The Problem of X-Ray Attenuation Estimation Accuracy in Multislice Computed Tomography
Abstract
Purpose. Revealing the trends of the inappropriate X-Ray attenuation estimations on MSCT.
Data and Methods. There have been analyzed abdominal CT results of 100 patients, archived in the Radiological Information System of Moscow. The standard water phantom has been scannedalsowith different parameters. Scans were made on 64-row detectors CT scanners.All devices were calibrated on water and air.
Results. There have been discovered inappropriate estimations of X-Ray attenuation, mainlays understating by 4–20 HU, more apparent in peripheral areas of the FOV. These distortions had resulted in the overdiagnosis of diffused diseases of liver, pancreasand kidney. Phantom scans have confirmed that the estimations of X-Ray attenuation coefficient are really inhomogeneous. The trend is the rising understatement from FOV center to periphery. This doesn’t depend on the tube current change in range of 100–550 mA. More appropriate estimations were noted using the narrowed FOV.
Conclusions. There is a problem of the inappropriate X-Ray attenuation estimations on MDCT, mainly as thefalse hypoattenuation, more in the FOV periphery,which does not depend on the tube current. FOV decrease and use of 5-mm slices for measurements may enhance the estimation accuracy.
About the Authors
A. I. GromovRussian Federation
professor, Chief Researcher of Expert Department of Radiology Research and Practical Center of Moscow Department of Healthcare
28/1, Srednyaya Kalitnikovskaya str., 107076, Moscow, Russia. Scientific and Practical Center of Medical Radiology. Phone: +7-495-276-04-36
A. V. Petraikin
Russian Federation
cand. of med. sci., Expert-radiologist of Consultative Department of Radiology Research and Practical Center of Moscow Department of Healthcare
N. S. Kulberg
Russian Federation
cand. of phys.-math. sci., Head of Medical Visualization Tools Development Department of Radiology Research and Practical Center of Moscow Department of Healthcare
S. Yu. Kim
Russian Federation
cand. of med. sci., Assistant Director of Radiology Research and Practical Center of Moscow Department of Healthcare
S. P. Morozov
Russian Federation
professor, Director of Radiology Research and Practical Center of Moscow Department of Healthcare
K. A. Sergunova
Russian Federation
Head of Technical Monitoring and Control Tools Development Department of Radiology Research and Practical Center of Moscow Department of Healthcare
M. S. Usanov
Russian Federation
Researcher of Medical Visualization Tools Development Department of Radiology Research and Practical Center of Moscow Department of Healthcare
References
1. Barrett J.F., Keat N. Artifacts in CT: recognition and avoidance. RadioGraphics. 2004; 24: 1679–1691.
2. Boas F.E., Fleischmann D. CT artifacts: Causes and reduction techniques. Imaging Med. 2012; 4 (2): 229–240.
3. Meganck J.A., Kozloff K.M., Thornton M.M. et al. Beam hardening artifacts in micro- computed tomography scanning can be reduced by X-ray beam filtration and the resulting images can be used to accurately measure BMD. Bone. 2009; 45 (6): 1104–1116.
4. Boas F.E., Fleischmann D. Evaluation of two iterative techniques for reducing metal artifacts in computed tomography. Radiology. 2011; 259 (3): 894–902.
5. Wagenaar D., van der Graaf E.R., van der Schaaf A., Greuter M.J.W. Quantitative Comparison of commercial and non-commercial metal artifact reduction techniques in computed tomography. PLOS ONE. 2015; 1: 1–9.
6. Меллер Т.Б., Райф Э. Норма при КТ- и МРТ-исследованиях. М.: МЕДпресс-информ, 2008. 255 с. Moeller T., Reif E. Normal findings in CT and MRI. M.: MEDpress-inform, 2008. 255 p. (In Russian)
7. Громов А.И., Ким С.Ю., Морозов С.П. и др. Проблема количественных измерений в многослойной компьютерной томографии при использовании систем снижения дозы облучения: Сборник тезисов Юбилейного Конгресса Российского общества рентгенологов и радиологов. М., 2016: 59–60. Gromov A.I., Kim S.Yu, Morosov S.P. et al. The problem of quantitative measurements in MDCT with dose reduction scanning: Jubilee Proceedings of Congress of the Russian Society of Radiology (RORR). Moscow, 2016: 59–60. (In Russian)
Review
For citations:
Gromov A.I., Petraikin A.V., Kulberg N.S., Kim S.Yu., Morozov S.P., Sergunova K.A., Usanov M.S. The Problem of X-Ray Attenuation Estimation Accuracy in Multislice Computed Tomography. Medical Visualization. 2016;(6):133-142. (In Russ.)