高分辨MRI对CAS斑块成分显示的病理对照研究

目的:通过影像和病理对照研究,分析和评价高分辨MRI对颈动脉粥样硬化斑块不同成分的显示效果,为颈动脉内膜切除术术前判断斑块的稳定性提供参考。方法:26例进行颈动脉内膜切除术的颈动脉粥样硬化性狭窄患者术前进行颈部高分辨MRI检查,取得4种不同序列的图像(T1WI、T2WI、PDWI和3D TOF);对手术取得的斑块标本进行病理学检查,并与最接近层面的MRI影像对比,分析斑块内不同成分的MRI影像特点。结果:手术取得28块斑块,分为238段,主要分布于颈总动脉和颈内动脉,病理上以复杂斑块为特征的IV-V型58段(24．37％)和VI型79段(33．19％)为主;在高分辨MRI影像上,斑块内纤维帽主要表现为TOF序列的带状低信号,钙化组织和纤维化组织分别表现为在所有序列影像上的不规则低信号和不特定信号,脂质池和坏死核在T1WI、PDWI和3D TOF序列上呈等至稍高信号,近期出血表现为T1WI、T2WI和PDWI序列的明显高信号。结论:高分辨MRI可以清楚显示动脉粥样硬化斑块,进行动脉管腔狭窄程度的测定,通过多序列影像联合分析还可以分辨斑块内部成分,有助于术前对斑块稳定性的判断。

The contrast pathological study of high resolution MRI on the plaque of carotid arteriosclerosis

Objective:To analyze and evaluate the imaging characteristics of the high resolution MRI on the different components of carotid arteriosclerosis plaque through the contrast study of imaging and pathology, in order to provide references for the pre-carotid endarterectomy (CEA) noninvasive estimation of the plaque stability. Methods:26 patients with carotid atherosclerotic stenosis scheduled for CEA underwent high resolution MRI examination pre-operation in a 1. 5-T scanner using a protocol that generated 4 contrast weighting sequences (T1WI, T2WI, PDWI, and 3D TOF); The plaques taken through operation was processed for the routine pathological studies,and contrasted with the MRI imaging of the closest layers to analyze the MR imaging characteristics of the different plaque components. Results:28 plaques were obtained through CEA and sectioned to 238 locations which were mainly distributed to the CCA and ICA. According to AHA classification, 58 locations (24. 37%) were -classified as type IV-V and 79 (33. 19%) as type VI which are characterized as complex plaques. The internal fibrous caps mainly represented a belt of hypo-intense signal on the sequence of TOF; the calcium represents a irregular hypo-intense signal and the fibrosis tissue varied signals on all sequences, the lipid pools and necrosis cores represented a iso-intense signal to slightly hyper-intense signal on the sequences of T1WI, PDWI and 3D TOF, while the hemorrhages represented a distinct hyper-intense signal on the sequences of T1WI, T2WI and PDWI. Conclusion: The high resolution MRI can not only clearly reveal the atherosclerosis plaque and used to accurately determine the degree of carotid stenosis, but also differentiate the different intro-plaque components through multi-contrast study, therefore are helpful for the pre-operation estimation of the plaque stability.