[18F]-Fluoroestradiol (FES) brain PET in the evaluation of patients with estrogen receptor positive breast cancer and known or suspected brain metastases.

Objective: Our purpose was to describe our initial institutional experience using dedicated brain [18F]-Fluoroestradiol (FES) PET/CT or PET/MRI in the management of patients with estrogen-receptor-positive (ER+) breast cancer brain metastases (BCBM), and compare to [18F]-Fluorodeoxyglucose (FDG) PET and MRI.

Materials & Methods: Patients with biopsy-proven ER+ disease and MRI findings of suspected new, progressive, or recurrent BCBM were included in this retrospective study. Clinical and demographic data were collected.

Assessment of dual time point protocols to produce parametric K images in FDG PET/CT: A virtual clinical study.

Purpose: This simulation study investigated the feasibility of generating Patlak K images using a dual time point (DTP-K) scan protocol involving two 3-min/bed routine static PET scans and, subsequently, assessed DTP-K performance for an optimal DTP scan time frame combination, against conventional Patlak K estimated from complete 0-93 min dynamic PET data.

Methods: Six realistic heterogeneous tumors of different characteristic spatiotemporal [F]FDG uptake distributions for three noise levels commonly found in clinical studies and 20 noise realizations (N = 360 samples) were produced by analytic simulations of the XCAT phantom. Subsequently, DTP-K images were generated by performing standard linear indirect Patlak analysis with t* -min (Patlak) using a scaled population-based input function (sPBIF) model on 66 combinations of early and late 3-min/bed static whole-body PET reconstructed images.

Outcomes and Mechanisms Associated With Selective Thalamic Neuronal Loss in Chronic Traumatic Brain Injury.

Importance: The chronic neuronal burden of traumatic brain injury (TBI) is not fully characterized by routine imaging, limiting understanding of the role of neuronal substrates in adverse outcomes.

Objective: To determine whether tissues that appear healthy on routine imaging can be investigated for selective neuronal loss using [11C]flumazenil (FMZ) positron emission tomography (PET) and to examine whether this neuronal loss is associated with long-term outcomes.

Design, Setting, And Participants: In this cross-sectional study, data were collected prospectively from 2 centers (University of Cambridge in the UK and Weill Cornell Medicine in the US) between September 1, 2004, and May 31, 2021.

Brain Fluid Clearance After Traumatic Brain Injury Measured Using Dynamic Positron Emission Tomography.

Brain fluid clearance by pathways including the recently described paravascular glymphatic system is a critical homeostatic mechanism by which metabolic products, toxins, and other wastes are removed from the brain. Brain fluid clearance may be especially important after traumatic brain injury (TBI), when blood, neuronal debris, inflammatory cells, and other substances can be released and/or deposited. Using a non-invasive dynamic positron emission tomography (PET) method that models the rate at which an intravenously injected radiolabeled molecule (in this case C-flumazenil) is cleared from ventricular cerebrospinal fluid (CSF), we estimated the overall efficiency of brain fluid clearance in humans who had experienced complicated-mild or moderate TBI 3-6 months before neuroimaging ( = 7) as compared to healthy controls ( = 9).

DOTATATE PET/MR Imaging Differentiates Secondary-Progressive from de Novo World Health Organization Grade 3 Meningiomas.

Background And Purpose: WHO grade 3 meningiomas are rare and poorly understood and have a higher propensity for recurrence, metastasis, and worsened clinical outcomes compared with lower-grade meningiomas. The purpose of our study was to prospectively evaluate the molecular profile, PET characteristics, and outcomes of patients with World Health Organization grade 3 meningiomas who were imaged with gallium 68 (Ga) DOTATATE PET/MR imaging.

Materials And Methods: Patients with World Health Organization grade 3 meningiomas enrolled in our prospective observational cohort evaluating the utility of (Ga) DOTATATE PET/MR imaging in somatostatin receptor positive brain tumors were included.

[Ga68] DOTATATE PET/MRI-guided radiosurgical treatment planning and response assessment in meningiomas.

Background: Our purpose was to determine the utility of [68Ga]-DOTATATE PET/MRI in meningioma response assessment following radiosurgery.

Methods: Patients with meningioma prospectively underwent postoperative DOTATATE PET/MRI. Co-registered PET and gadolinium-enhanced T1-weighted MRI were employed for radiosurgery planning.

Hybrid Magnetic Resonance Positron Emission Tomography Is Associated With Cardiac-Related Outcomes in Cardiac Sarcoidosis.

