Neck Angiography 검사의 선량과 화질

Radiation Dose and Image Quality in Neck Angiography : Comparison of Dual Source Computed Tomography and Multi-detector Computed Tomography

Purpose According to the development of devices from multi-detector computed tomography (MDCT) to dual source computed tomography(DSCT), protocol using DSCT with 140 kVp can be used in the examination of neck angiography. This can be considered to reduce beam hardening artifact at the portion of shoulder than when used single source CT with 120 kVp. for adapting to ALARA’s principle, we tried to make an optimal image quality with minimum dose and to compare with dose and image quality between DSCT and MDCT. Materials and methods Dose and image quality was compared and evaluated in each case of single source CT versus DSCT at examination of neck angiography. 16 channel MDCT(Somatom Sensation 16 Siemens, Germany) and DSCT(Somatom Definition Siemens, Germany) devices were utilized. Rando phantom(Model ART-200-5) and thermoluminescence dosimeter(TLD, GD352M, 12 mm) were used for measurement of dose according to protocol and organ’s dose figure. Lung-chest phantom(Model RS-330) was used for measuring the image quality. CTDIvol was presented by monitor of CT device and TLD was located in sensitive portion of radiation like thyroid, salivary gland, orbit. noise was assessed by making region of interest(ROI) in three sections of aortic arch level indicating severe artifacts. Also we compared an image using DSCT versus examination previously performed by 16 channel MDCT selecting a patient with similar body shape. Results CTDIvol value bas decreased more as dual source compares in single source 16 MDCT. Organ dose(thyroid, salivary gland, and orbit) has been decreased in dual source in comparison with other source. In the image quality, noise has been decreased in DSCT in comparison with single source and 16 MDCT. In fact, that also reduced artifact. Conclusion Protocol using of dual source is useful than single source, when organ dose and noise result analysis has used Rando phantom.