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Persliden, Jan
Publications (10 of 44) Show all publications
Larsson, P., Malusek, A., Persliden, J. & Alm Carlsson, G. (2006). Energy dependence in KAP-meter calibration coefficients: Dependence on calibration method, type of KAP-meter, and added filter close to the KAP-meter. Physics in Medicine and Biology
Open this publication in new window or tab >>Energy dependence in KAP-meter calibration coefficients: Dependence on calibration method, type of KAP-meter, and added filter close to the KAP-meter
2006 (English)In: Physics in Medicine and Biology, ISSN 0031-9155, E-ISSN 1361-6560Article in journal (Refereed) Submitted
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-14178 (URN)
Available from: 2006-11-30 Created: 2006-11-30 Last updated: 2017-12-13
Jansson, M., Geijer, H., Persliden, J. & Andersson, T. (2006). Reducing dose in urography while maintaining image quality - A comparison of storage phosphor plates and a flat-panel detector. European Radiology, 16(1), 221-226
Open this publication in new window or tab >>Reducing dose in urography while maintaining image quality - A comparison of storage phosphor plates and a flat-panel detector
2006 (English)In: European Radiology, ISSN 0938-7994, E-ISSN 1432-1084, Vol. 16, no 1, p. 221-226Article in journal (Refereed) Published
Abstract [en]

The introduction of new flat-panel detector technology often forces us to accept too high dose levels as proposed by the manufacturers. We need a tool to compare the image quality of a new system with the accepted standard. The aim of this study was to obtain a comparable image quality for two systems - storage phosphor plates and a flat-panel system using intravenous urography (IVU) as a clinical model. The image quality figure was calculated using a contrast-detail phantom (CDRAD) for the two evaluated systems. This allowed us to set a dose for the flat-panel system that gave equivalent image quality to the storage phosphor plates. This reduced detector dose was used in an evaluation of clinical images to find out if the dose reduction from the phantom study indeed resulted in images of equal clinical image quality. The image quality was assessed using image criteria of the European guidelines for IVU with visual grading analysis. Equivalent image quality in image pairs was achieved at 30% of the dose. The CDRAD contrast-detail phantom makes it possible to find dose levels that give equal image quality using different imaging systems. © Springer-Verlag 2005.

Keywords
Digital radiography, Flat-panel detector, Image quality, Phantoms
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-50322 (URN)10.1007/s00330-005-2772-3 (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-12Bibliographically approved
Norrman, E. & Persliden, J. (2005). A factorial experiment on image quality and radiation dose. Radiation Protection Dosimetry, 114(1-3), 246-252
Open this publication in new window or tab >>A factorial experiment on image quality and radiation dose
2005 (English)In: Radiation Protection Dosimetry, ISSN 0144-8420, E-ISSN 1742-3406, Vol. 114, no 1-3, p. 246-252Article in journal (Refereed) Published
Abstract [en]

To find if factorial experiments can be used in the optimisation of diagnostic imaging, a factorial experiment was performed to investigate some of the factors that influence image quality, kerma area product (KAP) and effective dose (E). In a factorial experiment the factors are varied together instead of one at a time, making it possible to discover interactions between the factors as well as major effects. The factors studied were tube potential, tube loading, focus size and filtration. Each factor was set to two levels (low and high). The influence of the factors on the response variables (image quality, KAP and E) was studied using a direct digital detector. The major effects of each factor on the response variables were estimated as well as the interaction effects between factors. The image quality, KAP and E were mainly influenced by tube loading, tube potential and filtration. There were some active interactions, for example, between tube potential and filtration and between tube loading and filtration. The study shows that factorial experiments can be used to predict the influence of various parameters on image quality and radiation dose. © The Author 2005. Published by Oxford University Press. All rights reserved.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-50463 (URN)10.1093/rpd/nch557 (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-12
Sjoholm, B., Geijer, H. & Persliden, J. (2005). Impact of digital imaging on radiation doses to the patient during X-ray examination of the urinary tract. Acta Radiologica, 46(6), 657-661
Open this publication in new window or tab >>Impact of digital imaging on radiation doses to the patient during X-ray examination of the urinary tract
2005 (English)In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 46, no 6, p. 657-661Article in journal (Refereed) Published
Abstract [en]

Purpose: To compare radiation doses given to patients undergoing IVU (intravenous urography) before and after digitalization of our X-ray department. Material and Methods: IVU examinations were monitored with dose area product meters before and after the X-ray department changed to digital techniques. The first step was a change from film-screen to storage phosphor plates, while the second step involved changing to a flat panel detector. Forty-two patients were included for the film-screen situation, 69 when using the storage phosphor plates, and 70 using the flat panel detector. Results: A dose reduction from 41.8 Gycm(2) to 31.5 Gycm(2) was achieved with the first step when the film-screen system was replaced with storage phosphor plates. A further reduction to 12.1 Gycm(2) was achieved using the flat panel detector. Conclusion: The introduction of the flat panel detectors made a considerable dose reduction possible.

