
    Ciesielski, Bartlomej
    Medical University of Gdansk, Gdańsk, Poland.
    De Angelis, Cinzia
    Istituto Superiore di Sanità, Rome, Italy.
    Della Monaca, Sara
    Istituto Superiore di Sanità, Rome, Italy.
    Garcia, Tristan
    CEA, LIST, Laboratoire National Henri Becquerel, Gif-sur-Yvette, France.
    Gustafsson, Håkan
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Medicinsk teknik i Östergötland.
    Hole, Eli Olag
    Department of Physics, University of Oslo (UiO), Oslo, Norway.
    Juniewicz, M.
    Medical University of Gdansk, Gdańsk, Poland.
    Krefft, K.
    Medical University of Gdansk, Gdańsk, Poland.
    Longo, Anna
    Dipartimento di Fisica e Chimica, Università di Palermo, Palermo, Italy.
    Leveque, Philippe
    Université Catholique de Louvain, Louvain, Belgium.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet.
    Marrale, Maurizio
    Dipartimento di Fisica e Chimica, Università di Palermo, Palermo, Italy.
    Michalec, Barbara
    The Henryk Niewodniczański Institute of Nuclear Physics, Kraków, Poland.
    Mierzwinska, Gabriela
    The Henryk Niewodniczański Institute of Nuclear Physics, Kraków, Poland.
    Rao, J. L.
    Sri Venkateswara University, Tirupati, Andhra Pradesh, India.
    Romanyukha, Alexander A.
    Naval Dosimetry Center, US Navy, Bethesda, MD, USA.
    Tuner, Hasan
    Department of Physics, Faculty of Art and Science, Balikesir University, 10145, Cagis, Balıkesir, Turkey.
    EPR dosimetry intercomparison using smart phone touch screen glass2014Ingår i: Radiation and Environmental Biophysics, ISSN 0301-634X, E-ISSN 1432-2099, Vol. 53, nr 2, s. 311-320Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents the results of an interlaboratory comparison of retrospective dosimetry using the electron paramagnetic resonance method. The test material used in this exercise was glass coming from the touch screens of smart phones that might be used as fortuitous dosimeters in a large-scale radiological incident. There were 13 participants to whom samples were dispatched, and 11 laboratories reported results. The participants received five calibration samples (0, 0.8, 2, 4, and 10 Gy) and four blindly irradiated samples (0, 0.9, 1.3, and 3.3 Gy). Participants were divided into two groups: for group A (formed by three participants), samples came from a homogeneous batch of glass and were stored in similar setting; for group B (formed by eight participants), samples came from different smart phones and stored in different settings of light and temperature. The calibration curves determined by the participants of group A had a small error and a critical level in the 0.37-0.40-Gy dose range, whereas the curves determined by the participants of group B were more scattered and led to a critical level in the 1.3-3.2-Gy dose range for six participants out of eight. Group A were able to assess the dose within 20 % for the lowest doses (< 1.5 Gy) and within 5 % for the highest doses. For group B, only the highest blind dose could be evaluated in a reliable way because of the high critical values involved. The results from group A are encouraging, whereas the results from group B suggest that the influence of environmental conditions and the intervariability of samples coming from different smart phones need to be further investigated. An alongside conclusion is that the protocol was easily transferred to participants making a network of laboratories in case of a mass casualty event potentially feasible.

  • 16.
    Forsgren, Mikael
    et al.
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US.
    Bengtsson, Ann
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Reumatologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Reumatologiska kliniken i Östergötland.
    Dahlqvist Leinhard, Olof
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Sören, Birgitta
    Linköpings universitet, Institutionen för medicin och hälsa, Sjukgymnastik. Linköpings universitet, Hälsouniversitetet.
    Brandejsky, Vaclav
    Depts Clinical Research and Radiology, University Bern, Bern, Switzerland.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Lundberg, Peter
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    31P MRS as a Potential Biomarker for Fibromyalgia2012Ingår i: Proceedings of the 20th Annaal Meeting & Exhibition, 5-11 May, Melbourne, Australia, 2012, s. 1493-1493Konferensbidrag (Refereegranskat)
    Abstract [en]

    Major clinical symptoms in fibromyalgia (FM) are muscle pain, stiffness and fatigue. Studies have shown reduced voluntary strength and exercise capacity, lower endurance and more muscular pain even at low workload. An impaired muscle energy metabolism has therefore been proposed as a result of the disease. An earlier study using magnetic resonance spectroscopy (MRS) showed that at maximal dynamic and static contractions the concentration of inorganic phosphate was lower in FM [1]. A decrease in ATP, ADP and PCr and an increase in AMP and creatine was found in FM biopsies [2]. The purpose of this study was to non-invasively analyze the quantitative content of  phosphagens in the resting muscle in FM in comparison to healthy controls using 31P MRS of the quadriceps muscle.

  • 17.
    Gerdle, Björn
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Rehabiliteringsmedicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Sinnescentrum, Smärt och rehabiliteringscentrum.
    Forsgren, Mikael
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US.
    Bengtsson, Ann
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Reumatologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Reumatologiska kliniken i Östergötland.
    Dahlqvist Leinhard, Olof
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US.
    Sören, B.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Reumatologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Reumatologiska kliniken i Östergötland.
    Karlsson, Anette
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Hälsouniversitetet.
    Brandejsky, Vaslav
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US.
    Lundberg, Peter
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US. Östergötlands Läns Landsting, Diagnostikcentrum, Röntgenkliniken i Linköping.
    Decreased muscle concentrations of ATP and PCR in the quadriceps muscle of fibromyalgia patients – A 31P-MRS study2013Ingår i: European Journal of Pain, ISSN 1090-3801, E-ISSN 1532-2149, Vol. 17, nr 8, s. 1205-1215Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND AND METHODS:

    Fibromyalgia (FMS) has a prevalence of approximately 2% in the population. Central alterations have been described in FMS, but there is not consensus with respect to the role of peripheral factors for the maintenance of FMS. 31P magnetic resonance spectroscopy (31P-MRS) has been used to investigate the metabolism of phosphagens in muscles of FMS patients, but the results in the literature are not in consensus. The aim was to investigate the quantitative content of phosphagens and pH in resting quadriceps muscle of patients with FMS (n = 19) and in healthy controls (Controls; n = 14) using (31) P-MRS. It was also investigated whether the concentrations of these substances correlated with measures of pain and/or physical capacity.

