Effectiveness of different vaccine platforms in reducing mortality and length of ICU stay in severe and critical cases of COVID-19 in the Omicron variant era: A national cohort study in Iran.

Various severe acute respiratory syndrome coronavirus 2 vaccines with different platforms have been administered worldwide; however, their effectiveness in critical cases of COVID-19 has remained a concern. In this national cohort study, 24 016 intensive care unit (ICU) coronavirus disease-2019 (COVID-19) admissions were included from January to April 2022. The mortality and length of ICU stay were compared between the vaccinated and unvaccinated patients. A total of 9428 (39.25%) patients were unvaccinated, and 14 588 (60.75%) patients had received at least one dose of the vaccine. Compared with the unvaccinated, the first, second, and third doses of vaccine resulted in 8%, 20%, and 33% lower risk of ICU mortality in the adjusted model, with risk ratio (RR): 0.92, 95% confidence interval (CI): 0.84-1.001, RR: 0.80, 95% CI: 0.77-0.83, and RR: 0.67, 95% CI: 0.64-0.71, respectively. The mean survival time was significantly shorter in the unvaccinated versus the fully vaccinated patients (hazard ratio [HR]: 0.84, 95% CI: 0.80-0.88); p < 0.001). All vaccine platforms successfully decreased the hazard of ICU death compared with the unvaccinated group. The duration of ICU stay was significantly shorter in the fully vaccinated than in unvaccinated group (MD, -0.62, 95% CI: -0.82 to -0.42; p < 0.001). Since COVID-19 vaccination in all doses and platforms has been able to reduce the risk of mortality and length of ICU-stay, universal vaccination is recommended based on vaccine availability.

Application of iPSCs derived pancreatic ß-like cells using pancreatic bio-scaffold.

This study aimed toengineer a pancreatic tissue. Intact rat pancreases were successfully decellularized, and were reseeded with human-induced pluripotent stem cells using different 2D and 3D culture growth factors. The differentiation process was assessed for the presence of a pancreas-like tissue. The histology and SEM analysis revealed cell attachment in all samples, except for the Exp4, and the Flow-cytometry provided 87% viability for the differentiated cells. In Exp1, PDX1 with the positive expression of 2.87±0.06 was dramatically higher than Exp2 with a 2.44±0.06 reaction. NGN3-reactions were 8±0.1 and 6.6±0.2 in Exp1 and Exp2 at P < 0.05, respectively. C-peptide with the expression of 7.5±0.7 in Exp3 was almost equal to that in Exp1 and Exp2. Glucagon (5.1±1) and PDX1 (3.2±0.82) in Exp3 indicated no significant difference. The significant upregulations of pancreatic endocrine markers (PDX1 and NGN3), and the cell-specific glucose transporter (GLUT2) were observed in the differentiated IPCs in the 3D culture of Exp2 after 21 days. The highest insulin and C-peptide concentrations were observed in Exp2. In Exp3, insulin secretion in response to high glucose and 10 mM arginine was 42.43 ±6.34 µU/ml. A decellularized pancreas in the presence of hiPSCs and growth factors could be efficiently used as a natural scaffold.

Whole-organ decellularization of the human uterus and in vivo application of the bio-scaffolds in animal models.

PURPOSE: The aim of this investigation was to design a perfusion-based decellularization protocol to provide whole human uterine bio-scaffolds with preserved structural and componential characteristics and to investigate the in vivo properties of the decellularized tissues. METHODS: Eight human uteri, donated by brain-dead patients, were decellularized by perfusion of sodium dodecyl sulfate (SDS) through the uterine arteries using a peristaltic pump. The bio-scaffolds were evaluated and compared with native human uterus regarding histological, immunohistochemical, structural, and bio-mechanical properties, in addition to CT angiographies to examine the preservation of the vascular networks. Subsequently, we obtained acellular patches and implanted them on uterine defects of female Wistar rats to investigate the bio-compatibility and regenerative potential of the bio-scaffolds. Finally, we performed immunostaining to investigate the potential role of circulating stem cells in recellularization of the implanted bio-scaffolds. RESULTS: The outcomes of this investigation confirmed the efficacy of the proposed protocol to provide whole human uterine scaffolds with characteristics and extra-cellular matrix components similar to the native human uterus. Subsequent in vivo studies demonstrated the bio-compatibility and the regenerative potential of the scaffolds and suggested a signaling pathway as an underlying mechanism for the regenerative process. CONCLUSIONS: To the best of our knowledge, this investigation provides the first efficient perfusion-based decellularization protocol for the human uterus to obtain whole-organ scaffolds. The outcomes of this investigation could be employed in future human uterus tissue engineering studies which could ultimately result in the development of novel treatments for female infertile patients.

