Overview: Hybrid PET/MR Imaging for Oncologic, Neurologic, and Cardiac Indications

This report provides an overview of hybrid positron emission tomography (PET) and magnetic resonance (MR) imaging for various indications that are under study. As such, this report does not include some sections typically found in standard Emerging Technology Evidence Reports (i.e., Incidence/Prevalence, Evidence Base, Results) because the report does not focus on the evidence regarding any particular clinical indication. Also, we do not include the usual evidence dashboard ratings related to the quality, quantity, and consistency of evidence because we are not analyzing clinical evidence.

Although methods have been available for a few years to fuse separate PET/MR images obtained in separate imaging rooms and protocols, this report focuses on hybrid system imaging in which both the machines combine and process images using U.S. Food and Drug Administration (FDA)-cleared hybrid systems housed in a single examination room.

Proprietary names: Biograph® mMR System, Ingenuity TruFlight (TF) PET/MR

Generic names: dual-modality imaging, emission computed tomography system, fusion imaging, hybrid PET/MRI, integrated hybrid whole-body PET/MR scanner, integrated whole-body PET/MR scanner, multi-modality imaging, simultaneous MR/PET hybrid imaging, simultaneous whole-body PET/MR, whole-body molecular MR system

Disease specialists use different types of imaging alone or in combination (i.e., computed tomography CT, PET, MR) at several points in a clinical pathway (i.e., diagnosis, staging, treatment planning, monitoring) for treating a patient with a particular disease that requires imaging as part of its management.

CT involves "imaging anatomical information from a cross-sectional plane of the body…. Each image is generated by a computer synthesis of x-ray transmission data obtained in many different directions in a given plane. "1 CT scans reveal bone and soft tissue (e.g., organs, muscles, tumors). Adjusting image contrast highlights tissues of similar density, and use of graphics software permits data assembly from multiple cross-sections into three-dimensional (3-D) images. CT aids in diagnosis and treatment planning by determining the precise density, size, and location of tumors.1

PET uses positron-emitting isotopes to radiolabel biomolecules without changing their properties, providing information about the human body at the level of cellular activity and metabolism.2 A major limitation of PET scans is that "they lack good spatial resolution and do not provide sufficient anatomical information."3 Combined PET/CT imaging can identify the location of abnormal metabolic activity within the body;4 however, the combination of PET and CT exposes the patient to additional radiation dose.3 Nonetheless, PET/CT imaging is typically used to...