Parametric imaging of myocardial blood flow with Rb PET: An accuracy and image quality analysis.

Background: We aimed to develop a framework for generating three-dimensional (3D) myocardial blood flow (MBF) images, computing their accuracy against clinically validated two-dimensional (2D) polar MBF maps of the left ventricle, and evaluating their improvements in image quality over relative myocardial perfusion imaging (MPI).

Methods: N = 40 patients with a wide range of defect severities and uptake dynamics were retrospectively studied. The FlowQuant™ software was used to generate reference MPI and polar MBF maps and was adapted for voxel-wise MBF mapping.

Role of Nuclear Imaging in Cardiac Stereotactic Body Radiotherapy for Ablation of Ventricular Tachycardia.

Ventricular tachycardia (VT) is a life-threatening arrhythmia common in patients with structural heart disease or nonischemic cardiomyopathy. Many VTs originate from regions of fibrotic scar tissue, where delayed electrical signals exit scar and re-enter viable myocardium. Cardiac stereotactic body radiotherapy (SBRT) has emerged as a completely noninvasive alternative to catheter ablation for the treatment of recurrent or refractory ventricular tachycardia.

Machine and deep learning models for accurate detection of ischemia and scar with myocardial blood flow positron emission tomography imaging.

Background: Quantification of myocardial blood flow (MBF) is used for the noninvasive diagnosis of patients with coronary artery disease (CAD). This study compared traditional statistics, machine learning, and deep learning techniques in their ability to diagnose disease using only the rest and stress MBF values.

Methods: This study included 3245 rest and stress rubidium-82 positron emission tomography (PET) studies and matching diagnostic labels from perfusion reports.

Cardiac PET Myocardial Blood Flow Quantification Assessment of Early Cardiac Allograft Vasculopathy.

Background: Positron emission tomography (PET) has demonstrated utility for diagnostic and prognostic assessment of cardiac allograft vasculopathy (CAV) but has not been evaluated in the first year after transplant.

Objectives: The authors sought to evaluate CAV at 1 year by PET myocardial blood flow (MBF) quantification.

Methods: Adults at 2 institutions enrolled between January 2018 and March 2021 underwent prospective 3-month (baseline) and 12-month (follow-up) post-transplant PET, endomyocardial biopsy, and intravascular ultrasound examination.

The Canadian Study of Arterial Inflammation in Patients with Diabetes and Recent Vascular Events, Evaluation of Colchicine Effectiveness (CADENCE): protocol for a randomised, double-blind, placebo-controlled trial.

Background: Inflammation is a key mediator in the development and progression of the atherosclerotic disease process as well as its resultant complications, like myocardial infarction (MI), stroke and cardiovascular (CV) death, and is emerging as a novel treatment target. Trials involving anti-inflammatory medications have demonstrated outcome benefit in patients with known CV disease. In this regard, colchicine appears to hold great promise.

Sex Differences in Systemic and Coronary Arterial Hemodynamics in Heart Failure With Preserved Ejection Fraction.

Heart failure (HF) with preserved ejection fraction (HFpEF) predominantly affects females. Systemic and coronary arterial abnormalities are present in HFpEF and may contribute to HFpEF in females. We performed a cross-sectional study of 32 participants with HFpEF and 26 controls.

Pharmacological and metabolic parameters of [F]flubrobenguane in clinical imaging populations.

Background: Cardiac sympathetic nervous system molecular imaging has demonstrated prognostic value. Compared with meta-[C]hydroxyephedrine, [F]flubrobenguane (FBBG) facilitates reliable estimation of SNS innervation using similar analytical methods and possesses a more convenient physical half-life. The aim of this study was to evaluate pharmacokinetic and metabolic properties of FBBG in target clinical cohorts.

Effects of ranolazine on right ventricular function, fluid dynamics, and metabolism in patients with precapillary pulmonary hypertension: insights from a longitudinal, randomized, double-blinded, placebo controlled, multicenter study.

Introduction: Right ventricular (RV) function is a major determinant of outcome in patients with precapillary pulmonary hypertension (PH). We studied the effect of ranolazine on RV function over 6 months using multi-modality imaging and biochemical markers in patients with precapillary PH (groups I, III, and IV) and RV dysfunction [CMR imaging ejection fraction (EF) < 45%] in a longitudinal, randomized, double-blinded, placebo-controlled, multicenter study of ranolazine treatment.

Methods: Enrolled patients were assessed using cardiac magnetic resonance (CMR) imaging, C-acetate and -F-FDG positron emission tomography (PET), and plasma metabolomic profiling, at baseline and at the end of treatment.

Exponential dosing to standardize myocardial perfusion image quality with rubidium-82 PET.

Background: Rb PET is commonly performed using the same injected activity in all patients, resulting in lower image quality in larger patients. This study compared Rb dosing with exponential vs proportional functions of body weight on the standardization of myocardial perfusion image (MPI) quality.

Methods: Two sequential cohorts of N = 60 patients were matched by patient weight.

