Evaluation of knowledge-based reconstruction for magnetic resonance volumetry of the right ventricle in tetralogy of fallot

Purpose: Evaluating right ventricular (RV) volumes and function is important in the clinical management of patients after tetralogy of Fallot (TOF) repair. Currently, cardiac magnetic resonance (CMR) using Simpson's method is the gold standard for RV quantitative assessment. However, this method is time consuming and not without sources of error. Knowledge-based reconstruction (KBR) is a new imaging tool for RV volumetry and has been recently validated on echocardiography. The aim of this study was to assess the feasibility, accuracy, and labor intensity of KBR on CMR datasets in a group of repaired TOF patients by comparison with measurements obtained by Simpson's method. Methods: Thirty five patients (mean age 14±3 years) after TOF repair were studied using KBR and Simpson's method. Parameters analyzed were RV end-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF) and post-processing time. All measurements were compared with the standard Simpson's method. Intraobserver, interobserver and intermethod variability was assessed using Pearson's correlation analysis, coefficients of variation and Bland-Altman analysis. Results: KBR was feasible and highly accurate as compared to Simpson's method. Intra- and intermethod variability for KBR measurements showed good agreements. When compared with Simpson's method, volumetry using KBR was faster (10.9±2.0 vs. 7.1±2.4 minutes, P<.001, respectively). Projection of the 3D model on a 2D image Projection of the 3D model on a 2D image Conclusion: In repaired TOF patients, KBR is a feasible, accurate and reproducible method for measuring RV volumes and function. In addition, the post-processing time of RV volumetry using KBR was significantly shorter when compared with Simpson's method.