Abstract：Objective: To observe the prevalence and anatomical features of myocardial bridging(MB) on dual-source computed tomography(DSCT), and to discuss their clinical significance. Material and Methods: Between December 2006 and March 2007, 272 patients with suspected coronary artery disease or others were referred to undergo DSCT coronary angiography(DSCTCA). Coronary arteries were segmented according to the guideline of the American Heart Association(AHA). The presence, locations, and associated pathological lesions of MB were recorded. All patients with MB on DSCTCA were subdivided into three groups according to DSCTCA findings and their clinical symptoms: first group, patients with MB associated with coronary lesions(atherosclerosis or stent); second group, patients with clinical symptoms but without coronary lesions; third group, patients without demonstrated coronary lesions and clinical symptoms. Fifteen patients underwent conventional coronary angiography(CAG). Anatomical features and diagnostic accuracy of MB on DSCTCA were analyzed using SPSS 11.5 version. 4D cine mode was performed in 10 patients with MB selected randomly to observe changes of MB in the entire cardiac cycle. Results: Sixty-three patients had MB in the 272 patients who underwent DSCTCA, giving the prevalence of 23.2% (63/272). Seventy-nine MB were detected with the mean length of (2.14±0.83)cm and mean depth of (0.33±0.10)cm. Of the 63 patients with MB, 49 patients with single MB(78%, 49/63); 29 in 7 segment, 17 in 8 segment, 1 in 9 segment, 2 in 16 segment. Twelve patients had double MB(19%, 12/63), which was common in both 7 and 8 segment(42%, 5/12). Two patients had triple MB(3%, 2/63). Of the 79 MB, 40 in 7 segment, 24 in 8 segment, 7 in 9 segment, 4 in 16 segment, 3 in 13 segment, and 1 in 10 segment. Statistical analysis showed the patients in group 1 were older than those in groups 2 and 3(P=0.001), and with longer and deeper MB(P=0.041, 0.021, respectively). Four MB showed in 15 patients who underwent CAG; however, 20 MB were detected on DSCT in the 15 patients, with two consistent MB on both methods(P＜0.001). 4D cine mode showed typical “milking effect” induced systolic compression of tunneled segment. Conclusions: The prevalence of MB in this study is 23.2%. DSCTCA can be used to show MB reliably and vividly, to demonstrate associated lesions of coronary arteries, and to uncover some patients symptoms with important value in the management of suspected coronary diseases.
2007, Vol. 18 
