Proceedings of the Cardiac PET Summit, 12 May 2014, Baltimore, MD : 3: Quantitation of myocardial blood flow

Review of cardiovascular imaging in the Journal of Nuclear Cardiology 2019: Single-photon emission computed tomography

In 2019, the Journal of Nuclear Cardiology published excellent articles pertaining to imaging in patients with cardiovascular disease. In this review, we will summarize a selection of these articles to provide a concise review of the main advancements that have recently occurred in the field and provide the reader with an opportunity to review a wide selection of articles. In the first article of this 2-part series, we focused on publications dealing with positron emission tomography, computed tomography, and magnetic resonance. This review will place emphasis on myocardial perfusion imaging using single-photon emission computed tomography summarizing advances in the field including in diagnosis and prognosis, non-perfusion variables, safety of testing, imaging in patients with heart failure and renal disease.

Diagnostic performance of the quantification of myocardium at risk from MPI SPECT/CTA 2G fusion for detecting obstructive coronary disease: A multicenter trial

BACKGROUND

The effective non-invasive identification of coronary artery disease (CAD) and its proper referral for invasive treatment are still unresolved issues. We evaluated our quantification of myocardium at risk (MAR) from our second generation 3D MPI/CTA fusion framework for the detection and localization of obstructive coronary disease.

METHODS

Studies from 48 patients who had rest/stress MPI, CTA, and ICA were analyzed from 3 different institutions. From the CTA, a 3D biventricular surface of the myocardium with superimposed coronaries was extracted and fused to the perfusion distribution. Significant lesions were identified from CTA readings and positioned on the fused display. Three estimates of MAR were computed on the 3D LV surface on the basis of the MPI alone (MARp), the CTA alone (MARa), and the fused information (MARf). The extents of areas at risk were used to generate ROC curves using ICA anatomical findings as reference standard.

RESULTS

Areas under the ROC curve (AUC) for CAD detection using MARf was 0.88 (CI = 0.75-0.95) and for MARp and MARa were, respectively 0.82 (CI = 0.69-0.92) and 0.75 (CI = 0.60-0.86) using the ≥70% stenosis criterion. AUCs for CAD localization (all vessels) using MARf showed significantly higher performance than either MARa or MARp or both.

CONCLUSIONS

Using ICA as the reference standard, MAR as the quantitative parameter, and AUC to measure diagnostic performance, MPI-CTA fusion imaging provided incremental diagnostic information compared to MPI or CTA alone for the diagnosis and localization of CAD.

Accurate myocardial blood flow measurements: Quality from start to finish is key to success

Overall repeatability and accuracy of myocardial blood flow measurements depend on the quality of the image data, the proper use of the quantitative software, and the training of clinical staff. Unlike most imaging tests, absolute blood flow measurements have the potential to provide accurate information beyond what is seen visually. This additive information has been shown to help identify multivessel disease, balanced ischemia, true normal studies, and quality control problems that may not be visible in the relative perfusion pattern. Absolute blood flow and flow reserve measurements have been shown to be useful and reproducible on a wide array of imaging systems, radiotracer delivery systems, and software approaches. Regardless of the technology or technique, these benefits can only be achieved when the quality of the study is sufficient and the clinical staff is properly trained on its implementation.

Multi-modality imaging: Bird's eye view from the 2016 American Heart Association Scientific Sessions

This review summarizes key imaging studies that were presented in the American Heart Association Scientific Sessions 2016 related to the fields of nuclear cardiology, cardiac computed tomography, cardiac magnetic resonance, and echocardiography. This bird's eye view will inform readers about multiple studies from these different modalities. We hope that this general overview will be useful for those that did not attend the conference as well as to those that did since it is often difficult to get exposure to many abstracts at large meetings. The review, therefore, aims to help readers stay updated on the newest imaging studies presented at the meeting.

Coronary microvascular dysfunction in women with nonobstructive ischemic heart disease as assessed by positron emission tomography

Traditional approaches for risk assessment of ischemic heart disease (IHD) are based on the physiological consequences of an epicardial coronary stenosis. Of note, normal coronary arteries or nonobstructive coronary artery disease (CAD) is a common finding in women with signs and symptoms of ischemia. Therefore, assessment of risk based on a coronary stenosis approach may fail in women. Positron emission tomography (PET) quantifies absolute myocardial blood flow (MBF) which may help to elucidate other mechanisms involved such as endothelial dysfunction and alterations in the smooth muscle cell relaxation responsible for IHD in women. The objective of the present review is to describe the current state of the art of PET imaging in assessing IHD in women with nonobstructive CAD.

Clinical use of quantitative cardiac perfusion PET: rationale, modalities and possible indications. Position paper of the Cardiovascular Committee of the European Association of Nuclear Medicine (EANM)

Until recently, PET was regarded as a luxurious way of performing myocardial perfusion scintigraphy, with excellent image quality and diagnostic capabilities that hardly justified the additional cost and procedural effort. Quantitative perfusion PET was considered a major improvement over standard qualitative imaging, because it allows the measurement of parameters not otherwise available, but for many years its use was confined to academic and research settings. In recent years, however, several factors have contributed to the renewal of interest in quantitative perfusion PET, which has become a much more readily accessible technique due to progress in hardware and the availability of dedicated and user-friendly platforms and programs. In spite of this evolution and of the growing evidence that quantitative perfusion PET can play a role in the clinical setting, there are not yet clear indications for its clinical use. Therefore, the Cardiovascular Committee of the European Association of Nuclear Medicine, starting from the experience of its members, decided to examine the current literature on quantitative perfusion PET to (1) evaluate the rationale for its clinical use, (2) identify the main methodological requirements, (3) identify the remaining technical difficulties, (4) define the most reliable interpretation criteria, and finally (5) tentatively delineate currently acceptable and possibly appropriate clinical indications. The present position paper must be considered as a starting point aiming to promote a wider use of quantitative perfusion PET and to encourage the conception and execution of the studies needed to definitely establish its role in clinical practice.