Voltaj ve Akım Değerlerinin Hasta Dozu Üzerindeki Etkilerinin CTDI Fantomu ile Araştırılması

Year 2019, , 327 - 334, 30.11.2019

İsmail Hakkı Sarpün , Aysun İnal Buket Çeçen

https://doi.org/10.29233/sdufeffd.605430

Cited By: 2

Abstract

Bilgisayarlı
tomografi (CT) günümüzde etkin bir şekilde kullanılan modern bir cihaz olup, tanısal
görüntülemede çok önemli bir yer tutmaktadır. Bu çalışmanın amacı, CT’de tüp voltajı (kVp), tüp akımı
(mAs) ve kesit kalınlığı değerlerini değiştirerek farklı çaplara sahip biri 16 cm çapında ve diğeri 32 cm çapında olan su eşdeğeri
silindirik iki adet fantomda
doz değişimlerini incelemektir. İyonizasyon odası ile okunan soğurulan
doz değerleri bilgisayarda var olan bir paket programı
yardımıyla ilgili parametrelere çevrilmiştir. Belli bir hacim için
hesaplanan CTDI_vol ve kesit alınan uzunluk boyunca aldığı toplam doz
değerini veren DLP değerleri karşılaştırılmıştır. Çalışma sonuçlarından da
görüldüğü gibi, doz artışı akım ve voltaj değerini arttırdıkça yükselmektedir.
Özellikle kafa fantomu örneğindeki gibi küçük ve zayıf hastalarda doz artışı
daha fazladır.

Keywords

CT, CTDI, Doz, Fantom

Supporting Institution

Akdeniz Üniversitesi BAPK

Project Number

FYL-2019-4804

Thanks

Bu çalışma, Buket Çeçen’in Yüksek lisans tez çalışması olup Akdeniz Üniversitesi BAPK FYL-2019-4804 nolu proje ile desteklenmiştir.

Effects of Voltage and Current Values to Patient Dose by CTDI Phantom

Abstract

Computed tomography
is a modern device and plays an important role in diagnostic imaging. The aim
of this study was to examine the dose changes in two water-equivalent
cylindrical phantoms with different diameters, one 16 cm in diameter and the
other 32 cm in diameter, by changing the tube voltage (kVp), tube current (mU)
and slices thickness values in CT. The absorbed dose values obtained by the
ionization chamber were converted to the relevant parameters by means of a
package program available on the computer. The calculated CTDI_vol
for a given volume and the DLP values giving the total dose value taken during
the cross-sectional length were compared. As can be seen from the results of
the study, the dose increases with increasing the current and voltage values.
Especially in small and thin patients such as the head phantom, the dose
increase is higher.

Keywords

CT, CTDI, Dose, Phantom

Project Number

FYL-2019-4804

References

• [1] S. Reynolds, “The downside of Diagnostic Imaging,” NCI Cancer Bulletin, 7(2), 8-9, 2010.
• [2] UNSCEAR, “Sources, effects and risks of ionization radiation,” UNSCEAR Report 2013 Vol. I, Report to General Assembly, New York, 2013, pp. 1-19.
• [3] AAPM, “The measurement, reporting, and management of radiation dose in CT,” AAPM Report No. 96, Report of AAPM Task Group 23 of the Diagnostic Imaging Council CT Committee, College Park, 2008, pp. 27-35.
• [4] AAPM, “Site specific dose estimates (SSDE) in pediatric and adult body CT examinations,” AAPM Report No. 204, Report of AAPM Task Group 204 of AAPM, College Park, 2011, pp. 41-56.
• [5] AAPM, “Comprehensive methodology for the evaluation of radiation dose in X-ray computed tomography,” AAPM Report No. 111, Report of AAPM Task Group 111: The future of CT dosimetry, College Park, 2010, pp. 21-23.
• [6] J. A. Bauhs, T. J. Vrieze, A. N. Primak, M. R. Bruesewitz, and C. H. McCollough, “CT dosimetry: comparison of measurement techniques and devices,” Radiographics, 28 (1), 245-253, 2008.
• [7] M. J. Siegel, B. Schmidt, D. Bradley, C. Suess, and C. Hildebolt, “Radiation dose and image quality in pediatric CT: effect of technical factors and phantom size and shape,” Radiology, 233 (2), 515-522, 2004.
• [8] J. J. DeMarco, C. H. Cagnon, D. D. Cody, D. M. Stevens, C. H. McCollough, M. Zankl, E. Angel, and M. F. McNitt-Gray, “Estimating radiation doses from multidetector CT using Monte Carlo simulations: effects of different size voxelized patient models on magnitudes of organ and effective dose,” Phys. Med. Biol., 52 (9), 2583-2597, 2007.
• [9] A. C. Turner, M. Zankl, J. J. DeMarco, C. H. Cagnon, D. Zhang, E. Angel, D. D. Cody, D. M. Stevens, C. H. McCollough, and M. F. McNitt-Gray, “The feasibility of a scanner-independent technique to estimate organ dose from MDCT scans: using CTDIvol to account for differences between scanners,” Med. Phys., 37 (4), 1816–1825, 2010.
• [10] S. M. Lee, W. Lee, J. W. Chung, E.-A. Park, and J. H. Park, "Effect of kVp on image quality and accuracy in coronary CT angiography according to patient body size: a phantom study," Int. J. of Cardiovascular Imaging, 29, 83-91, 2013.
• [11] Q. Li, H. Yua, L. Zhang, L. Fana, and S.-Y. Liu, "Combining low tube voltage and iterative reconstruction for contrast-enhanced CT imaging of the chest - Initial clinical experience," Clinical Radiology, 68 (5), 249-253, 2013.
• [12] Z. Szucs-Farkas, C. Schaller, S. Bensler, M. A. Patak, P. Vock, and S. T. Schindera, "Detection of pulmonary emboli with CT angiography at reduced radiation exposure and contrast material volume: comparison of 80 kVp and 120 kVp protocols in a matched cohort," Investigative Radiology, 44 (12), 793-799, 2009.
• [13] L. Schimmoller, R. S. Lanzman, S. Dietrich, J. Boos, P. Heusch, F. Miese, G. Antoch, and P. Kropil, "Evaluation of automated attenuation-based tube potential selection in combination with organ-specific dose reduction for contrast-enhanced chest CT examinations," Clinical Radiology, 69 (7), 721-726, 2014.
• [14] H. W. Goo, "CT radiation dose optimization and estimation: an update for radiologists," Korean Journal of Radiology, 13 (1), 1-11, 2012.
• [15] C. M. Heyer, P. S. Mohr, S. P. Lemburg, S. A. Peters, and V. Nicolas, "Image quality and radiation exposure at pulmonary CT angiography with 100- or 120-kVp protocol: prospective randomized study," Radiology, 245 (2), 577-583, 2007.
• [16] A. Sodickson, and M. Weiss, "Effects of patient size on radiation dose reduction and image quality in low-kVp CT pulmonary angiography performed with reduced IV contrast dose", Emerg. Radiol., 19 (5), 437-445, 2012.
• [17] P. Bjorkdahl, and U. Nyman, “Using 100- instead of 120-kVp computed tomography to diagnose pulmonary embolism almost halves the radiation dose with preserved diagnostic quality,” Acta Radiologica, 51 (3), 260-270, 2010.
• [18] R. Shah, A. K. Gupta, M. M. Rehani, A. K. Pande, and S. Mukhopadhyay, “Effect of reduction in tube current on reader confidence in pediatric computed tomography,” Clinical Radiology, 60, 224-231 2005.
• [19] D. P. Frush, C. C. Slack, C. L. Hollingsworth, G. S. Bisset, L. F. Donnelly, J. Hsieh, T. Lavin-Wensell, and J. R. Mayo, “Computer simulated radiation dose reduction for abdominal multidetector CT of pediatric patients,” AJR Am. J. Roentgenol. 2002;179: 1107-13.
• [20] J. Lucaya, J. Piqueras, P. Garcia-Pena, G. Enriquez, M. Garcia-Macias, and J. Sotil, “Low-dose high resolution CT of the chest in children and young adults: dose, cooperation, artifact incidence, and image quality,” AJR Am. J. Roengenol., 175 (4), 985-992, 2000.
• [21] I. R. Kamel, R. J. Hernandez, J. E. Martin, A. E. Schlesinger, L. T. Niklason, and K. E. Guire, “Radiation dose reduction of the pediatric pelvis,” Radiology, 190 (3), 683-687, 1994.
• [22] S. Saini, “Multi-detector row CT: principles and practice for abdominal applications,” Radiology, 233, 323-327, 2004.