Detection of the residual concentration of sodium dodecyl sulfate in the decellularized whole rabbit kidney extracellular matrix.

To optimize rabbit kidney decellularization protocol, using sodium dodecyl sulfate (SDS) as a commonly used detergent, a methylene blue based assay was employed for detecting the minimum nontoxic SDS level for future cell seeding. The rabbit kidney tissues were decellularized with the perfusion-based method and underwent several investigations to determine the efficacy of decellularization in preserving the extracellular matrix (ECM) and cell removal. SDS detection was performed by incubating with methylene blue and subsequent extraction with chloroform. MTT (3-(4, 5-dimethylthiazol-2-yr)-2,5-diphenyltetrazolium bromide) assay and SDS release were also evaluated during the entire process. After the first washing cycle, SDS concentration was 0.036, in 500 mL of the washing liquid, which slowly decreased and reached to 0.009 % after at the end of seventh washing cycle. In the 9th cycle, SDS was gradually decreased and reached to 0.003 %. SDS was significantly released after one week of incubation which ceased after ten washing cycles. The results of MTT assay demonstrated that different cells exhibited various sensitivity levels when exposed to serial concentrations of SDS. Human embryonic kidney cells (HEK293) with 0.003 % threshold for cellular toxicity and 87.4 % cell viability were more resistant compared with mesenchymal stem cells with 0.001 % threshold and 85.4 % cell viability. Colorimetric assay with methylene blue is a straightforward and non-invasive method to detect residual SDS present in tissue and can also prevent ECM destruction after several washings for detergent removal from decellularized tissues.

Early description of amniotomy in medieval Persia.

AIM: Artificial rupture of the amniotic membranes during the labor, which is called amniotomy, is a common procedure in modern obstetric and midwifery protocols. There is no definite agreement regarding the timing of amniotomy in a delayed labor. In this study, we have discussed the history of amniotomy in medieval Persia mentioning the Persian medicine recommendations in this regard. METHODS: We studied main Persian medicine textbooks such as Canon of Medicine by Avicenna to investigate the history of labor management and amniotomy indications. In addition, amniotomy in current literature was studied using PubMed and Google Scholar databases. RESULTS: Persian medicine has recommended artificial rupture of membranes for labor augmentation based on its own theories. Methods for facilitation of the labor have been divided into two groups: one group before and the other during the labor. Avicenna has carefully explained the indication of amniotomy. He has recommended artificial rupture of membranes in cases of intact membranes with cervical dilatation and fetal descent. A needle or a kind of surgical knife called Mabzaa had been introduced for this procedure. CONCLUSIONS: It seems that Iranian physicians are the first scholars who have introduced the amniotomy for labor management in the 11th century. Persian medicine recommendations for labor facilitation should be considered in future studies.

Seroprevalence of anti-hepatitis E antibodies and antigens among HIV-infected patients in Fars Province, southern Iran.