Background: Imaging with late gadolinium enhancement (LGE) magnetic resonance (MR) and F-fluorodeoxyglucose (F-FDG) PET allows complementary assessment of myocardial injury and disease activity and has shown promise for improved characterization of active cardiac sarcoidosis (CS) based on the combined positive imaging outcome, MR(+)PET(+).

Objectives: This study aims to evaluate qualitative and quantitative assessments of hybrid MR/PET imaging in CS and to evaluate its association with cardiac-related outcomes.

Methods: A total of 148 patients with suspected CS underwent hybrid MR/PET imaging.

Proline-directed yeast and human MAP kinases phosphorylate the Dot1p/DOT1L histone H3K79 methyltransferase.

Disruptor of telomeric silencing 1 (Dot1p) is an exquisitely conserved histone methyltransferase and is the sole enzyme responsible for H3K79 methylation in the budding yeast Saccharomyces cerevisiae. It has been shown to be highly phosphorylated in vivo; however, the upstream kinases that act on Dot1p are almost entirely unknown in yeast and all other eukaryotes. Here, we used in vitro and in vivo kinase discovery approaches to show that mitogen-activated protein kinase HOG1 (Hog1p) is a bona fide kinase of the Dot1p methyltransferase.

Taking Me away: the function of phosphorylation on histone lysine demethylases.

Histone lysine demethylases (KDMs) regulate eukaryotic gene transcription by catalysing the removal of methyl groups from histone proteins. These enzymes are intricately regulated by the kinase signalling system in response to internal and external stimuli. Here, we review the mechanisms by which kinase-mediated phosphorylation influence human histone KDM function.

Clinical application of a population-based input function (PBIF) for a shortened dynamic whole-body FDG-PET/CT protocol in patients with metastatic melanoma treated by immunotherapy.

Background: The aim was to investigate the feasibility of a shortened dynamic whole-body (dWB) FDG-PET/CT protocol and Patlak imaging using a population-based input function (PBIF), instead of an image-derived input function (IDIF) across the 60-min post-injection period, and study its effect on the FDG influx rate (Ki) quantification in patients with metastatic melanoma (MM) undergoing immunotherapy.

Methods: Thirty-seven patients were enrolled, including a PBIF modeling group (n = 17) and an independent validation cohort (n = 20) of MM from the ongoing prospective IMMUNOPET2 trial. All dWB-PET data were acquired on Vision 600 PET/CT systems.

The potential of a medium-cost long axial FOV PET system for nuclear medicine departments.

Purpose: Total body positron emission tomography (TB-PET) has recently been introduced in nuclear medicine departments. There is a large interest in these systems, but for many centers, the high acquisition cost makes it very difficult to justify their current operational budget. Here, we propose medium-cost long axial FOV scanners as an alternative.

Longitudinal alterations in gamma-aminobutyric acid (GABA) receptor availability over ∼ 1 year following traumatic brain injury.

Longitudinal alterations of gamma-aminobutyric acid (GABA) receptor availability following traumatic brain injury have remained uncharacterized and may reflect changes in neuronal structure and function linked to cognitive recovery. We measured GABA receptor availability using the tracer [11C]flumazenil in nine adults with traumatic brain injury (3-6 months after injury, subacute scan) and in 20 non-brain-injured individuals. A subset of subjects with traumatic brain injury (n = 7) were scanned at a second chronic time-point, 7-13 months after their first scan; controls (n = 9) were scanned for a second time, 5-11 months after the first scan.

Evaluating diagnostic accuracy and determining optimal diagnostic thresholds of different approaches to [Ga]-DOTATATE PET/MRI analysis in patients with meningioma.

Multiple approaches with [Ga]-DOTATATE, a somatostatin analog PET radiotracer, have demonstrated clinical utility in evaluation of meningioma but have not been compared directly. Our purpose was to compare diagnostic performance of different approaches to quantitative brain [Ga]-DOTATATE PET/MRI analysis in patients with suspected meningioma recurrence and to establish the optimal diagnostic threshold for each method. Patients with suspected meningioma were imaged prospectively with [Ga]-DOTATATE brain PET/MRI.

Physical performance of adaptive axial FOV PET scanners with a sparse detector block rings or a checkerboard configuration.

