CT血管成像检出心肌桥患者的^99Tc^m—MIBI门控心肌显像研究

^99Tc^m -MIBI gated myocardial perfusion imaging in patients with myocardial bridging diagnosed by CT angiography

目的探讨^99Tc^m-MIBI G-MPI对冠状动脉CT血管成像（CTA）检出心肌桥（MB）患者的临床价值。方法对象为62例（MB患者45例，对照组17例）经CTA（64排CT）检查并接受^99Tc^m-MIBIG-MPI的患者，分析其心肌灌注、室壁运动和左心室功能。所有患者行静息显像，其中17例MB患者和9例对照行运动负荷G-MPI。组间率的比较用，检验或确切概率法，计量资料用t检验比较差异。结果运动负荷和静息心肌显像对MB患者的心肌缺血和（或）灌注异常的阳性检出率分别为（1）门控半定量法：64．7％（11／17）、42．2％（19／45）；（2）目测法：41．2％（7／17）、22．2％（10／45），静息门控半定量法和目测法的阳性检出率差异有统计学意义（P=0．035）。静息显像对不同位置[近段0／7、中段19．4％（6／31）、远段4／7]和深度[表浅型16．7％（7／42）、纵深型3／3]MB的心肌灌注异常阳性检出率差异有统计学意义（x2=7．086，P〈0．05；P=0．008）。门控半定量法评价17例（有负荷显像结果）MB中可逆性缺血、固定缺血和混合性缺血分别占35．3％、23．5％和5．9％；室壁运动和室壁增厚率类型总积分反向分布异常、可逆性异常、固定异常所占百分比分别是23．5％、23．5％、11．8％和35．3％、29．4％、5．9％。不论静息相还是运动负荷相，MB组和对照组间LVEF和高峰充盈率差异均无统计学意义（t=-0．564～1．292，P均〉0．05）。结论^99Tc^m -MIBIG—MPI对CTA检出的MB患者的心肌缺血和（或）灌注异常及左心室功能状况评价有一定价值。

Objective To explore the clinical value of ^99Tc^m-MIBI G-MPI in patients diagnosed with myocardial bridging（MB） by CTA. Methods Forty-five patients with MB and 17 normal controls diagnosed by CTA（64 slices CT） were included. All patients underwent rest ^99Tc^m-MIBI G-MPI and 17 MB patients and 9 normal controls also underwent stress ^99Tc^m-MIBI G-MPI. Myocardial ischemia, function and wall motion were assessed. G-MPI results were compared with CTA results by X2 test, Fisher exact test and t test. Results In patients with MB, the positive rate of abnormal perfusion by gated stress ^99Tc^m-MIBI G- MPI was 64.7% （11/17） and 41.2% （7/17） using quantitative analysis and visual evaluation respectively; while the data were 42.2% （ 19/45 ） and 22.2% （ 10/45 ） by rest G-MPI （P = 0.035 ）. The positive rate by rest G-MPI in MB patients was significant different among mural coronary arteries of different depths and different locations. By quantitative analysis of the stress G-MPI, the reversible, fixed, and mixed ischemia patients were 4 （35.3%）, 6 （23.5%） and 1 （5.9%） respectively; the reversed, reversible and fixed abnormity of wall motion was found in 4 （23.5%）, 4 （23.5%） and 2 （ 11.8% ） patients respectively; the reversed, reversible and fixed wall thickening were found in 6 （35.3%）, 5 （29.4%） and 1 （5. 9% ） patients respectively. There was no significant difference in left ventricular ejection fraction and peak filling rate between MB patients and normal controls in both rest and stress studies （ t ： from - 0.564 to 1. 292, all P 〉 0.05）. Conclusion The G-MPI may be useful for the evaluation of myocardial ischemia and myocardial function simultaneously in patients with MB.