目的:报告一例颈内动脉(ICA)发育不全的李氏A型和D型合并病例,通过磁共振血管造影(MRA)诊断。
方法:一名患有头晕的60岁女性患者接受了头颅磁共振成像(MRI)和颅内区域的MRA,以评估脑和血管病变。磁共振机是3.0-T扫描仪。
结果:MRI显示无异常,除了多发性小白质病变。MRA显示左ICA不在,除了上面骨段,双侧ICA的突突旁段之间存在吻合血管,表示Lie的D型ICA。还存在左后交通动脉(PCoA)。因此,也有A型ICA发育不全的特征。双侧ICA和同侧PCoA之间的吻合血管口径相对较小。
结论:李氏D型ICA发育不全通常与前后循环不连通。我们遇到了一例D型和A型ICA联合发育不全。据我们所知,英文文献中没有类似病例的报道.这是第二例具有同侧PCoA专利的D型ICA发育不全。我们推测,在A型ICA发育不全的情况下,当PCoA的发育不足以支持侧支血流时,双侧ICA之间可能形成吻合血管。
OBJECTIVE: To report an unusual case of combined Lie\'s types A and D of internal carotid artery (ICA)
agenesis, diagnosed by magnetic resonance angiography (MRA).
METHODS: A 60-year-old woman with dizziness underwent cranial magnetic resonance imaging (MRI) and MRA of the intracranial region for the evaluation of brain and vascular lesions. The magnetic resonance machine was a 3.0-T scanner.
RESULTS: MRI showed no abnormalities, except for multiple small white matter lesions. MRA showed that the left ICA was absent, except for the supraclinoid segment, and an anastomotic vessel was present between the paraclinoid segments of the bilateral ICAs, indicating Lie\'s type D ICA agenesis. The left posterior communicating artery (PCoA) was also present. Thus, there were also features of type A ICA
agenesis. The anastomotic vessels between the bilateral ICAs and ipsilateral PCoA were relatively small in caliber.
CONCLUSIONS: Lie\'s type D ICA
agenesis usually does not communicate with the anterior and posterior circulations. We encountered a case of combined type D and type A ICA
agenesis. To our knowledge, no similar case has been reported in the English literature. This is the second case of type D ICA
agenesis with patent ipsilateral PCoA. We speculate that in case of type A ICA agenesis, when the development of the PCoA is insufficient to support collateral blood flow, an anastomotic vessel between bilateral ICAs may develop.