Optimal systolic and diastolic reconstruction windows for coronary CT angiography using dual-source CT.
OBJECTIVE
The purpose of this study was to determine the position of the optimal systolic and diastolic reconstruction intervals for coronary CT angiography using dual-source CT.


METHODS
In 90 patients, coronary dual-source CT angiography was performed without beta-blocking agents. Data were reconstructed in 5% steps throughout the R-R interval. Two independent readers selected optimal systolic and diastolic reconstruction windows for each major coronary vessel--the right coronary artery (RCA), left anterior descending artery (LAD), and left circumflex artery (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 of all patients was 68.7 beats per minute (bpm) (range, 43-119 bpm). The median optimal systolic reconstruction windows were at 35%, 30%, and 35% for the RCA, LAD, and LCX, respectively. The median optimal diastolic reconstruction window was at 75% for all vessels. The mean motion scores (+/- SD) in the systolic reconstructions were 1.9 +/- 0.8 (RCA), 1.7 +/- 0.5 (LAD), and 2.0 +/- 0.6 (LCX). The mean motion scores for the diastolic reconstructions were 1.7 +/- 0.9, 1.5 +/- 0.6, and 1.6 +/- 0.7, respectively. In patients with a heart rate of < 70 bpm, motion scores were significantly lower in diastole versus systole (1.3 +/- 0.4 and 1.9 +/- 0.5, respectively; p < 0.01). In most patients with a heart rate of > 80 bpm, motion scores were lower in systolic than in diastolic reconstructions (2.1 +/- 0.6 and 2.6 +/- 0.8, respectively; p < 0.05).


CONCLUSIONS
Using dual-source CT, the overall optimal reconstruction window is at 75% of the R-R interval in patients with low or intermediate heart rates. In patients with heart rates of > 80 bpm, systolic reconstructions often yield superior image quality compared with diastolic reconstructions.
Seifarth
Harald
H
Department of Clinical Radiology, University of Muenster, Albert-Schweitzer-Strasse 33, 8149 Muenster, Germany.
Wienbeck
Susanne
S
Püsken
Michael
M
Juergens
Kai-Uwe
KU
Maintz
David
D
Vahlhaus
Christian
C
Heindel
Walter
W
Fischbach
Roman
R
D000368:Aged; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000150:complications / Q000000981:diagnostic imaging*; D003971:Diastole; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013599:Systole; D014057:Tomography, X-Ray Computed / Q000379:methods*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology