Automated Cardiac Valve Tracking for Flow Quantification with Four-dimensional Flow MRI

Abstract

To compare four-dimensional flow MRI with automated valve tracking to manual valve tracking in patients with acquired or congenital heart disease and healthy volunteers. Materials and Methods: In this retrospective study, data were collected from 114 patients and 46 volunteers who underwent fourdimensional flow MRI at 1.5 T or 3.0 T from 2006 through 2017. Among the 114 patients, 33 had acquired and 81 had congenital heart disease (median age, 17 years; interquartile range [IQR], 13-49 years), 51 (45%) were women, and 63 (55%) were men. Among the 46 volunteers (median age, 28 years; IQR, 22-36 years), there were 19 (41%) women and 27 (59%) men. Two orthogonal cine views of each valve were used for valve tracking. Wilcoxon signed-rank test was used to compare analysis times, net forward volumes (NFVs), and regurgitant fractions. Intra-and interobserver variability was tested by using intraclass correlation coefficients (ICCs). Results: Analysis time was shorter for automated versus manual tracking (all patients, 14 minutes [IQR, 12-15 minutes] vs 25 minutes [IQR, 20-25 minutes]; P , .001). Although overall differences in NFV and regurgitant fraction were comparable between both methods, NFV variation over four valves was smaller for automated versus manual tracking (all patients, 4.9% [IQR, 3.3%-6.7%] vs 9.8% [IQR, 5.1%-14.7%], respectively; P , .001). Regurgitation severity was discordant for seven pulmonary valves, 22 mitral valves, and 21 tricuspid valves. Intra-and interobserver agreement for automated tracking was excellent for NFV assessment (intra-and interobserver, ICC  0.99) and strong to excellent for regurgitant fraction assessment (intraobserver, ICC  0.94; interobserver, ICC  0.89). Conclusion: Automated valve tracking reduces analysis time and improves reliability of valvular flow quantification with fourdimensional flow MRI in patients with acquired or congenital heart disease and in healthy volunteers.

Direct measurement of atrioventricular valve regurgitant jets using 4D flow cardiovascular magnetic resonance is accurate and reliable for children with congenital heart disease: a retrospective cohort study

“…Prior work using 4DF CMR and retrospective valve tracking annular inflow methods do not report their calculated AVVR as outcomes, instead comparing net inlet and outlet flows for internal validation, which limits direct comparison to our results as well as general clinical applicability [22,25]. Recent work has demonstrated feasibility of an automatic valve-tracking 4DF CMR technique with improved reliability and internal consistency in measuring net valve flow across all four cardiac valves compared to manual valve-tracking technique in a large cohort of subjects with CHD [36]. However, their RF measurements were not compared to a clinical standard (such as VOL) or outcome measures.…”

“…Recent advancements in 3D phase-contrast CMR (4D flow or 4DF) including compressed sensing, parallel imaging, and motion correction allow for practical solutions to these limitations with short scan times and creation of manually adjustable planes during postprocessing. 4DF is a validated and reliable method for the measurement of flow and volume that has become part of standard clinical imaging at some institutions [22][23][24][25][26][30][31][32][33][34][35][36][37][38][39]. While indirect methods of measuring AVVR have been validated with 4DF CMR [22-24, 36, 37, 40], data on directly measuring AVVR jets remain limited in the pediatric CHD population [24].…”

Age-associated changes in 4D flow CMR derived Tricuspid Valvular Flow and Right Ventricular Blood Flow Kinetic Energy

“…One of the key advantages of this is substantive time-saving. This is because no additional segmentation is required to derive KE parameters, and it takes less than a minute when compared to the automated retrospective valve tracking method, which takes around 4 minutes per-valve 27 . Moreover, in this study, RV diastolic KE parameters demonstrated good correlation to similarly defined 2D tricuspid flow metrics derived by retrospective valve tracking method.…”

Complicated Double-Orifice Mitral Regurgitation: Combined Hemodynamic Assessment Using Echocardiography and Four-Dimensional Flow Magnetic Resonance Imaging

“…9 A recent study of 114 patients with valve diseases showed excellent internal flow consistency across all four valves directly quantified with 4D flow MRI with automated valve tracking (6-mL difference between LV and RV stroke volumes). 10 Although the accuracy of Rvol by 4D flow MRI against the clinical standard CMR volumetric method needs further investigation, the CMR method also suffers from the propagation of individual measurement errors, as discussed in the previous paragraph.…”