    RESULTS:

    Significantly lower concentrations of adenosine triphosphate (ATP) and phosphocreatinine (PCr; 28-29% lower) were found in FMS. No significant group differences existed with respect to inorganic phosphate (Pi), Pi/PCr and pH. The quadriceps muscle fat content was significantly higher in FMS than in Controls [FMS: 9.0 ± 0.5% vs. Controls: 6.6 ± 0.6%; (mean ± standard error); P = 0.005]. FMS had significantly lower hand and leg capacity according to specific physical test, but there were no group differences in body mass index, subjective activity level and in aerobic fitness. In FMS, the specific physical capacity in the leg and the hand correlated positively with the concentrations of ATP and PCr; no significant correlations were found with pain intensities.

    CONCLUSIONS:

    Alterations in intramuscular ATP, PCr and fat content in FMS probably reflect a combination of inactivity related to pain and dysfunction of muscle mitochondria.

  • 18.
    Gustafsson, Håkan
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Danilczuk, M.
    Linköpings universitet, Tekniska högskolan.
    Sastry, M. D.
    Linköpings universitet, Tekniska högskolan.
    Lund, Anders
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemisk Fysik. Linköpings universitet, Tekniska högskolan.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Enhanced sensitivity of lithium dithionates doped with rhodium and nickel for EPR dosimetry2005Ingår i: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, ISSN 1386-1425, Vol. 62, nr 1-3, s. 614-620Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Electron paramagnetic resonance (EPR) studies of X-irradiated lithium dithionate, Li2S2O6·2H2O, doped with Ni and Rh have shown that these impurities enhance the yield of radicals formed by X-irradiation at room temperature. The signal in the doped samples, measured peak-to-peak of the single EPR derivative line attributed to the SO3 anion was about 3–4 times that of the pure lithium dithionate and more than 10 times stronger than the alanine signal. These impurities also shortened the spin-lattice relaxation time, T1, which gives the possibility to measure the doped samples at a higher microwave power. This implies that sensitivity could be further enhanced in the already sensitive EPR dosimeter material lithium dithionate.

  • 19.
    Gustafsson, Håkan
    et al.
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik.
    Kruczala, Krzysztof
    Krakow, Polen.
    Lund, Eva
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik.
    Schlick, Shulamith
    Detroit, USA.
    Visualizing the dose distribution and linear energy transfer by ID and 2D ESR imaging: A potassium dithionate dosimeter irradiated with C6+ and N7+ ions2008Ingår i: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 112, nr 29, s. 8437-8442Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We report the application of one- and two-dimensional (1D and 2D) spectral-spatial electron spin resonance imaging (ESRI) for visualizing the dose distribution and linear energy transfer (LET) in a potassium dithionate, K 2S2O6 (PDT), dosimeter irradiated with the heavy ions C6+ and N7+. The ESR spectrum in the irradiated PDT consists of a superposition of two isotropic signals assigned to two ·SO3- radicals, R1 and R2, with no hyperfine splittings and slightly different g values. The ID ESRI profiles clearly indicate the spatial penetration of the beams and the location of the sharp maximum dose, the "Bragg peak", detected for each beam. The depth penetrations are different: ≈2.3 mm for C6+ and ≈1.8 mm for N7+ beams, ±0.1 mm, beyond these limits, no radicals were detected. 2D spectral-spatial ESRI images reflect both the dose distribution and the spatial dependence of the relative intensities of radicals R1 and R2, an effect that is assigned to the depth variation of the LET. This study has demonstrated that ESRI is a promising new method for dose and LET determination. Of particular interest are applications in the field of radiotherapy with heavy ions, because in this case the Bragg peak is pronounced and the dose can be focused at specific depths while the surrounding areas are protected. © 2008 American Chemical Society.

  • 20.
    Gustafsson, Håkan
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet.
    Lund, Anders
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemisk Fysik. Linköpings universitet, Tekniska högskolan.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Potassium dithionate EPR dosimetry for determination of absorbed dose and LET distributions in different radiation qualities2011Ingår i: Radiation Measurements, ISSN 1350-4487, E-ISSN 1879-0925, Vol. 46, nr 9, s. 936-940Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    With an increasing interest in using protons and light ions for radiation therapy there is a need for possibilities to simultaneously determine both absorbed dose (D) and linear energy transfer, LET, (LΔ). Potassium dithionate (K2S2O6) tablets were irradiated in a conventional 6 MV linear accelerator photon beam and a N7+ beam (E = 33.5 MeV/u) respectively. The EPR spectrum of irradiated potassium dithionate is a narrow doublet consisting of two signals, R1 and R2, with different microwave power saturation properties. On the basis of identification in related substances by EPR and ENDOR, these two signals are assigned to two non-equivalent SO3 – radicals. Our experiments showed that the ratios of these two lines (R1/R2) were clearly connected to beam LET. Irrespective of the mechanistic details this investigation suggests a new method for measurement of absorbed dose and beam LET by using potassium dithionate EPR dosimetry.

  • 21.
    Gustafsson, Håkan
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Olsson, Sara
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Lithium formate EPR dosimetry for verifications of planned dose distrubutions prior to intensity modulated radiation therapy2008Ingår i: Physics in Medicine and Biology, ISSN 0031-9155, E-ISSN 1361-6560, Vol. 53, nr 17, s. 4667-4682Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The objective of the present investigation was to evaluate lithium formate electron paramagnetic resonance (EPR) dosimetry for measurement of dose distributions in phantoms prior to intensity-modulated radiation therapy (IMRT). Lithium formate monohydrate tablets were carefully prepared, and blind tests were performed in clinically relevant situations in order to determine the precision and accuracy of the method. Further experiments confirmed that within the accuracy of the current method, the dosimeter response was independent of beam energies and dose rates used for IMRT treatments. The method was applied to IMRT treatment plans, and the dose determinations were compared to ionization chamber measurements. The experiments showed that absorbed doses above 3 Gy could be measured with an uncertainty of less than 2.5% of the dose (coverage factor k = 1.96). Measurement time was about 15 min using a well-calibrated dosimeter batch. The conclusion drawn from the investigation was that lithium formate EPR dosimetry is a promising new tool for absorbed dose measurements in external beam radiation therapy, especially for doses above 3 Gy.