OBJECTIVE: HIV-infected patients have immunological and clinical features that might affect the pathogenesis, as well as the outcome of the HIV/HEV co-infection. The current study aimed to determine the seroprevalence of anti-HEV antibodies and HEV antigens among HIV-infected patients in Fars Province, Southwest Iran. METHODS: Blood samples (5 mL) were collected from 251 HIV-confirmed patients. Respective data, including patients' demographic information, were obtained for each patient. The presence of HEV antigens and anti-HEV antibodies (IgG) were assessed by commercial ELISA kits, based on the manufacturers' instructions. RESULTS: Out of 251 cases, 158 (62.9%) were male and 91 (36.3%) were female. Patients' age varied from 14 to 83 (mean: 40 ± 9.7) years. Out of 251 HIV positive cases, 26 (10.4%) were positive for anti-HEV IgG antibodies and 6 (2.4%) were positive for HEV-antigens. Also, 2 (0.8%) of the patients were positive for both anti-HEV IgG antibodies and antigens. Statistical analysis revealed no significant association between sex and seropositivity to either HEV antigen or antibodies. Moreover, no significant association was seen between age and seropositivity to HEV antigen or antibody (P = 0.622 and 0.945, respectively). CONCLUSION: Our results showed a relatively low prevalence of HEV-antibodies in HIV-infected patients, indicating that HIV positive patients may not be at greater risk of HEV infection than the general population. Moreover, HEV-antigen was detected in a few cases of HIV-infected individuals which indicate an acute or chronic HEV infection in these patients.

Correction to: Development of an efficient perfusion-based protocol for whole-organ decellularization of the ovine uterus as a human-sized model and in vivo application of the bioscaffolds.

This article was unintentionally published twice in this journal, by the same authors. Following should be considered the version of record and used for citation purposes.

Diagnostic performance of Echinococcus granulosus protoscolices antigens in the serodiagnosis of human cystic echinococcosis.

The development of suitable serological tests for the diagnosis of CE is still necessary. This study aimed to evaluate the efficacy of ELISA in the diagnosis of human cystic echinococcosis (CE), using parasite protoscolices antigens. Liver hydatid cysts were isolated from sheep infected with hydatid cysts and the protoscolices were isolated from the hydatid cyst fluid. Protoscolices crude antigen was prepared by mechanical disruption, plus freeze-thawing and sonication methods. Thirty sera samples of confirmed hydatid cyst patients, 30 samples of healthy individuals, and 30 samples of people with other infections were collected and the samples were evaluated in an ELISA system, using the crude protoscolices antigen. The sera samples were also simultaneously evaluated by antigen B-ELISA. The estimated value of sensitivity and specificity for the ELISA, using the crude protoscolices antigens, was 93.3% (95% CI: 76.4-98.8%) and 90% (95% CI: 78.8-95.8%), respectively. These values were 86.6 (95% CI: 68.3-95.6) and 91 (95% CI: 80.81-96.9) for the antigen-B based ELISA. Antigens prepared from protoscolices of hydatid cyst are suitable candidates for the serologic diagnosis of human CE. Further studies are needed to identify a single specific antigen among the protoscolices antigens to improve the diagnostic performance of these antigens.

Serum levels of anti-hepatitis B surface antibodies among vaccinated children aged 1 to 12 years in a rural community in Fars Province, southern Iran.

The present study aimed to find out the levels of anti-HBsAb among vaccinated children in a rural community in Fars Province, Southern Iran. Blood samples were taken from 550 children, aged 1-12 years (mean 6.4 ± 3.5), in 2017 from three villages in the area. A structured questionnaire was used to get the sociodemographic data of the subjects along with determinants concerning the Hepatitis B. Sera samples were examined for anti-HBsAb, using an ELISA commercial kit. Anti-HBsAb were detected in 468 (85.1%) of the subjects. Of the seropositive subjects, 37 (45.1%) were female and 45 (54.9%) were male. In the age group of 0-5 years, 88.7% of the subjects were seropositive. This rate was 84.3% and 78.1% in the age group of 6-10 years old and older than 10 years, respectively. There was a significant association (p < .05) between the anti-HBsAb and age. Findings of the current study revealed that children living in a rural community in southern Iran have appropriate protection against HBV even more than 10 years after being vaccinated. The decline in seropositivity rate of anti-HBsAb with age may further point out the need for a booster dose of HBV vaccine.

The evaluation of interleukin-4 and interleukin-13 in the serum of pulmonary sarcoidosis and tuberculosis patients.

BACKGROUND: Sarcoidosis and tuberculosis (TB) are two granulomatous inflammatory diseases with several common symptoms. The aim of the present study was to compare the serum levels of biomarkers including interleukin-4 (IL-4) and IL-13, calcium (Ca), hemoglobin, sedimentation rate, and lymphocyte-to-neutrophil ratio between patients with pulmonary TB, patients with sarcoidosis, and control group. MATERIALS AND METHODS: This case-control study was performed on patients referred to the Masih Daneshvari Hospital, Tehran, from April 2017 to 2018. In this study, 24 newly diagnosed patients with active pulmonary TB, 34 patients with pulmonary sarcoidosis, and 30 healthy individuals as the control group were enrolled. Demographic data, erythrocyte sedimentation rate (ESR), the ratio of neutrophil-to-lymphocyte (NLR), serum Ca level, hemoglobin (Hb), and IL-4 and IL-13 were compared between the study groups. Receiver operating characteristic (ROC) curve analysis, sensitivity, and specificity were also calculated using SPSS 16.0 software. RESULTS: The mean age was 47.71 ± 10.88 and 55.25 ± 21.58 years in the sarcoidosis and TB. The mean ESR in sarcoidosis patients was 21.45 ± 13.37 mm/h and 41.4 ± 17 mm/h in the TB group. The percentage of peripheral blood lymphocytes in sarcoidosis and TB patients was 28.02 ± 12.20 and 21.41 ± 12.49, respectively, which was significantly higher among patients with sarcoidosis. NLR was also 2.4 ± 1.6 and 4.4 ± 2.9 in sarcoidosis and TB patients, respectively, which showed a significant difference among the groups. Regarding the evaluation of the level of IL-4 and IL-13 in patients, it is worth noting that IL-4 in patients with sarcoidosis was 90 pg/ml compared to 20 pg/ml for TB patients (P < 0.001). There was no significant difference in the levels of IL-13 in the TB and control groups, which varied between 20 and 80 pg/ml (P = 0.35). However, its value was significantly higher in patients with sarcoidosis (P = 0.01) than in the healthy control group and TB (P = 0.01). The ROC curves showed that the diagnostic cutoff of ESR level, Ca, NLR, and Hb could be valuable due to the area under the curves. The cutpoint of 34 mm/h for ESR had a sensitivity of 86% as well as 80% specificity to distinguish TB from the sarcoidosis. CONCLUSION: Serum levels of the biomarkers indicated a stronger immunological background in sarcoidosis using NLR, Ca, ESR, and Hb.

Correction to: Development of an efficient perfusion-based protocol for whole-organ decellularization of the ovine uterus as a human-sized model and in vivo application of the bioscaffolds.

The original version of this article unfortunately contained a mistake. The affiliation of Fariba Ghorbani should be Tracheal Diseases Research Center (TDRC), National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran.

Development of an efficient perfusion-based protocol for whole-organ decellularization of the ovine uterus as a human-sized model and in vivo application of the bioscaffolds.

PURPOSE: The main purpose of this investigation was to determine an efficient whole-organ decellularization protocol of a human-sized uterus and evaluate the in vivo properties of the bioscaffold. METHODS: Twenty-four ovine uteri were included in this investigation and were decellularized by three different protocols (n 6). We performed histopathological and immunohistochemical evaluations, 4,6-diamidino-2-phenylindole (DAPI) staining, DNA quantification, MTT assay, scanning electron microscopy, biomechanical studies, and CT angiography to characterize the scaffolds. The optimized protocol was determined, and patches were grafted into the uterine horns of eight female Wistar rats. The grafts were extracted after 10 days; the opposite horns were harvested to be evaluated as controls. RESULTS: Protocol III (perfusion with 0.25% and 0.5% SDS solution and preservation in 10% formalin) was determined as the optimized method with efficient removal of the cellular components while preserving the extracellular matrix. Also, the bioscaffolds demonstrated native-like biomechanical, structural, and vascular properties. Histological and immunohistochemical evaluations of the harvested grafts confirmed the biocompatibility and recellularization potential of bioscaffolds. Also, the grafts demonstrated higher positive reaction for CD31 and Ki67 markers compared with the control samples which indicated eminent angiogenesis properties and proliferative capacity of the implanted tissues. CONCLUSIONS: This investigation introduces an optimized protocol for whole-organ decellularization of the human-sized uterus with native-like characteristics and a prominent potential for regeneration and angiogenesis which could be employed in in vitro and in vivo studies. To the best of our knowledge, this is the first study to report biomechanical properties and angiographic evaluations of a large animal uterine scaffold.

