主动脉夹层54例16层螺旋CT表现特征及其解剖、病理基础

目的明确主动脉夹层的16层螺旋CT及其图像后处理（即三维重建）的影像表现特征与其解剖、病理基础的相关性。方法54例经临床影像证实的主动脉夹层患者（典型夹层42例,壁内血肿12例）行16层螺旋CT平扫、增强扫描及三维重建。重点观察和评价夹层真假腔、内膜片、内膜破口以及重要分支血管的受累情况。结果（1）42例夹层真假腔、内膜片、内膜破口的显示率分别为100％、100％、97．6％。夹层真假腔及内膜片呈螺旋形走行41例（97．6％）。左肾动脉及右髂总动脉最易受夹层累及,均为20例（47．6％）。（2）12例壁内血肿、无内膜撕裂,10例（83．3％）平扫表现为主动脉壁呈新月形或环形稍高密度影,2例（16．7％）呈低密度改变;增强扫描均无强化。12例壁内血肿合并穿通性溃疡9例（75％）。结论16层螺旋CT横断面及其三维图像,能快速、准确显示主动脉夹层的病理解剖改变,为临床提供精细信息,对治疗方案的选择具有重要临床实用价值。

CT features and anatomic-pathologic basis of the 16-slice spiral CT for aortic dissection

OBJECTIVE: To determine the CT features and anatomic-pathologic basis of the 16-slice Spiral CT (SCT) for aortic dissection (AD). METHODS: Forty-two cases with typical aortic dissection (AD) and 12 cases with intramural hematoma (IMH) underwent 16-slice SCT, performed with unenhanced, contrast-enhanced scanning and three-dimensional reconstruction. More attention was put on the true and false lumen, intimal flap, the entry tear and the involvement of branches of AD. RESULTS: (1) True and false lumen and intimal flap of AD could be shown in all of 42 cases (100%), the entry tears were revealed in 41 cases (97.6%), and the true and false lumen and intimal flap extended spirally in 41 cases (97.6%). (2) For intramural hematoma (IMH), unenhanced CT depicted crescent-shaped areas with high attenuation extending along the walls of the aorta in 10 cases (83.3%), and low attenuation in 2 cases (16.7%), while contrast-enhanced CT showed no enhancement of attenuation in the crescent-shaped areas in all 12 cases. Nine cases (75%) of IMH were associated with penetrating aortic ulcer. CONCLUSIONS: The axial and three-dimensional images of 16-slice SCT can fast and exactly reveal the pathological and anatomical features of AD, and provide detailed imaging information for clinical therapy. It's very important for the selection of treatment methods.