A Study Of The Application Of Gemstone CT Coronary Angiography In The Assessment Of Myocardial Bridge

Objective1,To discuss the prevalence of MB-MCA detected by Gemstone MSCT and themorphological characteristics of myocardial bridge-mural coronary artery.2,To discuss the influence of myocardial bridge-mural coronary artery(MB-MCA) in LAD on coronary atherosclerosis.Subjects and Methods1.Gemstone CT was used to examine the 300 patients with suspected CAD after the routine preparation. MB was diagnosed according to its typical CT features. The position of the MB was counted. The length of MCA and thickness of MB were measured, and adjacent vessel morphology were assessed. The relationship between thickness and length of MB.2.The vessel with mural coronary artery(MCA) was divided into proximal segment, tunneled segment and distal segment of MB.The rate of atherosclerosis in each segment were calculated. The occurrence of AS in patients with superficial type and deep type of MB was analyzed. These patients were divided into atherosclerosis group and non-atherosclerosis group. A comparison was made between the occurrence of AS in patients with and without MB with software SPSS version 13.0.Results1.115 cases of MB were detected in 300 patients. 95 cases of MB were located in the middle segment of leftanterior descending coronary artery(LAD). 2 cases of MB were located in the middle of right coronary artery(RCA). 12 case of MB was located in diagonal branch. 6 cases of MB were located in 1eft circumflex coronary artery(CX).MB was found in both diagonal branch and obtuse marginal branch in 5 case. MCA could be encased partially by MB(69.6%,80/115) or covered completely (30.4%,35/115).The length of MCA was 12.0土65.77mm, the thickness of MB was 2.63土1.53mm. There is mild correlation between the length of MCA and the thickness of MB.2.95 cases of MB located in the middle segment of LAD were selected. Atherosclerosis was found 30 cases(31.5%,30/95)in proximal segment, 3 cases (3.2%,3/95) in distal segment and none in tunneled segment of the vessel with MCA. Proximal segment was prone to cause atherosclerosis. There was positive correlation between different type of MB and percentage of its atherosclerotic stenosis. The occurrence of AS was 34.7% in the LAD burdened MB and 55.7%.Conclusion1.MB has typical CT features. Gemstone CT is a relatively exact method in the diagnosis of MB and can be used to evaluate the anatomical characteristics of MB quantatively. MB is commonly found in the middle segment of LAD. There was correlation between the length and the thickness of MB. MB could be diagnosed accurately, non-invasivly and fast on MSCT.can display the morphous of MB directly by the use of long and minor axis view of MCA. MB were mostly found in the middle segment of LAD. MB could be diagnosed accurately, non-invasivly and fast on Gemstone CT.2.Atherosclerosis was proned to cause in proximal segment but seldom in tunneled segment or distal segment of MB. There is significant correlation between atherosclerosis in the proximal vessels and thickness of MB.The deep type of MB is prone to cause coronary atherosclerosis in the proximal vessels of MB than the superficial one. The occurrence of AS is lower in patients with MB than in patient without MB.