Coronary CT angiography in obese patients using 3rd generation dual-source CT: effect of body mass index on image quality

To evaluate the image quality of coronary CT angiography (CCTA) in obese patients using a 3(rd) generation, dual-source CT scanner. We retrospectively evaluated 102 overweight and obese patients who had undergone CCTA. Studies were performed with 3(rd) generation dual-source CT, prospectively ECG-triggered acquisition at 120 kV, and automated tube current modulation. Advanced modeled iterative reconstruction was used. Patients were divided into three BMI groups: 1)25-29.9 kg/m(2); 2)30-39.9 kg/m(2); 3) aeyen 40 kg/m(2). Vascular attenuation in the coronary arteries was measured. Contrast-to-noise ratio (CNR) was calculated. Image quality was subjectively evaluated using five-point scales. Image quality was considered diagnostic in 97.6 % of examinations. CNR was consistently adequate in all groups but decreased for groups 2 and 3 in comparison to group 1 as well as for group 3 compared to group 2 (p = 0.001, respectively). Subjective image quality was significantly higher in group 1 compared to group 3 (attenuation proximal: 4.8 +/- 0.4 vs. 4.4 +/- 0.6, p = 0.011; attenuation distal: 4.5 +/- 0.7 vs. 4.0 +/- 0.8, p = 0.019; noise: 4.7 +/- 0.6 vs. 3.8 +/- 0.7, p < 0.001). The mean effective dose was 9.5 +/- 3.9 mSv for group 1, 11.4 +/- 4.7 mSv for group 2 and 14.0 +/- 6.4 mSv for group 3. Diagnostic image quality can be routinely obtained at CCTA in obese patients with 3(rd) generation DSCT at 120 kV. aEuro cent Diagnostic CCTA can be routinely performed in obese patients with 3 (rd) generation DSCT. aEuro cent 120-kV tube voltage allows diagnostic image quality in patients with BMI > 40 kg/m (2) . aEuro cent 80-ml contrast medium can be administered without significant decline in vascular attenuation.