Aneurysmal 99m Tc-HMPAO Uptake in Brain Death.

ABSTRACT: A 41-year-old man was admitted to hospital due to sudden loss of consciousness. A regional brain perfusion SPECT/low-dose CT showed abnormal 99m Tc-HMPAO uptake in the right hemisphere frontotemporally without any other supratentorial or infratentorial radiotracer uptake. A neuropathological examination disclosed a middle cerebral artery aneurysm. Presumably, vessel wall fibrosis prevented collapse. Multiple transmural dissections of the fibrotic aneurysmal wall were the source of the subarachnoid hemorrhage. This interesting image shows that radiotracer accumulation in cerebral artery aneurysms can be a diagnostic pitfall in brain death scintigraphy assessment.

Self-harm, suicide and brain death: the role of the radiologist.

Suicide is a leading cause of death worldwide and takes many forms, which include hanging, jumping from a height, sharp force trauma, ingestion/poisoning, drowning, and firearm injuries. Self-harm and suicide are associated with particular injuries and patterns of injury. Many of these patterns are apparent on imaging. Self-harm or suicidal intent may be overlooked initially in such cases, particularly when the patient is unconscious or uncooperative. Correct identification of these findings by the radiologist will allow a patient's management to be tailored accordingly and may prevent future suicide attempts. The initial role of the radiologists in these cases is to identify life-threatening injuries that require urgent medical attention. The radiologist can add value by drawing attention to associated injuries, which may have been missed on initial clinical assessment. In many cases of self-harm and suicide, imaging is more reliable than clinical assessment. The radiologist may be able to provide important prognostic information that allows clinicians to manage expectations and plan appropriately. Furthermore, some imaging studies will provide essential forensic information. Unfortunately, many cases of attempted suicide will end in brain death. The radiologist may have a role in these cases in identifying evidence of hypoxic-ischaemic brain injury, confirming a diagnosis of brain death through judicious use of ancillary tests and, finally, in donor screening for organ transplantation. A review is presented to illustrate the imaging features of self-harm, suicide, and brain death, and to highlight the important role of the radiologist in these cases.

Transcranial Doppler and Color-Coded Doppler Use for Brain Death Determination in Adult Patients: A Pictorial Essay.

Transcranial Doppler (TCD) is a repeatable, at-the-bedside, helpful tool for confirming cerebral circulatory arrest (CCA). Despite its variable accuracy, TCD is increasingly used during brain death determination, and it is considered among the optional ancillary tests in several countries. Among its limitations, the need for skilled operators with appropriate knowledge of typical CCA patterns and the lack of adequate acoustic bone windows for intracranial arteries assessment are critical. The purpose of this review is to describe how to evaluate cerebral circulatory arrest in the intensive care unit with TCD and transcranial duplex color-coded doppler (TCCD).

Brain Death Confirmation by 18F-FDG PET/CT: A Case Series.

OBJECTIVES: Brain death is a state of irreversible loss of brain function in the cortex and brainstem. Diagnosis of brain death is established by clinical assessments of cranial nerves and apnea tests. Different conditions can mimic brain death. In addition, confirmatory tests may be falsely positive in some cases. In this study, we aimed to evaluate the role of positron emission tomography-computed tomography scan with 2-deoxy-2[18F]fluoro-D-glucose (18F-FDG-PET/CT) as an ancillary test in diagnosing brain death. MATERIALS AND METHODS: We analyzed 6 potential brain death donors for the confirmatory diagnosis of brain death using FDG-PET/CT. All 6 donors were brain dead by clinical criteria. All patients had electroencephalogram and brain computed tomography. Other than FDG-PET/CT, transcranial Doppler was performed in 1 patient, with other patients having no confirmatory ancillary imaging tests. Patients had nothing by mouth for 6 hours before imaging. Patients were supine in a semi-dark, noiseless, and odorless room with closed eyes. After 60 minutes of uptake,the brain PET/CT scan was performed with sequential time-of-flight-PET/CT (Discovery 690 PET/CT with 64 slices, GE Healthcare). The PET scan consisted of LYSO (Lu1.8Y0.2 SiO5) crystals with dimensions of 4.2 × 6.3 × 25 mm3. Three-dimension images were with scan duration of 10 minutes. RESULTS: The PET scan confirmed brain death in 5 of the 6 cases. However, we ruled out brain death using PET/CT in a 3-year-old child, although all clinical tests confirmed brain death. CONCLUSIONS: A PET scan illustrates a hollow skull phenomenon suggestive of brain death. It can be a powerful diagnostic tool to assess brain death.