  • 22.
    Gustafsson, Håkan
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Olsson, Sara
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Lund, Anders
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemisk Fysik. Linköpings universitet, Tekniska högskolan.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Ammonium formate, a compound for sensitive EPR dosimetry2004Ingår i: Radiation Research, ISSN 0033-7587, Vol. 161, nr 4, s. 464-470Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Alanine EPR dosimetry has been applied successfully when measuring intermediate and high radiation doses. Although the performance of alanine dosimetry is being improved, the sensitivity of the material is too low for a fast and simple low- dose determination. Here we present the results using ammonium formate as an EPR dosimeter material. Ammonium formate is seven times more sensitive than alanine, using spectrometer settings optimized for the latter. Deuterated ammonium formate is found to be more than eight times more sensitive than alanine. Analysis of signal stability with time shows that the ammonium formate signal is stable by 5 min after irradiation and that no change in signal intensity is found during 8 days. The atomic composition of ammonium formate is closer to that of tissue than alanine, and thus the energy dependence is smaller than that of alanine at photon energies below 200 keV. Power saturation studies indicate that the energy transfer between the spins and the lattice is fast in ammonium formate, which gives the possibility of using high microwave power without saturation to further increase the sensitivity. These results suggest that ammonium formate has some important properties required of an EPR dosimeter for applications in dosimetry in the dose range typical for radiation therapy.

  • 23.
    Israelsson, Axel
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Gustafsson, Håkan
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Dose response of xylitol and sorbitol for EPR retrospective dosimetry with applications to chewing gum2013Ingår i: Radiation Protection Dosimetry, ISSN 0144-8420, E-ISSN 1742-3406, Vol. 154, nr 2, s. 133-141Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The purpose of this investigation was to study the radiation-induced electron paramagnetic resonance signal in sweeteners xylitol and sorbitol for use in retrospective dosimetry. For both sweeteners and chewing gum, the signal changed at an interval of 1–84 d after irradiation with minimal changes after 4–8 d. A dependence on storage conditions was noticed and the exposure of the samples to light and humidity was therefore minimised. Both the xylitol and sorbitol signals showed linearity with dose in the measured dose interval, 0–20 Gy. The dose-response measurements for the chewing gum resulted in a decision threshold of 0.38 Gy and a detection limit of 0.78 Gy. A blind test illustrated the possibility of using chewing gums as a retrospective dosemeter with an uncertainty in the dose determination of 0.17 Gy (1 SD).

  • 24.
    Karakirova, Yordanka
    et al.
    Bulgarian Academy of Sciences.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Yordanov , Nicola D
    Bulgarian Academy of Sciences.
    EPR and UV investigation of sucrose irradiated with nitrogen ions and gamma-rays2008Ingår i: Radiation Measurements, ISSN 1350-4487, E-ISSN 1879-0925, Vol. 43, nr 8, s. 1337-1342Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Sucrose irradiated with N-ions and gamma-rays is investigated by EPR and UV spectroscopy. Irradiation doses are in the range of 20-380 Gy and linear energy transfer (LET) for N-ions of 90, 125 and 160 keV mu m(-1). All EPR spectra recorded in irradiated solid samples are identical, suggesting that generated free radicals are not sensitive to the radiation quality. The EPR response of free radicals linearly depends on the absorbed dose but when generated by N-ions it is always lower than that obtained by irradiation with the same absorbed dose from gamma-rays. Water solutions of irradiated sucrose exhibit UV absorption at 267 nm due to the product of free radicals recombination, which spectrum remains independent on the radiation quality. The intensity of this band however depends on the absorbed dose and for equal doses it is higher for samples irradiated with N-ions than with gamma-rays. For different high LET-radiations with N-ions and low-LET radiation from gamma rays is found an excellent linearity between the EPR signal intensity and the UV absorbance of the obtained water solution. The relation between EPR and UV response of N-ions irradiated samples is reciprocal as well as between them and gamma-irradiated samples suggesting different impact of the high-energy photons and heavy particles on the solid state. For low LET photon radiation with moderate dose rate the probability for a successful hitting of two neighboring molecules is low. Therefore, only a small part of low LET radiation-induced free radicals may be expected to recombine giving an UV detectable product. In opposite, because of the dense ionizations and heaviness of N-ions almost all molecules in the core of the track are ionized yielding mainly products of the recombined free radicals. In the outer part of the track delta particles, which are more like low LET radiation electrons, stands for ionizations and produces a small number of free radicals situated far from each other. Therefore, we can expect higher EPR response of sugar irradiated with a certain dose of gamma-rays than of heavy particles. Just the opposite behavior should be expected for the UV absorption, which should be higher in the irradiation with heavy particles than with gamma-rays. The reported observations suggest that a sucrose/UV/EPR dosimetric system seems to be very promising for dose determinations from both gamma and heavy particle radiation and indicate a method for simultaneous determination of absorbed dose and LET. It also seems to be a new way for calibration of EPR dosimeters irradiated with N-ions via UV spectrometry.

