Quantification of the severity of tricuspid regurgitation from cardiac magnetic resonance cine images

Background Today, there is no accepted approach to evaluate tricuspid regurgitation (TR) using cardiovascular magnetic resonance (CMR). Contrary to 4-chamber imaging planes, which often do not show the entire regurgitant jet, these jets are readily visualized in short-axis views in the right atrium (RA). We hypothesized that the size and signal intensity (SI) of the cross-sectional jet area in the short-axis views would reflect TR severity. Methods We studied 61 patients with ≥mild TR on echocardiography, who underwent CMR within 24 hours. The severity of TR was determined by color Doppler vena contracta (VC): severe (VC≥7 mm; N = 20), moderate (3<VC<7 mm; N = 21) and mild (VC≤3 mm; N = 20). CMR TR jet area and mean SI (normalized by that in the RA cavity away from the jet) were measured in a single short-axis frame that depicted maximum area.