Liu Xiaoyu MD, Presenter: Nothing to Disclose

Xiaoyan Meng MD, Abstract Co-Author: Nothing to Disclose

Hao Tang, Abstract Co-Author: Nothing to Disclose

To assess the clinical application of normalized utility of contrast medium and kVp based on patient body-mass-index (BMI) in abdominal CTA.

 Eighty patients with different BMI were enrolled to undergo unenhanced and enhanced dual-phase abdominal CT scan using 370mgI/ml concentration contrast medium. Patients were divided into 3 test groups and 1 control group based on their BMI value：group A (n=20, BMI<23) with 80kVp and a total volume of contrast medium at 200mgI/kg; group B (n=20, 23=<BMI<26), 100kVp and 250mgI/kg contrast medium; group C (n=20, BMI>=26), 120kVp and 300mgI/kg contrast medium. Group D (n=20, without BMI restriction) was scanned at 120kVp and with a total volume of contrast medium at 1ml/kg. CT number of aorta in the arterial phase (AP), portal vein in the portal phase (PP) and hepatic parenchyma in both phases was measured. Image quality was assessed and compared among the 4 groups by statistical method.

There was no significant difference for the CT value (in HU) of hepatic parenchyma in AP and PP among 4 groups (group A: 81.91±8.37 and 112.97±12.36; group B: 80.13±3.66 and 104.85±9.39; group C: 76.32±9.17 and 101.83±15.76; group D: 76.18±8.74 and 103.07±14.51, all p>0.05); The CT value (in HU) of the aorta during AP in group A (305.32±76.11) was significantly higher than the other 3 groups (272.54±54.85, 252.51±32.89, 262.99±41.62, respectively) (p<0.05). There was no difference for the CT value of the portal vein in PP among 4 groups (160.19±22.76, 147.13±19.97, 148.66±21.78 and 147.76±24.61, respectively) (p>0.05). There was no significantly difference in the subjective image quality score among 4 groups (4.55±0.51 vs. 4.75±0.45 vs. 4.65±0.48 vs. 4.73±0.46, respectively) (P>0.05). Volume CT dose index (CTDIvol, in mGy) were 33.58±4.47, 63.63±4.03, 96.06±7.12 and 98.89±7.04 for A, B, C and D groups, respectively.

BMI-dependent contrast medium injection and tube voltage selection scheme substantially reduces both contrast dose and rediation dose for patients with small BMI without adversely affecting vessel enhancement and image quality, compared with the conventional scan protocol.

The BMI-dependent contrast medium injection and tube voltage selection scheme in CT angiography (CTA)  improves patient safety without degradation of vessel enhancement and image quality  

Xiaoyu, L, Meng, X, Tang, H, The Clinical Application of Normalized Utility of Contrast Medium in Combination with BMI Dependent kVp in Abdominal CT Angiography (CTA).  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045728.html