Myocardial perfusion scan

AIMS: Lethal arrhythmias in hypertrophic cardiomyopathy (HCM) are widely attributed to myocardial ischaemia and fibrosis. How these factors modulate arrhythmic risk remains largely unknown, especially as invasive mapping protocols are not routinely used in these patients. By leveraging multiscale digital-twin technologies, we aim to investigate ischaemic mechanisms of increased arrhythmic risk in HCM. METHODS AND RESULTS: Computational models of human HCM cardiomyocytes, tissue and ventricles were used to simulate outcomes of phase 1A acute myocardial ischaemia...

BACKGROUND: Dynamic myocardial computed tomography perfusion (CTP) is a novel imaging technique that increases the applicability of CT for cardiac imaging; however, the scanning requires a substantial radiation dose. PURPOSE: To investigate the feasibility of dose reduction in dynamic CTP by comparing all-heartbeat acquisitions to periodic skipping of heartbeats. MATERIAL AND METHODS: We retrieved imaging data of 38 dynamic CTP patients and created new datasets with every fourth, third or second beat (Skip1:4, Skip1:3, Skip1:2, respectively) removed...

BACKGROUND: Guidelines recommend standard pre-operative cardiac screening in all liver transplantation (LT) recipients, despite the relatively low prevalence of obstructive coronary artery disease. Most LT recipients often have non-gated computed tomography (CT) performed of the chest and abdomen. This study evaluated the ability of coronary artery calcification (CAC) assessment on consecutively available scans, to identify a selection of low-risk patients, in whom further cardiac imaging can be safely withheld...

BACKGROUND: The coronary sinus reducer (CSR) is proposed to reduce angina in patients with stable coronary artery disease by improving myocardial perfusion. We aimed to measure its efficacy, compared with placebo, on myocardial ischaemia reduction and symptom improvement. METHODS: ORBITA-COSMIC was a double-blind, randomised, placebo-controlled trial conducted at six UK hospitals. Patients aged 18 years or older with angina, stable coronary artery disease, ischaemia, and no further options for treatment were eligible...

Myocardial perfusion imaging using single-photon emission computed tomography (SPECT), or myocardial perfusion SPECT (MPS) is a widely used clinical imaging modality for the diagnosis of coronary artery disease. Current clinical protocols for acquiring and reconstructing MPS images are similar for most patients. However, for patients with outlier anatomical characteristics, such as large breasts, images acquired using conventional protocols are often sub-optimal in quality, leading to degraded diagnostic accuracy...

BACKGROUND: The value of semiquantitative resting myocardial perfusion imaging (MPI) in coronary artery disease (CAD) is limited. At present, quantitative MPI can be performed by a new cadmium zinc tellurium single-photon emission computed tomography (CZT-SPECT) scan. The quantitative index of resting myocardial blood flow (MBF) has received little attention, and its manifestations and clinical value in the presence of unstable coronary blood flow have not been clarified. PURPOSE: In patients with ST-segment elevation myocardial infarction (STEMI), whether resting MBF can provide additional value of blood flow than semi-quantitative resting MPI is not sure...

Heart failure (HF) is a leading cause of morbidity and mortality in the United States and worldwide, with a high associated economic burden. This study aimed to assess whether artificial intelligence models incorporating clinical, stress test, and imaging parameters could predict hospitalization for acute HF exacerbation in patients undergoing SPECT/CT myocardial perfusion imaging. Methods: The HF risk prediction model was developed using data from 4,766 patients who underwent SPECT/CT at a single center (internal cohort)...

BACKGROUND: In type 2 diabetes mellitus (T2DM) patients, left ventricular systolic dyssynchrony (LVSD) with normal left ventricular ejection fraction (LVEF) and normal myocardial perfusion could referred to as subclinical myocardial damage, which is difficult to diagnose at an early stage. Epicardial adipose tissue, a distinctive heart-specific visceral fat, is closely related to various cardiovascular diseases. The objective of this study was to investigate the correlation between epicardial fat volume (EFV) and subclinical myocardial damage in T2DM patients...

PURPOSE: Firstly, to validate automatically and visually scored coronary artery calcium (CAC) on low dose CT (LDCT) scans with a dedicated calcium scoring CT (CSCT) scan. Secondly, to assess the added value of CAC scored from LDCT scans acquired during [15O]-water-PET myocardial perfusion imaging (MPI) on prediction of major adverse cardiac events (MACE). METHODS: 572 consecutive patients with suspected coronary artery disease, who underwent [15O]-water-PET MPI with LDCT and a dedicated CSCT scan were included...

OBJECTIVE: Perfusable tissue fraction (PTF) and myocardial flow reserve (MFR) from 15 O-water dynamic positron emission tomography (PET) are parameters of myocardial viability. However, myocardial motion causes errors in these values. We aimed to develop accurate estimation of PTF and MFR in ischemic lesions using an electro-cardiogram (ECG)-gated dynamic myocardial PET with 15 O-water. METHODS: Twenty-seven patients with ischemic heart disease were enrolled. All patients underwent percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG)...

