An anatomical analysis of liver volume and quality by ethnicity in a New Zealand population.

Background: Post-hepatectomy liver failure is a major cause of mortality, where future liver remnant (FLR) is the key controllable factor. Recommended minimum FLR is influenced by quality of liver parenchyma. Historical research has often failed to include Māori and Pacific Island (PI) populations despite worse health outcomes.

Faecal immunochemical test (FIT) based prioritisation of new patient symptomatic cases referred for colorectal investigation.

Aim: Quantitative faecal haemoglobin (fHb) measurement by faecal immunochemical test (FIT) is a powerful biomarker for colorectal cancer (CRC) and is incorporated in referral, prioritisation and triage protocols for symptomatic cases in other countries. We report our use of FIT to prioritise new patient symptomatic cases referred for colorectal investigation.

Method: Cases referred for investigation of new colorectal symptoms who were aged ≥50 years (≥40 years Māori/Pacific peoples), who would otherwise be triaged to non-urgent colonoscopy, were asked to provide a stool sample for FIT.

The Delphi of ORACLE: An Expert Consensus Survey for the Development of the Observational Risk Assessment of Contractures (Longitudinal Evaluation).

Objective: Despite rising prevalence rates, no standard tool is available to identify individuals at risk of developing contractures. This study aimed to gain expert consensus on items for the development of the Observational Risk Assessment Tool for Contractures: Longitudinal Evaluation (ORACLE) for care home residents.

Design: A two-round, online modified Delphi study.

Pre-training via Transfer Learning and Pretext Learning a Convolutional Neural Network for Automated Assessments of Clinical PET Image Quality.

Positron emission tomography (PET) using a fraction of the usual injected dose would reduce the amount of radioligand needed, as well as the radiation dose to patients and staff, but would compromise reconstructed image quality. For performing the same clinical tasks with such images, a clinical (rather than numerical) image quality assessment is essential. This process can be automated with convolutional neural networks (CNNs).

From bench to bedside: The mGluR5 system in people with and without Autism Spectrum Disorder and animal model systems.

The metabotropic glutamate receptor 5 (mGluR5) is a key regulator of excitatory (E) glutamate and inhibitory (I) γ-amino butyric acid (GABA) signalling in the brain. Despite the close functional ties between mGluR5 and E/I signalling, no-one has directly examined the relationship between mGluR5 and glutamate or GABA in vivo in the human brain of autistic individuals. We measured [F] FPEB (F-3-fluoro-5-[(pyridin-3-yl)ethynyl]benzonitrile) binding in 15 adults (6 with Autism Spectrum Disorder) using two regions of interest, the left dorsomedial prefrontal cortex and a region primarily composed of left striatum and thalamus.

The association between -methyl-d-aspartate receptor availability and glutamate levels: A multi-modal PET-MR brain imaging study in first-episode psychosis and healthy controls.

Background: Evidence from post-mortem studies and in vivo imaging studies suggests there may be reduced -methyl-d-aspartate receptor (NMDAR) levels in the hippocampus in patients with schizophrenia. Other studies have reported increased glutamate in striatum in schizophrenia patients. It has been hypothesised that NMDAR hypofunction leads to the disinhibition of glutamatergic signalling; however, this has not been tested in vivo.

Role of 3'-Deoxy-3'-[F] Fluorothymidine Positron Emission Tomography-Computed Tomography as a Predictive Biomarker in Argininosuccinate Synthetase 1-Deficient Thoracic Cancers Treated With Pegargiminase.

Introduction: Pegargiminase (ADI-PEG 20I) degrades arginine in patients with argininosuccinate synthetase 1-deficient malignant pleural mesothelioma (MPM) and NSCLC. Imaging with proliferation biomarker 3'-deoxy-3'-[F] fluorothymidine (F-FLT) positron emission tomography (PET)-computed tomography (CT) was performed in a phase 1 study of pegargiminase with pemetrexed and cisplatin (ADIPemCis). The aim was to determine whether FLT PET-CT predicts treatment response earlier than CT.