Correction to: Development of an efficient perfusion-based protocol for whole-organ decellularization of the ovine uterus as a human-sized model and in vivo application of the bioscaffolds.

The original version of this article unfortunately contained a mistake. The affiliation of Fariba Ghorbani should be Tracheal Diseases Research Center (TDRC), National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran

Decellularized Pancreas Matrix Scaffolds for Tissue Engineering Using Ductal or Arterial Catheterization.

INTRODUCTION: Diabetes is known as a worldwide disease with a great burden on society. Since therapeutic options cover a limited number of target points, new therapeutic strategies in the field of regenerative medicine are considered. Bioscaffolds along with islet cells would provide bioengineered tissue as a substitute for ß-cells. The perfusion-decellularization technique is considered to create such scaffolds since they mimic the compositional, architectural, and biomechanical nature of a native organ. In this study, we investigated 2 decellularization methods preserving tissue microarchitecture. METHODS: Procured pancreas from Sprague-Dawley rats was exposed to different percentages of detergent for 2, 4, and 6 h after cannulation via the common bile duct or aorta. RESULTS: High concentrations of sodium dodecyl sulfate (SDS), i.e., > 0.05%, resulted in tissue disruption or incomplete cell removal depending on the duration of exposure. In both methods, 6-h exposure to 0.05% SDS created a bioscaffold with intact extracellular matrices and proper biomechanical characteristics. Tissue-specific stainings revealed that elastic, reticular, and collagen fiber concentrations were well preserved. Quantitative findings showed that glycosaminoglycan content was slightly different, but hydroxyproline was in the range of native pancreas tissue. Dye infusion through ductal and vascular cannulation proved that the vascular network was intact, and scanning electron microscopy indicated a homogeneous porous structure. CONCLUSIONS: Using the detergent-based method, an effective and time-efficient procedure, a whole pancreas extracellular matrix bioscaffold can be developed that can be used as a 3D structure for pancreas tissue engineering-based studies and regenerative medicine applications.

A Critical Review on Phytochemistry, Pharmacology of Viola odorata L. and Related Multipotential Products in Traditional Persian Medicine.

Common violet (Viola odorata L., Violaceae) has shown various medical applications. Current study aimed to compile a review over chemical composition and medicinal properties of this plant in modern phytotherapy and its related multipotential products from traditional Persian medicine (TPM). Medicinal applications of V. odorata and respective products were derived from credible pharmaceutical textbooks of TPM (10th-18th century AD). In parallel, electronic databases including PubMed, Scopus, and ScienceDirect were explored for targeted purposes. Management of cough, fever, common cold, headache, insomnia, epilepsy, constipation, palpitation, dyspnea, dysuria, and skin diseases is of most applications of V. odorata, reported in TPM. On the other side, this herb plant has exerted antiinflammatory, analgesic, antioxidant, diuretic, antihypertensive, and antibacterial activities in modern phytotherapy. Violet TPM therapeutic preparations are including violet oil in the form of nasal or topical application for neurologic and skin disorders as well as pill, decoction, sweet syrup, and confection or semisolid oral preparations for skin, respiratory, gastrointestinal, and urinary ailments. Flavonoids, saponins, and alkaloids are responsible for pharmacological activities. Some medical applications of V. odorata in TPM have been proven by recent studies. However, more studies are needed to confirm these medicinal properties. Copyright © 2017 John Wiley & Sons, Ltd.

