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Woisetschläger, MischaORCID iD iconorcid.org/0000-0003-0066-4985
Publications (10 of 11) Show all publications
Woisetschläger, M., Blomma, J., Dahlström, N., Bivik Stadler, C. & Forsberg, D. (2019). Liver data from the Visual Sweden project DROID: Analytic Imaging Diagnostics Arena (AIDA). Linköping: Analytic Imaging Diagnostics Arena
Open this publication in new window or tab >>Liver data from the Visual Sweden project DROID: Analytic Imaging Diagnostics Arena (AIDA)
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2019 (English)Data set
Place, publisher, year
Linköping: Analytic Imaging Diagnostics Arena, 2019
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:liu:diva-154903 (URN)10.23698/aida/drli (DOI)
Note

Restricted access, Please contact Mischa.Woisetschlager@regionostergotland.se, claes.lundstrom@liu.se or joel.hedlund@liu.se to request access.

Available from: 2019-03-04 Created: 2019-03-04 Last updated: 2019-03-13Bibliographically approved
Woisetschläger, M., Landgren, F., Bivik Stadler, C. & Forsberg, D. (2019). Skeletal data from the Visual Sweden project DROID: Analytic Imaging Diagnostics Arena (AIDA). Linköping: Analytic Imaging Diagnostics Arena
Open this publication in new window or tab >>Skeletal data from the Visual Sweden project DROID: Analytic Imaging Diagnostics Arena (AIDA)
2019 (English)Data set
Place, publisher, year
Linköping: Analytic Imaging Diagnostics Arena, 2019
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:liu:diva-154900 (URN)10.23698/aida/drske (DOI)
Note

Restricted access, please contact Mischa.Woisetschlager@regionostergotland.se, claes.lundstrom@liu.se or joel.hedlund@liu.se to request access.

Available from: 2019-03-04 Created: 2019-03-04 Last updated: 2019-03-13Bibliographically approved
Woisetschläger, M. & Spångeus, A. (2018). Model for improved correlation of BMD values between abdominal routine Dual energy CT data and DXA scans. European Journal of Radiology, 99, 76-81
Open this publication in new window or tab >>Model for improved correlation of BMD values between abdominal routine Dual energy CT data and DXA scans
2018 (English)In: European Journal of Radiology, ISSN 0720-048X, E-ISSN 1872-7727, Vol. 99, p. 76-81Article in journal (Refereed) Published
Abstract [en]

Background

Osteoporosis is a common but underdiagnosed and undertreated disease causing severe morbidity and economic burden. The gold standard for detection of osteoporosis is DXA (dual energy x-ray absorptiometry), which is a dedicated examination for osteoporosis. Dual energy CT (DECT) examinations are increasingly used in daily routine for a wide variety of diagnoses. In the present study, we wanted to examine whether vBMD (volume bone mass density) could be evaluated as a side product in non-contrast as well as contrast phases as well as to evaluate a correction model taking known shortcomings for DXA into account.

Methods

A total of 20 patients, i.e. 79 vertebrae (one excluded due to vertebral fracture), mean age 71 years (range 43–85) with a mean BMI (body mass index) of 26 (range 17–33) were examined with both abdominal/pelvic DECT as well as DXA. Furthermore, aortic calcium was measured as well as the presence of osteoarthritis of the spine (OAS) and osteoarthritis in facet joints (OAF) with a 5-grade scaling system.

Results

A significant correlation was found between DXA BMD and vBMD from DECT with no contrast (WNC) (r = 0.424, p = 0.001), and with venous contrast (WVC) (r = 0.402, p < 0.001), but no significant correlation was found with arterial contrast (WAC). Using multivariate linear regression with DXA BMD as dependent, two models were created combining DECT WNC, aortic calciumscore (ACS), OAS and BMI yielding an R2 = 0.616 (model 1) and replacement of WNC to WVC a R2 = 0.612 (model 2). The Pearson correlation between DXA and predictive DXA BMD value of model 1 was r = 0.785 (p < 0.001) and model 2 r = 0.782 (p < 0.001).

