Comprehensive Non-invasive Versus Invasive Approach to Evaluate Cardiac Allograft Vasculopathy in Heart Transplantation: The CCTA-HTx Study.

Background: Coronary computed tomography angiography (CCTA) is emerging as a valuable tool for noninvasive surveillance of cardiac allograft vasculopathy (CAV) in patients with heart transplant (HTx). We assessed the diagnostic performance of a comprehensive CCTA-based approach compared with the invasive reference, which includes invasive coronary angiography, intravascular ultrasound, and fractional flow reserve, for detecting CAV.

Methods: This was a multicenter prospective study including 37 patients with HTx who underwent CCTA, invasive coronary angiography, intravascular ultrasound, and fractional flow reserve.

Myelin Imaging of the Spinal Cord in Animal Models and Patients with Multiple Sclerosis Using [C]MeDAS PET: A Translational Study.

Multiple sclerosis (MS) is a neurodegenerative disease characterized by demyelinated lesions in the brain and spinal cord. A few clinical studies using PET to image myelin in the brain have been performed, but none investigated the spinal cord. Because clinically relevant motor symptoms are primarily due to spinal cord damage, this translational study evaluated [C]-methyl-4,4'-diaminostilbene (MeDAS) as a PET tracer for myelin imaging in the rat and human spinal cord.

eGFR slope as predictor of mortality in heart failure patients.

Aims: Heart failure (HF) leads to an imbalance between heart and kidney function, resulting in poor outcomes. However, the prognostic significance of the estimated glomerular filtration rate (eGFR) trajectory in HF patients remains unclear. We analysed electronic health records (EHRs) of real-world HF patients, assessing eGFR trajectories and their impact on mortality.

Increased individual workload for nuclear medicine physicians over the past years: 2008-2023 data from The Netherlands.

Objecive: To investigate temporal trends in the individual workload of nuclear medicine physicians at a large tertiary care academic center between 2008 and 2023.

Methods: This study analyzed the reporting workload of nuclear medicine physicians in a large tertiary care academic center in The Netherlands on 36 unique (randomly sampled) calendar days, for each year between 2008 and 2023. The average daily departmental workload (measured with relative value units) was calculated for each year between 2008 and 2023.

Increased dopamine D/D receptor and serotonin transporter availability in male rats after spontaneous remission from repeated social defeat-induced depression; a PET study in rats.

Most pharmacological treatments for depression target monoamine transporters and about 50 % of treated patients attain symptomatic remission. Once remission is attained, it is hard to distinguish the changes on brain monoaminergic transmission induced by the antidepressants, from those associated to remission per se. In this study, we aimed at studying the brain of spontaneously remitted rats from repeated social defeat (RSD)-induced depression in terms of dopamine D/D receptor and serotonin transporter (SERT) availability, showing absence of depressive symptoms 2 weeks after RSD.

Reproducibility of Cardiac Multifrequency MR Elastography in Assessing Left Ventricular Stiffness and Viscosity.

Background: Cardiac magnetic resonance elastography (MRE) shows promise in assessing the mechanofunctional properties of the heart but faces clinical challenges, mainly synchronization with cardiac cycle, breathing, and external harmonic stimulation.

Purpose: To determine the reproducibility of in vivo cardiac multifrequency MRE (MMRE) for assessing diastolic left ventricular (LV) stiffness and viscosity.

Study Type: Prospective.

Update on the Role of [F]FDOPA PET/CT.

[F]-dihydroxyphenylalanine ([F]FDOPA) is a radiopharmaceutical used in a broad spectrum of diseases, including neuroendocrine tumors (NETs), congenital hyperinsulinism, parkinsonian syndromes and neuro-oncology. Genetic analysis and disease specific biomarkers may guide the optimum selection of patients that may benefit most from [F]FDOPA PET in different stages of several neuroendocrine neoplasms and in congenital hyperinsulinism. For clinical routine in neuro-oncology, indications for [F]FDOPA PET include tumor delineation and distinguishing between treatment related changes and recurrent disease.

Ultrashort Oncologic Whole-Body [F]FDG Patlak Imaging Using LAFOV PET.

Methods to shorten [F]FDG Patlak PET imaging procedures ranging from 65-90 to 20-30 min after injection, using a population-averaged input function (PIF) scaled to patient-specific image-derived input function (IDIF) values, were recently evaluated. The aim of the present study was to explore the feasibility of ultrashort 10-min [F]FDG Patlak imaging at 55-65 min after injection using a PIF combined with direct Patlak reconstructions to provide reliable quantitative accuracy of lung tumor uptake, compared with a full-duration 65-min acquisition using an IDIF. Patients underwent a 65-min dynamic PET acquisition on a long-axial-field-of-view (LAFOV) Biograph Vision Quadra PET/CT scanner.

