liu.seSearch for publications in DiVA
Endre søk
Begrens søket
1 - 37 of 37
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Treff pr side
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
Merk
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Antonsson, Johan
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Eriksson, Ola
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Blomstedt, Patric
    Department of Neurosurgery, University Hospital, Umeå, Sweden.
    Bergenheim, Tommy
    Department of Neurosurgery, University Hospital, Umeå, Sweden.
    Hariz, Marwan
    Department of Neurosurgery, University Hospital, Umeå, Sweden.
    Richter, Johan
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik.
    Zsigmond, Peter
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Neurokirurgi. Linköpings universitet, Hälsouniversitetet.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Diffuse reflectance spectroscopy measurements for tissue type discrimination during deep brain stimulation2008Inngår i: Journal of neural engineering, ISSN 1741-2560, Vol. 5, nr 2, s. 185-190Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Diffuse reflectance spectroscopy as a method for improving intracerebral guidance during functional neurosurgery has been investigated. An optical probe was developed for measurements during stereotactic and functional neurosurgery in man. The aim of the study was to investigate the spectral differences between white and grey matter and between white matter and functional targets. Diffuse reflectance spectroscopy measurements in ten patients were recorded at incremental steps towards and in three different functional targets (STN, GPi and Zi). The recorded spectra along the trajectory were sorted into white or grey matter, based on preoperative MRI images or the recorded spectral shape and intensity. The difference between tissue types was calculated as a quotient. Significant intensity differences between white and grey matter were found to be at least 14% (p < 0.05) and 20% (p < 0.0001) for MRI and spectral-sorted data respectively. The reflectance difference between white matter and the functional targets of GPi was higher than for STN and Zi. The results indicate that diffuse reflectance spectroscopy has a potential to be developed to a suitable complement to other intracerebral guidance methods.

  • 2.
    Haj-Hosseini, Neda
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska fakulteten.
    Milos, Peter
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Sinnescentrum, Neurokirurgiska kliniken US.
    Hildesjö, Camilla
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för kliniska vetenskaper. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk patologi och klinisk genetik.
    Hallbeck, Martin
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk patologi och klinisk genetik.
    Richter, Johan
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska fakulteten. Region Östergötland, Sinnescentrum, Neurokirurgiska kliniken US.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska fakulteten.
    Fluorescence spectroscopy and optical coherence tomography for brain tumor detection2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Resection of brain tumor is a challenging task as the tumor does not have clear borders and the malignant types specifically have often a diffuse and infiltrative pattern of growth. Recently, neurosurgical microscopes have been modified to incorporate fluorescence modules for detection of tumor when 5-aminolevulinic acid (5-ALA) is used as a contrast. We have in combination with the fluorescence microscopes implemented and evaluated a fluorescence spectroscopy based handheld probe for detecting the 5-aminolevulinic acid (ALA) induced protoporphyrin IX (PpIX) in the gliomas in 50 patients intraoperatively. The results show a significantly high sensitivity for differentiating tumor from the healthy tissue and distinguished fluorescence intensity levels in the tumor cell infiltration zone around the tumor. However, knowledge on association of the quantified fluorescence signals specifically in the intermediate inflammatory zone with the infiltrative tumor cells can be complemented with volumetric tissue imaging and a higher precision histopathological analysis. In this work, a spectral domain optical coherence tomography (OCT) system with central wavelength of 1325nm has been used to image the tissue volume that the fluorescence is collected from and is evaluated against histopathological analysis for a higher precision slicing. The results show that although healthy brain has a homogenous microstructure in the OCT images, the brain tumor shows a distinguished texture in the images correlated with the PpIX fluorescence intensity and histopathology.

  • 3.
    Haj-Hosseini, Neda
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska fakulteten.
    Milos, Peter
    Region Östergötland, Sinnescentrum, Neurokirurgiska kliniken US. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten.
    Richter, Johan
    Linköpings universitet, Institutionen för medicinsk teknik. Region Östergötland, Sinnescentrum, Neurokirurgiska kliniken US. Linköpings universitet, Tekniska fakulteten.
    Hallbeck, Martin
    Region Östergötland, Diagnostikcentrum, Klinisk patologi och klinisk genetik. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska fakulteten.
    A Multipurpose Guidance Probe for Stereotactic Biopsy Procedures2016Konferansepaper (Fagfellevurdert)
  • 4.
    Haj-Hosseini, Neda
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik.
    Milos, Peter
    Region Östergötland, Centrum för kirurgi, ortopedi och cancervård, Kirurgiska kliniken US.
    Richter, Johan
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska fakulteten. Region Östergötland, Sinnescentrum, Neurokirurgiska kliniken US.
    Hildesjö, Camilla
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för kliniska vetenskaper. Linköpings universitet, Medicinska fakulteten.
    Hallbeck, Martin
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk patologi och klinisk genetik.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska fakulteten.
    Detection of brain tumor using fluorescence and optical coherence tomography2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Resection of brain tumor is a challenging task as the tumor does not have clear borders and the malignant types specifically have often a diffuse and infiltrative pattern of growth. We have previously implemented and evaluated a fluorescence spectroscopy based handheld probe for detecting the 5-aminolevulinic acid induced protoporphyrin IX (PpIX) in the gliomas. To add another dimension to the brain tumor detection and volumetric analysis of the tissue that exhibits fluorescence, optical coherence tomography was investigated on tumor specimens.

    Material and Methods:

    A fluorescence microscopy and a spectroscopy system as reported previously were used for detecting the fluorescence signals [1, 2]. A total of 50 patients have been included for intraoperative assessment of the tumor borders using the fluorescence techniques. A spectral domain OCT imaging system (TELESTO II, Thorlabs, Inc., NJ, USA) with central wavelength of 1325 nm was used to study the tissue microstructure post operatively. The system has a resolution of 13 and 5.5 μm in the lateral and axial directions, respectively. Tissue specimens from three patients undergoing brain tumor surgery were studied using the OCT system.

    Results and Conclusion:

    Using fluorescence spectroscopy the tumor could be detected with a sensitivity of 0.84 which was significantly higher than that of the surgical microscope (0.30). Brain tissue appeared rather homogeneous in the OCT images however the highly malignant tissue showed a clear structural difference from the non-malignant or low malignant brain tumor tissue which could be related to the fluorescence signal intensities.

