Authors:

M Vecsey-Nagy¹ , B Szilveszter¹ , Á Jermendy¹ , M Kolossvary¹ , J Simon¹ , ZS Drobni¹ , B Merkely¹ , P Maurovich-Horvat¹ , ¹Semmelweis University Heart Center, Képalkotó Diagnosztikai Részleg - Budapest - Hungary ,

Citation:

Background: The excellent temporal and spatial resolution of currently used wide detector CT scanners enable precise assessment of coronary artery disease (CAD). However, no data is available regarding the degree of motion artifacts in images acquired by the recently introduced 560-slice CardioGraphe (CG) scanner.

Purpose: We aimed to assess the heart rate (HR) dependent presence and degree of motion artifacts in coronary CT angiography (CCTA) scans acquired by CG compared to a conventional 256-slice CT scanner.

Methods: In this retrospective study, we have compared the images of 75 patients who underwent CCTA with CG (240 ms rotation time) to 75 scans acquired by a 256-slice CT scanner (270 ms rotation time). The two groups were matched for age and gender. The mean age of the groups was 57.3 years, 49.3 % males. Motion artifacts were assessed using a Likert-type scale, ranging from 1 to 4 (1: non-diagnostic, 2: severe motion artifacts, 3: mild motion artifacts, 4: no motion artifacts). The patients were divided into 3 equal groups (50-50-50 patients) according to HR ranges during image acquisition (51-60/min, 61-70/min, above 71/min). The image quality of each of the 3 groups in both scanners was compared using Wilcoxon rank-sum test.

Results: The CG scanner had a better image quality, with reduced motion artifacts as compared to the 256-slice scanner (mean Likert-score 2.7 ± 0.9 vs. 2.3 ± 0.7, respectively, p<0.003). The CG images had higher Likert-scores in all 3 heart rate ranges (51-60/min, 61-70/min, 71+/min), which was statistically significant in the lower 2 of the 3 ranges (p=0.025, p=0.043, p=0.156, respectively).

Conclusion:  The new 560-slice CG scanner with 240 ms gantry rotation time allows for CCTA image acquisition with reduced motion artifacts as compared to a 256-slice scanner. The beneficial effect of fast gantry rotation was especially present at HR below 70/min.