The Evaluation Of The Transmural Myocardial Perfusion Of Left Ventricular Wall In The Rest State: Using640-Slice CT

Part1Influence of coronary artery stenosis on transmural myocardialperfusion of left ventricule in the rest:evaluation with640-slice CTObjective: To probe the influence of different branches and differentdegrees of the coronary artery stenosis on the myocardial transmural perfusionratio(TPR) of left ventricular wall, and to discuss the normal myocardial TPRof each territory of left ventricular wall in the rest state.Methods: CTA and CTP images of274patents, who were examinedwith Toshiba640-slice CT, were analyzed retrospectively. Patents weredivided into several groups according to the stenosis degree of coronaryartery and16segments. The differences of the relevant section TPR betweenthe normal group and the groups of different coronary artery stenosis degree,and the relationship of coronary artery stenosis degree and the relevant sectionTPR were evaluated.Result: Stenosis of left anterior descending artery (LAD) and leftcircumflex coronary artery (LCX) influenced even more obviously on TPRof left ventricular wall. The disease of LAD mainly influenced mid-anteriorsegment (R=-0.288), apical anterior segment （R=-0.263） andmid-anteroseptal segment (R=-0.196). Whereas, LCX artery mainly affectedbasal anterolateral segment (R=-0.241), basal inferolateral segment（R=-0.279）and apical lateral segment (R=-0.201). Effect of RCA rarelyinfluence the TPR of LV, if it was true, mainly influenced mid inferiorsegment. Moderate and severe stenosis of coronary artery lead more decine ofTPR of LV than that of mild group. TPR of anterior wall of left ventricularwas more sensitive to coronary artery lesion.The rest normal value of TPRand the mean TPR of the severe stenosis group in the territories of LAD, LCX and RCA were (1.14±0.09and1.07±0.13),(1.13±0.11and1.06±0.14) and(1.15±0.14and1.10±0.12) respectively.Conclusion: Different branches of coronary artery stenosis caninfluence TPR of different segments.There was a positive correlation betweendifferent degree of coronary artery stenosis and TPR of dominatedsegments.Rest normal value of TPR of LV were offered.Part2Effect of myocardial bridge on the transmuralmyocardial perfusion of left ventricule in the rest: evaluation with640slice CTObjective: To probe the influence of myocardial bridge andmyocardial bridge companying with atherosclerosis coronary artery on themyocardial transmural perfusion ratio(TPR) of left ventricule in the rest state.Methods: CT images of271patients with myocardial bridge werefound when using Toshiba640-slice CT for coronary artery CTA, and121cases whose CT images information was integrity were included forevaluation of myocardial perfusion retrospectively. These patients weredivided into several groups according to myocardial bridge thickness and withor without atherosclerosis.36normal cases were included as control group.Then the difference of TPR of the relevant segments between the controlgroup and the groups of different myocardial bridge thickness and with orwithout atherosclerosis were analyzed.Results: Atherosclerosis of the coronary artery segment proximal tomyocardial bridge was found in142of271patients (52.3%), and theincidence of atherosclerosis was49.6%(60/121) for121cases whose CTimages information was integrity.There was difference with statisticallysignificance (P＜0.05) between the myocardial bridge group and controlgroup for the TPR of basal anteroseptal, mid anterior, mid anteroseptal, apicalanterior, apical septal segments. There was no significant difference betweenisolated myocardial bridge group and control group for TPR in any segment. There was significant difference (P＜0.05) of TPR between the shallowmyocardial bridge group and control group for the of mid anterior,midanteroseptal and apical anterior segments. There was obvious difference ofTPR between the thick myocardial bridge accompanying with atherosclerosisgroup and control group for basal anteroseptal, mid anterior, mid anteroseptal,apical anterior, apical septal segments.Conclusion: Myocardial bridge can promote atherosclerosis in thecoronary artery segment proximal to myocardial bridge. Effect of isolatedmyocardial bridge on TPR of different segments has no obvious clinicalsignificance. Atherosclerosis in the coronary artery segment proximal tomyocardial bridge can influence TPR of different segments,especially the TPRof the apical and anterior segments.