Conclusion

There is a correlation between DXA BMD and DECT in non-contrast and venous contrast scans but not in arterial scans. The correlation is further improved by quantifying the degree of different confounding factors (osteoarthritis of the spine, body mass index and aortic calcium score) and taking these into account in an explanatory model. Future software solutions with DECT data as input data might be able to automatically measure the BMD in the trabecular bone as well as measuring the confounding factors automatically in order to obtain spinal DXA comparable BMD values.

Keywords
Osteoporosis;Bone mass density;Dual-energy CT;DXA;Osteoarthritis of the spine;Aortic calcium score
National Category
Clinical Medicine
Identifiers
urn:nbn:se:liu:diva-144039 (URN)10.1016/j.ejrad.2017.12.017 (DOI)000423344100010 ()29362154 (PubMedID)
Funder
Östergötland County Council
Note

Funding agencies: Medical Research Council of south east Sweden; ALF grants, Region Ostergotland, Sweden

Available from: 2018-01-05 Created: 2018-01-05 Last updated: 2018-02-12
Woisetschläger, M. & Spångeus, A. (2018). Model for improved correlation of BMD values between abdominal routine dual-energy CT data and DXA scans. In: : . Paper presented at European Congress of Radiology, Vienna, February 28 - March 4, Vienna, Italy.
Open this publication in new window or tab >>Model for improved correlation of BMD values between abdominal routine dual-energy CT data and DXA scans
2018 (English)Conference paper, Oral presentation with published abstract (Other academic)
Abstract [en]

Background:

Osteoporosis is a common but underdiagnosed and undertreated disease causing severe morbidity and economic burden. The gold standard for detection of osteoporosis is DXA (dual energy x-ray absorptiometry), which is a dedicated examination for osteoporosis. Dual energy CT (DECT) examinations are increasingly used in daily routine for a wide variety of diagnoses. In the present study, we wanted to examine whether vBMD (volume bone mass density) could be evaluated as a side product in non-contrast as well as contrast phases as well as to evaluate a correction model taking known shortcomings for DXA into account. 

Methods:

A total of 20 patients, i.e. 79 vertebrae (one excluded due to vertebral fracture), mean age 71 years (range 43 – 85) with a mean BMI (body mass index) of 26 (range 17 – 33) were examined with both abdominal/pelvic DECT as well as DXA.  Furthermore, aortic calcium was measured as well as the presence of osteoarthritis of the spine (OAS) and osteoarthritis in facet joints (OAF) with a 5-grade scaling system. 

Results:

A significant correlation was found between DXA BMD and vBMD from DECT without with no contrast (WNC) (r=0.424, p=0.001), and with venous contrast (WVC) (r=0.402, p<0.001), but no significant correlation was found with arterial contrast (WAC). Using multivariate linear regression with DXA BMD as dependent, two models were created combining DECT WNC, aortic calciumscore (ACS), OAS and BMI yielding an R2 = 0.616 (model 1) and replacement of WNC to WVC a R2 = 0.612 (model 2).  The Pearson correlation between DXA and predictive DXA BMD value of model 1 was r = 0.785 (p<0.001) and model 2 r = 0.782 (p<0.001).

Conclusion:

There is a correlation between DXA BMD and DECT in non-contrast and venous contrast scans but not in arterial scans. The correlation is further improved by quantifying the degree of different confounding factors (osteoarthritis of the spine, body mass index and aortic calcium score) and taking these into account in an explanatory model. Future software solutions with DECT data as input data might be able to automatically measure the BMD in the trabecular bone as well as measuring the confounding factors automatically in order to obtain spinal DXA comparable BMD values.

Keywords
osteoporosis, bone mass density, computed tomography, dual energy
National Category
Orthopaedics
Identifiers
urn:nbn:se:liu:diva-145654 (URN)
Conference
European Congress of Radiology, Vienna, February 28 - March 4, Vienna, Italy
Projects
Osteoporosprojekt PreFROST
Funder
Östergötland County Council
Available from: 2018-03-13 Created: 2018-03-13 Last updated: 2018-03-23Bibliographically approved
Falk, M., Sjödahl, R., Wiréhn, A.-B., Lagerfelt, M., Woisetschläger, M., Ahlström, U. & Myrelid, P. (2015). Modifierad brittisk modell kortade ledtid till datortomografi av kolon. Läkartidningen, 112
Open this publication in new window or tab >>Modifierad brittisk modell kortade ledtid till datortomografi av kolon
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2015 (Swedish)In: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, Vol. 112Article in journal (Refereed) Published
Abstract [en]

