Optimal Systolic and Diastolic Reconstruction windows for Coronary CT Angiography using Dual Source CT

Abstract

Objective: The purpose of this study was to determine the position of the optimal systolic and diastolic reconstruction interval for coronary CT angiography using Dual-Source-CT (DSCT).
Materials and methods: In 90 patients, coronary DSCT angiography was performed without a prescan administration of beta blocking agents. Data were reconstructed in 5 % steps throughout the RR interval. Two independent readers selected an optimal systolic and diastolic reconstruction window for each major coronary vessels (RCA, LAD and LCX) using a 3D-viewer and volume-rendering displays. The motion score for each vessel was graded from 1 (no motion artifacts) to 5 (severe motion artifacts over entire vessel).
Results: The average heart rate (HR) of all patients was 68.7 bpm (43-119 bpm). Median optimal systolic reconstruction windows were at 35 %, 30 % and 35 % (RCA, LAD and LCX). The median optimal diastolic reconstruction window was at 75% for all vessels. Motion scores in systolic reconstructions were 1.9 ± 0.8 (RCA), 1.7 ± 0.5 (LAD) and 2.0 ± 0.6 (LCX). Mean motion scores for diastolic reconstructions were 1.7 ± 0.9, 1.5 ± 0.6 and 1.6 ± 0.7. In patients with HR < 70, motion scores were significantly lower in diastole versus systole (1.3 ± 0.4 vs. 1.9 ± 0.5; p < 0.01). In most patients with HR > 80bpm motion scores were lower in systolic reconstructions (2.1 ± 0.6 vs. 2.6 ± 0.8, p < 0.05).
Conclusion: Using DSCT, the overall optimal reconstruction window is at 75 % of the RR-interval in patients with low or intermediate heart rates. In HR > 80 bpm, systolic reconstructions often yield superior image quality compared to diastolic reconstructions.

Seifarth H, Wienbeck S, Püsken M, Juergens KU, Maintz D, Vahlhaus C, Heindel W, Fischbach R.

AJR Am J Roentgenol. 2007 Dec;189(6):1317-23.