Correlation Analysis Of The Morphological Diversity Of The Left Coronary Artery And The Formation Of Atherosclerotic Plaques

PurposeThe main aim of our study was to measure the length,the dimensions and areas at different points including ostium,midportion and distal,the bifurcation angles and the types of the left main coronary artery(LM),on 320-slice spiral CT,and research the differences between men and women without left coronary atherosclerotic plaques.We also studied the relationship between the anatomical diversity of LM and the localization and formation of the atherosclerotic plaques.Materials and MethodsA total of 199 consecutive patients who underwent 320-slice spiral CT coronary angiography in our hospital between September 2017 and March 2018 were selected,including 98 females and 101 males,age 55 to 65 years old.According to the presence and severity of the plaques in the left coronary artery,the patients were divided into three groups,including 69 cases of the normal group,74 cases of the mild stenosis group,and 56 cases of the moderate-severe stenosis group.On the basis of the plaque positions,the coronary lesion group was further divided into proximal and distal lesions.If multiple lesions were coexist in any of the major branches,the most severe one was taken into consideration.According to the 3D volume rendering technology,the LM can be divided into four types: type I(biconcave-shaped pattern),type II(tapering pattern),type III(combined pattern,cone-shaped at the ostium and then tubular-shaped in the other parts of the vessel),and type IV(funnel-shaped pattern)We adopted the Japan Toshiba 320-row spiral CT scanner,the retrospective ECG gating and the 75% R-R intervals reconstruction.Using Vitrea Workstation software and reconstruction technologies such as the volume rendering,the maximum intensity projection,the multi-planar reformatting and the curved multi-planar reformation,the length of the LM,the dimensions and areas(at the ostium,midportion and distal of the LM),angle 1,2,and 3,the angles between LAD and LCX,LM and LAD,LM and LCX were measured.The diameter stenosis rate of the vessel was measured,and the locations of plaques were recorded.The statistics analyses were performed using SPSS 19.0 software.ResultsIn the normal group,the range of the LM length was 3 ~ 22 mm,the mean length was 9.73 mm.The largest and smallest mean cross-sectional diameters of the LM measured at the ostium were 3.98 and 5.31 mm,respectively;at the midportion,3.63 and 4.4 mm,respectively;and the distal portions,3.71 and 4.67 mm,respectively.The mean cross-sectional area measured at ostium,midportion and distal LM were 17.71mm2,12.77mm2 and 14.14mm2,respectively.The angles between LM and LAD,LM and LCX,LAD and LCX were 145.15 °,123.1 ° and 73.39 ° respectively.The angle 1,angle 2 and angle 3 were 93.59 °,111.64 ° and 70.57 ° respectively.The angles between LAD and LCX in women were smaller than those in men in the normal group(P=0.01).Forty out of 69 participants(58%)in normal group showed biconcave-shaped appearance of the LM(type I),13/69 participants(18.8%)showed tapering morphology(type II),7/69 participants(10.2%)had combined pattern(type III)and 9/69 participants(13%)had funnel-shaped appearance.In the comparison of the normal group,the proximal lesions group and the distal lesions group,the mean angle between LAD and LCX in the normal group was smaller than that in proximal lesions group(P = 0.018)and that in the distal lesions group(P = 0.026).In the comparison of the normal group,the mild stenosis group and the moderate-severe stenosis group,the overall distributions of LM types were different(P = 0.026),the mean angle between LAD and LCX in the normal group was smaller than that in the mild stenosis group(P = 0.013)and that in the moderatesevere stenosis group(P = 0.037).In the comparison of the normal group,the proximal mild stenosis group and the proximal moderate-severe stenosis group,the overall distributions of LM types were different(P = 0.04),the mean angle between LAD and LCX in the normal group were smaller than that in the proximal moderate-severe stenosis group(P = 0.021),and the mean length of the LM in the normal group was larger than that in the moderate-severe stenosis group(P = 0.026).ConclusionCoronary artery CTA imaging can be used to evaluate various anatomical features of coronary arteries.There is a difference in the overall composition of left main types between normal persons and patients with coronary heart disease.Short left main artery,wide angle between left anterior descending artery and circumflex artery can promote the formation of atherosclerotic plaque in left coronary artery.