  • 5.
    Haj-Hosseini, Neda
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Richter, Johan
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan. Östergötlands Läns Landsting, Rekonstruktionscentrum, Neurokirurgiska kliniken US.
    Andersson-Engel, Stefan
    Linköpings universitet, Tekniska högskolan.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Fluorescence guided resection of glioblastoma multiforme using an optical touch pointer-Clinical evaluation2010Konferansepaper (Fagfellevurdert)
  • 6.
    Haj-Hosseini, Neda
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Richter, Johan
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Östergötlands Läns Landsting, Rekonstruktionscentrum, Neurokirurgiska kliniken US. Linköpings universitet, Tekniska högskolan.
    Andersson-Engels, Stefan
    Department of Physics, Lund University.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Fiber optic based fluorescence guided cerebral glioma resection using a pulsed laser setup2008Konferansepaper (Fagfellevurdert)
  • 7.
    Haj-Hosseini, Neda
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Richter, Johan
    Östergötlands Läns Landsting, Rekonstruktionscentrum, Neurokirurgiska kliniken US. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Andersson-Engels, Stefan
    Lund University of Technology.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Fiber optic based fluorescence spectroscopy on glioblastoma multiforme using 5-aminolevulinic acid - Preliminary clinical results2009Konferansepaper (Annet vitenskapelig)
  • 8.
    Haj-Hosseini, Neda
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik.
    Richter, Johan
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Östergötlands Läns Landsting, Rekonstruktionscentrum, Neurokirurgiska kliniken US. Linköpings universitet, Tekniska högskolan.
    Andersson-Engels, Stefan
    Linköpings universitet, Tekniska högskolan.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Optical Touch Pointer for Fluorescence Guided Glioblastoma Resection Using 5-Aminolevulinic Acid2010Inngår i: Lasers in Surgery and Medicine, ISSN 0196-8092, E-ISSN 1096-9101, Vol. 42, nr 1, s. 9-14Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background and Objective

    Total tumor resection in patients with glioblastoma multiforme (GBM) is difficult to achieve due to the tumor's infiltrative way of growing and morphological similarity to the surrounding functioning brain tissue. The diagnosis is usually subjectively performed using a surgical microscope. The objective of this study was to develop and evaluate a hand-held optical touch pointer using a fluorescence spectroscopy system to quantitatively distinguish healthy from malignant brain tissue intraoperatively.

    Study Design/Materials and Methods

    A fluorescence spectroscopy system with pulsed modulation was designed considering optimum energy delivery to the tissue, minimal photobleaching of PpIX and omission of the ambient light background in the operating room (OR). 5-Aminolevulinic acid (5-ALA) of 5 mg/kg body weight was given to the patients with a presumed GBM prior to surgery. During the surgery a laser pulse at 405 nm was delivered to the tissue. PpIX in glioblastoma tumor cells assigned with peaks at 635 and 704 nm was detected using a fiber optical probe.

    Results/Conclusion

    By using the pulsed fluorescence spectroscopy, PpIX fluorescence is quantitatively detected in the GBM. An effective suppression of low power lamp background from the recorded spectra in addition to a significant reduction of high power surgical lights is achieved.

    Fulltekst (pdf)
    fulltext
  • 9.
    Haj-Hosseini, Neda
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Richter, Johan
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan. Östergötlands Läns Landsting, Rekonstruktionscentrum, Neurokirurgisk klinik.
    Andersson-Engels, Stefan
    Dept. of Physics, Lund University, Lund, Sweden.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Photobleaching behavior of protoporphyrin IX during 5-aminolevulinic acid marked glioblastoma detection2009Inngår i: Photonic Therapeutics and Diagnostics V / [ed] Nikiforos Kollias; Bernard Choi; Haishan Zeng; Reza S. Malek; Brian J. Wong; Justus F. R. Ilgner; Kenton W. Gregory; Guillermo J. Tearney; Laura Marcu; Henry Hirschberg; Steen J. Madsen, SPIE - International Society for Optical Engineering, 2009, s. 716131-1-716131-8Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The highly malignant brain tumor, glioblastoma multiforme (GBM), is difficult to fully delineate during surgical resection due to its infiltrative ingrowth and morphological similarities to surrounding functioning brain tissue. Selectiveness of GBM to 5-aminolevulinic acid (5-ALA) induced protoporphyrin IX (PpIX) is reported by other researchers to visualize tumor margins under blue light microscopy. To allow objective detection of GBM, a compact and portable fiber optic based fluorescence spectroscopy system is developed. This system is able to deliver excitation laser light (405 nm) in both the continuous and pulsed mode. PpIX fluorescence peaks are detected at 635 and 704 nm, using a fiber-coupled spectrometer. It is necessary to optimize the detection efficiency of the system as the PpIX quickly photobleaches during the laser illumination. A light dose of 2.5 mJ (fluence rate = 9 mJ/mm2) is experimentally approved to excite an acceptable level of fluourescence signal arising from glioblastoma. In pulsed illumination mode, an excitation dose of 2.5 mJ, with a dark interval of 0.5 s (duty cycle 50%) shows a significantly shorter photobleaching time in comparison to the continuous illumination mode with the same laser power (p < 0.05). To avoid photobleaching (the remaining signal is more than 90% of its initial value) when measuring with 2.5 mJ delivered energy, the time for continuous and pulsed illumination should be restricted to 2.5 and 1.1 s, respectively.

    Fulltekst (pdf)
    FULLTEXT01
  • 10.
    Haj-Hosseini, Neda
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Avdelningen för medicinsk teknik. Linköpings universitet, Tekniska fakulteten.
    Richter, Johan
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Tekniska fakulteten. Region Östergötland, Sinnescentrum, Neurokirurgiska kliniken US.
    Hallbeck, Martin
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelning för neurobiologi. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk patologi.
    Milos, Peter
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Sinnescentrum, Neurokirurgiska kliniken US.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Avdelningen för medicinsk teknik. Linköpings universitet, Tekniska fakulteten.
    Stereotactic Brain Tumor Optical Biopsy2018Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    To provide guidance for targeting diagnostic tumor tissue and to avoid vessel rupture during the biopsy procedure an application specific fiber optic probe was devel-oped. The setup incorporated an in-house developed fluorescence spectroscopy system for 5-aminolevulinic acid (5-ALA) induced protopophyrin IX (PpIX) for detection in the tumor, and laser Doppler flowmeter (LDF) system for measurement of blood perfusion. Fluorescence and blood flow were recorded millimeter-wise towards the pre-calculated target. In conclusion, the optical probe made real-time detection of tumor possible and has a potential for vessel detection during the biopsy procedures. Moreover, the PpIX fluorescence, autofluorescence and blood flow in the tumor could be studied at precise positions in the brain and the tumor. In the next step, further anal-ysis will be added.

