Image quality in obese patients undergoing 256-row computed tomography coronary angiography

To evaluate, objectively and subjectively, the feasibility of 256-row computed tomography coronary angiography (CTCA) in obese patients. 256-row CTCA was performed in 68 symptomatic patients (age 61 ± 10 years, 37 females), 39 obese (body mass index—BMI > 30 kg/m²) and 29 non-obese. Retrospective analysis was performed by two observers who assessed the image quality of each coronary segment using a 4-point subjective scale (1 excellent to 4 non-diagnostic), and another blinded observer measured objective image parameters. BMI in the obese group was 35 ± 5 (32–65) Kg/m², and 24 ± 3 (16–29) Kg/m² in the non-obese (P = 0.004). Average subjective image quality was similar in obese (1.41 ± 0.40) and non-obese (1.34 ± 0.40) patients, P = 0.17. Proportion of coronary artery segments with non-diagnostic image quality was low in both groups (0.7% in obese and 0.2% in non-obese, P = 0.31). Signal to noise and contrast to noise ratios were not significantly lower in obese than in non-obese patients (9.4 ± 3 vs. 12 ± 2.5, P = 0.16 and 11.1 ± 3.8 vs. 13.7 ± 2.9, P = 0.07 respectively). However, dose length product (1167 ± 567 vs. 827 ± 375 mGy × cm, P = 0.014) and image noise (44 ± 13 vs. 35 ± 5 HU, P < 0.001) were higher in the obese patient group. Image quality was preserved in obese patients undergoing 256-row CTCA at the cost of increased radiation exposure and image noise.