OBJECTIVEThe present study was designed to answer several concerns disclosed by systematic reviews indicating no evidence to support the use of computed tomography angiography (CTA) in the diagnosis of brain death (BD). Therefore, the aim of this study was to assess the effectiveness of CTA for the diagnosis of BD and to define the optimal tomographic criteria of intracranial circulatory arrest.METHODSA unicenter, prospective, observational case-control study was undertaken. Comatose patients (Glasgow Coma Scale score ≤ 5), even those presenting with the first signs of BD, were included. CTA scanning of arterial and venous vasculature and transcranial Doppler (TCD) were performed. A neurological determination of BD and consequently determination of case (BD group) or control (no-BD group) was conducted. All personnel involved with assessing patients were blinded to further tests results. Accuracy of BD diagnosis determined by using CTA was calculated based on the criteria of bilateral absence of visualization of the internal cerebral veins and the distal middle cerebral arteries, the 4-point score (4PS), and an exclusive criterion of absence of deep brain venous drainage as indicated by the absence of deep venous opacification on CTA, the venous score (VS), which considers only the internal cerebral veins bilaterally.RESULTSA total of 106 patients were enrolled in this study; 52 patients did not have BD, and none of these patients had circulatory arrest observed by CTA or TCD (100% specificity). Of the 54 patients with a clinical diagnosis of BD, 33 met the 4PS (61.1% sensitivity), whereas 47 met the VS (87% sensitivity). The accuracy of CTA was time related, with greater accuracy when scanning was performed less than 12 hours prior to the neurological assessment, reaching 95.5% sensitivity with the VS.CONCLUSIONSCTA can reliably support a diagnosis of BD. The criterion of the absence of deep venous opacification, which can be assessed by use of the VS criteria investigated in this study, can confirm the occurrence of cerebral circulatory arrest.Clinical trial registration no.: 12500913400000068 (clinicaltrials.gov)

BACKGROUND AND PURPOSE: 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. MATERIALS AND METHODS: 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. RESULTS: 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% (P Ͻ .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. CONCLUSIONS: 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. ABBREVIATIONS: BD ϭ brain death; ICM ϭ iodinated contrast medium; ICV ϭ internal cerebral vein; SD ϭ skull defect; SF ϭ stasis filling

No abstract

Pitfalls in vascular imaging when brain death is suspected: multiparametric multidetector computed tomography as a complementary diagnostic tool Armadilhas em imagem vascular na suspeita de morte encefálica: tomografia computadorizada multidetectores como uma ferramenta diagnóstica complementar

No abstract