Improvement of automated right ventricular segmentation using dual-bolus contrast media injection with 256-slice coronary CT angiography

Rationale and Objectives: To investigate the effect of dual-bolus contrast media injection (dual-CM) on the accuracy of automated right ventricular (RV) segmentation on coronary computed tomography angiography (CCTA). Materials and Methods: A total of 104 patients with suspected and known coronary artery disease underwent 256-slice CCTA with retrospective electrocardiographic (ECG) gating. The patients were divided into 51 patients who underwent single-bolus CM injection (single-CM) and 53 patients who underwent dual-CM. The dual-CM method consisted of an initial bolus of CM followed by an injection of dilute CM with saline (CM:saline, 1:9). Three-dimensional CCTA images were automatically segmented into the RV, left ventricle (LV), and myocardium using commercially available software (Comprehensive Cardiac Analysis; Philips Medical Systems, Cleveland, OH). Prevalence and locations of segmentation errors were compared between single-CM and dual-CM. Segmentation errors were defined as segment deviation of >1cm from the actual ventricular margin. Results: Prevalence of segmentation errors was significantly lower with dual-CM than with single-CM in the diastolic phase (4/41 vs. 20/41, respectively; P<.01), and there was no difference between the two methods in the systolic phase (2/12 vs. 2/10, respectively). With dual-CM and single-CM, the locations of segmentation errors were mostly the RV wall (4/53 and 18/51, respectively) and secondly the LV wall (2/53 and 9/51, respectively). Conclusions: Dual-CM improved the accuracy of automated ventricular segmentation using diastolic data from 256-slice CCTA.