The role of optic nerve sheath diameter measurement in the diagnosis of brain death.

OBJECTIVE: The aim of this study is to evaluate the correlation between optic nerve sheath diameter (ONSD) measured using computed tomography (CT), and ONSD measured using bedside ultrasonography (USG) in the diagnosis of brain death. PATIENTS AND METHODS: A total of 21 brain-dead patients were included in the study. The ONSD values of these patients were measured using both USG and CT before and after brain death, and the relationship between these measurements was evaluated. RESULTS: There was a high level of correlation between the right-left eye ONSD measurements conducted before brain death using USG and CT, respectively (p=0.000, p=0.001). There was a high level of correlation between the right-left eye ONSD measurements conducted after brain death using USG and CT, respectively (p=0.000, p=0.00). Pre-brain death ONSD mean values of both left and right eyes, measured using USG and CT, were found to be statistically significantly lower than the mean values of post-brain death measurements. CONCLUSIONS: In conclusion, a statistically significant difference was found between the optic nerve sheath diameter values measured before and after brain death using USG and CT. At the same time, it was determined that the values of the optic nerve sheath diameter measured using both CT and USG were correlated.

Ancillary radionuclide perfusion studies in the determination of death by neurologic criteria: methods, interpretation, and lexicon-a user guide for the clinician.

Radionuclide perfusion studies have an established ancillary role in determination of death by neurologic criteria (DNC). While critically important, these examinations are not well understood by individuals outside of the imaging specialties. The purpose of this review is to clarify relevant concepts and nomenclature and provide a lexicon of relevant terminology of value to non-nuclear medicine practitioners who wish to better understand these examinations. Radionuclides were first employed to evaluate cerebral blood flow in 1969. Radionuclide DNC examinations that use lipophobic radiopharmaceuticals (RPs) entail a flow phase followed immediately by blood pool images. On flow imaging, presence of intracranial activity within the arterial vasculature is scrutinized following arrival of the RP bolus into the neck. Lipophilic RPs designed for functional brain imaging were introduced to nuclear medicine in the 1980s and were engineered to cross the blood-brain-barrier and be retained in the parenchyma. The lipophilic RP 99mTc-hexamethylpropyleneamine oxime (99mTc-HMPAO) was first used as an ancillary investigation in DNC in 1986. Examinations using lipophilic RPs entail both flow and parenchymal phase images. According to some guidelines, parenchymal phase uptake should be assessed by tomographic imaging, while other investigators consider simple planar imaging sufficient. Findings of perfusion on either the flow or parenchymal phase of the examination effectively precludes DNC. If the flow phase is omitted or somehow compromised, the parenchymal phase remains sufficient for DNC. A priori, parenchymal phase imaging is superior to flow phase imaging for several reasons and lipophilic RPs are favoured over lipophobic RPs in that both flow and parenchymal phase imaging are performed. Disadvantages of lipophilic RPs are increased cost and the need to procure them from a central laboratory, which can prove difficult, especially outside usual working hours. According to most current guidelines, both lipophilic and lipophobic RP categories are acceptable for use in ancillary investigations in DNC, with a growing overt preference for studies using the lipophilic RPs based on their ability to capture the parenchymal phase. The new adult and pediatric Canadian recommendations favour use of lipophilic RPs to variable degrees, specifically 99mTc-HMPAO, the lipophilic moiety which has undergone the greatest validation. Although ancillary use of radiopharmaceuticals is quite settled in multiple DNC guidelines and best practices, several areas of further research remain open to investigation. Examens auxiliaires de perfusion nucléaire pour la détermination du décès selon des critères neurologiques : méthodes, interprétation et lexique-un guide de l'utilisateur à l'intention du clinicien.

RéSUMé: Les examens de la perfusion nucléaire jouent un rôle auxiliaire bien établi dans la détermination du décès selon des critères neurologiques (DCN). Bien qu'ils soient d'une importance cruciale, ces examens ne sont pas bien compris par les personnes en dehors des spécialités d'imagerie. Le but de cette revue est de clarifier les concepts et la nomenclature pertinents et de fournir un lexique de terminologie pertinente utile aux praticiens non spécialisés en médecine nucléaire qui souhaitent mieux comprendre ces examens. Les radionucléides ont été utilisés pour la première fois pour évaluer la circulation sanguine cérébrale en 1969. Les examens de DCN par radionucléides qui utilisent des produits radiopharmaceutiques (RP) lipophobes impliquent une phase de circulation suivie immédiatement d'images de pool sanguin. Sur l'imagerie en circulation, la présence d'une activité intracrânienne dans le système vasculaire artériel est examinée après l'arrivée du bolus de RP dans le cou. Les RP lipophiles conçus pour l'imagerie cérébrale fonctionnelle ont été introduits en médecine nucléaire dans les années 1980 et ont été conçus pour franchir la barrière hémato-encéphalique et être retenus dans le parenchyme. Le RP lipophile 99mTc-hexaméthylpropylèneamine-oxime (99mTc-HMPAO) a été utilisé pour la première fois comme examen auxiliaire pour le DCN en 1986. Les examens utilisant des RP lipophiles impliquent à la fois des images de circulation et de phase parenchymateuse. Selon certaines lignes directrices, l'absorption durant la phase parenchymateuse devrait être évaluée par imagerie tomographique, tandis que d'autres chercheurs considèrent qu'une imagerie planaire simple suffit. Les résultats de perfusion sur la phase de circulation ou la phase parenchymateuse de l'examen excluent effectivement un DCN. Si la phase de circulation est omise ou compromise d'une manière ou d'une autre, la phase parenchymateuse reste suffisante pour établir un DCN. A priori, l'imagerie en phase parenchymateuse est supérieure à l'imagerie en phase de circulation pour plusieurs raisons et les RP lipophiles sont privilégiés par rapport aux RP lipophobes parce que l'imagerie en circulation et en phase parenchymateuse sont toutes deux réalisées. Les inconvénients des RP lipophiles sont l'augmentation des coûts et la nécessité de les obtenir auprès d'un laboratoire central, ce qui peut s'avérer difficile, surtout en dehors des heures de travail habituelles. Selon la plupart des lignes directrices actuelles, les catégories de RP lipophiles et lipophobes sont toutes deux acceptables pour une utilisation dans les examens auxiliaires pour un DCN, avec une préférence manifeste croissante pour les études utilisant les RP lipophiles en fonction de leur capacité à capturer la phase parenchymateuse. Les nouvelles recommandations canadiennes pour adultes et enfants privilégient l'utilisation de RP lipophiles à des degrés variables, en particulier le 99mTc-HMPAO, le fragment lipophile qui a subi la plus grande validation. Bien que l'utilisation auxiliaire des produits radiopharmaceutiques soit tout à fait établie dans de multiples lignes directrices et meilleures pratiques de DCN, plusieurs domaines de recherche supplémentaires restent ouverts à l'étude.

Ultrasound Scanning in Lung Procurement. Protocol for Decision-Making With the Purpose of Increasing Transplant Eligible Lungs.

BACKGROUND: The main obstacle to obtaining lungs for transplantation is the shortage of donors. Once potential donors have been offered to transplant programs, the acceptance rate is highly variable, ranging from 5% to 20%. Minimizing donor leakage by converting potential lung donors into real donors is one of the key elements to improve results, and it is essential to have tools that facilitate decision-making in this scenario. The selection and rejection of transplantation-eligible lungs are usually made with chest x-rays; however, lung ultrasound scanning has shown better sensitivity and specificity for diagnosing pulmonary pathologies. Lung ultrasound scanning allows us to identify the reversible causes of low PaO2/fraction of inspired oxygen (FIO2) ratio, thus enabling the establishment of specific interventions, which, if proved successful, could turn lungs into transplant-eligible lungs. The available literature on its use in managing brain death donors and lung procurement is extremely scarce. METHODS: A simple protocol aimed at identifying and treating the main reversible causes of low PaO2/FIO2 ratio to aid in decision-making is presented in this paper. CONCLUSION: Lung ultrasound is a powerful, useful, and cheap technique available at the donor's bedside. It is conspicuously underused, despite being potentially helpful in decision-making by minimizing the discarding of donors, thus probably increasing the number of lungs sui for transplantation.

The use of cerebral computed tomographic angiography as an ancillary investigation to support a clinical diagnosis of death using neurological criteria: a consensus guideline.

This multidisciplinary consensus statement was produced following a recommendation by the Faculty of Intensive Care Medicine to develop a UK guideline for ancillary investigation, when one is required, to support the diagnosis of death using neurological criteria. A multidisciplinary panel reviewed the literature and UK practice in the diagnosis of death using neurological criteria and recommended cerebral CT angiography as the ancillary investigation of choice when death cannot be confirmed by clinical criteria alone. Cerebral CT angiography has been shown to have 100% specificity in supporting a diagnosis of death using neurological criteria and is an investigation available in all acute hospitals in the UK. A standardised technique for performing the investigation is described alongside a reporting template. The panel were unable to make recommendations for ancillary testing in children or patients receiving extracorporeal membrane oxygenation.

Use of duplex echoencephalography to evaluate brain death in children: A novel approach to the diagnosis.

BACKGROUND AND PURPOSE: Brain death is defined as the irreversible cessation of brain function with a known etiology. This study aims to establish the value of duplex echoencephalography (DEG) in children fulfilling clinical brain death diagnostic criteria. METHODS: DEG must show intracranial brain structures. Power Doppler is used to assess venous flow when feasible. Color Doppler patterns in all major arteries are assessed. Spectral analysis of arterial flow is divided into four grades: grade 1: inverted flow during entire diastole with time average peak velocity (TAPV) less or equal to zero; grade 2: disappearance of the inverted diastolic flow at the end of diastole; grade 3: oscillating pattern in early diastole; and grade 4: no diastolic flow with systolic blip. To fulfill diagnosis of brain death, brain perfusion must be lost for 30 minutes. RESULTS: DEG is performed in 41 pediatric patients. In infants, loss of venous flow occurs regardless of the etiology. Grade 1 is the most common arterial color flow pattern and TAPV is always below zero. A pulsatile color flow is associated with three other types of flow patterns (grades 2-4). TAPV is not calculated, when there is loss of diastolic flow. Diagnosis of brain death is validated using nuclear brain scan in 4 patients. Two have a grade 1 flow pattern, while the other two have a grade 4 flow pattern. CONCLUSIONS: In children, DEG following a strict protocol can be used to confirm diagnosis of brain death in the appropriate clinical setting.

Brain death in children: is computed tomography angiography reliable as an ancillary test?

BACKGROUND: The diagnosis of brain death is primarily clinical. Sometimes ancillary tests are needed. OBJECTIVE: This study compared sensitivity and interobserver agreement of the 10-, 7- and 4-point CT angiography scoring systems for the diagnosis of brain death in children. MATERIALS AND METHODS: CT angiography examinations of 50 pediatric patients with a clinical diagnosis of brain death were evaluated according to 10-, 7- and 4-point scoring systems. Images were evaluated by two radiologists who considered the vessel opacification first in the arterial phase (A0-V50) and then in the venous phase (A0-V50). We evaluated interobserver agreement for the assessment of vessel opacification and diagnosis of brain death. We compared the differences among brain death diagnoses between children with craniotomy-craniectomy defects, open fontanelles and preserved bone integrity. We subdivided children into two groups according to age: ≤ 2 years and > 2 years. We calculated sensitivities according to age groups. RESULTS: Using the clinical exam as the reference standard, we found sensitivities for 10-, 7- and 4-point scoring systems to be 70%, 88% and 92% in the A0-V50 method and 40%, 82% and 82% in the A50-V50 method, respectively. Percentage agreement between readers was 78% for the 7-point scale using the A0-V50 method and more than 90% for other scoring systems for both the A0-V50 method and the A50-V50 method. The sensitivity was much lower in children with open anterior fontanelles compared to the groups with preserved bone integrity and with a craniotomy-craniectomy defect. CONCLUSION: Just as in adult age groups, in children the 4-point scale appears to be more sensitive than the 10- and 7-point scales for CT angiography-based assessment of brain death. Because the scoring systems have similar sensitivities, they could be used as ancillary tests in pediatric cases.