Keywords
digital radiography, dosimetry, urinary
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-46068 (URN)10.1080/02841850510021616 (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-13
Persliden, J. (2005). Patient and staff doses in interventional X-ray procedures in Sweden. Radiation Protection Dosimetry, 114( 1-3), 150-157
Open this publication in new window or tab >>Patient and staff doses in interventional X-ray procedures in Sweden
2005 (English)In: Radiation Protection Dosimetry, ISSN 0144-8420, E-ISSN 1742-3406, Vol. 114, no 1-3, p. 150-157Article in journal (Refereed) Published
Abstract [en]

Interventional procedures in radiology are of concern because of irradiation doses to the patients and also to the staff. A questionnaire sent to all radiology departments in Sweden showed that 11,350 procedures were performed annually 1996-1997. In a follow-up study, data from patient procedures were recorded. Type of procedure, dose-area product (DAP) values, fluoroscopy times, number of radiography series and patient data were recorded. For some procedures, staff doses were measured. Skin doses to the patients were also calculated where possible. Results: A total of 380 interventional procedures were described. The procedures were grouped into cranial, neck and thorax, intestine and abdominal, uro/genital and pelvis and extremities. DAP and fluoroscopy times (mean values) were 200 Gy cm2 for 57 min, 57 Gy cm2 for 16 min, 270 Gy cm2 for 35 min, 212 Gy cm2 for 37 min, 67 Gy cm2 for 21 min, respectively, for the named procedures. Maximum patient skin doses exceeded threshold values for erythema (2 Gy) in cranial, neck/thorax and intestine/abdominal procedures. Effective doses to the patients could be high, 200 mSv. Conclusion: It was found that patient doses could exceed threshold values for skin erythema (2 Gy) and temporary epilation (3 Gy). Hence, the procedures require immediate improvement. © The Author 2005. Published by Oxford University Press. All rights reserved.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-28529 (URN)10.1093/rpd/nch539 (DOI)13680 (Local ID)13680 (Archive number)13680 (OAI)
Available from: 2009-10-09 Created: 2009-10-09 Last updated: 2017-12-13
Pettersson, H., Fälth-Magnusson, K., Persliden, J. & Scott, M. (2005). Radiation risk and cost-benefit analysis of a paediatric radiology procedure: Results from a national study. British Journal of Radiology, 78(925), 34-38
Open this publication in new window or tab >>Radiation risk and cost-benefit analysis of a paediatric radiology procedure: Results from a national study
2005 (English)In: British Journal of Radiology, ISSN 0007-1285, E-ISSN 1748-880X, Vol. 78, no 925, p. 34-38Article in journal (Refereed) Published
Abstract [en]

A national study was performed to investigate radiation doses and associated risks to patients during X-ray fluoroscopy-guided small intestinal biopsies in the investigation of coeliac disease. Thermoluminescent dosemeters (TLD) and questionnaires were sent to 42 of the 43 paediatric departments in Sweden performing these biopsies. During the study period (2 × 3 weeks) 257 biopsies were recorded, representing about 10% of annually performed paediatric investigations. The results show that the absorbed dose during biopsy ranged from 0.04 mGy to 23.8 mGy (mean 1.87 mGy). The fluoroscopy time ranged from 2 s to 663 s (mean 60 s). The collective dose from the procedure amounts to 4.7 manSv year-1. Thus, the annual excess cancer mortality, including severe hereditary effects, can be estimated at 0.6-0.7 cases per year. However, significant dose saving can be obtained by proper choice of sedation and biopsy equipment. © 2005 The British Institute of Radiology.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-45530 (URN)10.1259/bjr/79694026 (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-13
Geijer, H. & Persliden, J. (2005). Varied tube potential with constant effective dose at lumbar spine radiography using a flat-panel digital detector. Radiation Protection Dosimetry, 114( 1-3), 240-245
Open this publication in new window or tab >>Varied tube potential with constant effective dose at lumbar spine radiography using a flat-panel digital detector
2005 (English)In: Radiation Protection Dosimetry, ISSN 0144-8420, E-ISSN 1742-3406, Vol. 114, no 1-3, p. 240-245Article in journal (Refereed) Published
Abstract [en]

The purpose of the study was to evaluate the image quality at different tube potential (kV) settings using anteroposterior lumbar spine radiography as a model. An Alderson phantom was used with a flat-panel detector. The tube potential varied between 48 and 125 kV while the tube charge (mAs) was adjusted to keep an effective dose of 0.11 mSv. Image quality was assessed with a visual grading analysis and with a CDRAD contrast-detail phantom together with a computer program. The VGA showed inferior image quality for the higher kV settings, ≥ 96 kV with similar results for the contrast-detail phantom. When keeping the effective dose fixed, it seems beneficial to reduce kV to get the best image quality despite the fact that the mAs is not as high as with automatic exposure. However, this cannot be done with automatic exposure, which is set for a constant detector dose.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-28706 (URN)10.1093/rpd/nch509 (DOI)13870 (Local ID)13870 (Archive number)13870 (OAI)
Available from: 2009-10-09 Created: 2009-10-09 Last updated: 2017-12-13
Persliden, J. (2004). Digital radiology and the radiological protection of the patient. European Radiology, Supplement, 14(1), 50-58
Open this publication in new window or tab >>Digital radiology and the radiological protection of the patient
2004 (English)In: European Radiology, Supplement, ISSN 1613-3749, Vol. 14, no 1, p. 50-58Article in journal (Refereed) Published
Abstract [en]