  • 11.
    Haj-Hosseini, Neda
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik.
    Richter, Johan
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska fakulteten. Region Östergötland, Sinnescentrum, Neurokirurgiska kliniken US.
    Hallbeck, Martin
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk patologi och klinisk genetik.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Low dose 5-aminolevulinic acid: Implications in spectroscopic measurements during brain tumor surgery2015Inngår i: Photodiagnosis and Photodynamic Therapy, ISSN 1572-1000, E-ISSN 1873-1597, Vol. 12, nr 2, s. 209-214Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background

    Using 5-aminolevulinic acid (ALA) as an intraoperative fluorescence contrast has been proven to improve the resection of glioblastoma and contribute to prolonged patient survival. ALA accumulates as protoporphyrin IX (PpIX) in the tumor cells and is administered in an advised dose of 20 mg/kg body weight (b.w.) for brain tumor resection using fluorescence surgical microscopes. PpIX fluorescence availability and intensities of a four folds lower ALA dose (5 mg/kg b.w.) has been investigated in glioblastomas and skin using a spectroscopy system adapted for surgical guidance.

    Methods

    A total of 30 adult patients diagnosed with high grade gliomas were included in the analysis. ALA was orally administered in doses of 5 mg/kg b.w. (n = 15) dissolved in orange juice or 20 mg/kg b.w. (n = 15) dissolved in water. A fluorescence spectroscopy system with a handheld fiber-optical probe was used for performing the quantitative fluorescence measurements.

    Results

    The binominal comparison of the diagnostic performance parameters showed no significant statistical difference (p > 0.05). The median fluorescence values in tumor were 2-3 times higher for the high ALA dose group. No PpIX was detected in the skin of the patients in the low dose group (0/4) while PpIX was detected in the skin of the majority of the patients in the high ALA dose group (13/14).

    Conclusions

    Application of 5 mg/kg ALA was evaluated as equally reliable as the higher dose regarding the diagnostic performance when guidance was performed using a spectroscopic system. Moreover, no PpIX was detected in the skin of the patients.

    Fulltekst (pdf)
    fulltext
  • 12.
    Haj-Hosseini, Neda
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Avdelningen för medicinsk teknik. Linköpings universitet, Tekniska fakulteten.
    Richter, Johan
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Sinnescentrum, Neurokirurgiska kliniken US.
    Kobayashi Frisk, Lisa
    Linköpings universitet, Institutionen för medicinsk teknik, Avdelningen för medicinsk teknik. Linköpings universitet, Tekniska fakulteten.
    Milos, Peter
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Sinnescentrum, Neurokirurgiska kliniken US.
    Hallbeck, Martin
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk patologi.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Avdelningen för medicinsk teknik. Linköpings universitet, Tekniska fakulteten.
    Fluorescence Guidance for Brain Tumor Biopsies2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    To provide guidance during stereotactic biopsy in brain tumors, fluorescence spectroscopy was used in ten patients. It was shown that the fiber optical probe could provide real-time guidance with clear fluorescence in all patients.

  • 13.
    Haj-Hosseini, Neda
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Avdelningen för medicinsk teknik. Linköpings universitet, Tekniska fakulteten.
    Richter, Johan
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Tekniska fakulteten. Region Östergötland, Sinnescentrum, Neurokirurgiska kliniken US.
    Milos, Peter
    Region Östergötland, Sinnescentrum, Neurokirurgiska kliniken US. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten.
    Hallbeck, Martin
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelning för neurobiologi. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk patologi.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Avdelningen för medicinsk teknik. Linköpings universitet, Tekniska fakulteten.
    5-ALA fluorescence and laser Doppler flowmetry for guidance in a stereotactic brain tumor biopsy2018Inngår i: Biomedical Optics Express, E-ISSN 2156-7085, Vol. 9, nr 5, s. 2284-2296Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A fiber optic probe was developed for guidance during stereotactic brain biopsy procedures to target tumor tissue and reduce the risk of hemorrhage. The probe was connected to a setup for the measurement of 5-aminolevulinic acid (5-ALA) induced fluorescence and microvascular blood flow. Along three stereotactic trajectories, fluorescence (n = 109) and laser Doppler flowmetry (LDF) (n = 144) measurements were done in millimeter increments. The recorded signals were compared to histopathology and radiology images. The median ratio of protoporphyrin IX (PpIX) fluorescence and autofluorescence (AF) in the tumor was considerably higher than the marginal zone (17.3 vs 0.9). The blood flow showed two high spots (3%) in total. The proposed setup allows simultaneous and real-time detection of tumor tissue and microvascular blood flow for tracking the vessels.

    Fulltekst (pdf)
    fulltext
  • 14.
    Haj-Hosseini, Neda
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Medicinska fakulteten.
    Richter, Johan
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Tekniska fakulteten.
    Milos, Peter
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Sinnescentrum, Neurokirurgiska kliniken US.
    Hallbeck, Martin
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk patologi och klinisk genetik.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska fakulteten.
    Optical guidance for stereotactic brain tumor biopsy procedures-preliminary clinical evaluation2017Konferansepaper (Fagfellevurdert)
    Abstract [en]

    During stereotactic biopsy on suspected tumors in the brain, tissue samples are harvested to determine the malignancy. To provide guidance for finding the diagnostic tumor sites and to avoid vessel rupture, an application specific probe was developed. The setup incorporated spectroscopy for detection of 5-aminolevulinic acid induced protoporphyrin (PpIX) fluorescence and blood flow using laser Doppler flowmetry. The PpIX fluorescence was significantly different in the tumor compared to the gliotic marginal zone (p < 0.05). In conclusion, the systems made real-time tumor detection and vessel tracking possible. Moreover, the autofluorescence and blood perfusion could be studied in the tumor.

