大、小肾下型腹主动脉瘤的CT形态学特点

CT morphological characteristics of large and small infrarenal abdominal aortic aneurysm

目的评价大、小肾下型腹主动脉瘤(AAA)的CT形态学特点。方法对45例肾下型AAA患者行64层螺旋CT血管成像(CTA),并测定AAA形态学指标。以直径5 cm为界,将患者分为大、小AAA两组,比较两组AAA的临床危险因素及形态学差异,分析瘤体大小与其他形态学特点的相关性。结果大AAA患者(n=25)收缩压小于小AAA(n=20)(P<0.05),吸烟比例大于小AAA(P<0.05)。大AAA瘤体长度、近远端瘤颈直径、后壁血栓分布几率及瘤壁钙化积分大于小AAA(P<0.05)。AAA瘤体长度与近端瘤颈角度(r=0.418,P<0.01)及近端瘤颈直径呈正相关(r=0.411,P<0.01),与入口角度(r=-0.478,P<0.01)及近端瘤颈长度呈负相关(r=-0.562,P<0.01)。结论肾下型AAA的瘤体大小与其他形态学特点具有一定的相关性。

Objective To evaluate the morphological characteristics of large and small infrarenal abdominal aortic aneurysm （AAA） with 64-slice spiral CT angiography （CTA）. Methods Forty-five patients with infrarenal true AAA underwent CTA. The morphological characteristics of AAA were evaluated. The patients were divided into two groups; small AAA （diameter（5 cm, n=20） and large AAA （diameter≥5.0 cm, n=25）. The clinical risk factors and morphological characteristics between small and large AAA were compared. The correlation between the size of AAA and the other mor- phological characteristics was analyzed. Results Compared to patients with small AAA, those with large AAA showed lower systolic blood pressure and larger prevalence of smoking （P〈0.05）. The length of aneurysms body, diameter of proximal and distal neck, the prevalence of thrombus in posterior wall, and aneurysm wall calcification score in large AAA were significantly larger than those of small AAA （P〈0.05）. The length of AAA was positively correlated with proximal neck angle （r=0. 418, P〈0.01） and diameter （r=0. 411, P〈0.01）, whereas negatively correlated with entry angle （r=0. 478, P〈0.01）and proximal neck length （r=-0. 562, P〈0.01）. Conclusion The size of infrarenal AAA is associated with the other morphological characteristics.