多层螺旋CT对冠状动脉粥样硬化斑块性质的诊断价值

Value of multi-slice computed tomography in diagnosis of coronary plaque characterization

目的分析离体冠状动脉内不同病理类型的粥样硬化斑块的 CT 值范围,探讨利用 CT值对不同类型的粥样硬化斑块进行定性诊断的可行性。方法选取25例离体心脏标本,其中冠状动脉内含有粥样硬化斑块的心脏标本9例。将造影剂稀释后,注入冠状动脉标本内,分别应用16排、64排螺旋 CT 机对标本进行薄层扫描,对发现的粥样硬化斑块进行 CT 值测量后,制成切片,进行病理分型。结果 CT 共发现冠状动脉粥样硬化斑块38个,通过与病理对照,得出当管腔 CT 值约为370 HU时,16排 CT 的测量结果为软斑块的平均 CT 值为(53±12)HU,纤维斑块的平均 CT 值为(106±17)HU,钙化斑块的平均 CT 值为(429±94)HU;64排 CT 的测量结果为软斑块的平均 CT 值为(51±13)HU,纤维斑块的平均 CT 值为(110±19)HU,钙化斑块的平均 CT 值为(435±87)HU。3种类型斑块间的 CT 值差异有统计学意义,软斑块的 CT 值明显低于纤维斑块,纤维斑块的 CT 值明显低于钙化斑块。16排和64排螺旋 CT 对3种类型斑块的 CT 值测量结果差异无统计学意义。结论应用 CT 可以对冠状动脉粥样硬化斑块进行无创性评价,CT 值是鉴别不同类型的冠状动脉粥样硬化斑块的一个很有价值的指标,对冠状动脉粥样硬化斑块的鉴别诊断具有重要意义。

Objective To investigate the value of multi-slice computed tomography in diagnosis of different types of coronary atherosclerotic plaques. Methods Twenty-eight patients undergoing CT angiography （CTA） with normal coronary arteries were randomly selected to measure the CT values of different sections of the 4 main branches of coronary artery. Twenty-five specimens of human heart from the bodies of the patients who died of non-cardiogenic diseases were scanned by 16-slice CT scanner and 64-slice CT scanner： a mixture of CT contrast media and normal saline was injected into the coronary arteries to achieve in-vivo-like contrast enhancement within the coronary artery lumen to detect atherosclerotic plaques. The CT values of plaques were measured in several regions of interest （ROI） selected in each plaque. The CT images thus obtained were evaluated by 2 experienced radiologists. There are nine specimens with coronary atherosclerotic plaques among them. Then the atherosclerotic lesions in the coronary were made into tissue specimens to undergo pathological examination. Results 7560 CT values were obtained from the 28 patients. Thirty-eight atherosclerotic plaques were found by CAT in 9 heart specimens and confirmed by pathology. When the CT value of coronary lumen was 370 HU, the predominant lipid-rich plaque showed a mean CT value of 53±12 HU; the fibrous-rich plaque showed a mean CT value of 106±17 HU; and the calcified plaque showed a mean CT value of 429±94 HU measured by 16-slice CT; and the predominant lipid-rich plaque showed a mean CT value of 51±13 HU; the fibrous-rich plaque showed a mean CT value of 110±19 HU ; and the calcified plaque showed a mean CT value of 435±87 HU measured by 64-slice CT. The CT value of the fibrous-rich plaque was significantly higher than that of the lipid-rich plaque （P=0.008） , and lower than that of the calcified plaque （ P 〈 0. 01 ）. There was no significant difference between the results obtained by the two kinds of CT scanners. Conclusion CTA can non-invasively assess the atherosclerotic plaques.