The British national Institute for Health and Care Excellence (NICE) has presented guidelines based on signs and symptoms which should raise a suspicion of colorectal cancer. A slightly modified version of these guidelines, adapted to Swedish conditions, named Swedish NICE (sNICE) criteria, was implemented at eight primary care centres. By following the sNICE criteria, cases with higher degree of suspicion of colorectal cancer were advised for computer tomography (CT) of the colon, whereas cases of low degree of suspicion were advised for the considerably less time and patient demanding CT of the abdomen. For patients with isolated anal symptoms without presence of sNICE criteria, active expectancy for six weeks was recommended, followed by renewed consideration. Results showed that the ratio between CT colon and CT abdomen was reduced from 2.2 to 1.1 after introduction of the sNICE criteria. Also, the proportion of patients undergoing CT colon within two weeks from admittance was increased from 3 to 25 %. We conclude that the sNICE criteria may be a useful supportive tool for the primary care physician.

Abstract [sv]

Vid misstanke om kolorektal cancer är det angeläget att patienter där misstankegraden är hög får genomgå snar utredning och diagnostik. På många håll i landet föreligger oönskat långa väntetider för sådan utredning.

Användningen av ett evidensbaserat beslutsstöd för kolonutredning, baserat på riktlinjer från brittiska NICE (National Institute for Health and Care Excellence), implementerades på 8 vårdcentraler i Östergötland.

Efter implementeringen förkortades ledtider till datortomografi av kolon, diagnos och behandling.

Beslutsstödet bidrog till att patienter där graden av misstanke om kolorektal cancer var låg kunde styras om till att genomgå datortomografi av buken i stället för av kolon.

Place, publisher, year, edition, pages
Stockholm, Sweden: Läkartidningen Förlag AB, 2015
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:liu:diva-126059 (URN)26485132 (PubMedID)
Available from: 2016-03-14 Created: 2016-03-14 Last updated: 2018-03-23Bibliographically approved
Sarabjeet, S., Pourjabbar, S., Khawaja, R., Padole, A., Choy, G., Kalra, M., . . . Persson, A. (2013). Prospectively Acquired Low Doses in Abdominal CT and Role of Sinogram Affirmed Iterative REconstruction. In: : . Paper presented at RSNA 2013.
Open this publication in new window or tab >>Prospectively Acquired Low Doses in Abdominal CT and Role of Sinogram Affirmed Iterative REconstruction
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2013 (English)Conference paper, Poster (with or without abstract) (Other academic)
Abstract [en]

Assessment of the effect of Sinogram Affirmed iterative reconstruction (Safire) and Filtered Back Projection (FBP) technique on abdominal CT examination acquired at 200 mAs, 100 mAs, and 50 mAs.METHOD AND MATERIALS24 patients (mean age 64 ± 14 years, M:F 10 :14) gave informed consent for an IRB approved prospective study for additional research images through the abdomen on 128 slice MDCT (Siemens Flash) at 100 mAs and 50 mAs over a scan length of 10 cm using combined modulation technique. Images through entire abdomen were acquired at 200 mAs. The 50 and 100 mAs datasets were each reconstructed with FBP and four settings of Safire (S1, S2, S3, S4). The FBP 200 mAs images were compared side-by-side with FBP and Safire images from 50 and 100 mAs. The number and location of lesions, lesion size, lesion conspicuity, visibility of small structures were assessed by two experienced abdominal radiologists. The diagnostic acceptability was recorded on a four point scale (1= fully acceptable, 4= unacceptable). Objective noise and HU values were measured in liver and the descending aorta. The noise power spectrum was analyzed for FBP and different Safire settings.RESULTSA total of 43 lesions were detected on both FBP and Safire images. Minor blocky or pixilated appearance of 50 and 100 mAs images was noted at S3 and S4 Safire settings. No significant artifacts were noted on S1 and S2 Safire images. Image noise was suboptimal in FBP 100 and 50 mAs images, whereas noise was acceptable with S1, S2 and S3 and better than average on S4 setting. Safire could render 100 mAs images as fully acceptable for diagnostic confidence but 50 mAs Safire images were deemed to have lower diagnostic confidence compared to 200 mAs. As compared to 50 mAs FBP, objective noise was lower by 22.8% (22.9/29.7) on S1, 35% (19.3/29.7) on S2, 44.3% on S3 (16.7/29.3) and 54.8% (13.4/29.7) on S4 (p<0.001). Noise power spectrum analysis showed that Safire retains the noise power spectral signature similar to FBP, in spite of progressive noise reduction with higher iteration settingsCONCLUSIONSafire enabled reconstruction provides diagnostically acceptable abdominal CT images acquired at 100 mAs (50% reduced dose) but 50 mAs Safire images are not completely diagnostically acceptable despite reduced image noiseCLINICAL RELEVANCE/APPLICATIONRadiation dose reduction down to 100 mAs is achievable with Safire enabled abdominal CT examinations