A tumor volume and performance status model to predict outcome before treatment in diffuse large B-cell lymphoma.

Aggressive large B-cell lymphoma (LBCL) has variable outcomes. Current prognostic tools use factors for risk stratification that inadequately identify patients at high risk of refractory disease or relapse before initial treatment. A model associating 2 risk factors, total metabolic tumor volume (TMTV) >220 cm3 (determined by fluorine-18 fluorodeoxyglucose positron emission tomography coupled with computed tomography) and performance status (PS) ≥2, identified as prognostic in 301 older patients in the REMARC trial (#NCT01122472), was validated in 2174 patients of all ages treated in 2 clinical trials, PETAL (Positron Emission Tomography-Guided Therapy of Aggressive Non-Hodgkin Lymphomas; N = 510) and GOYA (N = 1315), and in real-world clinics (N = 349) across Europe and the United States.

Factors associated with joint contractures in adults: a systematic review with narrative synthesis.

Purpose: The primary objective of the review was to collate the available evidence on factors associated with joint contractures in adults.

Methods: A systematic literature search was conducted on MEDLINE, CINAHL, AMED, and EMBASE. Studies that involved participants aged ≥18 and assessed joint contracture as a primary or secondary outcome were included.

Test-retest repeatability and interobserver variation of healthy tissue metabolism using 18F-FDG PET/CT of the thorax among lung cancer patients.

Objectives: The aim of this study was to assess the test-retest repeatability and interobserver variation in healthy tissue (HT) metabolism using 2-deoxy-2-[18F]fluoro-d-glucose (18F-FDG) PET/computed tomography (PET/CT) of the thorax in lung cancer patients.

Methods: A retrospective analysis was conducted in 22 patients with non-small cell lung cancer who had two PET/CT scans of the thorax performed 3 days apart with no interval treatment. The maximum, mean and peak standardized uptake values (SUVs) in different HTs were measured by a single observer for the test-retest analysis and two observers for interobserver variation.

A case-control evaluation of pulmonary and extrapulmonary findings of incidental asymptomatic COVID-19 infection on FDG PET-CT.

Objectives: To describe the findings of incidental asymptomatic COVID-19 infection on FDG PET-CT using a case-control design.

Methods: Incidental pulmonary findings suspicious of asymptomatic COVID-19 infection on FDG PET-CT were classified as a (positive RT-PCR test) or case (no/negative RT-PCR test). cases were identified using a 4:1 control:case ratio.

N-methyl-D-aspartate receptor availability in first-episode psychosis: a PET-MR brain imaging study.

N-methyl-D-aspartate receptor (NMDAR) hypofunction is hypothesised to underlie psychosis but this has not been tested early in illness. To address this, we studied 40 volunteers (21 patients with first-episode psychosis and 19 matched healthy controls) using PET imaging with an NMDAR selective ligand, [F]GE-179, that binds to the ketamine binding site to index its distribution volume ratio (DVR) and volume of distribution (V). Hippocampal DVR, but not V, was significantly lower in patients relative to controls (p = 0.

Reproducibility of findings in modern PET neuroimaging: insight from the NRM2018 grand challenge.

The reproducibility of findings is a compelling methodological problem that the neuroimaging community is facing these days. The lack of standardized pipelines for image processing, quantification and statistics plays a major role in the variability and interpretation of results, even when the same data are analysed. This problem is well-known in MRI studies, where the indisputable value of the method has been complicated by a number of studies that produce discrepant results.

Correlations between DW-MRI and F-FDG PET/CT parameters in head and neck squamous cell carcinoma following definitive chemo-radiotherapy.

Background: Posttreatment diffusion-weighted magnetic resonance imaging (DW-MRI) and 18F-fluorodeoxygluocose ( F-FDG) positron emission tomography (PET) with computed tomography (PET/CT) have potential prognostic value following chemo-radiotherapy (CRT) for head and neck squamous cell carcinoma (HNSCC). Correlations between these PET/CT (standardized uptake value or SUV) and DW-MRI (apparent diffusion coefficient or ADC) parameters have only been previously explored in the pretreatment setting.