Myocardial work and risk stratification in patients with severe aortic valve stenosis referred for transcatheter aortic valve replacement.

Background: Transcatheter aortic valve replacement(TAVR) has shown clear survival benefits in severe aortic valve stenosis(AS). However, patients unable to recover left ventricle function remain at risk with poor long-term survival. This single-center prospective study aims to analyze the supplementary benefits of myocardial work(MW) assessment for baseline risk stratification in patients with severe AS referred for TAVR.

Effect of contrast phase on quantitative analysis of skeletal muscle and adipose tissue by computed tomography.

Objectives: Significant variability exists in the contrast phases applied during computed tomography (CT) studies when assessing morphometric measurements of muscle area (CT-assessed sarcopenia) and density (CT-assessed myosteatosis) and visceral adipose tissue area (CT-assessed visceral obesity). This study explored the impact of contrast phase timing on changes in morphometric measurements of body composition.

Methods: This single-center retrospective cohort study included 459 patients undergoing a multiphase CT scan.

Spatial distribution of cerebral microbleeds and FLAIR hyperintensities on follow-up MRI after radiotherapy for lower grade glioma.

Background And Purpose: Cerebral microbleeds (CMBs) and fluid-attenuated-inversion recovery (FLAIR) hyperintensities on brain MRI scans after radiotherapy (RT) are considered markers for microvascular damage and related cognitive changes. However, the spatial distribution using existing scoring systems as well as colocation of these imaging biomarkers remain unclear, hampering clinical interpretation. This study aims to elucidate the distribution and colocation of these markers in patients with lower grade glioma (LGG).

Can Internal Carotid Arteries Be Used for Noninvasive Quantification of Brain PET Studies?

Because of the limited axial field of view of conventional PET scanners, the internal carotid arteries are commonly used to obtain an image-derived input function (IDIF) in quantitative brain PET. However, time-activity curves extracted from the internal carotids are prone to partial-volume effects due to the limited PET resolution. This study aimed to assess the use of the internal carotids for quantifying brain glucose metabolism before and after partial-volume correction.

Caloric restriction reduces proteinuria in male rats with established nephropathy.

Reducing proteinuria is a crucial approach in preventing kidney function loss. Previous preclinical studies indicated that caloric restriction (CR) imposed at a young age protects against age-related proteinuria. However, these studies have not explored CR in established renal disease.

Reading room assistants to reduce workload and interruptions of radiology residents during on-call hours: Initial evaluation.

Purpose: To determine how much timesaving and reduction of interruptions reading room assistants can provide by taking over non-image interpretation tasks (NITs) from radiology residents during on-call hours.

Methods: Reading room assistants are medical students who were trained to take over NITs from radiology residents (e.g.

Effects of the adenosine A receptor antagonist KW6002 on the dopaminergic system, motor performance, and neuroinflammation in a rat model of Parkinson's disease.

Adenosine A-receptors (AR) and dopamine D-receptors (DR) are known to work together in a synergistic manner. Inhibiting ARs by genetic or pharmacological means can relief symptoms and have neuroprotective effects in certain conditions. We applied PET imaging to evaluate the impact of the AR antagonist KW6002 on DR availability and neuroinflammation in an animal model of Parkinson's disease.

Pharmacokinetic Analysis of [F]FES PET in the Human Brain and Pituitary Gland.

Purpose: Estrogen receptors (ER) are implicated in psychiatric disorders. We assessed if ER availability in the human brain could be quantified using 16α-[F]-fluoro-17β-estradiol ([F]FES) positron emission tomography (PET).

Procedures: Seven post‑menopausal women underwent a dynamic [F]FES PET scan with arterial blood sampling.

Small vessel disease burden and functional brain connectivity in mild cognitive impairment.

Background: The role of small vessel disease in the development of dementia is not yet completely understood. Functional brain connectivity has been shown to differ between individuals with and without cerebral small vessel disease. However, a comprehensive measure of small vessel disease quantifying the overall damage on the brain is not consistently used and studies using such measure in mild cognitive impairment individuals are missing.

Characterization of a novel model for atherosclerosis imaging: the apolipoprotein E-deficient rat.

Background: The apolipoprotein E-deficient (apoE) mouse is a well-established model for studying atherosclerosis. However, its small size limits its use in longitudinal positron emission tomography (PET) imaging studies. Recently, the apoE rat has emerged as an alternative.