[The influence of motion artifacts conditioned by reconstruction, on the coronary calcium score in multislice spiral CT].
The influence of motion artifacts conditioned by reconstruction, on the coronary calcium score in multislice spiral CT.


OBJECTIVE
A major problem of the quantification of coronary calcifications is a high variability of the coronary calcium score between recurrent examinations and different observers. Aim of our study is to evaluate the influence of different RR-intervals on the coronary calcium score utilizing retrospectively gated Multislice Spiral CT (MSCT) data sets.


METHODS
50 consecutive patients underwent MSCT examination (Somatom Volume Zoom, Siemens, Forchheim, G) utilizing a standardized scan protocol (4 x 2.5 mm collimation, 3 mm increment, tube current 133 mAs, tube voltage 120 kV). Retrospectively gated image reconstruction was performed every 10 % of the RR interval. Coronary calcification was evaluated by the Agatston score. Coronary risk assessment was performed in all patients with image reconstruction beginning at 80 % of the RR interval. The reconstruction intervals with the least motion artifacts were identified and chosen as reference for a reevaluation of the coronary risk. The results of different reconstruction times were compared.


RESULTS
The mean calcium score was 551.6. The calcium score varied between 512.2 (90 %) and 571.7 (70 %), depending on the image reconstruction interval. Compared to the mean calcium score a new classification of the coronary risk was necessary in 7/50 of the patients at 80 % reconstruction interval, and in 2/50 of the patients at 50 % of the RR interval, respectively.


CONCLUSIONS
Movement of the coronary arteries at different image reconstruction intervals has an important influence on the coronary calcium score. Based on our data, we propose image reconstruction at 50 % of the RR interval for evaluation of the coronary calcium score by MSCT.
Mahnken
A H
AH
Klinik für Radiologische Diagnostik, Universitätsklinikum der RWTH-Aachen, Germany. mahnken@rad.rwth-aachen.de
Sinha
A M
AM
Wildberger
J E
JE
Krombach
G A
GA
Schmitz-Rode
T
T
Günther
R W
RW
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D002114:Calcinosis / Q000000981:diagnostic imaging*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology; D015588:Observer Variation; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed