Background In the diagnosis of brain death (BD), computed tomography angiography (CTA) results in some cases show intracranial filling, leading to diagnostic confusion. Because cerebral circulatory arrest commences at the capillary level, we hypothesized that computed tomography perfusion (CTP) would be a more sensitive approach than CTA; therefore, the aim of the study was to compare the sensitivities of CTP and CTA in the diagnosis of BD. Material and Methods Whole brain CTP was performed in patients in the intensive care unit diagnosed with BD and CTA was derived from CTP datasets. Cerebral blood flow (CBF) and volume (CBV) were calculated in all brain regions. The CTP findings were interpreted as being consistent with a diagnosis of BD (positive) when CBF and CBV in all regions of interest (ROIs) were below 10 ml/100 g/min and 1.0 ml/100 g, respectively. The CTA findings were interpreted using a 4-point grading system. Results A total of 50 patients were included in the study. The CTP results revealed CBF from 0.00 to 9.98 ml/100 g/min (mean, 1.98 ± 1.68 ml/100 g/min) and CBV from 0.00 to 0.99 ml/100 g (mean, 0.14 ± 0.12 ml/100 g) and were thus interpreted as positive in all 50 patients. In contrast, the CTA results suggested 7 negative cases,

IntroductionThe standardized diagnostic criteria for computed tomographic angiography (CTA) in diagnosis of brain death (BD) are not yet established. The aim of the study was to compare the sensitivity and interobserver agreement of the three previously used scales of CTA for the diagnosis of BD.MethodsEighty-two clinically brain-dead patients underwent CTA with a delay of 40 s after contrast injection. Catheter angiography was used as the reference standard. CTA results were assessed by two radiologists, and the diagnosis of BD was established according to 10-, 7-, and 4-point scales.ResultsCatheter angiography confirmed the diagnosis of BD in all cases. Opacification of certain cerebral vessels as indicator of BD was highly sensitive: cortical segments of the middle cerebral artery (96.3 %), the internal cerebral vein (98.8 %), and the great cerebral vein (98.8 %). Other vessels were less sensitive: the pericallosal artery (74.4 %), cortical segments of the posterior cerebral artery (79.3 %), and the basilar artery (82.9 %). The sensitivities of the 10-, 7-, and 4-point scales were 67.1, 74.4, and 96.3 %, respectively (p < 0.001). Percentage interobserver agreement in diagnosis of BD reached 93 % for the 10-point scale, 89 % for the 7-point scale, and 95 % for the 4-point scale (p = 0.37).ConclusionsIn the application of CTA to the diagnosis of BD, reducing the assessment of vascular opacification scale from a 10- to a 4-point scale significantly increases the sensitivity and maintains high interobserver reliability.

IntroductionStasis filling, defined as delayed, weak, and persistent opacification of proximal segments of the cerebral arteries, is frequently found in brain dead patients. This phenomenon causes a major problem in the development of reliable computed tomographic angiography (CTA) protocol in the diagnosis of brain death (BD). The aim of our study was to characterize stasis filling in the diagnosis of BD. To achieve this, we performed a dynamic evaluation of contrast enhancement of the cerebral and extracranial arteries in patients with BD and controls.MethodsStudy population included 30 BD patients, who showed stasis filling in computed tomographic perfusion (CTP) series. Thirty patients, after clipping of an intracranial aneurysm, constituted the control group. The study protocol consisted of CTA, CTP, and angiography. Time–density curves (TDCs) of cerebral and extracranial arteries were generated using 40-s series of CTP.ResultsCerebral TDCs in BD patients represented flat curves in contrast to TDCs in controls, which formed steep and narrow Gaussian curves. We found longer time to peak enhancement in BD patients than in controls (32 vs. 21 s; p < 0.0001). In BD patients, peak enhancement in the cerebral arteries occurred with a median delay of 14.5 s to peak in extracranial arteries, while no delay was noted in controls (p < 0.0001). Cerebral arteries in BD patients showed lower peak enhancement than controls (34.5 vs. 81.5 HU; p < 0.0001). In all BD patients, CTP revealed zero values of cerebral blood flow and volume. Angiography showed stasis filling in 14 (46.7 %) and non-filling in 16 (53.3 %) cases.ConclusionA confrontation of stasis filling with CTP results showed that stasis filling is not consistent with preserved cerebral perfusion, thus does not preclude diagnosis of BD.

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SummaryBackgroundSplenic artery aneurysm and pseudoaneurysm are rare pathologies. True aneurysms are usually asymptomatic. Aneurysm rupture occurring in 2–3% of cases results in bleeding into the lesser sack, peritoneal space or adjacent organs typically presenting as abdominal pain and hemodynamic instability. In contrast, pseudoaneurysms are nearly always symptomatic carrying a high risk of rupture of 37–47% and mortality rate of 90% if untreated. Therefore, prompt diagnosis and treatment are essential in the management of patients with splenic artery pseudoaneurysm. Typical causes include pancreatitis and trauma. Rarely, the rupture of a pseudoaneurysm presents as upper gastrointestinal (UGI) bleeding. Among causes, peptic ulcer is the casuistic one.Case ReportThis report describes a very rare case of recurrent UGI bleeding from a splenic artery pseudoaneurysm caused by a penetrating gastric ulcer. After negative results of endoscopy and ultrasound, the diagnosis was established in CT angiography. The successful treatment consisted of surgical ligation of the bleeding vessel and suture of the ulcer with preservation of the spleen and pancreas, which is rarely tried in such situations.ConclusionsThe most important factor in identifying a ruptured splenic artery pseudoaneurysm as a source of GI bleeding is considering the diagnosis. UGI hemorrhage from splenic artery pseudoaneurysm can have a relapsing course providing false negative results of endoscopy and ultrasound if performed between episodes of active bleeding. In such cases, immediate CT angiography is useful in establishing diagnosis and in application of proper therapy before possible recurrence.