National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:liu:diva-115753 (URN)
Conference
RSNA 2013
Available from: 2015-03-18 Created: 2015-03-18 Last updated: 2017-03-07
Kalra, M. K., Woisetschläger, M., Dahlström, N., Singh, S., Digumarthy, S., Do, S., . . . Persson, A. (2013). Sinogram-Affirmed Iterative Reconstruction of Low-Dose Chest CT: Effect on Image Quality and Radiation Dose. American Journal of Roentgenology, 201(2), W235-W244
Open this publication in new window or tab >>Sinogram-Affirmed Iterative Reconstruction of Low-Dose Chest CT: Effect on Image Quality and Radiation Dose
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2013 (English)In: American Journal of Roentgenology, ISSN 0361-803X, E-ISSN 1546-3141, Vol. 201, no 2, p. W235-W244Article in journal (Refereed) Published
Abstract [en]

OBJECTIVE. The purpose of this study is to compare sinogram-affirmed iterative reconstruction (SAFIRE) and filtered back projection (FBP) reconstruction of chest CT acquired with 65% radiation dose reduction.

SUBJECTS AND METHODS. In this prospective study involving 24 patients (11 women and 13 men; mean [+/- SD] age, 66 +/- 10 years), two scan series were acquired using 100 and 40 Quality Reference mAs over a 10-cm scan length in the chest with a 128-MDCT scanner. The 40 Quality Reference mAs CT projection data were reconstructed with FBP and four settings of Safire (S1, S2, S3, and S4). Six image datasets (FBP with 100 and 40 Quality Reference mAs, and S1, S2, S3, S4 with 40 Quality Reference mAs) were displayed on a DICOM-compliant 55-inch 2-megapixel monitor for blinded evaluation by two thoracic radiologists for number and location of lesions, lesion size, lesion margins, visibility of small structures and fissures, and diagnostic confidence. Objective noise and CT values were measured in thoracic aorta for each image series, and the noise power spectrum was assessed. Data were analyzed with analysis of variance and Wilcoxon signed rank tests.

RESULTS. All 186 lesions were seen on 40 Quality Reference mAs SAFIRE images. Diagnostic confidence on SAFIRE images was higher than that for FBP images. Except for the minor blotchy appearance on SAFIRE settings S3 and S4, no significant artifacts were noted. Objective noise with 40 Quality Reference mAs S1 images (21.1 +/- 6.1 SD of HU) was significantly lower than that for 40 Quality Reference mAs FBP images (28.5 +/- 8.1 SD of HU) (p andlt; 0.001). Noise power spectra were identical for SAFIRE and FBP with progressive noise reduction with higher iteration SAFIRE settings.

CONCLUSION. Iterative reconstruction (SAFIRE) allows reducing the radiation exposure by approximately 65% without losing diagnostic information in chest CT.

Place, publisher, year, edition, pages
American Roentgen Ray Society (ARRS), 2013
Keywords
iterative reconstruction, low-dose chest CT, radiation dose reduction
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-96707 (URN)10.2214/AJR.12.9569 (DOI)000322225400008 ()
Note