  • 25.
    Kolbun, Natallia
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet.
    Adolfsson, Emelie
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet.
    Gustafsson, Håkan
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet.
    High-resolution mapping of 1D and 2D dose distributions using X-band electron paramagnetic resonance imaging2014Ingår i: Radiation Protection Dosimetry, ISSN 0144-8420, E-ISSN 1742-3406, Vol. 159, nr 1-4, s. 182-187Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Electron paramagnetic resonance imaging (EPRI) was performed to visualise 2D dose distributions of homogenously irradiated potassium dithionate tablets and to demonstrate determination of 1D dose profiles along the height of the tablets. Mathematical correction was applied for each relative dose profile in order to take into account the inhomogeneous response of the resonator using X-band EPRI. The dose profiles are presented with the spatial resolution of 0.6 mm from the acquired 2D images; this value is limited by pixel size, and 1D dose profiles from 1D imaging with spatial resolution of 0.3 mm limited by the intrinsic line-width of potassium dithionate. In this paper, dose profiles from 2D reconstructed electron paramagnetic resonance (EPR) images using the Xepr software package by Bruker are focussed. The conclusion is that using potassium dithionate, the resolution 0.3 mm is sufficient for mapping steep dose gradients if the dosemeters are covering only +/- 2 mm around the centre of the resonator.

  • 26. Komaguchi, K
    et al.
    Matsubara, Y
    Shiotani, M
    Gustafsson, Håkan
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiofysik.
    Lund, Eva
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiofysik. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Lund, Anders
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemisk Fysik.
    An ESR and ENDOR study of irradiated 6Li-formate2007Ingår i: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy, ISSN 1386-1425, E-ISSN 1873-3557, Vol. 66, nr 3, s. 754-760Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Lithium formate (6LiOOCH·H2O), 95% 6Li enrichment, combined with an exchange of crystallization water with D2O was investigated. The ESR spectrum of the radiation induced free radicals stable at room temperature consists of a singlet with a narrow line width, 0.92 mT. 6Li has smaller magnetic moment and nuclear spin, which resulted in the narrower line width accompanied with an increase in peak amplitude. In comparison with lithium formate with natural isotopic composition, 6Li (7.5%, I = 1) and 7Li (92.5%, I = 3/2), the sensitivity was increased by a factor of two. With optimised spectrometer settings 6Li formate had seven times higher sensitivity compared to alanine. Therefore this material is proposed as a dosimeter material in a dose range down to 0.1 Gy. The g and the 13C-hyperfine (hf) tensors of the CO2- radical anion, major paramagnetic products, were evaluated to be g = (2.0037, 1.9975, 2.0017), and A(13C) = (465.5, 447.5, 581.3) MHz for polycrystalline samples at room temperature. Furthermore, the 1H-hf and 6Li-hf tensors observed for the surroundings of CO2- by ENDOR technique were in fairly good agreement with DFT calculations. The CO2- radicals are found to be so stable that the formate is applicable to the ESR dosimetry, because of fully relaxing in a fully relaxed geometrical structure of the CO2- component and remaining tight binding with the surroundings after the H atom detachment from HCO2-. © 2006 Elsevier B.V. All rights reserved.

  • 27.
    Lund, Anders
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemisk Fysik. Linköpings universitet, Tekniska högskolan.
    Olsson, Sara
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Radiofysik.
    Bonora, M
    Lund, Eva
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Radiofysik.
    Gustafsson, Håkan
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Radiofysik.
    New materials for ESR dosimetry2002Ingår i: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy, ISSN 1386-1425, E-ISSN 1873-3557, Vol. 58, nr 6, s. 1301-1311Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    New materials for electron spin resonance (ESR) dosimetry have been investigated with the aim to find systems more sensitive than L-alanine accepted as a standard for high dose determinations. Among the investigated systems ammonium tartrate, 2-methylalanine, salts of formic acids and dithionates have been found to be more sensitive than alanine by a factor 2-10. The lower limit applies to tissue equivalent materials, while much higher sensitivities were obtained with formates and dithionates containing heavier atoms. The increased sensitivity was mainly attributed to suitable ESR properties of the room temperature stable radicals as regards spectral shape (narrow lines, little or no hyperfine structure) and microwave saturation properties (short relaxation times). The radical structures have when necessary been clarified by ENDOR spectroscopy, while the saturation properties have been screened by pulsed ESR measurements.

  • 28.
    Lund, Eva
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Omvårdnad.
    Job satisfaction among Swedish nurses and laboratory technologists.1999Ingår i: British journal of nursing (Mark Allen Publishing), ISSN 0966-0461, Vol. 8, s. 948-952Artikel i tidskrift (Refereegranskat)
  • 29.
    Lund, Eva
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet.
    Adolfsson, Emelie
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet.
    Kolbun, Natallia
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet.
    Gustafsson, Håkan
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet.
    EPR imaging of dose distributions aiming at applications in radiation therapy2014Ingår i: Radiation Protection Dosimetry, ISSN 0144-8420, E-ISSN 1742-3406, Vol. 159, nr 1-4, s. 130-136Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A one-dimensional electron paramagnetic resonance (EPR) imaging method for visualisation of dose distributions in photon fields has been developed. Pressed pellets of potassium dithionate were homogeneously irradiated in a Co-60 radiation field to 600 Gy. The EPR analysis was performed with an X-Band (9.6 GHz) Bruker E540 EPR and EPR imaging spectrometer equipped with an E540 GC2X two-axis X-band gradient coil set with gradients along the y axis (along the sample tube) and z axis (along B-0) and an ER 4108TMHS resonator. Image reconstruction, including deconvolution, baseline corrections and corrections for the resonator sensitivity, was performed using an in-house-developed Matlab code for the purpose to have a transparent and complete algorithm for image reconstruction. With this method, it is possible to visualise a dose distribution with an accuracy of similar to 5 % within +/- 5 mm from the centre of the resonator.

