Cerebral and myocardial kinetics of [C]acetoacetate and [C]β-hydroxybutyrate: A comparative crossover study in healthy rats.

Background: Ketone metabolism has been studied using positron emission tomography (PET) with the radiotracers [C]acetoacetate and [C]β-hydroxybutyrate. However, whether these two radiotracers actually yield equivalent estimates of cerebral and myocardial ketone metabolism has not yet been investigated. This study aimed to investigate and compare the kinetics of both tracers in the brain and heart of healthy rats under varying levels of circulating ketones at baseline and after a single-dose exogenous ketone ester (KE) supplement.

A 3-Week Ketogenic Diet Increases Skeletal Muscle Insulin Sensitivity in Individuals With Obesity: A Randomized Controlled Crossover Trial.

A ketogenic diet (KD) can induce weight loss and improve glycemic regulation, potentially reducing the risk of type 2 diabetes development. To elucidate the underlying mechanisms behind these beneficial effects of a KD, we investigated the impact of a KD on organ-specific insulin sensitivity (IS) in skeletal muscle, liver, and adipose tissue. We hypothesized that a KD would increase IS in skeletal muscle.

Guiding early revascularization using [15O]H2O positron emission tomography myocardial perfusion imaging: impact of atrial fibrillation.

Aims: Myocardial perfusion imaging (MPI) using [15O]H2O positron emission tomography (PET) is used to guide the selection of patients with angina for invasive angiography and possible revascularization. Our study evaluated (i) whether atrial fibrillation (AF) reduces global hyperaemic myocardial blood flow (MBF) and (ii) whether [15O]H2O PET MPI effectively guides revascularization procedures for patients with ongoing AF.

Methods And Results: We prospectively recruited 346 patients with angina and persistent or paroxysmal AF referred for baseline/hyperaemic [15O]H2O PET MPI.

A ketogenic diet lowers myocardial fatty acid oxidation but does not affect oxygen consumption: a study in overweight humans.

Objective: A ketogenic diet (KD) characterized by very low carbohydrate intake and high fat consumption may simultaneously induce weight loss and be cardioprotective. The "thrifty substrate hypothesis" posits that ketone bodies are more energy efficient compared with other cardiac oxidative substrates such as fatty acids. This work aimed to study whether a KD with presumed increased myocardial ketone body utilization reduces cardiac fatty acid uptake and oxidation, resulting in decreased myocardial oxygen consumption (MVO ).

Intravenous and oral whole body ketone dosimetry, biodistribution, metabolite correction and kinetics studied by (R)-[1-C]β-hydroxybutyrate ([C]OHB) PET in healthy humans.

Background: Ketones are increasingly recognized as an important and possibly oxygen sparing source of energy in vital organs such as the heart, the brain and the kidneys. Drug treatments, dietary regimens and oral ketone drinks designed to deliver ketones for organ and tissue energy production have therefore gained popularity. However, whether ingested ketones are taken up by various extra-cerebral tissues and to what extent is still largely unexplored.

Myocardial perfusion imaging by O-HO positron emission tomography predicts clinical revascularization procedures in symptomatic patients with previous coronary artery bypass graft.

Aims: We wanted to assess if O-HO myocardial perfusion imaging (MPI) in a clinical setting can predict referral to coronary artery catheterization [coronary angiography (CAG)], execution of percutaneous coronary intervention (PCI), and post-PCI angina relief for patients with angina and previous coronary artery bypass graft (CABG).

Methods And Results: We analysed 172 symptomatic CABG patients referred for O-HO positron emission tomography (PET) MPI at Aarhus University Hospital Department of Nuclear Medicine & PET Centre, of which five did not complete the scan. In total, 145 (87%) enrolled patients had an abnormal MPI.

Clinical use of cardiac 18 F-FDG viability PET: a retrospective study of 44 patients undergoing post-test revascularization.

The coupling between coronary artery disease and the development of ischemic heart failure is well-established. For these patients, assessment of potentially viable but dysfunctional myocardial tissue (hibernation) is considered critical to guide optimal surgical treatment. Assessment with positron emission tomography (PET) theoretically provides measurements of hibernating tissue and maximal myocardial glucose uptake (MGU) in all cardiac territories.

Early acquisition of [F]FDOPA PET/CT imaging in patients with recurrent or residual medullary thyroid cancer is safe-and slightly better!

Purpose: The aim of this study was to compare early (15 min) and late (60 min) [F]FDOPA PET/CT acquisition times in the detection of recurrence/residual disease in medullary thyroid cancer (MTC) patients.

Materials And Methods: Thirty-two dual-phase [F]FDOPA PET scans were retrospectively reviewed. Scan indications were (1) suspected recurrence of MTC, (2) treatment monitoring, or (3) restaging.