Cerebral circulatory arrest diagnosed with transoral Doppler ultrasonography.

We describe the case of a patient with malignant stroke in whom brain death was diagnosed by evaluating the neck vessels by transoral ultrasonography.

Comparison of early- and late-phase CT angiography findings in brain death.

BACKGROUND: Late-phase images on computed tomography angiography (CTA), traditionally used for assessing cerebral circulatory arrest in brain death, suffer from suboptimal diagnostic yield due to stasis filling. Herein, we assessed contrast filling in individual intracranial arteries and veins in the early and late phases of CTA in patients with clinically confirmed brain death. METHODS: Contrast opacification within 28 arterial/venous segments was evaluated in both phases of CTA in 79 patients. This information was combined with reports in the literature to calculate prevalence of contrast filling in different intracranial vessels. Additionally, diagnostic sensitivity of 4-point, 7-point, and 10-point scores defined for brain death were compared among ratings based on early, late, and both phases (arteries rated on early, veins rated on late phase) of imaging. RESULTS: The median (IQR) number of vessel segments with contrast opacification was 0 (0-2) in early phase and 6 (0-10) in late phase. All segments showed increased prevalence of opacification when evaluated in late phase (p < 0.05). The M4 segments of MCA, internal cerebral veins, and vein of Galen had the lowest percentage of opacification in both phases. The sensitivity of 4-, 7-, and 10-point scoring algorithms increased from 59-91% to 94-99% when ratings were performed using early-phase images rather than based solely on late-phase images. CONCLUSIONS: The incorporation of early-phase images might be considered as a strategy to improve the sensitivity of CTA as an ancillary test in confirming brain death, especially in patients without missing or questionable elements in clinical examination.

Loss of cerebral blood flow and cerebral perfusion pressure in brain death: A transcranial Duplex ultrasonography study.

PURPOSE: We investigated cerebral perfusion pressure (CPP) at the time loss of cerebral blood flow (CBF) occurred during brain death (BD). We hypothesized that a critical closing pressure (CrCP) may be reached before CPP drops to 0 mmHg. MATERIALS AND METHODS: 14 patients with increasing intracranial pressure (ICP) leading to BD were included. Transcranial Duplex (TCD) ultrasonography was used to investigate CBF. Starting at a CPP of 30 mmHg, TCD was repeated until waveforms indicated loss of CBF. We then analyzed CPP by the time TCD indicated absent CBF and clinical BD was established. RESULTS: In 12 patients, CPP was positive when clinical BD was manifest and TCD illustrated absent CBF. Across all patients, mean CPP at clinical BD manifestation was 10.0 mmHg (range 0-20 mmHg); mean CPP by the time CBF stopped was 7.5 mmHg (0-20 mmHg). In four patients, clinical BD preceded loss of CBF. Here, the mean CPP difference from clinical BD to loss of CBF was 8.8 mmHg (5-15 mmHg). CONCLUSIONS: CrCP may be reached although CPP is still positive, resulting in complete loss of CBF and BD. By including bedside TCD, neuromonitoring may contribute to early identification of patients at risk to experience loss of CBF and subsequent BD.

Cerebral blood vessels and perfusion in the pediatric brain death: five cases studied by neuroimaging.

PURPOSE: To detect the cerebral blood vessels and perfusion using neuroimaging modalities including computed tomography angiography (CTA), computed tomography perfusion (CTP), and arterial spin labeling (ASL) in children with brain death (BD). METHODS: According to the current children's BD criteria, 5 children (3 males, 2 females, mean age of 5.65 years) with BD were enrolled from January 2019 to December 2020. The imaging features of CTA, CTP, and ASL were evaluated to analyze the visualization of important intracranial blood vessels and the states of the cerebral blood flow (CBF) and cerebral blood volume (CBV) related to the region of interest (ROI) brain tissue during the two clinical assessments for BD. RESULTS: The "4-point scale" scoring system of CTA was applied to evaluate BD and no negative results were detected. The CTP results of the 5 children suggested the cessation of cerebral circulation with 100% positive results. The ranges of CBF and CBV were 0.00-9.52 ml/100 g/min (mean value 4.95 ± 1.69 ml/100 g/min) and 0.00-1.34 ml/100 g (mean value 0.36 ± 0.20 ml/100 g), respectively. One patient also underwent ASL examination, which demonstrated a significant reduction in whole brain perfusion, indicating the absence of cerebral circulation. The CBF values of the brainstem, basal ganglia, and prefrontal lobe were 11.61 ± 1.49 ml/100 g/min, 7.81 ± 2.42 ml/100 g/min, and 9.94 ± 2.01 ml/100 g/min, respectively. CONCLUSION: Neuroimaging examinations particularly CTA and CTP reveal well the hemodynamic and cerebral blood vessels changes of BD, which can be used as supplementary supportive evidence for the declaration of brain death in children.