  • 15.
    Haj-Hosseini, Neda
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Richter, Johan
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Sinnescentrum, Neurokirurgiska kliniken US.
    Olivecrona, Magnus
    Department of Neurosurgery, Umeå University.
    Hillman, Jan
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Neurokirurgi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Sinnescentrum, Neurokirurgiska kliniken US.
    Hallbeck, Martin
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Experimentell patologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk patologi och klinisk genetik.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Fluorescence guided spectroscopy versus fluorescence microscopy for brain tumor resection2013Konferansepaper (Annet vitenskapelig)
  • 16.
    Haj-Hosseini, Neda
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Richter, Johan
    Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Sinnescentrum, Neurokirurgiska kliniken US. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Fluorescence spectroscopy for ALA-guided glioblastoma resection using a fiber-optical probe2012Konferansepaper (Fagfellevurdert)
  • 17.
    Haj-Hosseini, Neda
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Medicinska fakulteten.
    Richter, Johan
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Medicinska fakulteten.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Photodiagnostics in Brain Tumor Surgery2014Inngår i: Medicinteknikdagarna, Göteborg, 14-16 oktober, 2014: Sammanfattningar, Göteborg: Svensk förening för medicinsk teknik och fysik , 2014Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Since getting approved for clinical application in neurosurgery 5-aminolevulinic acid (ALA), that is a fluorescence contrast agent, has attracted the interest of many neurosurgical clinics to implement it in their surgical routine. ALA naturally exists in the body and the external administration of the substance induces accumulation of a fluorophore known as protoporphyrin IX (PpIX) in the malignant cells due to a broken blood brain barrier and the altered enzyme levels in the brain tumor. The detection and visualization of PpIX in the clinical routine is conventionally performed using a modified neuro surgical microscope. As a complementary technique for detection of ALA-induced fluorescence and to perform objective and quantitative measurements, our group has developed a spectroscopy system adapted to the equipment in the operating room. The system includes a hand-held fiber optic probe which can be integrated in the neuronavigation and stereotactic systems. The main advantages of the system are the ease of use, high sensitivity, quantitative fluorescence detection and the possibility of applying a low dose of fluorescence contrast agent while obtaining equally reliable results as with the high dose. In this contribution we present our experience, gains and challenges from implementation of the system during brain tumor surgery in forty adult patients. The methods and systems are currently being adapted for implementation during operations of pediatric brain tumors.

  • 18.
    Haj-Hosseini, Neda
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Hälsouniversitetet.
    Richter, Johan
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Sinnescentrum, Neurokirurgiska kliniken US.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Quantitative ALA photodiagnostics in Neurosurgery2014Konferansepaper (Annet vitenskapelig)
  • 19.
    Hemm, Simone
    et al.
    Institute for Medical and Analytical Technologies (IMA), FHNW, Switzerland.
    Richter, Johan C.O.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan. Östergötlands Läns Landsting, Sinnescentrum, Neurokirurgiska kliniken US.
    Zsigmond, Peter
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Neurokirurgi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Sinnescentrum, Neurokirurgiska kliniken US.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Optical measurements for guidance during deep brain stimulation implantation2011Konferansepaper (Fagfellevurdert)
  • 20.
    Hemm, Simone
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Zsigmond, Peter
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Neurokirurgi. Östergötlands Läns Landsting, Sinnescentrum, Neurokirurgiska kliniken US.
    Richter, Johan
    Östergötlands Läns Landsting, Rekonstruktionscentrum, Neurokirurgiska kliniken US. Linköpings universitet, Institutionen för medicinsk teknik.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik.
    Laser doppler for guidance during DBS-typical optical trajectories toward Vim and STN2012Konferansepaper (Annet vitenskapelig)
  • 21.
    Ilias, Michail
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Richter, Johan
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Westermark, Frida
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Tekniska högskolan.
    Brantmark, Martin
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Tekniska högskolan.
    Andersson-Engels, Stefan
    Department of Physics, Lund Institute of Technology, Lund, Sweden.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Evaluation of a Fiber-Optic Fluorescence Spectroscopy System to Assist Neurosurgical Tumor Resections2007Inngår i: Novel Optical Instrumentation for Biomedical Applications III (Proceedings Volume) / [ed] Christian D. Depeursinge, Bellingham, Washington, USA: SPIE - International Society for Optical Engineering, 2007, Vol. 6631, s. 66310W-1-66310W-8Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The highly malignant brain tumor, glioblastoma multiforme, is difficult to totally resect without aid due to its infiltrative way of growing and its morphological similarities to surrounding functioning brain under direct vision in the operating field. The need for an inexpensive and robust real-time visualizing system for resection guiding in neurosurgery has been formulated by research groups all over the world. The main goal is to develop a system that helps the neurosurgeon to make decisions during the surgical procedure. A compact fiber optic system using fluorescence spectroscopy has been developed for guiding neurosurgical resections. The system is based on a high power light emitting diode at 395 nm and a spectrometer. A fiber bundle arrangement is used to guide the excitation light and fluorescence light between the instrument and the tissue target. The system is controlled through a computer interface and software package especially developed for the application. This robust and simple instrument has been evaluated in vivo both on healthy skin but also during a neurosurgical resection procedure. Before surgery the patient received orally a low dose of 5-aminolevulinic acid, converted to the fluorescence tumor marker protoporphyrin IX in the malignant cells. Preliminary results indicate that PpIX fluorescence and brain tissue autofluorescence can be recorded with the help of the developed system intraoperatively during resection of glioblastoma multiforme.

  • 22.
    Ilias, Michail
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik.
    Richter, Johan
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik.
    Wårdell, Karin
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik.
    Andersson-Engels, Stefan
    Inst för fysik Lunds tekniska högskola.
    Ett optiskt instrument för intraoperativ registrering av fluorescensspektra vid resektion av hjärntumörer - Ett framtida beslutsstödssystem för kirurgen?2007Inngår i: Medicinteknikdagarna,2007, 2007Konferansepaper (Annet vitenskapelig)
  • 23. Bestill onlineKjøp publikasjonen >>
    Richter, Johan
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Tekniska fakulteten.
    Fluorescence Guided Resection of Brain Tumors: Evaluation of a Hand-held Spectroscopic Probe2017Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Malignant gliomas grow infiltrative in the brain and can therefore not be completely removed by neurosurgical means. However, for an optimized oncological treatment it has proven useful to resect as much as possible of tumor. The identification of the tumor in the marginal zone is difficult but crucial. Studies have shown that visualization of the specific enhancement of 5-aminolevulinic acid(5-ALA) in the tumor can help to maximize the resection. The Department of Biomedical Engineering, Linköping University, has developed an optical hand-held probe (HHP) to identify tumor tissue with a high sensitivity by means of fluorescence spectroscopy.

    The technical design and the optical properties of the probe were gradually developed in a standard neurosurgical setting during resection of malignant gliomas. The device could easily be implemented in the operating room, meeting all requirements in terms of sterile handling and without interference of any kind with other equipment. The integration of the device in a navigation system and its use in combination with a blue light surgical microscope were simple. Measurements in 27 operations during resection of malignant gliomas were compared to results from biopsies from the same tumor locations. The equipment was tested as a stand-alone device (n = 180), integrated in a navigation system or in combination with the blue light microscope (n = 190). A ratiocal culated from the measurements enabled objective and comparable values for different tissue types, in correspondence with the findings from the histopathological examinations and in accordance with the navigation system as well as with the surgical microscope.The marginal zone was explored and tumor fluorescence could be identified beyond the fluorescence as seen through the microscope. A higher sensitivity of the HHP was confirmed; the specificity was lower.

