颈动脉粥样硬化性血管壁面积的测量:16层螺旋CT血管成像与高分辨磁共振成像对比研究

Atherosclerotic area measurement in the vascular wall of the carotid artery: comparison between 16-slice computed tomography angiography and high-resolution magnetic resonance imaging

目的通过与高分辨MRI对比分析,评价多层螺旋CT血管成像(CTA)定量测量颈动脉粥样硬化性血管壁面积的准确性。方法18例无症状患者(男15,女3,平均63岁),至少一侧颈内动脉(超声多谱勒检查)诊断为50%～79%狭窄。1周内分别进行CTA和高分辨MRI检查。以颈动脉分叉为标志,将CTA图像和MR图像进行匹配。在工作站选择每名患者双侧颈动脉有斑块形成的层面分别测量动脉外界、管腔和血管壁的面积。由2名放射科医师分别进行测量,取平均值作为最后的结果。统计采用相关性分析和Bland-Altman分析评价CTA和高分辨MRI测量的相关性和差异。结果所测量的总共167层血管管径和斑块的大小各自不同。CTA与高分辨MRI测量血管外界、管腔和血管壁面积的相关系数分别为0.98、0.98and0.96,呈极强的相关性;CTA与高分辨MRI测量结果的差异分别为(0.16±5.71)mm2、(4.47±1.44)mm2和(-4.31±5.73)mm2。结论作为评价粥样硬化斑块程度的指标,由CTA测量的颈动脉血管壁斑块面积与高分辨MRI测量的结果相近。CTA扫描时间更短、扫描范围更大。这样,在追随观察颈动脉粥样硬化患者的病情变化,尤其是有MR检查禁忌证或MR检查过程中不能合作的患者,CTA可以成为高分辨MRI的一种替代检查方法。

Object To assess the accuracy of computed tomography angiography （CTA） in quantifying atherosclerotic area in the vascular wall of the carotid artery in comparison with high-resolution magnetic resonance imaging （MRI）.Methods Eighteen subjects （15 males and 3 females aged 63±8 years） with ≥50% stenosis in at least one carotid artery were enrolled in this study.CTA and high-resolution MRI scans （in-plane pixel size of 0.25 mm×0.25 mm for both） were conducted within 1 week on a multi-slice spiral CT scanner and a 1.5T MR scanner （Signa,GE Medical Systems）,respectively.CTA images were matched with MR images with the carotid bifurcation as the mark.For each patient,multiple matched slices with carotid atherosclerotic plaques in the bilateral carotid arteries were selected to measure the outer wall boundary （OWB） area,lumen area and wall area.Bland-Altman analysis and Pearson correlation coefficients were used to analyze the correlations of the area measurements between CTA and high-resolution MRI.Results A wide range of lesion size （vascular wall area） was found in these patients.Strong correlations were noted between CTA and high-resolution MRI with the correlation coefficients for OWB area,lumen area and wall area of 0.98,0.98 and 0.96,respectively.The mean differences between CTA and high-resolution MRI were 0.16±5.71 mm2,4.47±1.44 mm2 and -4.31±5.73 mm2 for OWB area,lumen area and wall area,respectively.Conclusion Compared to high-resolution MRI,CTA is also a reliable method to measure carotid vascular wall area.CTA might become an alternative modality to high-resolution MRI for follow-up examination of patients with carotid artery atherosclerosis,especially in uncooperative patients or patients with contra-indications for MRI.