From the Section of Neuroradiology (D.M.N., A.C.M.M.Jr., A.J.d.R.)
From the Section of Neuroradiology (D.M.N., A.C.M.M.Jr., A.J.d.R.).
AJNR Am J Neuroradiol. 2019 Jul;40(7):1177-1183. doi: 10.3174/ajnr.A6100. Epub 2019 Jun 13.
Intracranial pressure modifications caused by a skull defect, such as craniectomy or craniotomy, may change the hemodynamics and decrease the accuracy of CTA to confirm brain death. This study aimed to evaluate the impact of a skull defect and the interpretation criteria of images on this diagnostic test.
A series of consecutive patients with a clinical diagnosis of brain death underwent CTA (case group), while the control group comprised patients with acute ischemic stroke in the same period. CTA criteria adopted to confirm brain death were the absence of opacification of the M4 branches and internal cerebral veins. The evaluation also included the presence of "stasis filling." Cases were stratified as intact skull, craniotomy, and craniectomy. Three neuroradiologists evaluated all examinations independently.
In the case group, according to the Frampas criteria, the sensitivity of CTA to confirm brain death was 95.5% in patients with intact skull, 87.5% with craniotomy, and 60% with craniectomy. False-negative diagnoses of brain death were 15.6%, related to stasis filling in 71.4% ( < .001). However, according to the "modified Frampas criteria," the sensitivity of CTA to confirm brain death was 100% in patients with intact skull, 93.8% with craniotomy, and 80% with craniectomy. False-negative diagnoses of brain death were found in 6.2% of patients, and there was no stasis filling. CTA showed 100% specificity in the control group. There were no disagreements among observers.
CTA had a high diagnostic accuracy and reproducibility to confirm brain death in patients with an intact skull. The modified Frampas criteria increased the sensitivity of CTA, particularly in patients with a skull defect. A concurrent skull defect, especially craniectomy, can decrease the sensitivity of CTA to confirm brain death.
颅骨缺损（如颅骨切除术或颅骨切开术）引起的颅内压改变可能会改变血液动力学，降低 CTA 确认脑死亡的准确性。本研究旨在评估颅骨缺损和图像解释标准对该诊断测试的影响。
一系列临床诊断为脑死亡的连续患者接受 CTA（病例组），而同期急性缺血性卒中患者为对照组。采用 CTA 确认脑死亡的标准为 M4 分支和脑内静脉不显影。评估还包括“停滞充盈”的存在。病例分为颅骨完整、开颅术和颅骨切除术。三位神经放射科医生独立评估所有检查。
在病例组中，根据 Frampas 标准，颅骨完整患者 CTA 确认脑死亡的敏感性为 95.5%，开颅术患者为 87.5%，颅骨切除术患者为 60%。15.6%的脑死亡诊断为假阴性，与 71.4%的停滞充盈有关（<0.001）。然而，根据“改良 Frampas 标准”，颅骨完整患者 CTA 确认脑死亡的敏感性为 100%，开颅术患者为 93.8%，颅骨切除术患者为 80%。6.2%的患者出现脑死亡假阴性诊断，且无停滞充盈。对照组 CTA 特异性为 100%。观察者之间无分歧。
在颅骨完整的患者中，CTA 具有很高的诊断准确性和可重复性，可确认脑死亡。改良 Frampas 标准提高了 CTA 的敏感性，尤其是在颅骨缺损的患者中。并发颅骨缺损，尤其是颅骨切除术，会降低 CTA 确认脑死亡的敏感性。
