Aims: The aim of this study is to present a contrast media (CM) protocol for the dynamic visualisation of the tricuspid valve (TV) and tricuspid annulus (TA) with CT.
Methods and results: Fifteen patients with no cardiac abnormalities (controls), 15 patients with functional tricuspid regurgitation (FTR) <3+, and 13 patients with FTR ≥3+ underwent a dedicated cardiac CT protocol. Using advanced visualisation, segmentation and analysis software, the annular area, entire annular circumference, its three parts, and annular diameters were measured by two independent, blinded readers. The homogeneity of attenuation in the right heart was 63 HU in the RA and 46 HU in the RV, showing a significant negative correlation with the degree of FTR (r=–0.61, p<0.001). The annular area, entire annulus and diameters were larger in patients with FTR compared to controls (p<0.05). There were significant differences between systole and diastole in controls and patients with FTR <3+ and FTR ≥3+ for the annular area and annulus (p<0.05). The annulus was significantly smaller (all, p<0.05) in 2D compared to 3D (systematic underestimation: 1.0-1.3 mm), the difference decreasing with increasing FTR grades.
Conclusions: This study introduces an individually tailored CM protocol for optimised visualisation of the TV with CT. We found dynamic changes of the geometry within the cardiac cycle and between 3D and 2D measurements, the latter systematically underestimating the true size of the TA. Use of this CM protocol enables accurate imaging of the dynamic geometry of the TA prior to transcatheter valve repair.