Aim: To evaluate stage III and IV HNSCC at 12-weeks post-CRT for the correlation between SUV and ADC values and their interval changes from pretreatment imaging.

Evaluation of [N]ammonia positron emission tomography as a potential method for quantifying glutamine synthetase activity in the human brain.

Purpose: The conversion of synaptic glutamate to glutamine in astrocytes by glutamine synthetase (GS) is critical to maintaining healthy brain activity and may be disrupted in several brain disorders. As the GS catalysed conversion of glutamate to glutamine requires ammonia, we evaluated whether [N]ammonia positron emission tomography (PET) could reliability quantify GS activity in humans.

Methods: In this test-retest study, eight healthy volunteers each received two dynamic [N]ammonia PET scans on the morning and afternoon of the same day.

Imaging niacin trafficking with positron emission tomography reveals in vivo monocarboxylate transporter distribution.

Introduction: A sufficient dietary intake of the vitamin niacin is essential for normal cellular function. Niacin is transported into the cells by the monocarboxylate transporters: sodium-dependent monocarboxylate transporter (SMCT1 and SMCT2) and monocarboxylate transporter (MCT1). Despite the importance of niacin in biological systems, surprisingly, its in vivo biodistribution and trafficking in living organisms has not been reported.

Imaging Biotin Trafficking In Vivo with Positron Emission Tomography.

The water-soluble vitamin biotin is essential for cellular growth, development, and well-being, but its absorption, distribution, metabolism, and excretion are poorly understood. This paper describes the radiolabeling of biotin with the positron emission tomography (PET) radionuclide carbon-11 ([C]biotin) to enable the quantitative study of biotin trafficking in vivo. We show that intravenously administered [C]biotin is quickly distributed to the liver, kidneys, retina, heart, and brain in rodents-consistent with the known expression of the biotin transporter-and there is a surprising accumulation in the brown adipose tissue (BAT).

The impact of hypoglycaemia awareness status on regional brain responses to acute hypoglycaemia in men with type 1 diabetes.

Aims/hypothesis: Impaired awareness of hypoglycaemia (IAH) in type 1 diabetes increases the risk of severe hypoglycaemia sixfold and can be resistant to intervention. We explored the impact of IAH on central responses to hypoglycaemia to investigate the mechanisms underlying barriers to therapeutic intervention.

Methods: We conducted [O]water positron emission tomography studies of regional brain perfusion during euglycaemia (target 5 mmol/l), hypoglycaemia (achieved level, 2.

Ingested bread clip as an unexpected diagnostic tool.

We describe a case where a bread clip has in fact became lodged adjacent to a portion of small bowel affected by a deposit of previously undiagnosed metastatic serous carcinoma of likely ovarian origin.

Defining the optimal method for measuring baseline metabolic tumour volume in diffuse large B cell lymphoma.

Purpose: Metabolic tumour volume (MTV) is a promising prognostic indicator in diffuse large B cell lymphoma (DLBCL). Optimal thresholds to divide patients into 'low' versus 'high' MTV groups depend on clinical characteristics and the measurement method. The aim of this study was to compare in consecutive unselected patients with DLBCL, different software algorithms and published methods of MTV measurement using FDG PET.

A Population Approach to Guide Amisulpride Dose Adjustments in Older Patients With Alzheimer's Disease.

Objective: We have previously reported high dopamine D2/3 receptor occupancies at low amisulpride concentrations in older people with Alzheimer's disease (AD), during off-label treatment of AD-related psychosis. This post hoc analysis explored pharmacokinetic (concentration) and pharmacodynamic (prolactin, D2/3 occupancy) contributions to symptom reduction and extrapyramidal side effects (EPS) to inform AD-specific dose adjustments.

Methods: Population pharmacokinetic-pharmacodynamic models were developed by combining pharmacokinetic data from a phase 1 study in 20 healthy older people with pharmacokinetic prolactin, [¹⁸F]fallypride D2/3 receptor imaging, and clinical outcome data from 28 older patients prescribed open amisulpride (25-75 mg/d) to treat AD-related psychosis.