This paper discusses some of the recent advances in the use of noninvasive imaging applied to patients with hypertrophic cardiomyopathy. Echocardiography and cardiac CT are briefly discussed with respect to their power to detect apical aneurysmal disease. Echo phenotype-genotype correlations and the ability of echo to characterize myocardial work are reviewed. Positron emission tomography (PET) is reviewed in the context of ischaemia imaging and also the use of a new tracer which may allow for recognition of early activation of the fibrosis pathway...

PURPOSE: Long axial field-of-view (LAFOV) positron emission tomography (PET) systems allow to image all major organs with one bed position, which is particularly useful for acquiring whole-body dynamic data using short-lived radioisotopes like 82 Rb. METHODS: We determined the absorbed dose in target organs of three subjects (29, 40, and 57 years old) using two different methods, i.e., MIRD and voxel dosimetry. The subjects were injected with 407.0 to 419.61 MBq of [82 Rb]Cl and were scanned dynamically for 7 min with a LAFOV PET/CT scanner...

BACKGROUND: It is clinically needed to explore a more efficient imaging protocol for single photon emission computed tomography (SPECT) myocardial blood flow (MBF) quantitation derived from cadmium zinc telluride (CZT) SPECT camera for the routine clinical utilization. METHODS: One hundred and twenty patients with matched clinical characteristics and angiographic findings who completed one-day rest/stress SPECT imaging with either the intermittently sequential imaging (ISI) protocol (two dynamic and two electrocardiography (ECG)-gated scans) or the continuous rapid imaging (CRI) protocol (two dynamic/ECG-gated scans) were included...

BACKGROUND: Despite its potential benefits, the utilization of stress-only protocol in clinical practice has been limited. We report utilizing stress-first single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). METHODS: We assessed 12,472 patients who were referred for SPECT-MPI between 2013 and 2020. The temporal changes in frequency of stress-only imaging were assessed according to risk factors, mode of stress, prior CAD history, LV function, and symptom status...

The presence of impaired microvascular coronary flow (MCF) identified by positron emission tomography myocardial perfusion imaging (PET-MPI) has been described in hypertrophic obstructive cardiomyopathy (HOCM) patients, contributes to blunted myocardial perfusion during vasodilator stress, and is a strong predictor of poor prognosis. A 45-year-old female with hypertension and obesity presented with angina. Her PET-MPI displayed vasodilator stress-induced global LV ischemia. However, her coronary angiogram revealed no obstructive coronary disease...

OBJECTIVES: This study assessed the imaging characteristics, pharmacokinetics and safety of XTR004, a novel 18 F-labeled Positron Emission Tomography (PET) myocardial perfusion imaging tracer, after a single injection at rest in humans. METHODS: Eleven healthy subjects (eight men and three women) received intravenous XTR004 (239-290 megabecquerel [MBq]). Safety profiles were monitored on the dosing day and three follow-up visits. Multiple whole-body PET scans were conducted over 4...

BACKGROUND: Fluorodeoxyglucose positron emission tomography (FDG PET) with glycolytic metabolism suppression plays a pivotal role in diagnosing cardiac sarcoidosis. Reorientation of images to match perfusion datasets is critical and myocardial segmentation enables consistent image scaling and quantification. However, both are challenging and labor intensive. We developed a 3D U-Net deep learning (DL) algorithm for automated myocardial segmentation in cardiac sarcoidosis FDG PET. METHODS: The DL model was trained on 316 patients' FDG PET scans, and left ventricular contours derived from perfusion datasets...

BACKGROUND: Quantitative CMR first pass perfusion maps are conventionally acquired with 3 short-axis views (basal, mid and apical) in every heartbeat (3SAX/1RR). Thus, a significant part of the LV myocardium, including the apex, is not covered. The aims of this study were 1) to investigate if perfusion maps acquired with 3 short-axis views sampled every other RR-interval (2RR) yield comparable quantitative measures of myocardial perfusion (MP) as 1RR and 2) to assess if acquiring 3 additional perfusion views (i...

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BACKGROUND: Acute aortic dissection (AAD) with impaired perfusion of the left coronary artery has a poor prognosis, even after urgent radical aortic surgery, due to extensive myocardial damage. Although Impella, a microaxial-flow catheter pump, is useful in managing acute myocardial infarction, it is generally contraindicated in patients with AAD because it is an intra-aortic device and the aortic structure is compromised in these cases. Here, we introduce a novel intervention that allowed a planned aortic repair after managing circulation using Impella and venoarterial extracorporeal membrane oxygenation in a case of AAD with left main trunk malperfusion...