64层螺旋CT评价左冠状动脉狭窄程度与心肌灌注的相关性

Evaluation of the association between left coronary artery stenosis degree and myocardial perfusion by 64 multi-slice

目的分析64层螺旋CT冠状动脉CT血管成像（CTA）检查中，心肌灌注与左冠状动脉狭窄程度及陈旧性心肌梗死心肌活性的相关性。方法分析223例行64层CT冠状动脉CTA检查患者增强扫描图像，依照左冠状动脉狭窄程度分为正常（91例）、轻度（72例）、中度（36例）及重度狭窄组（24例），重度狭窄组中11例为陈旧性心肌梗死，分别测量每组患者心尖部、室间隔前部及左心室侧壁心肌密度，并进行方差分析；另外在CTA增强及延迟扫描图像中测量陈旧性心肌梗死患者梗死区及正常区域心肌密度，并进行方差分析。结果（1）左冠状动脉重度狭窄组心尖部、室间隔前部及左心室侧壁的心肌密度分别为（55．8±21．4）、（87．8±3．3）和（86．8±7．9）HU，均低于正常组的相应部位[分别为（75．3±7．5）、（98．2±5．2）、（95．6±11．6）HU，P均〈0．05]。轻度狭窄组和中度狭窄组与正常组这3个部位心肌密度的差异无统计学意义。（2）陈旧性心肌梗死患者正常区域延迟后心肌密度明显低于增强时[（70．9±8．3）HU比（98．7±7．3）HU，P〈0．01]，梗死区延迟后心肌密度高于增强时[（42．5±15．7）HU比（17．8±4．1）HU，P〈0．01]。结论应用64层CT冠状动脉CTA测量心肌密度可初步判断左冠状动脉狭窄的严重程度，心肌延迟强化可初步判定陈旧性心肌梗死的心肌活性。

Objective To evaluate the association between left coronary artery stenosis degree and myocardial perfusion by 64 multi-slice CT. Methods A total of 223 patients undel^Nent 64 multi-slice CT coronary artery images （CTA） were included and divided into normal group（91 cases）, mild stenosis group （72 cases） , moderate stenosis group （ 36 cases） and severe stenosis group （ 24 cases ）. Myocardial density was measured at apical, septal and lateral segments. Myocardial density in infarcted segments was compared to non-infarct segments in 11 patients with old myocardial infarction （all from severe stenosis group ）. Results Myocardial density was significantly lower at apical segments [ （55.8 ± 21.4） HU vs. （75.3 ± 7. 5）HU], at septal segment [ （87. 8± 3.3） HU vs. （98.2 ± 5.2）HU and at lateral segment [ （86.8 ± 7.9） HU vs. （ 95.6 ± 11.6 ） HU ] in severe stenosis group than in normal group （ all P 〈 0. 05 ）. Myocardial density of patients with old myocardial infarction was significantly reduced in non-infarct segment [ （70. 9 ± 8.3）HU vs. （98.7 ±7.3）HU,P 〈0.01] and increased in infarct segment [（42.5 ± 15.7）HU vs. （ 17. 8 ± 4. 1 ） HU,P 〈 0. 01 ] post contrast enhancement. Conclusion CTA could be used to evaluate the severity of the left coronary artery stenosis based on myocardial density measurement. Myocardial delayed enhancement derived from CTA could be used to identify infarct segements.