Funding Agencies|Siemens Healthcare||

Available from: 2013-08-23 Created: 2013-08-23 Last updated: 2017-12-06Bibliographically approved
Woisetschläger, M., Dahlström, N., Singh, S., Choy, G., O´connor, O., Blake, M. A., . . . Persson, A. (2012). Radiation dose reduction with Sinogram Affirmed Iterative REconstruction (Safire) technique for abdominal CT. Paper presented at European Congress of Radiology, 2012, Vienna.
Open this publication in new window or tab >>Radiation dose reduction with Sinogram Affirmed Iterative REconstruction (Safire) technique for abdominal CT
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2012 (English)Conference paper, Published paper (Other academic)
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-75778 (URN)
Conference
European Congress of Radiology, 2012, Vienna
Available from: 2012-03-09 Created: 2012-03-09 Last updated: 2017-03-07
Kalra, M. K., Woisetschläger, M., Dahlström, N., Sing, S., Lindblom, M., Choy, G., . . . Persson, A. (2012). Radiation Dose Reduction with Sinogram Affirmed Iterative Reconstruction Technique for abdominal Computer Tomography. Journal of Computer Assisted Tomography, 36(3), 339-346
Open this publication in new window or tab >>Radiation Dose Reduction with Sinogram Affirmed Iterative Reconstruction Technique for abdominal Computer Tomography
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2012 (English)In: Journal of Computer Assisted Tomography, ISSN 0363-8715, Vol. 36, no 3, p. 339-346Article in journal (Refereed) Published
Abstract [en]

Purpose: The objective of this study was to assess the effect of Sinogram Affirmed Iterative Reconstruction (SAFIRE) and filtered back-projection (FBP) techniques on abdominal computed tomography (CT) performed with 50% and 75% radiation dose reductions.

Methods: Twenty-four patients (mean age, 64 ± 14 years; male-female ratio, 10:14) gave informed consent for an institutional review board–approved prospective study involving acquisition of additional research images through the abdomen on 128-slice multi–detector-row CT (SOMATOM Definition Flash) at quality reference mAs of 100 (50% lower dose) and 50 (75% lower dose) over a scan length of 10 cm using combined modulation (CARE Dose 4D). Standard-of-care abdominal CT was performed at 200 quality reference mAs, with remaining parameters held constant. The 50- and 100-mAs data sets were reconstructed with FBP and at 4 SAFIRE settings (S1, S2, S3, S4). Higher number of SAFIRE settings denotes increased strength of the algorithm resulting in lower image noise. Two abdominal radiologists independently compared the FBP and SAFIRE images for lesion number, location, size and conspicuity, and visibility of small structures, image noise, and diagnostic confidence. Objective noise and Hounsfield units (HU) were measured in the liver and the descending aorta.

Results: All 43 lesions were detected on both FBP and SAFIRE images. Minor blocky, pixelated appearance of 50% and 75% reduced dose images was noted at S3 and S4 SAFIRE but not at S1 and S2 settings. Subjective noise was suboptimal in both 50% and 75% lower-dose FBP images but was deemed acceptable on all SAFIRE settings. Sinogram Affirmed Iterative Reconstruction images were deemed acceptable in all patients at 50% lower dose and in 22 of 24 patients at 75% lower dose. As compared with 75% reduced dose FBP, objective noise was lower by 22.8% (22.9/29.7), 35% (19.3/29.7), 44.3% (16.7/29.3), and 54.8% (13.4/29.7) on S1 to S4 settings, respectively (P < 0.001).

Conclusions: Sinogram Affirmed Iterative Reconstruction–enabled reconstruction provides abdominal CT images without loss in diagnostic value at 50% reduced dose and in some patients also at 75% reduced dose.

Place, publisher, year, edition, pages
USA: Lippincott Williams & Wilkins, 2012
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-75846 (URN)10.1097/RCT.0b013e31825586c0 (DOI)000304201200013 ()
Available from: 2012-03-12 Created: 2012-03-12 Last updated: 2017-03-07
Dahlström, N., Woisetschläger, M., Singh, S., Digumarthy, M., Kalra, M. & Persson, A. (2012). Role of Sinogram Affirmed Iterative Reconstruction(Safire) technique in image quality and radiation dose reduction for chest CT examinations. Paper presented at European Congress of Radiology, 2012, Vienna.
Open this publication in new window or tab >>Role of Sinogram Affirmed Iterative Reconstruction(Safire) technique in image quality and radiation dose reduction for chest CT examinations
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2012 (English)Conference paper, Published paper (Other academic)
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-75777 (URN)
Conference
European Congress of Radiology, 2012, Vienna
Available from: 2012-03-09 Created: 2012-03-09 Last updated: 2017-03-07
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-0066-4985

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