Abstract 1907: Diagnostic Accuracy Of 64-slice Computed Tomography For Diagnosis Of Aortic Regurgitation In Patients Referred To Coronary CT Angiography
Purpose. to evaluate whether aortic valve regurgitation (AR) can be diagnosed with 64-slice computed tomography (CT) in comparison to the diagnostic standard transthoracic echocardiography (TTE) in patients referred to coronary CT angiography
Methods. 81 patients were examined with multidetector CT (Sensation64, Siemens): 64×0.6mm;0.33s;120kV/700–900mAs;~ 90 ml iodixanol (Visipaque320) or iomeprol (Iomeron400,Bracco) at 6 ml/s flow rate, image reconstruction with retrospective ECG-gating during mid/late diastole (65%– 80% RR-IV);0.75mm eff.sl./inc.0.4/B25F. The diagnostic criterion for AR was an incomplete co-adaption of aortic valve leaflets which was measured planimetrically in cm2 (central aortic regurgitation area (ARA)). A previous unenhanced CT calcium score scan was performed. All patients underwent TTE, AR was graduated as mild, moderate or severe by using semi-quantitative analysis of Doppler regurgitation jet (jet length/width;PHT method).
Results. The diagnostic accuracy of 64-slice CT for detection of aortic regurgitation (AR) was 73.3% (33/45); specificity 97% (35/36); PPV 97% (33/34); NPV 74% (35/47). All 12 false negative findings were graduated as “mild” by TTE which was missed by CT because of severe valve calcification (mean 3053.1±1700 Agatston) in 9 pts;2 pts had bicuspid valves. The diagnostic accuracy of CT for detection of moderate and severe AR was: sensitivity 95% (20/21), specificity 100%, PPV 100%, NPV 98%. Measurement of the ARA by CT (mean 0.34 cm2±0.36) was significantly correlated with the severity of AR by TTE (r=0.86 Spearman;p<0.001).
Conclusion. 64-slice CT accurately detects moderate and severe aortic regurgitation in patients referred to coronary CT angiography but mild aortic regurgitation is frequently missed in the presence of severe valve calcification or bicuspid valves