Atlas for reporting PET myocardial perfusion imaging and myocardial blood flow in clinical practice

Atlas for reporting PET myocardial perfusion imaging and myocardial blood flow in clinical practice: an information statement from the American Society of Nuclear Cardiology

J Nucl Cardiol. 2023;30:2850-2906.

Panithaya Chareonthaitawee, MD
Timothy M. Bateman, MD
Rob S. Beanlands, MD
Viviany R. Taqueti, MD, MPH
Christiane C. Wiefels, MD
Mouaz H. Al-Mallah, MD

Introduction
Over the past decade, PET myocardial perfusion imaging (MPI) has experienced significant growth as a pivotal diagnostic and prognostic clinical tool in the non-invasive evaluation of patients with suspected or known obstructive coronary artery disease (CAD), and coronary microvascular dysfunction (CMD). The technical advantages of PET MPI, characterized by its high spatial and contrast resolution, in conjunction with consistent and robust attenuation correction, have facilitated the generation of high-quality images with elevated diagnostic precision, and translated into effective risk stratification in diverse clinical scenarios. In addition to its capacity for visualizing assessment of left ventricular (LV) myocardial perfusion, PET MPI has introduced routine quantification of absolute global and regional myocardial blood flow (MBF) at rest and with stress. Augmented by the computation of myocardial blood flow reserve (MFR), this approach has incremental diagnostic and prognostic value in obstructive CAD and CMD and other clinical scenarios. Acknowledging its strengths, the Centers of Medicare and Medicaid Services (CMS) approved PET MPI for reimbursement two decades ago. In 2020, absolute quantitation of myocardial blood flow, positron emission tomography, rest and pharmacologic stress was given a Category 1 code, 78434. Under the Hospital Outpatient Prospective Payment System, it is bundled in with the primary procedure and should be reported in studies when it is performed. In the Physician Fee Schedule, it is an add-on code and separately payable by CMS and recognized as an essential component of PET MPI when performed. Moreover, the specific Current Procedural Terminology (CPT) codes diverge based on whether image acquisition involves a dedicated PET system or a hybrid PET/CT setup. The increasing adoption of PET MPI and quantification of MBF in clinical practice necessitates a pragmatic and concise approach for reporting and conveying results to referring practitioners and their patients. In 2017, the American Society of Nuclear Cardiology (ASNC) published a Guideline for standardized reporting of nuclear cardiology procedures, which presented a structured framework for all nuclear cardiology reports and emphasized standardized data elements and interpretation.1 Reporting PET MPI and MBF findings also requires understanding of the technical and clinical considerations of quantitative PET imaging, as outlined in joint statements from ASNC and the Society of Nuclear Medicine and Molecular Imaging (SNMMI).2,3 Interpreting physicians are encouraged to read and understand these three documents given their critical importance to the performance, interpretation, and reporting of PET MPI and MBF quantification. As the application of PET MPI and MBF quantification continues to expand within the clinical domain,4 there has been a concurrent interest in exploring diverse strategies to effectively communicate the multifaceted data from relative, semi-quantitative, and quantitative MPI and PET/CT in a format that is actionable and most useful clinically. In response, ASNC has endorsed this current document as a companion reporting atlas to the previously mentioned publications. The intent is to provide interpreting physicians with a range of approaches for reporting assorted combinations of semi-quantitative perfusion, absolute MBF quantification, and other pertinent findings, including those derived from the CT portion of the examinations.

This document is divided into three sections: structured reporting elements, including reporting of MBF and MFR; overall impression considerations; and case examples with sample reporting templates from the writing committee members’ practice.

Read More