Abdominal pain in a young lady with inverted Meckel's diverticulum: a case report.

Meckel diverticulum is the most common congenital anomaly of the gastrointestinal tract which is located in small bowel within 2 feet of the ileocecal valve. Nevertheless, an inverted Meckel's diverticulum is an uncommon condition believed to result from aberrant peristalsis in that specific area. This article showed signs, symptoms, and possible clinical presentations using CARE guidelines in a case of inverted Meckel's diverticulum and reviews other possible features lastly, definitive treatment, results, and case follow-up were shown to refresh, and raise surgeons' awareness of this rare disorder.

Successful Surgical Management of Ruptured Hepatic Artery Pseudoaneurysm Post-Liver Retransplant: A Case Report.

INTRODUCTION: Hepatic Artery Pseudoaneurysm (HAP) is a rare and potentially fatal complication following liver transplantation, with unclear etiology. Various predisposing factors, including local infections, biliary-enteric anastomosis, particularly Roux-en-Y hepaticojejunostomy, vascular interventions, and iatrogenic injuries, have been identified. PRESENTATION OF CASE: We report a case of HAP occurring after liver re-transplantation in a twenty-year-old male patient who had initially undergone liver transplantation for cirrhosis resulting from autoimmune hepatitis. Subsequently diagnosed with chronic ischemic liver disease accompanied by diffuse cholangiopathy and a liver abscess, the patient underwent a liver re-transplantation. Within the early days post-re-transplantation, the patient presented symptoms of gastrointestinal bleeding and sudden hypotension. A high clinical suspicion led to prompt laparotomy, ultimately successful preserving both the graft and the recipient's life. DISCUSSION: HAP is an uncommon complication following liver transplantation. This condition may remain asymptomatic until the rupture of the HAP, which can result in gastrointestinal bleeding, hypotension, and, eventually, mortality. While there have been emerging non-surgical techniques proposed for HAP treatment, surgical intervention remains the definitive solution for preserving the graft and ensuring the recipient's survival. CONCLUSION: HAP, while uncommon, represents a life-threatening complication post-transplantation. In the event of rupture, immediate intervention is imperative for the patient's survival. Hence, it is critical for surgeons to be cautious about this complication, recognize its symptoms, and be aware of associated risk factors.

Reoperation etiologies in the initial hospital stay after liver transplantation: a single-center study from Iran.

Background: Liver transplantation (LT) is widely recognized as a life-saving therapy for patients with end-stage liver disease. However, due to certain posttransplant complications, reoperations or endovascular interventions may be necessary to improve patient outcomes. This study was conducted to examine reasons for reoperation during the initial hospital stay following LT and to identify its predictive factors. Methods: We evaluated the incidence and etiology of reoperation in 133 patients who underwent LT from brain-dead donors over a 9-year period based on our experiences. Results: A total of 52 reoperations were performed for 29 patients, with 17 patients requiring one reoperation, seven requiring two, three requiring three, one requiring four, and one requiring eight. Four patients underwent liver retransplantation. The most common cause of reoperation was intra-abdominal bleeding. Hypofibrinogenemia was identified as the sole predisposing factor for bleeding. Frequencies of comorbidities such as diabetes mellitus and hypertension did not differ significantly between groups. Among patients who underwent reoperation due to bleeding, the mean plasma fibrinogen level was 180.33±68.21 mg/dL, while among reoperated patients without bleeding, it was 240.62±105.14 mg/dL (P=0.045; standard mean difference, 0.61; 95% confidence interval, 0.19-1.03). The initial hospital stay was significantly longer for the reoperated group (47.5±15.5 days) than for the non-reoperated group (22.5±5.5 days). Conclusions: Meticulous pretransplant assessment and postoperative care are essential for the early identification of predisposing factors and posttransplant complications. In order to enhance graft and patient outcomes, any complications should be addressed without hesitation, and appropriate intervention or surgery should not be delayed.

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.