Mesh modeling of system geometry and anatomy phantoms for realistic GATE simulations and their inclusion in SPECT reconstruction.

Objective.Monte-Carlo simulation studies have been essential for advancing various developments in single photon emission computed tomography (SPECT) imaging, such as system design and accurate image reconstruction. Among the simulation software available, Geant4 application for tomographic emission (GATE) is one of the most used simulation toolkits in nuclear medicine, which allows building systems and attenuation phantom geometries based on the combination of idealized volumes. However, these idealized volumes are inadequate for modeling free-form shape components of such geometries. Recent GATE versions alleviate these major limitations by allowing users to import triangulated surface meshes.Approach.In this study, we describe our mesh-based simulations of a next-generation multi-pinhole SPECT system dedicated to clinical brain imaging, called AdaptiSPECT-C. To simulate realistic imaging data, we incorporated in our simulation the XCAT phantom, which provides an advanced anatomical description of the human body. An additional challenge with the AdaptiSPECT-C geometry is that the default voxelized XCAT attenuation phantom was not usable in our simulation due to intersection of objects of dissimilar materials caused by overlap of the air containing regions of the XCAT beyond the surface of the phantom and the components of the imaging system.Main results.We validated our mesh-based modeling against the one constructed by idealized volumes for a simplified single vertex configuration of AdaptiSPECT-C through simulated projection data of123I-activity distributions. We resolved the overlap conflict by creating and incorporating a mesh-based attenuation phantom following a volume hierarchy. We then evaluated our reconstructions with attenuation and scatter correction for projections obtained from simulation consisting of mesh-based modeling of the system and the attenuation phantom for brain imaging. Our approach demonstrated similar performance as the reference scheme simulated in air for uniform and clinical-like123I-IMP brain perfusion source distributions.Significance.This work enables the simulation of complex SPECT acquisitions and reconstructions for emulating realistic imaging data close to those of actual patients.

Systematic literature review of lymphatic imaging-guided procedural management of Noonan syndrome.

OBJECTIVES: To assess through literature case analysis how advances in lymphatic imaging, interventional radiology, and lymphatic vascular microsurgery illuminate and improve the lymphatic-flow status in select patients with Noonan syndrome (NS) who have undergone surgical intervention as a part of their comprehensive and individualized treatment plan. Also, we sought to illustrate the spectrum of lymphatic complications that can occur in this patient population when lymphatic flow through abnormal vasculature is surgically disrupted. METHODS: A literature review was performed by searching "Noonan AND Lymphatic AND Imaging" in the PubMed database. Inclusion criteria for this study were (1) diagnosis and clinical description of at least one original patient with NS, (2) imaging figures depicting lymphatic structure and function or a description of lymphatic imaging findings when a figure is not present, and (3) documentation of either lymphatic surgical intervention or lymphatic complications resulting from other procedures. Patient cases were first grouped by documented surgical intervention type, then clinical outcomes and lymphatic imaging results were compared. RESULTS: A total of 18 patient cases from 10 eligible publications were included in our review. Lymphatic imaging findings across all patients included lymphatic vessel dysplasia along with flow disruption (n = 16), thoracic duct malformations (n = 12), dermal lymphatic reflux (n = 7), and dilated lymphatic vessels (n = 4). Lymphovenous anastomosis (n = 4) resulted in rapid improvement of patient symptoms and signs. New-onset lymphatic manifestations noted over 10 to 20 years for two of these patients were chylothorax (n = 1), erysipelas (n = 1), and gradual-onset nonchylous scrotal lymphorrhea (n = 1). Targeted endovascular lymphatic disruption via sclerosis, embolization, or ablation (n = 8) results were mixed depending on the degree of central lymphatic involvement and included resolution of symptoms (n = 1), postoperative abdominal hemorrhage (n = 1), stable condition or minor improvement (n = 5), and death (n = 2). Large lymphatic vessel ligation or accidental incision (n = 6) occurred during thoracotomy (n = 4), scrotoplasty (n = 1), or inguinal lymph node biopsy (n = 1). These resulted in postoperative onset of new-onset regional lymphatic reflux (n = 5), chylothorax (n = 4), death (n = 3), or persistent or unchanged symptoms (n = 1). CONCLUSIONS: Imaging of the central lymphatics enabled characterization of lymphatic developmental features and guided operative management of lymphatic vascular defects in patients with NS. This review of the literature suggests that the surgical preservation or enhancement of central lymphatic return in patients with NS may improve interventional outcomes, whereas the disruption of central lymph flow has significant potential to cause severe postoperative complications and worsening of the patient's clinical condition.

Intraoperative Simulation: Team Training for Resuscitation While Using Intraoperative Computed Tomography: 2-Dimensional Operative Video.

Spine surgeons increasingly use intraoperative computed tomography (iCT) to facilitate surgery. iCT has several advantages, including the ability to decrease radiation exposure, improve surgical accuracy, and decrease operative time.1-3 However, the large footprint of the equipment can impede fast patient access in the event of an emergency resuscitation. This challenge is compounded when the patient is prone with rigid head fixation. To achieve fast, high-quality resuscitation, a large team must overcome numerous challenges. Cohesive team functioning under these circumstances requires planning, practice, and refinement.4 As a result of our simulation sessions, we have made several changes to the setup of our iCT cases. The following equipment is now routinely used: extralong tubing between the anesthesia circuit and patient, portable vital monitor, additional intravenous access is obtained, and extension tubing is used with all lines. We have created educational diagrams to streamline 2 challenging processes: optimal bed placement (for supination) and removal of equipment from the operating room (OR) to accommodate an influx of emergency personnel and equipment. Since the implementation of this protocol, 1 prone posterior cervical patient had intraoperative cardiac arrest. The protocol was followed. Return of spontaneous circulation was achieved within 5 min. The patient was discharged from the hospital with no neurological sequelae. During debriefing, stakeholders uniformly credited the simulated practice with this positive outcome. Emergency planning is a multifaceted process that continually evolves. With a steady flux of personnel and equipment, ongoing practice is essential to ensure readiness. Here, we share the key elements of our twice-yearly simulation. This simulation was performed on a training mannequin. This study did not involve human subjects. Any depictions of care rendered to nonidentifiable patients were standard (nonexperimental).

Roadmap for Conducting Neuroscience Research in the COVID-19 Era and Beyond: Recommendations From the SNACC Research Committee.

The coronavirus disease 2019 (COVID-19) pandemic has impacted many aspects of neuroscience research. At the 2020 Society of Neuroscience in Anesthesiology and Critical Care (SNACC) Annual Meeting, the SNACC Research Committee met virtually to discuss research challenges encountered during the COVID-19 pandemic along with possible strategies for facilitating research activities. These challenges and recommendations are included in this Consensus Statement. The objectives are to: (1) provide an overview of the disruptions and challenges to neuroscience research caused by the COVID-19 pandemic, and; (2) put forth a set of consensus recommendations for strengthening research sustainability during and beyond the current pandemic. Specific recommendations are highlighted for adapting laboratory and human subject study activities to optimize safety. Complementary research activities are also outlined for both laboratory and clinical researchers if specific investigations are impossible because of regulatory or societal changes. The role of virtual platforms is discussed with respect to fostering new collaborations, scheduling research meetings, and holding conferences such that scientific collaboration and exchange of ideas can continue. Our hope is for these recommendations to serve as a valuable resource for investigators in the neurosciences and other research disciplines for current and future research disruptions.

Efficacy of denileukin diftitox in subcutaneous panniculitis-like T-cell lymphoma.

Subcutaneous panniculitis-like lymphomas (SPTCLs) are a heterogeneous group of diseases characterized by pleomorphic lymphocytes infiltrating the subcutis in a lobular panniculitis-like pattern. Characterization of SPTCL based on T-cell phenotype has prognostic significance in that most patients with the alpha/beta T-cell phenotype of SPTCL demonstrate clinically indolent behavior, whereas those with gamma/delta variant typically manifest more aggressive disease. In the past, traditional therapies have included single-agent or systemic multi-agent chemotherapy with or without radiation therapy, immunosuppressive therapies, or, in refractory patients, bone marrow transplantation. We describe complete clinical regression of disease and a median response duration of > 6 months in 2 patients with SPTCL treated with corticosteroids and denileukin diftitox. Furthermore, the addition of bexarotene to denileukin diftitox restored a clinical response in 1 of the patients after disease progression, suggesting the activity of this combination in patients with SPTCL.

Extramedullary Breast Relapse of Acute Lymphoblastic Leukemia Controlled with a Second Allogeneic/Autologous Hematopoietic Cell Transplant.

Relapse of acute lymphoblastic leukemia (ALL) in the breast is uncommon and often precedes systemic relapse, resulting in poor survival. We report the development of breast involvement of ALL in a 20-year-old woman 32 months after a related allogeneic peripheral blood hematopoietic cell transplantation (PBHCT) in first remission. This extramedullary relapse occurred in the continuous presence of complete donor chimerism. After systemic re-induction chemotherapy and a second PBHCT using donor cells that had been cryopreserved at first transplant, our patient has remained in second complete remission for more than 44 months.

Mortality rates and hemorrhagic complications in asian-pacific islanders during treatment of acute myocardial infarction.

The management of acute myocardial infarction balances the benefits of antiplatelet and anticoagulant therapies against the risk for hemorrhage. The investigators report that Asian-Pacific islanders and patients with renal insufficiency have an increased rate of bleeding complications with hospitalized for acute myocardial infarction.

Soluble form of receptor for advanced glycation end products is associated with obesity and metabolic syndrome in adolescents.

