冠状动脉粥样硬化斑块的64层CT冠脉造影评价

Evaluation of Coronary Atherosclerotic Plaque by 64-slice CT Coronary Angiography

目的:探讨64层CT对冠状动脉粥样硬化斑块的识别能力及各种类型斑块在CT血管造影(CTA)上的密度差异。方法:16例冠状动脉内超声(ICUS)检查阳性患者纳入研究,年龄49～73岁。全部病例在ICUS后72小时内进行CTA检查(Philips Brilliance 64层螺旋CT,回顾性心电门控采集模式,层厚0.67mm)。对照ICUS所观察的24个节段进行分析,逐一记录每个斑块的位置、CT值及组织分型,同时以10mm/段计算无动脉粥样硬化的正常血管段数,并与ICUS结果一一对照,统计分析64层螺旋CT识别斑块的敏感性以及识别正常血管段的特异性,并根据ICUS对斑块的组织学分型计算各型斑块的CT值。结果:对照研究的24个节段ICUS共发现27个斑块,其中软斑5个,中间斑块8个,钙化斑块8个,混斑6个。64层螺旋CT能正确探查出其中26个斑块,漏诊中间斑块1个,敏感性为96.3%。不含斑块的以10mm为单位长度的节段共34个,冠状动脉CTA正确识别了其中33个节段,特异性为97.1%。CTA共发现26个斑块,对照ICUS对斑块的组织学分型,软斑的平均CT值为(46±16)HU,中间斑块为(121±50)HU,钙化斑块为(712±268)HU,软斑、中间斑块及钙化斑块三者的CT值间差异存在统计学意义(P<0.05)。结论:64层CT冠脉造影能有效检测冠状动脉粥样硬化斑块,一定程度上可取代ICUS。钙化斑块密度较高,CTA上易于同中间斑块和软斑区分,但后两者之间不易区分。

Purpose： To discuss the ability of 64-slice spiral CT in detecting coronary atherosclerotic types and to study the density of each types of plaques on CT angiography （CTA）. Methods： Sixteen patients were undertaken 64-slice spiral CT and Inner-Coronary Ultrasound （ICUS）. A total of 24 coronary segments were imaged and analyzed. CT images were evaluated for the locations and areas of plaques in the coronary segments. The CT value of every plaque was measured. Results were compared with that of ICUS in a blind method. Results： 1.There were 27 plaques, which included 5 soft plaques, 8 intermediate plaques, 6 calcified plaques and 6 mixed plaques, found by ICUS. Twenty-six plaques of them were detected by 64-slice spiral CT. The sensitivity for the detection of plaque was 96.3%. There were 34 segments without plaque. Thirty-three segments of them were detected by 64-slice spiral CT. The specificity was 97.1%. 2.There were 26 plaques affirmed on CTA images. The CT values of soft plaque, intermediate plaque and calcified plaque were （46 ＋ 16） HU, （121＋ 50） HU and （712 ＋ 268） HU, respectively. There was statistical significant difference between the CT value of soft plaque, intermediate plaque and calcified plaque （P〈0.05）. Conclusion： 1. 64-slice spiral CT has a good accuracy in detecting the atherosclerotic plaque which can replace ICUS to be a noninvasive method in diagnosis of coronary heart disease. 2. The calcified plaque can be easily differentiated from intermediate plaque and soft plaque because of its high density. But the CT values of intermediate plaque and soft plaque still have partial overlap.