    The combined use of the HHP with a navigation system and with asurgical microscope was beneficial.

    Delarbeid
    1. Evaluation of a Fiber-Optic Fluorescence Spectroscopy System to Assist Neurosurgical Tumor Resections
    Åpne denne publikasjonen i ny fane eller vindu >>Evaluation of a Fiber-Optic Fluorescence Spectroscopy System to Assist Neurosurgical Tumor Resections
    Vise andre…
    2007 (engelsk)Inngår i: Novel Optical Instrumentation for Biomedical Applications III (Proceedings Volume) / [ed] Christian D. Depeursinge, Bellingham, Washington, USA: SPIE - International Society for Optical Engineering, 2007, Vol. 6631, s. 66310W-1-66310W-8Konferansepaper, Publicerat paper (Annet vitenskapelig)
    Abstract [en]

    The highly malignant brain tumor, glioblastoma multiforme, is difficult to totally resect without aid due to its infiltrative way of growing and its morphological similarities to surrounding functioning brain under direct vision in the operating field. The need for an inexpensive and robust real-time visualizing system for resection guiding in neurosurgery has been formulated by research groups all over the world. The main goal is to develop a system that helps the neurosurgeon to make decisions during the surgical procedure. A compact fiber optic system using fluorescence spectroscopy has been developed for guiding neurosurgical resections. The system is based on a high power light emitting diode at 395 nm and a spectrometer. A fiber bundle arrangement is used to guide the excitation light and fluorescence light between the instrument and the tissue target. The system is controlled through a computer interface and software package especially developed for the application. This robust and simple instrument has been evaluated in vivo both on healthy skin but also during a neurosurgical resection procedure. Before surgery the patient received orally a low dose of 5-aminolevulinic acid, converted to the fluorescence tumor marker protoporphyrin IX in the malignant cells. Preliminary results indicate that PpIX fluorescence and brain tissue autofluorescence can be recorded with the help of the developed system intraoperatively during resection of glioblastoma multiforme.

    sted, utgiver, år, opplag, sider
    Bellingham, Washington, USA: SPIE - International Society for Optical Engineering, 2007
    Serie
    Proceedings of SPIE - International Society for Optical Engineering, ISSN 0277-786X ; Vol. 6631
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-38407 (URN)10.1117/12.728546 (DOI)44225 (Lokal ID)9780819467751 (ISBN)44225 (Arkivnummer)44225 (OAI)
    Konferanse
    Novel optical instrumentation for biomedical applications III : 17-19 June 2007, Munich, Germany
    Tilgjengelig fra: 2009-10-10 Laget: 2009-10-10 Sist oppdatert: 2018-03-23bibliografisk kontrollert
    2. Optical Touch Pointer for Fluorescence Guided Glioblastoma Resection Using 5-Aminolevulinic Acid
    Åpne denne publikasjonen i ny fane eller vindu >>Optical Touch Pointer for Fluorescence Guided Glioblastoma Resection Using 5-Aminolevulinic Acid
    2010 (engelsk)Inngår i: Lasers in Surgery and Medicine, ISSN 0196-8092, E-ISSN 1096-9101, Vol. 42, nr 1, s. 9-14Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Background and Objective

    Total tumor resection in patients with glioblastoma multiforme (GBM) is difficult to achieve due to the tumor's infiltrative way of growing and morphological similarity to the surrounding functioning brain tissue. The diagnosis is usually subjectively performed using a surgical microscope. The objective of this study was to develop and evaluate a hand-held optical touch pointer using a fluorescence spectroscopy system to quantitatively distinguish healthy from malignant brain tissue intraoperatively.

    Study Design/Materials and Methods

    A fluorescence spectroscopy system with pulsed modulation was designed considering optimum energy delivery to the tissue, minimal photobleaching of PpIX and omission of the ambient light background in the operating room (OR). 5-Aminolevulinic acid (5-ALA) of 5 mg/kg body weight was given to the patients with a presumed GBM prior to surgery. During the surgery a laser pulse at 405 nm was delivered to the tissue. PpIX in glioblastoma tumor cells assigned with peaks at 635 and 704 nm was detected using a fiber optical probe.

    Results/Conclusion

    By using the pulsed fluorescence spectroscopy, PpIX fluorescence is quantitatively detected in the GBM. An effective suppression of low power lamp background from the recorded spectra in addition to a significant reduction of high power surgical lights is achieved.

    sted, utgiver, år, opplag, sider
    Wiley-Blackwell, 2010
    Emneord
    background light suppression • fluorescence spectroscopy • glioblastoma multiforme • intraoperative
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-53946 (URN)10.1002/lsm.20868 (DOI)
    Tilgjengelig fra: 2010-02-15 Laget: 2010-02-15 Sist oppdatert: 2017-12-12bibliografisk kontrollert
    3. Fluorescence Spectroscopy Measurements in Ultrasonic Navigated Resection of Malignant Brain Tumors
    Åpne denne publikasjonen i ny fane eller vindu >>Fluorescence Spectroscopy Measurements in Ultrasonic Navigated Resection of Malignant Brain Tumors
    2011 (engelsk)Inngår i: Lasers in Surgery and Medicine, ISSN 0196-8092, E-ISSN 1096-9101, Vol. 43, nr 1, s. 8-14Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Background and Objective: Glioblastoma multiforme is a highly malignant primary brain tumor. It has no border but at best a marginal zone, however, invisible to the surgeon. An optical touch pointer (OTP) enabling differentiation of healthy and tumor tissue by means of fiber-optic fluorescence spectroscopy has been developed. In combination with an ultrasonic navigation system, the OTP may be used for demarcation of resectable tumor tissue. The aim of the study was to evaluate the clinical performance of OTP during surgery of malignant brain tumors. 

    Study Design/Materials and Methods: Nine patients were operated on with the standard surgical procedure, including white light microscopy and navigation. A total of 5 mg/kg bodyweight of 5-amino-levulin acid was orally administrated before surgery. The OTP was calibrated into the ultrasound-based navigation system and measurements were performed in tumor core and along the tumor border. The ratio between the protoporphyrin IX fluorescence at 635 nm and the autofluorescence was used for quantifications of data. Biopsies (n =20), ultrasound images (n = 30), and visual inspection (n =180) were compared to the fluorescence ratio. 

    Results/Conclusion : Healthy and tumor tissue could be identified and differentiated with the OTP(P < 0.001). The fluorescence ratio in average was 0 outside the tumor and low in the gliotic edema zone around the tumor. It increased in the marginal zone and was highest in the solid tumor tissue. In the necrotic tissue, in the center of the tumor, the ratio in average was 0. The OTP can be used in combination with ultrasound-based navigation and may help to determine whether to resect otherwise not identifiable tissue.

