Quantification of Tricuspid Valve Regurgitation With 2D and 4D-Flow MRI: Comparison of Different Methods in Adult Patients With Ebstein's Anomaly.

BACKGROUND

Ebstein's anomaly (EA) is a congenital heart disorder involving tricuspid valve dysplasia and right heart abnormalities resulting in severe tricuspid regurgitation (TR). Multiple techniques assess regurgitation severity, but their correlation with EA severity markers remains unclear.

PURPOSE: To compare MRI techniques for quantifying TR and regurgitant volume (RVol) in adults with EA.

STUDY TYPE: Retrospective.

SUBJECTS: Thirty-three adult patients with EA (15 males/18 females).

FIELD STRENGTH/SEQUENCE: 3T or 1.5-Tesla, 2D-phase contrast (2D-PC gradient echo) and 4D-flow (gradient echo).

ASSESSMENT: RVol was measured using three methods: (1) 2D-indirect: subtraction of systolic pulmonary artery (PA) forward flow (2D-PC) from functional right ventricular stroke volume (fRVSV); (2) 4D-indirect: subtraction of PA systolic forward flow from tricuspid diastolic forward flow using 4D-flow; (3) 4D-direct: direct jet measurement with 4D-flow. Correlations were evaluated between RVol and severity markers (left ventricular ejection fraction [LVEF], functional right ventricular end-diastolic volume [fRVEDV], fRV/LV ratio, severity index volume, total right/left volume index, fRVEF).

STATISTICAL TESTS: Pearson or Spearman correlation coefficients (p < 0.05) significant.

RESULTS

The 4D-direct method had the highest correlation with the mean RVol (2D-indirect: r = 0.93, 4D-indirect: r = 0.93; 4D-direct: r = 0.95) and with severity markers: total right/left volume index (0.84, 0.64, 0.87), the fRVEDV (0.66, 0.58, 0.71), fRV/LVratio (0.81, 0.75, 0.87), and severity index volume (0.45, 0.59, 0.66).

DATA

CONCLUSION

4D-flow enables intrinsic RVol quantification independent of fRV segmentation, with the direct jet method outperforming indirect approaches.

TECHNICAL EFFICACY: Stage 2.