主动脉不典型夹层的电子束CT诊断

Atypical aortic dissection (intramural hematoma) of aorta: diagnosis of electron beam computer tomography

目的 评价电子束CT(EBCT)在主动脉不典型夹层诊断中的临床应用。方法 1994年5月至 2 0 0 0年 4月 15 0 0 0例EBCT检查中诊断主动脉夹层 2 63例 ,其中 2 5例为不典型夹层。男 2 1例 ,女 4例。全部患者均以主诉急性胸痛入院检查。采用Imatron 15 0 XP型EBCT扫描机 ,连续容积增强扫描 ,层厚 3mm ,扫描时间为 0 1s。扫描范围自主动脉弓水平至左右髂动脉分叉处 ,共 14 0层。结果不典型夹层EBCT血管造影 (EBCTA) :直接征象为 :( 1) 2 5例主动脉壁均呈半月状或环状增厚 ,达 5～2 3mm ,平均 15 3mm ,无内膜破裂形成的双腔主动脉征象 ,CT值 5 0～ 87HU ,累及长度为 2 5～4 9 0cm ,平均 16 3cm ;( 2 )内膜钙化移位 5例 ;( 3 ) 6例治疗后EBCT随访 ,管壁厚度呈动态变化。间接征象为 :( 1)主动脉壁增厚溃疡形成 7例 ;( 2 )动脉粥样硬化性改变 12例。上述征象结合临床急性胸痛病史 ,诊断可以成立。病变累及升主动脉 (StanfordA型 ) 6例 ;仅累及降主动脉 (StanfordB型 ) 19例。全部病例临床均采取保守治疗 ,其中 6例EBCT复查 ,3个月至 1年血肿吸收。结论 急诊胸痛鉴别诊断中EBCT对主动脉不典型夹层诊断是一种无创、安全、有效的诊断方法 。

Objective To evaluate the clin ical application of electron beam comp uter tomography (EBCT) in diagnosis of atypical aortic dissection. Metho ds Betw een May 1994 and April 2000, 236 patients with aortic dissection were scanned by electron beam CT (EBCT) from 15 000 cases. Out of which, 25 patients (female 4, male 21) were atypical dissection. All patients complained of acute chest pain. Contrast-enhanced EBCT was carried out by Imatron 150-X P system. Continues vo lu me scanning mode (CVS) was performed to obtain 140 slice from aortic arch to ili ac bifurcation with slice thickness of 3 mm. Results The EBCT angiographic (EBCT A) direct features of atypical dissection were as follows: (1)continuous low den sity crescentic or circle areas along the wall of aorta (25 cases) with CT value of 50-87 HU, 5-23 mm in aortic wall thickness and 16.3 cm in length; (2)displ acement of intimal calcification (5 cases); (3)the change of aortic wall thic kness with follow up (6/6). The indirect features included: (1)aortic atheroscle rotic ulcers (7 cases); (2) atherosclerotic plaque and calcification on the aort ic wall (12 cases). According to above features, EBCT can confirm the diagnosis of atypical aortic dissection when the patient has acute chest pain. Among the 2 5 cases, ascending aorta(Stanford A type) and descending aorta (Stanford B ty pe)were involved in 6 and 19, respectively. In the follow up study with EBCT, i ntramural hematoma was completely absent in 6 patients after 3 months to 1 year. Conclusion For the differential diagnosis of acute chest pain, EBCT can confir m the diagnosis of atypical aortic dissection. EBCT is a noninvasive and safe me thod and it is useful for the follow up study.