    Emneord
    5-amino-levulin acid (5-ALA);fluorescence-guided resection (FGR);glioblastoma multiforme;optical touch pointer (OTP);protoporphyrin IX (PpIX) fluorescence;ultrasound navigation
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-64689 (URN)10.1002/lsm.21022 (DOI)000286440300002 ()
    Tilgjengelig fra: 2011-02-01 Laget: 2011-02-01 Sist oppdatert: 2017-12-11bibliografisk kontrollert
    4. Combination of Hand-Held Probe and Microscopy for Fluorescence Guided Surgery in the Brain Tumor Marginal Zone
    Åpne denne publikasjonen i ny fane eller vindu >>Combination of Hand-Held Probe and Microscopy for Fluorescence Guided Surgery in the Brain Tumor Marginal Zone
    2017 (engelsk)Inngår i: Photodiagnosis and Photodynamic Therapy, ISSN 1572-1000, Vol. 18, s. 185-192Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Background

    Visualization of the tumor is crucial for differentiating malignant tissue from healthy brain during surgery, especially in the tumor marginal zone. The aim of the study was to introduce a fluorescence spectroscopy-based hand-held probe (HHF-probe) for tumor identification in combination with the fluorescence guided resection surgical microscope (FGR-microscope), and evaluate them in terms of diagnostic performance and practical aspects of fluorescence detection.

    Material and Methods

    Eighteen operations were performed on 16 patients with suspected high-grade glioma. The HHF-probe and the FGR-microscope were used for detection of protoporphyrin (PpIX) fluorescence induced by 5-aminolevulinic acid (5-ALA) and evaluated against histopathological analysis and visual grading done through the FGR-microscope by the surgeon. A ratio of PpIX fluorescence intensity to the autofluorescence intensity (fluorescence ratio) was used to quantify the spectra detected by the probe.

    Results

    Fluorescence ratio medians (range 0 – 40) measured by the probe were related to the intensity of the fluorescence in the FGR-microscope, categorized as “none” (0.3, n = 131), “weak” (1.6, n = 34) and “strong” (5.4, n = 28). Of 131 “none” points in the FGR-microscope, 88 (67%) exhibited fluorescence with the HHF-probe. For the tumor marginal zone, the area under the receiver operator characteristics (ROC) curve was 0.49 for the FGR-microscope and 0.65 for the HHF-probe.

    Conclusions

    The probe was integrated in the established routine of tumor resection using the FGR-microscope. The HHF-probe was superior to the FGR-microscope in sensitivity; it detected tumor remnants after debulking under the FGR-microscope. The combination of the HHF-probe and the FGR-microscope was beneficial especially in the tumor marginal zone.

    sted, utgiver, år, opplag, sider
    Amsterdam: Elsevier, 2017
    Emneord
    High-grade glioma, Fluorescence guided resection (FGR), 5-Aminolaevulinic acid (5-ALA), Fluorescence spectroscopy, Protoporphyrin (PpIX)
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-134849 (URN)10.1016/j.pdpdt.2017.01.188 (DOI)000404315000028 ()28223144 (PubMedID)
    Merknad

    Funding agencies: Swedish Governmental Agency for Innovation Systems (Vinnova); Swedish Foundation for Strategic Research (SSF); Swedish Research Council (VR) [311-2006-7661, 523-2013-2735]; NovaMedTech; Swedish Childhood Cancer Foundation [MT 2013-0043]; ALF Grants Region

    Tilgjengelig fra: 2017-03-08 Laget: 2017-03-08 Sist oppdatert: 2019-10-14bibliografisk kontrollert
    Fulltekst (pdf)
    fulltext
    Download (pdf)
    omslag
    Download (jpg)
    presentationsbild
  • 24.
    Richter, Johan C.O.
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan. Östergötlands Läns Landsting, Rekonstruktionscentrum, Neurokirurgiska kliniken US.
    Haj-Hosseini, Neda
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Andersson-Engels, Stefan
    Department of Physics, Lund University.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Fluorescence Spectroscopy Measurements in Ultrasonic Navigated Resection of Malignant Brain Tumors2011Inngår i: Lasers in Surgery and Medicine, ISSN 0196-8092, E-ISSN 1096-9101, Vol. 43, nr 1, s. 8-14Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background and Objective: Glioblastoma multiforme is a highly malignant primary brain tumor. It has no border but at best a marginal zone, however, invisible to the surgeon. An optical touch pointer (OTP) enabling differentiation of healthy and tumor tissue by means of fiber-optic fluorescence spectroscopy has been developed. In combination with an ultrasonic navigation system, the OTP may be used for demarcation of resectable tumor tissue. The aim of the study was to evaluate the clinical performance of OTP during surgery of malignant brain tumors. 

    Study Design/Materials and Methods: Nine patients were operated on with the standard surgical procedure, including white light microscopy and navigation. A total of 5 mg/kg bodyweight of 5-amino-levulin acid was orally administrated before surgery. The OTP was calibrated into the ultrasound-based navigation system and measurements were performed in tumor core and along the tumor border. The ratio between the protoporphyrin IX fluorescence at 635 nm and the autofluorescence was used for quantifications of data. Biopsies (n =20), ultrasound images (n = 30), and visual inspection (n =180) were compared to the fluorescence ratio. 

    Results/Conclusion : Healthy and tumor tissue could be identified and differentiated with the OTP(P < 0.001). The fluorescence ratio in average was 0 outside the tumor and low in the gliotic edema zone around the tumor. It increased in the marginal zone and was highest in the solid tumor tissue. In the necrotic tissue, in the center of the tumor, the ratio in average was 0. The OTP can be used in combination with ultrasound-based navigation and may help to determine whether to resect otherwise not identifiable tissue.

  • 25.
    Richter, Johan C.O.
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan. Östergötlands Läns Landsting, Sinnescentrum, Neurokirurgiska kliniken US.
    Haj-Hosseini, Neda
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Fluorescence Spectroscopy based identification of Glioblastoma multiforme2011Konferansepaper (Fagfellevurdert)
  • 26.
    Richter, Johan
    et al.
    Östergötlands Läns Landsting, Sinnescentrum, Neurokirurgiska kliniken US. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska fakulteten.
    Haj Hosseini, Neda
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska fakulteten.
    Hallbeck, Martin
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelning för neurobiologi. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk patologi.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Avdelningen för medicinsk teknik. Linköpings universitet, Tekniska fakulteten.
    Combination of Hand-Held Probe and Microscopy for Fluorescence Guided Surgery in the Brain Tumor Marginal Zone2017Inngår i: Photodiagnosis and Photodynamic Therapy, ISSN 1572-1000, Vol. 18, s. 185-192Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background

    Visualization of the tumor is crucial for differentiating malignant tissue from healthy brain during surgery, especially in the tumor marginal zone. The aim of the study was to introduce a fluorescence spectroscopy-based hand-held probe (HHF-probe) for tumor identification in combination with the fluorescence guided resection surgical microscope (FGR-microscope), and evaluate them in terms of diagnostic performance and practical aspects of fluorescence detection.