Factores clínico-radiológicos asociados con muerte encefálica precoz / Clinico-radiological related to early brain death factors

Objective: To identify clinical and radiological factors associated to early evolution to brain death (BD), defined as occurring within the first 24 h. Design A retrospective cohort study was made covering the period 2015−2017. Setting An adult Intensive Care Unit (ICU).Patients/methodsEpidemiological, clinical and imaging (CT scan) parameters upon admission to the ICU in patients evolving to BD. Results A total of 166 patients with BD (86 males, mean age 62.7 years) were analyzed. Primary cause: intracerebral hemorrhage 42.8%, subarachnoid hemorrhage 18.7%, traumatic brain injury 17.5%, anoxia 9%, stroke 7.8%, other causes 4.2%. Epidemiological data: arterial hypertension 50%, dyslipidemia 34%, smoking 33%, antiplatelet medication 21%, alcoholism 19%, anticoagulant therapy 15%, diabetes 15%. The Glasgow Coma Score (GCS) upon admission was 3 in 68.8% of the cases in early BD versus in 38.2% of the cases in BD occurring after 24 h (p = 0.0001). Eighty-five patients presented supratentorial hematomas with a volume of 90.9 ml in early BD versus 82.7 ml in BD > 24 h (p = 0.54). The mean midline shift was 10.7 mm in early BD versus 7.8 mm in BD > 24 h (p = 0.045). Ninety-one patients presented ventriculomegaly and 38 additionally ependymal transudation (p = 0.021). Thirty-six patients with early BD versus 24 with BD > 24 h presented complete effacement of basal cisterns (p = 0.005), sulcular effacement (p = 0.013), loss of cortico-subcortical differentiation (p = 0.0001) and effacement of the suprasellar cistern (p = 0.005). The optic nerve sheath measurements showed no significant differences between groups.ConclusionsEarly BD (>24 h) was associated to GCS < 5, midline shift, effacement of the basal cisterns, cerebral sulci and suprasellar cistern, and ependymal transudation (AU)

Objetivo: Identificar los factores clínico-radiológicos que se asocian a evolución precoz a muerte encefálica (ME), definida esta como la ocurrida en ≤24 horas Diseño Estudio de cohortes retrospectivo desde 2015 hasta 2017, ambos incluidos. Ámbito Servicio de Medicina Intensiva (SMI) de adultos.Pacientes y métodoAnálisis de variables clínico-epidemiológicas y de la TC craneal de ingreso en pacientes con evolución a ME. Resultados Se analizaron 166 ME, 86 varones, edad media 62,7 años, 42,8% hemorragia intracerebral, 18,7% HSA, 17,5% TCE, 7,8% ictus isquémico, 9% anoxia y 4,2% otras causas; 50% HTA, 34% dislipemia, 33% tabaquismo, 21% antiagregación, 19% enolismo. El 15% anticoagulación, 15% diabetes. El GCS fue tres en el 68,8% en ME precoz frente 38,2% en ME >24 h (p 0,0001); 85 hematoma supratentorial (90,9 mL en ME precoz vs. 82,7 mL ME tardía, p 0,54); 12 hematoma infratentorial. Desplazamiento medio de línea media 10,7 mm en ME precoz vs. 7,8 mm en ME tardía (p 0,045); 91 pacientes ventriculomegalia y 38 trasudado periependimario (p 0,021). Borramiento completo de cisternas basales 36 en ME precoz frente a 24 en ME tardía (p 0,005), borramiento de surcos (p 0,013), pérdida de diferenciación córtico-subcortical (p 0,0001) y ausencia de cisterna supraselar (p 0,005). La medición de la vaina del nervio óptico no mostró diferencias significativas entre los dos grupos.ConclusionesSe asoció con ME ≤ 24 horas el GCS < 5, el desplazamiento de línea media, la pérdida de diferenciación córtico-subcortical, el borramiento de surcos, el borramiento completo de cisternas basales, de la cisterna supraselar y la presencia de trasudado periependimario (AU)

