多层螺旋CT血管成像对主动脉壁内血肿的诊断价值

The diagnostic value of multi-slice spiral CT angiography in aortic intramural hematoma

目的:探讨主动脉壁内血肿(aortic intramural hematoma,IMH)的多层螺旋CT(multi-slice spiral computer tomography,MSCT)特征及其临床价值。方法:经MSCT血管成像(multi-slice spiral computer tomography angiography,MSCTA)诊断的IMH21例,使用16层螺旋CT血管成像,应用多平面重建、最大密度投影和曲面重建,观察并统计分析IMH受累解剖部位及其分型、IMH影像学特征、IMH厚度对受累主动脉管径的影响、并发主动脉溃疡情况、继发改变。结果:①受累解剖部位及其分型:主动脉弓、升主动脉、胸段降主动脉及腹主动脉受累分别占2例、4例、12例及16例,以降主动脉最常见(P<0.05);按照Standford分型标准,A型4例,B型17例;无腹腔干、肠系膜上动脉、双肾动脉及肠系膜下动脉受累。②IMH影像学特征:平扫呈环形或新月形的稍高密度影,增强扫描无强化,环形和新月形稍高密度影分别占2例、19例;IMH壁内钙化内移占15/21(71.43%),与未见壁内钙化内移之间的IMH差异有统计学意义(P<0.05)。③IMH厚度与受累主动脉管径的关系:血肿厚度平均(8.81±3.70)mm,受累主动脉管径平均(32.58±6.59)mm,两者之间比值以小于1/4者为主,占17/21(80.95%)(P<0.05)。④并发主动脉溃疡:表现为主动脉管壁不光滑,并可见局限性龛影形成,本组病例中合并主动脉溃疡4例。⑤继发改变:左心增大(左心室增大占2例,左心室及左心房均增大占4例);胸腔积液6例。结论:MSCT血管成像能够反映IMH的影像学特点,可作为IMH的重要检查方法。

Objective：To explore the multi -slice computed tomographic （MSCT） feature of aortic intramural hematoma （IMH） , and to assess the value of MSCT in clinic. Methods：21 consecutive patients with MSCT angiography confirmed IMH were enrolled into our study and underwent contrast enhanced scanning by 16-slice mutidetector CT. The lesion location and the typing of IMH, imaging feature of IMH, the relationship between thickness of the lesion and aortic diameter, whether complicating aortic penetrating ulcer, and the secondary changes, were determined based on traverse, Multiplanar Reconstruction （MPR）, Maximum Intensity Projection （MIP） and Curved Planar Reconstruction （CPR） images, and all data were evaluated by chi square test. Results： Among 21 cases （1） The le- sion location and the typing of IMH： the common positions of the region contained aortic arch, descending aorta, thoracic and abdomi- nal aorta, each observed in 2, 4, 12 and 16 cases. There were significantly difference in the common positions of the region （ P 〈 0.05 ） , and the most common positions were descending aorta;according to Standford classification criteria, it contained 4 Stand- ford A and 17 Standford B, and there were no main branching vessels involved, these vessels included celiac trunk, superior mesenter- ic artery, renal artery and inferior mesenteric artery. （2） Imaging feature of IMH： Among all were performed as crescent-shaped or ring -shaped thickened aortic wall, increased attenuation of the aortic wall thickening on non-contrast CT, without enhancement on enhanced scanning, the crescent - shaped or ring_-shaped thickened aortic wall was observed in 2 and 19 cases. Intrinsic wall calcification was pres- ent about 15/21 （71.43 % ）, there was significantly difference compared with those without intrinsic wall calcification （P 〈 0.05 ）. （3） The relationship between thickness of the lesion and aortic diameter： The mean thickness of the IMH was（ 8.81 ± 3.70）mm, and the mean aortic diameter at the location of the IMH lesion was 32.58 ± 6.59 ram. Lesion 〈 1/4 diameter was 17/21 （80. 95% ） （P 〈 0. 05 ）. （4） The aortic intima became unsmooth where aortic penetrating ulcer was occurred, and frequently complicated with niche sign. 4 cases were seen in our study. （5） Secondary changes, increased heart volume （ contained 2 cases of enlarged of left ventricular and 4 cases of both enlarged of left ventricular and left auricle ） and pleural effusion was observed in 6 cases. Conclusion ： This study confirms MSCT angiography ima- ging can reflect the imaging feature of IMH, and can be used as an important examination for IMH.