    Material and Methods

    Eighteen operations were performed on 16 patients with suspected high-grade glioma. The HHF-probe and the FGR-microscope were used for detection of protoporphyrin (PpIX) fluorescence induced by 5-aminolevulinic acid (5-ALA) and evaluated against histopathological analysis and visual grading done through the FGR-microscope by the surgeon. A ratio of PpIX fluorescence intensity to the autofluorescence intensity (fluorescence ratio) was used to quantify the spectra detected by the probe.

    Results

    Fluorescence ratio medians (range 0 – 40) measured by the probe were related to the intensity of the fluorescence in the FGR-microscope, categorized as “none” (0.3, n = 131), “weak” (1.6, n = 34) and “strong” (5.4, n = 28). Of 131 “none” points in the FGR-microscope, 88 (67%) exhibited fluorescence with the HHF-probe. For the tumor marginal zone, the area under the receiver operator characteristics (ROC) curve was 0.49 for the FGR-microscope and 0.65 for the HHF-probe.

    Conclusions

    The probe was integrated in the established routine of tumor resection using the FGR-microscope. The HHF-probe was superior to the FGR-microscope in sensitivity; it detected tumor remnants after debulking under the FGR-microscope. The combination of the HHF-probe and the FGR-microscope was beneficial especially in the tumor marginal zone.

    Fulltekst (pdf)
    fulltext
  • 27.
    Richter, Johan
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan. Östergötlands Läns Landsting, Sinnescentrum, Neurokirurgiska kliniken US.
    Haj-Hosseini, Neda
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Fluorescence guided brain tumour resection2014Konferansepaper (Annet vitenskapelig)
  • 28.
    Richter, Johan
    et al.
    Linköpings universitet, Tekniska högskolan. Östergötlands Läns Landsting, Rekonstruktionscentrum, Neurokirurgiska kliniken US. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik.
    Haj-Hosseini, Neda
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik.
    Andersson-Engels, Stefan
    Department of Physics, Lund University, Sweden.
    Wårdell, Karin
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik.
    Tumor resection with fiber-optic fluorescence spectroscopy system, ultrasound based neuronavigation and peroperative CT-scan2008Inngår i: XVIII Congress of the European Society for Stereotactic and Functional Neurosurgery,2008, 2008Konferansepaper (Annet vitenskapelig)
  • 29.
    Wårdell, Karin
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Blomstedt, P.
    Department of Neurosurgery, University Hospital, Umeå, Sweden.
    Richter, Johan
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik.
    Antonsson, Johan
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik.
    Eriksson, Ola
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik.
    Zsigmond, Peter
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Neurokirurgi. Östergötlands Läns Landsting, Rekonstruktionscentrum, Neurokirurgiska kliniken US.
    Bergenheim, A.T.
    Department of Neurosurgery, University Hospital, Umeå, Sweden.
    Hariz, M.I.
    Department of Neurosurgery, University Hospital, Umeå, Sweden, Institute of Neurology, University College London, London, United Kingdom.
    Intracerebral microvascular measurements during deep brain stimulation implantation using laser doppler perfusion monitoring2007Inngår i: Stereotactic and Functional Neurosurgery, ISSN 1011-6125, E-ISSN 1423-0372, Vol. 85, nr 6, s. 279-286Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The aim of the study was to investigate if laser Doppler perfusion monitoring (LDPM) can be used in order to differentiate between gray and white matter and to what extent microvascular perfusion can be recorded in the deep brain structures during stereotactic neurosurgery. An optical probe constructed to fit in the Leksell® Stereotactic System was used for measurements along the trajectory and in the targets (globus pallidus internus, subthalamic nucleus, zona incerta, thalamus) during the implantation of deep brain stimulation leads (n = 22). The total backscattered light intensity (TLI) reflecting the grayness of the tissue, and the microvascular perfusion were captured at 128 sites. Heartbeat-synchronized pulsations were found at all perfusion recordings. In 6 sites the perfusion was more than 6 times higher than the closest neighbor indicating a possible small vessel structure. TLI was significantly higher (p < 0.005) and the perfusion significantly lower (p < 0.005) in positions identified as white matter in the respective MRI batch. The measurements imply that LDPM has the potential to be used as an intracerebral guidance tool.

    Fulltekst (pdf)
    fulltext
  • 30.
    Wårdell, Karin
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Johansson, Johannes
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Richter, Johan
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan. Östergötlands Läns Landsting, Sinnescentrum, Neurokirurgiska kliniken US.
    Blomstedt, Patric
    Dept of Neurosurgery, Umeå University Hospital, Sweden.
    Optical measurements for guidance during deep brain stimulation surgery2009Inngår i: World Congress on Medical Physics and Biomedical Engineering / [ed] Olaf Dössel and Wolfgang C. Schlegel, Berlin/Heidelberg: Springer , 2009, s. 516-517Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Deep brain stimulation (DBS) is an established treatment for Parkinson’s disease and related movement disorders. The success of DBS is highly dependent on electrode location, electrical parameter settings and the surgical procedure. In this paper an overview of the current status of optical measurements for intracerebral guidance performed during DBS implantation is presented. Laser Doppler perfusion monitoring and/or reflection spectroscopy measurements have been done in relation to more than 70 DBS lead implantations to wards targets in the deep brain structures. The techniques have also been compared with impedance monitoring, and simulation of the measurement depth has been done with Monte Carlo technique. These studies show that grey-white matter boundaries can be determined with a resolution higher than for both impedance measurements and magnetic resonance imaging.

