16排螺旋CT对冠状动脉斑块的诊断价值

目的探讨16排螺旋CT（16-mulddetector spiral computed tomography,16-MDCT）检测和区分冠状动脉斑块的准确性。方法对2005年8月至2006年3月68例拟诊为冠心病的患者先行16-MDCT检查,4天内再行定量冠状动脉造影（QCA）和血管内超声（IVUS）检查,冠状动脉血管腔直径狭窄（DS）≥50％定义为有意义的狭窄,分别测量斑块的CT密度,单位为CT值（Hounsfield units,HU）,根据冠状动脉斑块的CT值区分斑块性质并作出分类：（1）软斑块：CT值为≤50HU;（2）纤维斑块（中等斑块）：CT值为50—119HU;（3）钙化斑块≥120HU。结果在112段16-MDCT和QCA均诊断为冠状动脉狭窄≥50％的病变中,其敏感性为91．8％（112／122）,特异性为97．8％（556／568）,共96段有意义的狭窄病变纳入研究,分别位于左前降支57段,左回旋支17段,右冠状动脉14段,左主干8段。IVUS发现软斑块21个（21．9％）、纤维斑块36个（37．5％）、钙化斑块38个（39．5％）,混合性斑块（纤维钙化斑块）1个（1．1％）,16-MDCT发现软斑块20个,平均CT值（11±36）HU（-27～42HU）、纤维斑块37个,平均CT值（83±20）Hu（58—105HU）、钙化斑块39个,平均CT值（292±80）HU（167—530HU）,差异有统计学意义（P〈0．05）。结论无创性16排螺旋CT冠状动脉成像技术不仅可诊断冠状动脉狭窄病变,同时对区分钙化斑块及非钙化斑块有较高的诊断价值。

Diagnostic value of multidetector spiral computed tomography in identifying the composition of coronary atherosclerotic plaques

OBJECTIVE: To estimate the feasibility of 16-multidetector spiral computed tomography (16-MDCT) on detecting coronary plaques in comparison with intravascular ultrasound (IVUS). METHODS: Sixty-eight patients suspected of coronary heart diseases were examined by 16-MDCT, quantitative coronary angiography (QCA) and IVUS. Coronary stenosis was defined as lumen diameter reduction (DS) >or= 50%. Hounsfield units (HU) were used to determine different types of plaques: soft plaque (or= 120 HU). RESULTS: Compared to QCA, the sensitivity and the specificity for patients with DS >or= 50% were 91.8% (112/122) and 97.8% (556/568) respectively, the positive and negative predictive value were 90.3% (112/124) and 98.2% (556/566) respectively. In 96 plaques evaluated both by 16-MDCT and IVUS, 20 and 21 soft plaques, 37 and 36 fibrous plaques, 39 and 38 calcified plaques were identified by 16-MDCT and IVUS respectively. HU value of soft (11 +/- 36), fibrous (83 +/- 20), and calcified (292 +/- 80) plaques were significantly different (P < 0.05). CONCLUSIONS: Noninvasive 16-MDCT could correctly estimate coronary stenosis and coronary plaques compositions.