  • 30.
    Lund, Eva
    et al.
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiofysik. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Gustafsson, Håkan
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiofysik.
    Danilczuk, M
    Sastry, M D
    Lund, Anders
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemisk Fysik.
    Vestad, T A
    Malinen, E
    Hole, E O
    Sagstuen, E
    Formates and dithionates: sensitive EPR-dosimeter materials for radiation therapy2005Ingår i: 6 th International symposium on ESR dosimetry and applications,2005, England: Pergamon Press , 2005, s. 317-Konferensbidrag (Refereegranskat)
  • 31.
    Lund, Eva
    et al.
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiofysik. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Gustafsson, Håkan
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiofysik.
    Danilczuk, M
    Sastry, M
    Lund, Anders
    Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Vestad, T-A
    Malinen, E
    Hole, E O
    Sagstuen, E
    Formates and dithionates: sensitive EPR dosimeter materialsfor radiation therapy2004Ingår i: Applied Radiation and Isotopes, ISSN 0969-8043, E-ISSN 1872-9800, Vol. 62, s. 317-324Artikel i tidskrift (Refereegranskat)
  • 32.
    Lund, Eva
    et al.
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiofysik.
    Gustafsson, Håkan
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiofysik.
    Danilczuk, M
    Sastry, MD
    Lund, Anders
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemisk Fysik.
    Compounds of Li-6 and natural Li for EPR dosimetry in photon/neutron mixed radiation fields2004Ingår i: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy, ISSN 1386-1425, E-ISSN 1873-3557, Vol. 60, nr 6, s. 1319-1326Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Formates and dithionates of Li-6, enriched and Li-7 in natural composition of Li offer a possibility to measure the absorbed dose from photons and thermal neutrons in a mixed radiation field for instance at a boron neutron capture therapy (BNCT) facility. Tests with formates and dithionates of enriched 6Li and lithium compounds with natural composition have been performed at the BNCT facility at Studsvik, Sweden. Irradiations have been performed at 3 cm depth in a Perspex phantom in a fluence rate of thermal neutrons 1.8 x 10(9) n cm(-2) s(-1). The compounds were also irradiated in a pure X-ray field from a 4 MV linear accelerator at 5 cm depth in a phantom with accurately determined absorbed doses. The signal intensity and shape was investigated within 3 h after the irradiation. A single line spectrum attributed to the CO2- radical was observed after irradiation of lithium formate. An increase in line width occurring after neutron irradiation in comparison with photon irradiation of the Li-6 sample was attributed to dipolar broadening between CO2- radicals trapped in the tracks of the alpha particles. A spectrum due to the SO3- radical anion was observed after irradiation of lithium dithionate. The signal amplitude increased using the Li-6 in place of the Li with natural composition of isotopes, in studies with low energy X-ray irradiation. Due to the decreased line width, caused by the difference in g(N) and I between the isotopes, the sensitivity with Li-6 dithionate may be enhanced by an order of magnitude compared to alanine dosimetry. After comprehensive examination of the different combinations of compounds with different amounts of Li-6 and Li-7 regarding dosimetry, radiation chemistry and EPR properties these dosimeter material might be used for dose determinations at BNCT treatments and for biomedical experiments. Interesting properties of the radical formation might be visible due to the large difference in ionization density of neutrons compared to photons. (C) 2003 Elsevier B.V. All rights reserved.

  • 33.
    Lund, Eva
    et al.
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik.
    Gustafsson, Håkan
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik.
    Danilczuk, M
    Sastry, MD
    Lund, Anders
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemisk Fysik.
    Vestad, TA
    Malinen, E
    Hole, EO
    Sagstuen, E
    Formates and dithionates: sensitive EPR-dosimeter materials for radiation therapy2005Ingår i: Applied Radiation and Isotopes, ISSN 0969-8043, E-ISSN 1872-9800, Vol. 62, nr 2, s. 317-324Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Polycrystalline, formates and dithionates are promising materials for EPR dosimetry, as large yields of radiation induced stable radicals are formed with a linear dose response. Rapid spin relaxation rates were detected in many of the substances, indicating that a high microwave power can be applied during EPR acquisition in order to improve sensitivity. Different techniques used to further improve the sensitivity, such as the replacement of Li-7 with Li-6 or exchange of protons with deuterons in the corresponding crystalline matrices and metal ion doping are discussed. It is concluded that formates and dithionates may be up to 10 times as sensitive as L-alpha-alanine. (C) 2004 Elsevier Ltd. All rights reserved.

  • 34.
    Lund, Eva
    et al.
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Radiofysik.
    Kendall, Sally
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för nervsystem och rörelseorgan, Rehabiliteringsmedicin. Östergötlands Läns Landsting, Medicincentrum, Smärt- och rehabiliteringscentrum.
    Janerot-Sjöberg, Birgitta
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Klinisk fysiologi. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Bengtsson, Ann
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för molekylär och klinisk medicin, Reumatologi. Östergötlands Läns Landsting, Medicincentrum, Länskliniken för Reumatologi i Östergötland.
    Muscle metabolism in fibromyalgia studied by P-31 magnetic resonance spectroscopy during aerobic and anaerobic exercise2003Ingår i: Scandinavian Journal of Rheumatology, ISSN 0300-9742, E-ISSN 1502-7732, Vol. 32, nr 3, s. 138-145Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objective: To investigate mechanisms underlying the reduced work capacity of fibromyalgia (FM) patients were compared to healthy controls at specified workloads, using P-31 magnetic resonance spectroscopy (MRS). Methods: The forearm flexor muscle group was examined with MRS at rest, at sub maximal and at maximal controlled dynamic work as well as at maximal isometric contraction. Aerobic fitness was determined by bicycle ergonometry. Results: Metabolite concentrations and muscle pH were similar for patients and controls at lower workloads. At maximal dynamic and static contractions the concentration of inorganic phosphate was lower and at static contractions the pH decrease was smaller in patients. The performed work by patients was only 50% compared to controls and the patients experienced more pain. Maximal oxygen uptake was lower in the fibromyalgia group. Expired gas-analysis in this group showed ventilatory equivalents at similar relative levels of maximal work capacity. Conclusion: Fibromyalgia patients seem to utilise less of the energy rich phosphorous metabolites at maximal work despite pH reduction. They seemed to be less aerobic fitted and reached the anaerobic threshold earlier than the controls.

