Pinto A N, Ferro J M, Canhão P, Campos J
Department of Neurology, Hospital St. Maria, Lisbon, Portugal.
Acta Neurochir (Wien). 1993;124(2-4):79-81. doi: 10.1007/BF01401126.
Angiography is usually recommended in perimesencephalic subarachnoid haemorrhage (PM SAH) to rule out a basilar artery aneurysm. However it is not known how often aneurysms are found among patients with a CT pattern of PM haemorrhage or the frequency of this CT pattern after rupture of posterior circulation aneurysms.
CTs of all SAH caused by posterior circulation aneurysms admitted from 1/85 to 12/92 where reviewed by two examiners. Late (> 72h) examinations were excluded. The remaining CTs were classified in perimesencephalic (PM) or non PM.
81 posterior circulation aneurysms were collected. Only one PM-like CT pattern was found, due to ruptured posterior communicating artery aneurysm (1.3%; 95% Cl (confidence intervals) = .03-6.7%). During the same period 37 PM SAH with negative angiographic results were admitted. The likelihood of finding an aneurysm in a patient with an early CT showing a PM distribution of haematic densities was 2.7% (95% Cl = .07-.14%).
Although the probability of finding an aneurysm in a SAH patient with a PM CT pattern is low, a complete 4-vessel angiogram must be obtained.
对于大脑中脑周围蛛网膜下腔出血（PM SAH）患者，通常建议进行血管造影以排除基底动脉瘤。然而，目前尚不清楚在具有PM出血CT表现的患者中动脉瘤的发现频率，以及后循环动脉瘤破裂后这种CT表现的出现频率。
对1985年1月至1992年12月收治的所有由后循环动脉瘤引起的SAH患者的CT进行了两位检查者的回顾性分析。排除了延迟（>72小时）检查。将其余的CT分为中脑周围型（PM）或非PM型。
共收集到81例后循环动脉瘤。仅发现1例类似PM的CT表现，系由后交通动脉瘤破裂所致（1.3%；95%置信区间（CI）=.03 - 6.7%）。同期收治了37例血管造影结果为阴性的PM SAH患者。早期CT显示血液密度呈PM分布的患者中发现动脉瘤的可能性为2.7%（95%CI =.07 -.14%）。
尽管具有PM CT表现的SAH患者中发现动脉瘤的概率较低，但仍必须进行完整的四血管血管造影。