Anti-inflammatory effect of biologic therapy in patients with psoriatic disease: A prospective cohort FDG PET study.

Aim: The aim of the study was to evaluate the changes in central vascular inflammation measured by FDG PET and myocardial blood flow reserve (MFR) determined by Rb PET following therapy with biologic agents for 6 months in patients with psoriatic arthritis (PsA) and/or cutaneous psoriasis (PsO) (group 1) and compare with PsO subjects receiving non-biologic therapy (group 2) and controls (group 3).

Methods And Results: Target-to-background ratio (TBR) by FDG PET in the most diseased segment of the ascending aorta (TBR) was measured to assess vascular inflammation. Rb PET studies were used to assess changes in left ventricular MFR.

Improved precision of SPECT myocardial blood flow using a net tracer retention model.

Background: Noninvasive quantification of absolute myocardial blood flow (MBF) and myocardial flow reserve (MFR) provides incremental benefit to relative myocardial perfusion imaging (MPI) to diagnose and manage heart disease. MBF can be measured with single-photon emission computed tomography (SPECT) but the uncertainty in the measured values is high. Standardization and optimization of protocols for SPECT MBF measurements will improve the consistency of this technique.

Automated dynamic motion correction improves repeatability and reproducibility of myocardial blood flow quantification with rubidium-82 PET imaging.

Background: Patient motion reduces the accuracy of PET myocardial blood flow (MBF) measurements. This study evaluated the effect of automatic motion correction on test-retest repeatability and inter-observer variability in a clinically relevant population.

Methods: Patients with known or suspected CAD underwent repeat rest Rb PET scans within minutes as part of their scheduled rest-stress perfusion study.

Negative Association of Smoking History With Clinically Manifest Cardiac Sarcoidosis: A Case-Control Study.

Background: The etiology of sarcoidosis is still unknown and is likely related to a genetic susceptibility to unidentified environmental trigger(s). Our group and others have extensively described a specific phenotype of primarily Caucasian patients who have clinically manifest cardiac sarcoidosis (CS). In this study, we sought to explore whether smoking is associated with this specific phenotype of sarcoidosis.

Myocardial perfusion quantification with Rb-82 PET: good interobserver agreement of Carimas software on global, regional, and segmental levels.

Purpose: To estimate the interobserver agreement of the Carimas software package (SP) on global, regional, and segmental levels for the most widely used myocardial perfusion PET tracer-Rb-82.

Materials And Methods: Rest and stress Rb-82 PET scans of 48 patients with suspected or known coronary artery disease (CAD) were analyzed in four centers using the Carimas SP. We considered values to agree if they simultaneously had an intraclass correlation coefficient (ICC) > 0.

Metabolic activity of the left and right atria are differentially altered in patients with atrial fibrillation and LV dysfunction.

Background: Alterations in atrial metabolism may play a role in the perpetuation of atrial fibrillation (AF). This study sought to compare F-fluorodeoxyglucose (FDG) uptake on PET, in patients with LV dysfunction versus those without AF.

Methods: Seventy-two patients who underwent myocardial viability assessment were evaluated.

Static CT myocardial perfusion imaging: image quality, artifacts including distribution and diagnostic performance compared to Rb PET.

Background: Rubidium-82 positron emission tomography (Rb PET) MPI is considered a noninvasive reference standard for the assessment of myocardial perfusion in coronary artery disease (CAD) patients. Our main goal was to compare the diagnostic performance of static rest/ vasodilator stress CT myocardial perfusion imaging (CT-MPI) to stress/ rest Rb PET-MPI for the identification of myocardial ischemia.

Methods: Forty-four patients with suspected or diagnosed CAD underwent both static CT-MPI and Rb PET-MPI at rest and during pharmacological stress.

Anti-inflammatory effect of rosuvastatin in patients with HIV infection: An FDG-PET pilot study.

Aims: This study aimed to evaluate markers of systemic as well as imaging markers of inflammation in the ascending aorta, bone marrow, and spleen measured by 18F-FDG PET/CT, in HIV+ patients at baseline and following therapy with rosuvastatin.

Methods And Results: Of the 35 HIV+ patients enrolled, 17 were randomized to treatment with 10 mg/day rosuvastatin and 18 to usual care for 6 months. An HIV- control cohort was selected for baseline comparison of serum inflammatory markers and monocyte markers of inflammation.

Cardiac Sympathetic Positron Emission Tomography Imaging with -[F]Fluorobenzylguanidine is Sensitive to Uptake-1 in Rats.

Dysfunction of the cardiac sympathetic nervous system contributes to the development of cardiovascular diseases including ischemia, heart failure, and arrhythmias. Molecular imaging probes such as -[I]iodobenzylguanidine have demonstrated the utility of assessing neuronal integrity by targeting norepinephrine transporter (NET, uptake-1). However, current radiotracers can report only on innervation due to suboptimal kinetics and lack sensitivity to NET in rodents, precluding mechanistic studies in these species.