Time-resolved magnetic resonance imaging of contrast kinetics to identify severe tricuspid valve regurgitation.

Introduction: The gold standard for identifying and grading tricuspid valve regurgitation is transthoracic echocardiography. However, the acoustic window using transthoracic echocardiography is not always sufficient to quantify the amount of regurgitation. Time-resolved imaging of contrast kinetics (TRICKS) is a 4-dimensional magnetic resonance angiography option with high spatial and temporal resolution. The aim of the present study is to find out whether identification of patients with severe tricuspid valve regurgitation by using TRICKS angiography is feasible.

Methods: TRICKS angiography was performed in a 3T-CMR-scanner after antecubital injection of gadolinium dimeglumine during breath hold. Retrograde appearance of contrast agent in the hepatic veins was classified as severe tricuspid regurgitation (TR). Additional semi quantification of retrograde perfusion was performed by temporal signal intensity curve (SIC) analysis in the hepatic veins close to their drainage into the inferior vena cava. Transthoracic echocardiography (TTE) using the actual European guidelines on the management of valvular heart disease served as gold standard forTR grading.

Results: 185 patients (57 +/- 17 years) with TR ranging from no to severe TR were analysed prospectively. 14 (7.6%) patients had severe TR, 27 (14.6%) showed moderate, 137 (74.1%) mild and 7 (3.8%) no TR. TRICKSangiography identified 13 patients with retrograde contrast appearance in the hepatic veins, of whom all had severe TR in TTE. No patient with echocardiographic mild or moderate TR was graded as severe TR using TRICKSangiography. One patient with echocardiographic severe TR showed neither in the visual analysis nor in SIC analysis retrograde appearance of contrast agent in the hepatic veins. Overall, the sensitivity for detecting severe TR using TRICKSangiography was 93% with a specificity of 100%. The positive predictive value was 100%, the negative predictive value 99%. For severe TR there was no intra- and interobserver variability.

Conclusion: MRTRICKSangiography is a very reliable tool to identify patients with severeTR by the imaging of retrograde appearance of contrast agent in the hepatic veins. Sensitivity and specificity of this approach is very high with no intra- and interobserver variability.