  • 35.
    Lund, Eva
    et al.
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Radiofysik. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Kyllönen, JE
    Grindborg, JE
    Lindborg, L
    Performance testing of personal dosemeters from eleven dosimetry services in Sweden2001Ingår i: Radiation Protection Dosimetry, ISSN 0144-8420, E-ISSN 1742-3406, Vol. 96, nr 1-3, s. 99-103Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Swedish regulation, SSI FS 98:5, requires that radiological workers of category A use dosemeters from an approved personal dosimetry service. The 11 services operating in Sweden at the moment use five different types of dosemeter. All have been tested for their ability to determine Hp(10) and some of them to determine Hp(0.07) according to the European Commission report Radiation Protection 73, EUR 14852, of 1994. The five unique systems have been tested regarding the angular and energy dependence of the response of the dosemeters. The test points for the determination of Hp(10) are all, except one, within the trumpet curve and for the unique systems it is shown that the uncertainty related to angular response at three different energies is within the required ▒40% except for the lowest X ray quality 40 kV. The energy dependence dominates over the directional dependence and the choice of radiation quality for calibration is of great importance for the system performance.

  • 36.
    Lund, Eva
    et al.
    Linköpings universitet, Institutionen för medicin och vård, Radiofysik. Linköpings universitet, Hälsouniversitetet.
    Pernicka, Frantisek
    Institute of Radiation Dosimetry, Czeckoslovak Academy of Sciences, Prague, Czeck Republic.
    Carlsson, Carl A
    Linköpings universitet, Institutionen för medicin och vård, Radiofysik. Linköpings universitet, Hälsouniversitetet.
    Experimental determination of the angular dependence of the directional dose equivalent, H’(d), for ISO “narrow” X ray fields and 137Cs γ-rays measured in a PMMA sphere and a PMMA slab phantom1993Rapport (Övrigt vetenskapligt)
    Abstract [en]

    For the purpose of calibrating individual dosimeters in X-ray fields conversion factors from air kerma free in air to dose equivalent at a specified depth in a phantom have been calculated among others by Grosswendt (1991, 1992). By means of Monte Carlo calculations the angular dependence factor for photon beams of oblique incidence is also studied for different phantom shapes and compositions as well as for different X-ray qualities. However, till now there has been a lack of experimental verification of the angular dependence factors.

    In this investigation the conversion factor from air kerma to Hp(10) has been determined for the following X-ray qualities: 40 kV, 80 kV, and 295 kV, ISO "narrow" spectra and for 137Cs γ-rays using thermoluminescent (TL) dosimeters. The angular dependence factor H'(10,α)/H'(10,0o) has also been experimentally determined for the same X-ray and γ -ray qualities and for different angles between 0o and 180o.

    The conversion factors are found to be in good agreement with the calculated ones for the PMMA sphere phantom, while some minor discrepancies are found between the experimental and calculated angular dependence factors for the 30x30x15cm3 PMMA slab phantom.

    The difference in angular dependence obtained for the slab and the sphere is discussed as well as the possibility to underestimate the personal dose equivalent, Hp(10), compared to effective dose, E.

  • 37.
    Lund, Eva
    et al.
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiofysik. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Wirell, Staffan
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiologi.
    Salerud, Göran
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik.
    Basgruppsträffar gemensamma för teknologer och lärarstuderande inom ämnet "Radiologiska bilder"1997Ingår i: CUP-konferens,1997, 1997Konferensbidrag (Övrigt vetenskapligt)
  • 38.
    Nilsson, Håkan
    et al.
    Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Matscheko, G.
    Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Alm Carlsson, G.
    Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Measurements of energy spectra from high dose rate 192Ir sources with a compton scattering spectrometer1994Ingår i: Measurement assurance in dosimetry: Proceedings of an International Symposium on Measurement Assurance in Dosimetry, 1994, s. 289-297Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    A Compton scattering spectrometer has been used for spectral measurement of high dose rate (HDR) 192Ir sources. On the basis of the Compton formula a measured distribution of scattered photons is used for the calculation of the primary spectrum leaving the source. The two main reasons for measuring the photon energy distribution from such HDR sources are, firstly, to obtain accurate input for Monte Carlo calculations of the dose distribution and, secondly, to calibrate ionization chambers. The lack of spectral information causes calibration laboratories great difficulties in such work. A third possible reason concerns quality assurance with respect to source impurities, etc. The measured spectrum shows good agreement with the spectrum expected from theoretical considerations.

  • 39.
    Nilsson, Jonas
    et al.
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Radiofysik. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Lund, Eva
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Radiofysik. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Lund, Anders
    The effects of UV-irradiation on the ESR-dosimetry of tooth enamel2001Ingår i: Applied Radiation and Isotopes, ISSN 0969-8043, E-ISSN 1872-9800, Vol. 54, nr 1, s. 131-139Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Tooth enamel has been shown to be an excellent dosimeter material for retrospective dosimetry. A complication is that it is sensitive to ultraviolet light (UV), creating a signal that interferes with the dosimetric signal. Irradiation of tooth enamel by UV-light induces a mixture of stable and unstable free radicals. The unstable radicals disappear in about three weeks. Stable radicals are created both at the dosimetric peak and at the same g-value as the native peak. The stable peak coinciding with the native peak shows saturation behavior both for UVA/B- and UVC-light. The signal intensity from the sun is roughly estimated to induce a signal comparable to 15 mGy/h from 60 kV X-rays. The blue lamps used by dentists when hardening plastic repairs contain a narrow tail in the UVA/B-region, and it is shown here that these lamps also contribute to the stable peak coincident with the native peak. The contribution to the dosimetry peak, though negligible, at least for the irradiation times is used in this work. Most of the problems with UVA/B-induced signal contributions can probably be avoided by not using front teeth and teeth close to plastic repairs. (C) 2000 Elsevier Science Ltd.Tooth enamel has been shown to be an excellent dosimeter material for retrospective dosimetry. A complication is that it is sensitive to ultraviolet light (UV), creating a signal that interferes with the dosimetric signal. Irradiation of tooth enamel by UV-light induces a mixture of stable and unstable free radicals. The unstable radicals disappear in about three weeks. Stable radicals are created both at the dosimetric peak and at the same g-value as the native peak. The stable peak coinciding with the native peak shows saturation behavior both for UVA/B- and UVC-light. The signal intensity from the sun is roughly estimated to induce a signal comparable to 15 mGy/h from 60 kV X-rays. The blue lamps used by dentists when hardening plastic repairs contain a narrow tail in the UVA/B-region, and it is shown here that these lamps also contribute to the stable peak coincident with the native peak. The contribution to the dosimetry peak, though negligible, at least for the irradiation times is used in this work. Most of the problems with UVA/B-induced signal contributions can probably be avoided by not using front teeth and teeth close to plastic repairs.