The wide dynamic range of the digital detectors and the capabilities of post-processing allow obtaining more information from the radiographic images and avoiding retakes. Using phosphor plates in the image formation process, it has been possible to lower the dose to the patient. In digital radiography, several authors report the possibility to substantially lower the radiation dose to the patient while maintaining or even increasing the image quality. In conventional radiography, increased patient dose results in a dark image. In digital radiography the brightness of the image does not depend on patient dose. High patient doses can result in low-noise, high-contrast digital images, therefore, optimization of examinations is of vital importance in digital radiography. Special emphasis should be directed to paediatrics. The digital technique is very useful in reducing the dose both in fluoroscopy and radiography, however, special procedures for children are needed. © Springer-Verlag 2004.

Keywords
Digital radiography, Flat-panel detectors, Image quality, Phosphor plates, Radiation dose
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-45565 (URN)10.1007/s10406-004-0008-2 (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2011-01-12
Persliden, J., Helmrot, E., Hjort, P. & Resjö, M. (2004). Dose and image quality in the comparison of analogue and digital techniques in paediatric urology examinations.. European Radiology, 14(4), 638-644
Open this publication in new window or tab >>Dose and image quality in the comparison of analogue and digital techniques in paediatric urology examinations.
2004 (English)In: European Radiology, ISSN 0938-7994, E-ISSN 1432-1084, Vol. 14, no 4, p. 638-644Article in journal (Refereed) Published
Abstract [en]

In paediatric radiology it has been recognised that children have a higher risk of developing cancer from the irradiation than adults (two to three times); therefore, increased attention has been directed towards the dose to the patient. In this study the effect on patient dose and image quality in replacing the exposure in micturating cystourethrography (MCUG) examinations with the stored fluoroscopy image has been investigated. In the intravenous urography (IVU) examination we compared analogue and digital image quality, but the dose measurements were performed on a phantom. Standard clinical X-ray equipment was used. Sixty-eight patients in each of two centres were studied for the MCUG. Doses were measured with a dose-area product (DAP) meter and the image quality was scored. A non-parametric statistical analysis was performed. For the IVU, a phantom was used in the dose measurements but clinical images were scored in the comparison between analogue and digital images. For the MCUG, replacing the exposure with stored fluoroscopy images lowered the DAP value from 0.77 to 0.50 Gy cm2. The image quality did not show any difference between the techniques; however, if reflux was to be graded, exposure was needed. For the IVU, the doses could be lowered by a factor of 3 using digital techniques. The image quality showed no statistical difference between the two techniques. There is a potential for a substantial dose reduction in both MUCG and IVU examinations using digital techniques.

Keywords
Radiation dose - Image quality - Paediatric radiology - Urology
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-21487 (URN)10.1007/s00330-003-2144-9 (DOI)
Available from: 2009-10-02 Created: 2009-10-02 Last updated: 2017-12-13
Jangland, L., Sanner, E. & Persliden, J. (2004). Dose reduction in computed tomography by individualized scan protocols. Acta Radiologica, 45(3), 301-307
Open this publication in new window or tab >>Dose reduction in computed tomography by individualized scan protocols
2004 (English)In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 45, no 3, p. 301-307Article in journal (Refereed) Published
Abstract [en]

Purpose: To find a method of adjusting the mAs-value in relation to the size of the patient undergoing computed tomography (CT) examination as a means of minimizing the radiation dose to the patient. Material and Methods: A correction factor to be applied on the tube charge for each patient was calculated using two mathematical methods. This approach was tested on 4 Perspex phantoms of different sizes and geometries. Noise was measured in the images with and without use of the correction factors. Retrospectively, correction factors were calculated for 12 CT examinations of the abdomen and the dose reduction was estimated for these patient studies. Results: The variations in noise measured in the images of the different phantoms were dramatically reduced by both methods. The retrospectively performed patient study showed that the largest correction factor was 7 times greater than the smallest, which means that a dose reduction factor of 7 is possible in the extreme case. Conclusion: Our proposed methods of adjusting the applied tube charge (mAs-value) in relation to the size of the patient can be used on the vast majority of CT systems. The potential for dose reduction is great, especially for small patients.

Keywords
computed tomography, dose reduction, noise
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-46229 (URN)10.1080/02841850410004814 (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-13
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