The aim of this cross-sectional study was to investigate the relationship between soluble form of receptor for advanced glycation end products (sRAGE), obesity, and metabolic syndrome (MetS) in adolescents. A total of 522 male and 561 female adolescents were enrolled into the final analyses. Anthropometric parameters, blood pressure, blood biochemistry, fasting insulin, and plasma sRAGE levels were measured. In males, sRAGE was significantly and inversely correlated with waist circumference (WC), body mass index (BMI), systolic blood pressure, triglyceride (TG), low density lipoprotein cholesterol (LDL-C), and homeostasis model assessment-insulin resistance (HOMA-IR). Only WC and BMI were significantly and inversely correlated with sRAGE in females. Using linear regression analysis adjusting for age and gender, significant association was found between sRAGE and WC, BMI, TG, LDL-C, and HOMA-IR in adolescents of either gender (P < 0.05). This association was abolished when further adjusting BMI. In addition, sRAGE was significantly and inversely correlated with the increasing number of components of MetS in males (P for trend = 0.006) but not in females (P for trend = 0.422). In conclusion, plasma sRAGE is associated with obesity and MetS among adolescents. BMI may be the most important determinant of sRAGE levels in adolescents.

Prevalence and trend of dyslipidaemia from 1996 to 2006 among normal and overweight adolescents in Taiwan.

OBJECTIVES: To evaluate the trend of dyslipidaemia from 1996 to 2006 and examine its relationship with weight status among adolescents in Taiwan. DESIGN: 2 cross-sectional surveys were conducted in 1996 and 2006. SETTING: The junior high schools in Taipei. PARTICIPANTS: After multistage sampling, total of 1500 and 1283 junior high school students were chosen in 1996 and 2006. After excluding missing data, a total of 1353 (676 boys and 677 girls) and 1203 (585 boys and 618 girls) children were included in the final analyses in 1996 and 2006. OUTCOME MEASURES: Anthropometric measures as body height and weight were measured, and body mass index (BMI) was calculated. Blood lipid profiles as total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol were measured. RESULTS: From 1996 to 2006, the prevalence of dyslipidaemia and hypercholesterolaemia significantly increased from 13% (95% CI 11.3% to 15.0%) to 22.3% (95% CI 20.0% to 24.7%) and 6.2% (95% CI 5.0% to 7.6%) to 13.8% (95% CI 11.9% to 15.9%), respectively. The prevalence of hypertriglyceridaemia and low HDL-C dyslipidaemia increased from 3% (95% CI 1.8% to 4.5%) to 4.3% (95% CI 2.8% to 6.2%) and 6.5% (95% CI 4.8% to 8.6%) to 11.6% (95% CI 9.1% to 14.5%), with significance seen only in boys. When compared with normal weight participants, overweight boys and girls faced a 2-fold and 1.6-fold increased risk of dyslipidaemia, respectively, in the 2006 study. The increased risk of low HDL-C dyslipidaemia for overweight participants was 2.6-fold and 7.2-fold in boys and girls, respectively. In 2006, each unit increment of BMI was associated with 28%, 13% and 13% risk of hypertriglyceridaemia, low HDL-C and dyslipidaemia for boys, and 25% risk of low HDL-C dyslipidaemia in girls. CONCLUSIONS: The prevalence of dyslipidaemia had increased significantly for boys and girls in normal weight and overweight adolescents. Early screening of dyslipidaemia and weight intervention programmes in adolescents will be the key to prevent dyslipidaemia and cardiovascular-related comorbidities.

Lifestyle modification and behavior therapy effectively reduce body weight and increase serum level of brain-derived neurotrophic factor in obese non-diabetic patients with schizophrenia.

The goal of the study was to elucidate the relationship between serum circulating brain-derived neurotrophic factor (BDNF) and body weight reduction via lifestyle modification and behavior therapy in obese non-diabetic patients with chronic schizophrenia. Thirty-three obese non-diabetic subjects with schizophrenia treated with stable antipsychotic medication in a day-care unit for at least 3 months were recruited. Thirty age-, body weight-matched subjects without psychiatric disorders were enrolled as controls. All participants underwent a 10-week weight reduction program, including lifestyle modification, psychosocial treatment, behavior therapy and exercise in the day-care unit. Blood biochemistry, serum BDNF, adipokine (adiponectin), inflammatory markers (C-reactive protein, tumor necrosis factor-alpha and interleukin-6) and oral glucose tolerance test were evaluated before and after the program. Serum BDNF concentrations were significantly lower among patients with schizophrenia compared to control subjects. Serum BDNF levels were significantly increased following the weight reduction program. Elevations in serum BDNF levels were positively correlated with body weight and body mass index reduction. Altogether, our results demonstrate that a non-pharmacological weight reduction program effectively reduces body weight with significant elevation of serum BDNF levels in obese non-diabetic patients with schizophrenia.