Using Monte-Carlo simulations, we evaluated the physical performance of a hypothetical state-of-the-art clinical PET scanner with adaptive axial field-of-view (AFOV) based on the validated GATE model of the Siemens Biograph VisionPET/CT scanner.Vision consists of 16 compact PET rings, each consisting of 152 mini-blocks of 5 × 5 Lutetium Oxyorthosilicate crystals (3.2 × 3.

Dynamic Ga-DOTATATE PET/MRI in the Diagnosis and Management of Intracranial Meningiomas.

Purpose To evaluate dynamic gallium 68 (Ga) tetraazacyclododecane tetraacetic acid octreotate (DOTATATE) brain PET/MRI as an adjunct modality in meningioma, enabling multiparametric standardized uptake value (SUV) and Patlak net binding rate constant () imaging, and to optimize static acquisition period. Materials and Methods In this prospective study (ClinicalTrials.gov no.

PET/MR Imaging of Somatostatin Receptor Expression and Tumor Vascularity in Meningioma: Implications for Pathophysiology and Tumor Outcomes.

Background And Purpose: Meningiomas, the most common primary intracranial tumor, are vascular neoplasms that express somatostatin receptor-2 (SSTR2). The purpose of this investigation was to evaluate if a relationship exists between tumor vascularity and SSTR2 expression, which may play a role in meningioma prognostication and clinical management.

Materials And Methods: Gallium-68-DOTATATE PET/MRI with dynamic contrast-enhanced (DCE) perfusion was prospectively performed.

Complete Genome Sequence of Community-Associated Methicillin-Resistant Staphylococcus aureus Sequence Type 1, SCC IV[2B], Isolated in the 1990s from Northern Western Australia.

Sequence type 1 (ST1) methicillin-resistant Staphylococcus aureus (MRSA) SCC IV[2B] has become one of the most common community-associated MRSA clones in Australia. We report the complete genome sequence of one of the earliest isolated Australian S. aureus ST1-MRSA-IV strains, WBG8287, isolated from an Indigenous Australian patient living in the remote Kimberley region of Western Australia.

Complete Genome Sequences of Three of the Earliest Community-Associated Methicillin-Resistant Staphylococcus aureus Strains Isolated in Remote Western Australia.

Initially reported in Western Australia in the 1980s, community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has become a major cause of S. aureus infections globally. We report the complete genome sequences of three of the earliest CA-MRSA strains isolated from remote Australian Indigenous communities in the Kimberley region of Western Australia.

Scan-rescan measurement repeatability of F-FDG PET/MR imaging of vascular inflammation.

Non-invasive positron emission tomography (PET) of vascular inflammation and atherosclerotic plaque by identifying increased uptake of F-fluordeoxyglucose (F-FDG) is a powerful tool for monitoring disease activity, progression, and its response to therapy. F-FDG PET/computed tomography (PET/CT) of the aorta and carotid arteries has become widely used to assess changes in inflammation in clinical trials. However, the recent advent of hybrid PET/magnetic resonance (PET/MR) scanners has advantages for vascular imaging due to the reduction in radiation exposure and improved soft tissue contrast of MR compared to CT.

Population-based input function for TSPO quantification and kinetic modeling with [C]-DPA-713.

Introduction: Quantitative positron emission tomography (PET) studies of neurodegenerative diseases typically require the measurement of arterial input functions (AIF), an invasive and risky procedure. This study aims to assess the reproducibility of [C]DPA-713 PET kinetic analysis using population-based input function (PBIF). The final goal is to possibly eliminate the need for AIF.

[Ga]-DOTATATE PET/MRI as an adjunct imaging modality for radiation treatment planning of meningiomas.

Background: Meningiomas express high levels of somatostatin receptor 2 (SSTR2). SSTR2-targeted PET imaging with [Ga]-DOTATATE can aid with distinguishing residual meningioma from reactive changes in the postoperative setting. We present initial dosimetric analyses, acute events, and local control data utilizing [Ga]-DOTATATE PET/MRI-assisted target delineation for prospectively-treated intermediate-risk meningiomas.

Prospective study of dynamic whole-body 68Ga-DOTATOC-PET/CT acquisition in patients with well-differentiated neuroendocrine tumors.

To present the feasibility of a dynamic whole-body (DWB) Ga-DOTATOC-PET/CT acquisition in patients with well-differentiated neuroendocrine tumors (WD-NETs). Sixty-one patients who underwent a DWB Ga-DOTATOC-PET/CT for a histologically proven/highly suspected WD-NET were prospectively included. The acquisition consisted in single-bed dynamic acquisition centered on the heart, followed by the DWB and static acquisitions.