Powsner R A, O'Tuama L A, Jabre A, Melhem E R
Department of Radiology, Boston Medical Center, Boston University School of Medicine, Massachusetts 02118, USA.
J Nucl Med. 1998 May;39(5):765-9.
Cerebral vasospasm is a frequent complication after subarachnoid hemorrhage and contributes to overall morbidity and mortality. Arteriography is the standard test for determining the presence of vasospasm. A retrospective review of 16 patients with cerebral aneurysm was undertaken to assess the sensitivity and specificity of SPECT for diagnosis of vasospasm. Fourteen patients were hospitalized after subarachnoid hemorrhage and 2 patients were hospitalized for elective aneurysmal clipping. The patients' condition on discharge was correlated to clinical and SPECT evidence of vasospasm.
Vasospasm was defined as the new onset of neurological signs and symptoms not explained by rebleed or hydrocephalus. A total of 20 SPECT studies were performed for 16 patients during their admission and 14 of 16 patients had a single angiographic study.
Thirteen of 16 patients had 14 episodes of clinical evidence of vasospasm and 14 SPECT studies were performed in these 13 patients. The sensitivity and specificity of SPECT in this retrospective study were 89% (8/9) and 71% (5/7), respectively. Our small sample of arteriograms yielded in comparison a sensitivity of 67% (2/3) and specificity of 100% (9/9). The one false-negative SPECT study occurred in conjunction with the one false-negative arteriogram in the presence of clinical findings consistent with vasospasm. Three false-positive SPECT studies occurred in 2 patients who had perfusion abnormalities in areas of normal CT findings without clinical or arteriographic evidence of vasospasm. Five of 5 patients who died became unresponsive as a result of clinically presumed vasospasm and 4 of 5 of these patients had diffuse or hemispheric SPECT perfusion defects. Of the 11 patients who survived, none became unresponsive; 1 of 11 had positive diffuse or hemispheric perfusion defects.
SPECT is a sensitive and fairly specific test for corroboration of clinical findings of vasospasm. A negative SPECT study may obviate the need for arteriography. Unresponsiveness is the best predictor of poor outcome; however, hemispheric SPECT perfusion deficits are also associated with poor outcome.
脑血管痉挛是蛛网膜下腔出血后常见的并发症，会增加总体发病率和死亡率。血管造影是确定是否存在血管痉挛的标准检查。对16例脑动脉瘤患者进行回顾性研究，以评估单光子发射计算机断层扫描（SPECT）诊断血管痉挛的敏感性和特异性。14例患者因蛛网膜下腔出血住院，2例患者因择期动脉瘤夹闭术住院。患者出院时的状况与血管痉挛的临床及SPECT证据相关。
血管痉挛定义为无法用再出血或脑积水解释的新出现的神经体征和症状。16例患者住院期间共进行了20次SPECT检查，16例患者中有14例进行了单次血管造影检查。
16例患者中有13例出现14次血管痉挛的临床证据，对这13例患者进行了14次SPECT检查。在这项回顾性研究中，SPECT的敏感性和特异性分别为89%（8/9）和71%（5/7）。相比之下，我们少量的血管造影片的敏感性为67%（2/3），特异性为100%（9/9）。1例假阴性SPECT检查与1例假阴性血管造影检查同时出现，当时存在与血管痉挛一致的临床发现。2例患者出现3例假阳性SPECT检查，这些患者在CT表现正常的区域存在灌注异常，但无血管痉挛的临床或血管造影证据。5例死亡患者中有5例因临床推测的血管痉挛而无反应，其中4例患者存在弥漫性或半球性SPECT灌注缺损。11例存活患者中，无一例无反应；11例中有1例存在阳性弥漫性或半球性灌注缺损。
SPECT是一项用于证实血管痉挛临床发现的敏感且相当特异的检查。SPECT检查结果为阴性可能无需进行血管造影。无反应是预后不良的最佳预测指标；然而，半球性SPECT灌注缺损也与预后不良相关。
