ASNC says PET is now the preferred nuclear imaging test for CAD

The American Society of Nuclear Cardiology (ASNC) has shared its official answer to a decades-long debate over which cardiac nuclear imaging modality is the best for evaluating heart patients. In a new position statement, the group officially recommended that cardiac positron emission tomography (PET), if available, be used to evaluate all patients with suspected coronary artery disease (CAD) who are candidates for myocardial perfusion imaging (MPI). The statement was published in full in the Journal of Nuclear Cardiology.[1]

This is a significant moment in the world of nuclear imaging. The statement’s authors include six former ASNC presidents, and it codifies the group’s push in the past several years to get hospitals to buy more PET systems. 

The statement emphasizes extensive scientific research, worldwide clinical experience, and the latest multisocietal cardiology guidelines affirming cardiac PET’s high diagnostic accuracy, powerful risk stratification and low radiation exposure. ASNC has also highlighted PET’s expanded ability to assess coronary microvascular disease, myocardial viability, cardiac sarcoidosis, cardiac amyloidosis and infection.

“Based on the massive amount of clinical and scientific information now available and the latest U.S. and European guidelines, ASNC now recommends that PET MPI with myocardial blood flow (MBF), if available, should be the preferred modality for patients who meet criteria for MPI,” ASNC Past President Timothy Bateman, MD, the lead author of the position statement, said in a press release. “There are no clinical scenarios or patient subgroups where cardiac PET with myocardial blood flow should be excluded.”

Single photon emission computed tomography (SPECT) has been the workhorse nuclear imaging modality for cardiac perfusion studies since the 1970s. The introduction of PET in the 1990s brought improved image quality, and hybrid PET-CT systems with CT attenuation correction further pushed the needle in favor of PET. But barriers of greater cost, expensive radiotracers and low access to PET systems limited its wider use.

While there have been incremental technology improvements in SPECT technology with digital detectors, AI attenuation correction software and SPECT-CT, PET has maintained a lead in image quality. It also provides added value with its myocardial blood flow (MBF) assessments, especially for the evaluation of microvascular disease, which is not detectable on SPECT.

The position statement also detailed the clinical advantages of cardiac PET MPI, including increased diagnostic accuracy, risk stratification, reproducible myocardial blood flow quantification and more rapid exam times. The CT component of PET-CT also adds anatomical information and the ability to add on CT calcium scoring on the same exam.