Effect of Concentration of Contrast Medium on Coronary CT Angiography
Thanongchai Siriapisith MD*, Supavadee Karuwanarint BSc (RT)*, Chulaluk Boonma BSc (RT)*, Venus Wisetsaeng BSc (RT)*
Affiliation : * Department of Radiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok
Objective : To compare concentration of contrast medium for vascular opacification at ascending aorta using
retrospective reconstruction of coronary CT angiography.
Study design: Retrospective study.
Material and Method: Eighty-four patients undergoing coronary CT angiography with 16 multi-detector
rows at Siriraj Hospital between September 2003 and July 2004 were included in this study. The patients were
categorized into two groups. The first group was administrated with 350 mgI/ml contrast medium and the
second group was administrated with 370 mgI/ml contrast medium. The total amount of contrast medium was
about 140 ml (20 ml for timing bolus and 120 ml for CT angiography) in both groups. The CT density on peak
contrast administration at ascending aorta was measured and compared between the two groups.
Results : The mean density at ascending aorta in 350 mgI/ml and 370 mgI/ml were 362.96 HU (SD 67.53) and
354.44 (SD 59.39), respectively. There was no statistically significant difference in mean density at the
ascending aorta between the two groups.
Conclusion : Administration of contrast medium with different concentrations of 350 or 370 mgI/ml showed no
statistical difference on enhancement of the ascending aorta in coronary CT angiography (p < 0.05).
Keywords : Coronary artery, CT angiography, Multidetector row CT, Cardiac imaging, Contrast media, Contrast enhancement