  • 40.
    Olsson, Sara
    et al.
    Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen. Linköpings universitet, Hälsouniversitetet.
    Bagherian, Shahrbanou
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemisk Fysik. Linköpings universitet, Hälsouniversitetet.
    Lund, Eva
    Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen. Linköpings universitet, Hälsouniversitetet.
    Alm Carlsson, Gudrun
    Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen. Linköpings universitet, Hälsouniversitetet.
    Lund, Anders
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemisk Fysik. Linköpings universitet, Tekniska högskolan.
    Ammonium tartrate as an ESR dosimeter material1999Ingår i: Applied Radiation and Isotopes, ISSN 0969-8043, E-ISSN 1872-9800, Vol. 50, nr 5, s. 955-965Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study is one step in the search for an ESR dosimeter material with a higher signal intensity than the commonly used l-α-alanine, to be useful in the clinical dose range (approximately 0.1–20 Gy). The substance ammonium tartrate was found and investigated regarding signal intensity, radical stability, dose response and dose resolution. The ESR signal intensity of ammonium tartrate was shown to be more than twice the intensity of the alanine signal. The data indicate that an unstable radiation induced radical contributes to the ESR signal initially; after a couple of hours it has converted to a secondary radical which has a decay slow enough to be considered stable during the first two weeks after irradiation. Ammonium tartrate has a linear dose response in the investigated range of 0.5–4000 Gy and a dose resolution of 0.1 Gy at the 0.5 Gy level where, as a comparison, the corresponding value for alanine is 0.3 Gy. We thus find the substance suitable for clinical dosimetry.

  • 41.
    Olsson, Sara
    et al.
    Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen. Linköpings universitet, Hälsouniversitetet.
    Bergstrand, Eva S.
    Department of Physics, University of Oslo, Norway.
    Carlsson, Åsa K.
    Medical Radiation Physics, Stockholm University and Karolinska Institute, Stockholm, Sweden.
    Hole, Eli O.
    Department of Physics, University of Oslo, Norway.
    Lund, Eva
    Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen. Linköpings universitet, Hälsouniversitetet.
    Radiation dose measurements with alanine/agarose gel and thin alanine films around a 192Ir brachytherapy source, using ESR spectroscopy2002Ingår i: Physics in Medicine and Biology, ISSN 0031-9155, E-ISSN 1361-6560, Vol. 47, nr 8, s. 1333-1356Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Alanine/agarose gel and alanine films in stacks have been used for measurements of absorbed dose around an HDR 192Ir source in a vaginal cylinder-applicator, with and without a 180° tungsten shield. The gel and the films were analysed by means of ESR spectroscopy and calibrated against an ion chamber in a 4 MV photon beam to obtain absolute dose values. The gel serves as both dosimeter and phantom material, and the thin (130 μm) films are used to achieve an improved spatial resolution in the dose estimations.

    Experimental values were compared with Monte Carlo simulations using two different codes. Results from the measurements generally agree with the simulations to within 5%, for both the alanine/agarose gel and the alanine films.

  • 42.
    Olsson, Sara K.
    et al.
    Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen. Linköpings universitet, Hälsouniversitetet.
    Lund, Eva
    Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen. Linköpings universitet, Hälsouniversitetet.
    Lund, Anders
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemisk Fysik. Linköpings universitet, Tekniska högskolan.
    Development of ammonium tartrate as an ESR dosimeter material for clinical purposes2000Ingår i: Applied Radiation and Isotopes, ISSN 0969-8043, E-ISSN 1872-9800, Vol. 52, nr 5, s. 1235-1241Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The crystalline substance ammonium tartrate is investigated with respect to its suitability as a clinical dosimetry material. The properties investigated are: the radical stability for absorbed doses relevant for clinical use, the improvement in sensitivity when the crystals are deuterated and the linear electron tranfer (LET)-dependence. After photon irradiation to an absorbed dose of 20 Gy, the signal increases rapidly during the first 6 h. After this period, the changes are more moderate and can be corrected for. The signal-to-noise ratio of irradiated ammonium tartrate is twice the corresponding value of alanine. By deuterating the crystals, the sensitivity can be further improved by a factor of 1.4. As expected, the signal decreases with increasing LET of the radiation, but no changes in the spectrum shape was observed.

  • 43.
    Olsson, Sara
    et al.
    Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Erickson, R.
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Hälsouniversitetet.
    Dose response and fading characteristics of an Alanine-Agarose gel1996Ingår i: Applied Radiation and Isotopes, ISSN 0969-8043, E-ISSN 1872-9800, Vol. 47, nr 11-12, s. 1211-1217Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The dose response of an alanine-agarose gel, analyzed by ESR spectrometry, and the stability of the radiation-induced free radicals have been investigated. The stability of the ESR signal is higher for dosimeter samples analyzed at 77 K than for dried samples, analyzed at room-temperature. The dose response is linear to within ±2% in the absorbed dose interval 2–100 Gy. The variations in spectral line shape were analyzed at temperatures between 77 and 270 K. The experimental ESR spectrum at 77 K was compared with a simulated spectrum of polycrystals of L-α-alanine.

