Semiautomatic Three-Dimensional Threshold-Based Cardiac Computed Tomography Ventricular Volumetry in Repaired Tetralogy of Fallot: Comparison with Cardiac Magnetic Resonance Imaging

Abstract

ObjectiveTo assess the accuracy and potential bias of computed tomography (CT) ventricular volumetry using semiautomatic three-dimensional (3D) threshold-based segmentation in repaired tetralogy of Fallot, and to compare them to those of two-dimensional (2D) magnetic resonance imaging (MRI).Materials and MethodsThis retrospective study evaluated 32 patients with repaired tetralogy of Fallot who had undergone both cardiac CT and MRI within 3 years. For ventricular volumetry, semiautomatic 3D threshold-based segmentation was used in CT, while a manual simplified contouring 2D method was used in MRI. The indexed ventricular volumes were compared between CT and MRI. The indexed ventricular stroke volumes were compared with the indexed arterial stroke volumes measured using phase-contrast MRI. The mean differences and degrees of agreement in the indexed ventricular and stroke volumes were evaluated using Bland-Altman analysis.ResultsThe indexed end-systolic (ES) volumes showed no significant difference between CT and MRI (p > 0.05), while the indexed end-diastolic (ED) volumes were significantly larger on CT than on MRI (93.6 ± 17.5 mL/m2 vs. 87.3 ± 15.5 mL/m2 for the left ventricle [p < 0.001] and 177.2 ± 39.5 mL/m2 vs. 161.7 ± 33.1 mL/m2 for the right ventricle [p < 0.001], respectively). The mean differences between CT and MRI were smaller for the indexed ES volumes (2.0–2.5 mL/m2) than for the indexed ED volumes (6.3–15.5 mL/m2). CT overestimated the stroke volumes by 14–16%. With phase-contrast MRI as a reference, CT (7.2–14.3 mL/m2) showed greater mean differences in the indexed stroke volumes than did MRI (0.8–3.3 mL/m2; p < 0.005).ConclusionCompared to 2D MRI, CT ventricular volumetry using semiautomatic 3D threshold-based segmentation provides comparable ES volumes, but overestimates the ED and stroke volumes in patients with repaired tetralogy of Fallot.

Volumetric Severity Assessment of Ebstein Anomaly Using Three-Dimensional Cardiac CT: A Feasibility Study

“…Other researchers have suggested that volumetric quantification using a 3D imaging modality may expedite a better understanding of the relationship between the RV status and disease severity in Ebstein anomaly [4,5]. In particular, the use of 3D threshold-based segmentation could eliminate the time-consuming and reader-dependent manual endocardial tracings for ventricular volumetry as demonstrated in previous studies [7,9]. The threshold-based approach was reported to show high reproducibility with an inter-measurement difference of 1.0±1.1%, and intraclass correlation coefficient of 1.0 [24].…”

“…A semiautomatic 3D threshold-based segmentation method, in which the papillary muscles and trabeculations were excluded from the ventricular cavity, was used to quantify the ventricular volumes. A segmentation threshold separating the interventricular septal myocardium from the adjacent ventricular blood was regarded to be optimal [9]. The valve and venoatrial planes were manually adjusted.…”

“…CVIA heart disease because of its short examination time, high image quality, and wide availability. Cardiac CT is not only useful for morphologic evaluation, but also ventricular function analysis [8,9]. The concerns regarding radiation risks from cardiac CT have dramatically diminished with the optimized low-dose CT protocols [10][11][12].…”

“…The concerns regarding radiation risks from cardiac CT have dramatically diminished with the optimized low-dose CT protocols [10][11][12]. Volumetric assessments using high-resolution 3D cardiac CT may be advantageous over the conventional cardiac MRI method in congenital heart disease, and are frequently used at our institution [9]. However, no prior studies have evaluated these volumetric assessments in patients with Ebstein anomaly.…”

Cardiovascular CT in Cyanotic Congenital Heart Disease

“…1 a Segmentation of a cardiac CT in a 1-day-old neonate with complex double outlet right ventricle, d-malposed great vessels, and an aortic coarctation, in preparation for rapid prototyping. b 3D-printed and digital cardiac models (lateral walls removed to show intracardiac anatomy) equivalent volume assessment between CT and MRI if a CT scanner with appropriate temporal resolution is used, but mild overestimation of RV end-diastolic volumes has also been reported [59,60].…”