Long Axial Field of View PET: A New Era of Quantitative PET Imaging for Prospective Applications Beyond Classical Theranostics.

The scope of molecular imaging can be expanded beyond pure theranostic pairs, defined as radiolabeled agents sharing the same molecular target or the same label, towards any image-guided therapy scheme regardless of the chemical relationship between the imaging and therapeutic agents.

Long Axial Field-of-view PET: A New Era of Quantitative PET Imaging for Theranostic Applications in Clinic.

Long axial field-of-view PET (LAFOV) PET offers a dramatic increase not only in the area simultaneously scanned at any given time and bed position but also in sensitivity compared to conventional PET, enabling, among other benefits, streamlined whole-body dynamic and multiparametric imaging, delayed acquisitions, and accurate tracer quantification with reduced injected dose. These capabilities allow more precise and complete evaluation of tumor distribution, kinetics, and heterogeneity-essential for personalizing radiopharmaceutical therapy (RPT) for optimal safety and efficacy. Current one-protocol-fits-all RPT schemes, based on fixed activity and fixed scheduling, do not account for patient-specific biology.

Validating the Utility of Supervised Clustering Algorithm for Precise [C]DPA-713 PET Brain Image Quantification.

The reliance of quantitative PET imaging on the arterial input function makes brain PET challenging to perform in certain populations, limiting the sample size. To address this challenge, a supervised clustering algorithm (SVCA) has been introduced as an alternative. Our objective was to validate SVCA's performance for brain PET with [C]DPA-713 that targets a putative marker of brain injury and repair.

Preoperative PET/MRI and radio-guided surgery using [Cu64]DOTATATE in meningioma: a feasibility study. Illustrative case.

Background: Meningiomas are the most common primary intracranial neoplasms. Gross-total resection, the primary treatment goal, is not achieved in up to 50% of patients, affecting progression-free and overall survival. The traditionally used intraoperative assessment of resection extent using the Simpson grade has recently been shown to be less accurate than postoperative MRI.

[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.

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.

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.

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.

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.

Comparison of Correction Techniques for the Spill in Effect in Emission Tomography.

In positron emission tomography (PET) imaging, accurate clinical assessment is often affected by the partial volume effect (PVE) leading to overestimation (spill-in) or underestimation (spill-out) of activity in various small regions. The spill-in correction, in particular, can be very challenging when the target region is close to a hot background region. Therefore, this study evaluates and compares the performance of various recently developed spill-in correction techniques, namely: background correction (BC), local projection (LP), and hybrid kernelized (HKEM) methods.

Assessment of different quantification metrics of [F]-NaF PET/CT images of patients with abdominal aortic aneurysm.

Background: We aim to assess the spill-in effect and the benefit in quantitative accuracy for [F]-NaF PET/CT imaging of abdominal aortic aneurysms (AAA) using the background correction (BC) technique.

Methods: Seventy-two datasets of patients diagnosed with AAA were reconstructed with ordered subset expectation maximization algorithm incorporating point spread function (PSF). Spill-in effect was investigated for the entire aneurysm (AAA), and part of the aneurysm excluding the region close to the bone (AAA).

Physical performance of a long axial field-of-view PET scanner prototype with sparse rings configuration: A Monte Carlo simulation study.

Purpose: There is a growing interest in extending the axial fields-of-view (AFOV) of PET scanners. One major limitation for the widespread clinical adoption of such systems is the multifold increase in the associated material costs. In this study, we propose a cost-effective solution to extend the PET AFOV using a sparse detector rings configuration.