Invitation to participate in a multi-center study for validation of cerebral computed tomography angiography and computed tomography perfusion in the determination of cerebral circulatory arrest during brain death/death by neurological criteria diagnosis procedure in paediatric population below 12 years of age.

We would like to invite paediatric intensive care units (PICU) to join our multi-center trial concerning patient population < 12 y/o and aiming at: • validation of computed tomography angiography (CTA)/computed tomography perfusion (CTP) tests for brain death/death by neurological criteria (BD/DNC) diagnosis procedures, • validation of duplex Doppler insonation of extracranial segments of the internal cerebral arteries and the vertebral arteries for choosing an optimal time for CTA/CTP testing.

Real-Time Tissue Elastography to Evaluate Hepatic Hypoxic-Ischemic Injury Caused by Brain Death.

ABSTRACT: This study aimed to explore the potential of real-time tissue elastography (RTE) in evaluating hepatic hypoxic-ischemic injury caused by brain death. We performed RTE and biopsy for 50 donated liver. Hematoxylin-eosin staining was used to observe hepatocyte acidophilic change. Liver grafts were divided into 2 groups, one nonacidophilic change (n = 7) and the other with acidophilic change (n = 43). Correlation and difference analysis were performed for hematoxylin-eosin staining results and RTE parameters. The result indicated that 4 of the 11 RTE parameters, namely, the area of low strain within the region of interest (%AREA), contrast (CONT), inverse difference moment (IDM), and correlation (CORR) were related to hepatocytes acidophilic change (r = 0.284, P = 0.046; r = 0.349, P = 0.013; r = -0.444, P = 0.001; r = -0.381, P = 0.00). Whereas %AREA and CONT of the nonacidophilic change group were lower than that of the acidophilic change group (P < 0.05), IDM and CORR in nonacidophilic change group were higher than that of the acidophilic change group (P < 0.05); the remaining parameters were not statistically different between 2 groups (P > 0.05). Analysis of receiver operating characteristic curve indicated that the area under the curve of %AREA, CONT, IDM, and CORR were 0.75, 0.79, 0.81, and 0.77, respectively. Based on this, we concluded that the quantitative analysis parameters of RTE could preliminary assess hepatic hypoxic-ischemic injury caused by brain death.

Transcranial Doppler: A Useful Tool to Predict Brain Death Still Not Confirmed by Clinical Assessment.

BACKGROUND: Diagnosing brain death (BD) with accuracy and urgency is of great importance because an early diagnosis may guide the clinical management, optimize hospital beds, and facilitate organ transplantation. The clinical diagnosis of nonreactive and irreversible coma can be confirmed with additional tests. Among the complimentary exams that may testify brain circulatory arrest, transcranial Doppler (TCD) can be an option. It is a real-time, bedside, inexpensive, noninvasive method that assesses cerebral blood flow. In patients with suspected BD, especially those who are under sedative drugs, early diagnosis is imperative. The aim of the present study was to evaluate the role of TCD in predicting BD. METHODS: One hundred consecutive comatose patients with a Glasgow Coma Scale score of less than 5, owing to different etiologies, were included. TCD was performed in all patients. The TCD operator was blinded for clinical and neurologic data. This study is in compliance with the Declaration of Helsinki. RESULTS: Sixty-nine patients with TCD-brain circulatory collapse were diagnosed later with BD. Of the 31 patients with brain circulatory activity, 8 (25.8%) were clinically brain dead and 23 (74.2%) were alive. TCD showing brain circulatory collapse had a sensitivity of 89.6%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 74.2%. CONCLUSION: TCD is highly specific (100%) and sensitive (89.6%) as a method to confirm the clinical diagnosis of BD, even in patients under sedation. The possibility of patients presenting with cerebral circulatory activity and clinical diagnosis of BD was demonstrated to occur.