  • 44.
    Salerud, Göran
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik.
    Gunnarsson, S.
    Lund, Eva
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiofysik. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Problem Based Learning (PBL) and cirricula redesign in BioMedical Engineering (BME) in the framework of Concieve Design Implement and Operate (CDIO) initiative2005Ingår i: Biomedical Engineering Educational Summit meeting,2005, 2005Konferensbidrag (Övrigt vetenskapligt)
  • 45.
    Salerud, Göran
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik.
    Lund, Eva
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiofysik. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Multiprofessional education in Biomedical Engineering using PBL2000Ingår i: Int Academy Medical and Biological Engineering. Workshop on Biomedical Engineering Education.,2000, 2000Konferensbidrag (Övrigt vetenskapligt)
  • 46.
    Salerud, Göran
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik.
    Lund, Eva
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Medicinsk radiofysik. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Multiprofessional education in Biomedical Engineering with individual learning documents for students evaluation and assessment2000Ingår i: Biomedical Engineering Educational Summit meeting,,2000, 2000Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

      

  • 47.
    Salih, Isam
    et al.
    Linköpings universitet, Institutionen för medicin och vård.
    Bäckström, Mattias
    Man-Technology-Environment Research Centre, Örebro University, Örebro, Sweden.
    Karlsson, Stefan
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Pettersson, Håkan
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Impact of fluoride and other aquatic parameters on radon concentration in natural waters2004Ingår i: Journal of Applied Radiation & Isotopes, ISSN 0969-8043, Vol. 60, nr 1, s. 99-104Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Radon (222Rn) accumulation in water in relation to stable elements was studied for the purpose of determining factors influencing the transfer of 222Rn to and from water. In 72 groundwater samples, 222Rn and about 70 analytical parameters were analysed using radiometric and ICP-MS techniques. Using multivariate statistics (partial least squares), it was observed that 222Rn has a positive correlation with fluoride and uranium. The correlation with fluoride was further investigated by a laboratory time-scale experiment to measure the emanation of 222Rn from water as a function of fluoride, pH and carbonate. The transfer of 222Rn from water was measured by continuous monitoring in air in a closed loop set-up. It was observed that fluoride in water adhere or trap 222Rn preferably in acidic water (pH 3). It is suspected that natural physical processes (such as diffusion and microbubble phenomenon) are less effective to transport 222Rn in the presence of fluoride.

  • 48.
    Salih, Isam
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Pettersson, Håkan
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Determination of 222Rn and 226Ra in water using a large volume ionisation chamber2000Ingår i: Journal of Environmental Radioactivity, ISSN 0265-931X, Vol. 48, nr 2, s. 235-245Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A new method for measuring 222Rn and 226Ra in water has been devised. It is based on exhaling radon to a void volume by continuous bubbling of air through the water. The exhaled radon is then transferred in a closed circuit to a modified radon gas pulse ionisation chamber for alpha-spectrometric measurements. About 86% of the radon in water is transferred from 0.75 l of water to the void volume (3.2 l). The set-up offers direct and specific 222Rn measurements for a wide range of concentrations and shows a low detection limit (LLD=45 mBq l−1 for 8 h counting time). Radium in water is measured, via radon, after sample storage for a month. The method was compared with gamma ray spectrometry for radon and for radium, the latter after pre-concentration by co-precipitation with MnO2 from 10 l water samples. An excellent agreement between the two techniques was obtained. As a part of a radon survey, the method was employed for analysis of drinking water from bedrock wells.

  • 49.
    Salih, Isam
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Pettersson, Håkan
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Uranium and thorium series radionuclides in drinking water from drilled bedrock wells: correlation to geology and bedrock radioactivity and dose estimation2002Ingår i: Radiation protection dosimetry, ISSN 0144-8420, Vol. 102, nr 3, s. 249-258Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Natural radioactivity in drinking water from 328 drilled wells was studied in correlation to source parameters. Poor correlation to both aquifer geology and bedrock radioactivity was observed. Concentrations of 238U, 226Ra, 228Ra, 222Rn and 210Po in groundwater samples was in the ranges <0.027-5.3, <0.016-4.9, <0.014-1.24, 5-8105 and <0.05-0.947 Bq.l(-1) respectively. In about 80% of the sites the radon concentration exceeds the Nordic recommended exemption level for radon in drinking water and 15% of the sites exceed the action limit. The effective doses from ingestion were calculated and presented in association with geology. Doses due to ingestion ranged between 0.05 and 20.4 mSv.y(-1), where the average contribution from 222Rn amounted to 75%. In comparison, the effective doses from inhalation of indoor 222Rn ranged between 0.2 and 20 mSv.y(-1). The average contribution from inhalation of 222Rn in air to the total effective dose (ingestion+inhalation) was 58 +/- 22%, 73 +/- 18% and 77 +/- 16% (1 SD) for the age categories 1 y, 10 y and adults respectively.

  • 50.
    Salih, Isam
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Pettersson, Håkan
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Radiofysikavdelningen.
    Sivertun, Åke
    Linköpings universitet, Institutionen för datavetenskap, GIS - Geografiska informationssystem. Linköpings universitet, Tekniska högskolan.
    Lund, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet.
    Spatial correlation between radon (222Rn) in groundwater and bedrock uranium (238U): GIS and geostatistical analyses2002Ingår i: Journal of Spatial Hydrology, ISSN 1530-4736, Vol. 2, nr 2, s. 1-10Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study describes approaches to create surface maps of radon in groundwater based on measurements of radon (222Rn) in drilled bedrock wells at unevenly distributed sites and uranium bedrock maps from the South East of Sweden, the Östergotland county (N 58°14’ – N 58°56’and E 14°53’ – E 16°06’), see figure 1. Geostatistical techniques of inverse distance weighted(IDW), kriging and cokriging were compared in terms of their interpolation power and correlation between the produced radon in the water layer and the bedrock uranium layer. The goal of these analyses and calculations is to improve our understanding concerning the factors influencing the transport of radon. Therefore, these interpolation techniques were investigated by optimizing parameters that are used in the specific interpolation. Using the IDW interpolator method at fixed radius enabled us to determine the linkage or search distances for auto correlation, and linkage between radon in water and bedrock. This method showed good agreement with the cokriging method when using uranium concentration as a secondary variable. Good interpolation layers (with least root mean square errors RMSE=232) were obtained by kriging. However, the kriged radon surface showed poor correlation with bedrock uranium layers. The best radon in waterlayer that match with uranium in bedrock layer was produced using IDW interpolator (RMSE=377, using all points). The correlation coefficient (R2) is 0.5 while for the kriging method the best correlation is R2 = 0.1. A compromise between the two approaches is demonstrated.

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