    Fulltekst (pdf)
    FULLTEXT01
  • 31.
    Wårdell, Karin
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Rejmstad, Peter
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Hemm-Ode, Simone
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan. Institute for Medical and Analytical Technologies, University of Applied Sciences and Art Northwestern Switzerland, Basel.
    Richter, Johan
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan. Östergötlands Läns Landsting, Sinnescentrum, Neurokirurgiska kliniken US.
    Zsigmond, Peter
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neurovetenskap. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Sinnescentrum, Neurokirurgiska kliniken US.
    Microvascular Blood Flow in the Deep Brain Structures - Laser Doppler Measurements during DBS-implantations2014Inngår i: Movement Disorders 2014, Volym 29, Suppl 1 :1271, 2014Konferansepaper (Annet vitenskapelig)
  • 32.
    Wårdell, Karin
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Richter, Johan C.O.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan. Östergötlands Läns Landsting, Sinnescentrum, Neurokirurgiska kliniken US.
    Zsigmond, Peter
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Neurokirurgi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Sinnescentrum, Neurokirurgiska kliniken US.
    Hemm, Simone
    Institute for Medical and Analytical Technologies, University of Applied Sciences, Northwestern Switzerland.
    Optical measurements for guidance during deep brain stimulation implantation2011Konferansepaper (Fagfellevurdert)
  • 33.
    Wårdell, Karin
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Richter, Johan
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Sinnescentrum, Neurokirurgiska kliniken US.
    Zsigmond, Peter
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Neurokirurgi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Sinnescentrum, Neurokirurgiska kliniken US.
    Hemm, Simone
    Fachhochschule Nordwestschweiz.
    Intraoperative laser doppler measurements for navigation during deep brain stimulation implantation2012Konferansepaper (Annet vitenskapelig)
  • 34.
    Wårdell, Karin
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Avdelningen för medicinsk teknik. Linköpings universitet, Tekniska fakulteten.
    Zsigmond, Peter
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Sinnescentrum, Neurokirurgiska kliniken US.
    Richter, Johan
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Tekniska fakulteten. Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Sinnescentrum, Neurokirurgiska kliniken US.
    Hemm, Simone
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Tekniska fakulteten. Institute for Medical and Analytical Technologies, University of Applied Sciences and Arts Northwestern Switzerland, Muttenz, Switzerland.
    Optical Guidance System for Deep Brain Stimulation Surgery: from Experimental Studies to Clinical Use2018Inngår i: , Hollywood, Florida, United States, 2018, artikkel-id CTh2B.3Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Laser Doppler flowmetry (LDF) has been adapted for optical guidance during stereotactic deep brain stimulation (DBS) surgery. It has been used in more than 130 DBS implantations. The necessary steps to go from experimental studies to clinical use in the neurosurgical setting are reviewed.

  • 35.
    Wårdell, Karin
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Zsigmond, Peter
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Neurokirurgi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Sinnescentrum, Neurokirurgiska kliniken US.
    Richter, Johan
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Sinnescentrum, Neurokirurgiska kliniken US.
    Hemm, Simone
    University of Applied Sciences Northwestern Switzerland .
    Optical Measurements for Guidance during Deep Brain Stimulation Implantation2012Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Deep brain stimulation (DBS) is an established treatment for Parkinson’s disease and related movement disorders. The success of DBS is highly dependent on electrode location, electrical parameter settings and the surgical procedure. In this paper an overview of the current status of optical measurements for intracerebral guidance performed during DBS implantation is presented. Laser Doppler perfusion monitoring and/or reflection spectroscopy measurements have been done in relation to more than 70 DBS lead implantations to wards targets in the deep brain structures. The techniques have also been compared with impedance monitoring, and simulation of the measurement depth has been done with Monte Carlo technique. These studies show that grey-white matter boundaries can be determined with a resolution higher than for both impedance measurements and magnetic resonance imaging.

  • 36.
    Wårdell, Karin
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik.
    Zsigmond, Peter
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Neurokirurgi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Sinnescentrum, Neurokirurgiska kliniken US.
    Richter, Johan
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Neurokirurgi. Linköpings universitet, Hälsouniversitetet.
    Hemm, Simone
    University of Applied Sciences Northwestern Switzerland, Institute for Medical and Analytical Technologies, Muttenz, Switzerland..
    Relationship Between Laser Doppler Signals and Anatomy During Deep Brain Stimulation Electrode Implantation Toward the Ventral Intermediate Nucleus and Subthalamic Nucleus2013Inngår i: Neurosurgery, ISSN 0148-396X, E-ISSN 1524-4040, Vol. 72, nr 2, s. 127-140Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    BACKGROUND: Deep brain stimulation (DBS) requires precise and safe navigation to the chosen target. Optical measurements allow monitoring of gray-white tissue boundaries (total light intensity [TLI]) and microvascular blood flow during stereotactic procedures.

    OBJECTIVE: To establish the link between TLI/blood flow and anatomy along trajectories toward the ventral intermediate nucleus (Vim) and subthalamic nucleus (STN).

    METHODS: Stereotactic laser Doppler measurements were obtained with millimeter precision from the cortex toward the Vim (n = 13) and STN (n = 9). Optical trajectories of TLI and blood flow were created and compared with anatomy by superimposing the Schaltenbrandt-Wahren atlas on the patients' pre- and postoperative images. Measurements were divided into anatomic subgroups and compared statistically.

    RESULTS: Typical TLI trajectories with well-defined anatomic regions could be identified for the Vim and STN. TLI was significantly lower (P < .001) and microvascular blood flow significantly higher (P = .01) in the Vim targets. Of 1285 sites, 38 showed blood flow peaks, 27 of them along the Vim trajectories. High blood flow was more common close to the sulci and in the vicinity of the caudate/putamen. Along 1 Vim trajectory, a slight bleeding was suspected during insertion of the probe and confirmed with postoperative computed tomography.

    CONCLUSION: Laser Doppler is useful for intraoperative guidance during DBS implantation because simultaneous measurement of tissue grayness and microvascular blood flow can be done along the trajectory with millimeter precision. Typical but different TLI trajectories were found for the Vim and STN.

    Fulltekst (pdf)
    fulltext
  • 37.
    Xie, Haiyan
    et al.
    Dept. of Physics, Lund University, Sweden.
    Haj-Hosseini, Neda
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Richter, Johan
    Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Tekniska högskolan. Östergötlands Läns Landsting, Sinnescentrum, Neurokirurgiska kliniken US.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Andersson-Engels, Stefan
    Dept. of Physics, Lund University, Sweden.
    Fluorescence spectroscopy for guiding malignant brain tumour resection with Optical Touch Pointer2010Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Glioblastoma multiforme (GBM), a highly malignant primary brain tumor, is difficult to distinguish from from its surrounding functioning tissue under direct vision in the operating field, since it grows in an infiltrative growth pattern. The main challenge in the surgical treatment of GBM is to fully resect the tumor and avoid neurological impairment. In this paper we extend previous proof-of-principle studies by extending the clinical potential of OTP with the introduction of more sophisticated multivariate analysis schemes. The aim is to distinguish tumor and healthy tissue as well as possible using singular value decomposition (SVD) and cluster analysis methods.

1 - 37 of 37
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf