Estimation of Diastolic Filling Pressure with Cardiac CT in Comparison with Echocardiography Using Tissue Doppler Imaging: Determination of Optimal CT Reconstruction Parameters.

Objective: To determine the optimal CT image reconstruction parameters for the measurement of early transmitral peak velocity (E), early peak mitral septal tissue velocity (E'), and E / E'.

Materials And Methods: Forty-six patients underwent simultaneous cardiac CT and echocardiography on the same day. Four CT datasets were reconstructed with a slice thickness/interval of 0.9/0.9 mm or 3/3 mm at 10 (10% RR-interval) or 20 (5% RR-interval) RR-intervals. The E was calculated by dividing the peak transmitral flow (mL/s) by the corresponding mitral valve area (cm). E' was calculated from the changes in the left ventricular length per cardiac phase. E / E' was then estimated and compared with that from echocardiography.

Results: For assessment of E / E', CT and echocardiography were more strongly correlated ( < 0.05) with a slice thickness of 0.9 mm and 5% RR-interval ( = 0.77) than with 3 mm or 10% RR-interval. The diagnostic accuracy of predicting elevated filling pressure (E / E' ≥ 13, n = 14) was better with a slice thickness of 0.9 mm and 5% RR-interval (87.0%) than with 0.9 mm and 10% RR-interval (71.7%) ( = 0.123) and significantly higher than that with a slice thickness of 3 mm with 5% (67.4%) and 10% RR-interval (63.0%), ( < 0.05), respectively.

Conclusion: Data reconstruction with a slice thickness of 0.9 mm at 5% RR-interval is superior to that with a slice thickness of 3 mm or 10% RR-interval in terms of the correlation of E / E' between CT and echocardiography. Thin slices and frequent sampling also allow for more accurate prediction of elevated filling pressure.