Abstract
18F-FDG PET/CT has become the reference standard in oncologic imaging against which the performance of other imaging modalities is measured. The promise of PET/MRI includes multiparametric imaging to further improve diagnosis and phenotyping of cancer. Rather than focusing on these capabilities, many investigators have examined whether 18F-FDG PET combined with mostly anatomic MRI improves cancer staging and restaging. After a description of PET/MRI scanner designs and a discussion of technical and operational issues, we review the available literature to determine whether cancer assessments are improved with PET/MRI. The available data show that PET/MRI is feasible and performs as well as PET/CT in most types of cancer. Diagnostic advantages may be achievable in prostate cancer and in bone metastases, whereas disadvantages exist in lung nodule assessments. We conclude that 18F-FDG PET/MRI and PET/CT provide comparable diagnostic information when MRI is used simply to provide the anatomic framework. Thus, PET/MRI could be used in lieu of PET/CT if this approach becomes economically viable and if reasonable workflows can be established. Future studies should explore the multiparametric potential of MRI.
Footnotes
Published online Jan. 7, 2016.
Learning Objectives: On successful completion of this activity, participants should be able to (1) describe the different PET/MRI designs available for cancer assessment; (2) understand how photon attenuation correction for PET/MRI is done; and (3) evaluate whether PET/MRI provides diagnostic advantages over PET/CT in cancer.
Financial Disclosure: Dr. Czernin has ownership (unrelated to the paper) in Sofie Biosciences, Momentum Biosciences, and Trethera Corporation. Dr. Herrmann has ownership (unrelated to the paper) in SurgicEye and Sofie Biosciences and is a member of the advisory board of OctreoPharm Sciences GmbH. The authors of this article have indicated no other relevant relationships that could be perceived as a real or apparent conflict of interest.
CME Credit: SNMMI is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to sponsor continuing education for physicians. SNMMI designates each JNM continuing education article for a maximum of 2.0 AMA PRA Category 1 Credits. Physicians should claim only credit commensurate with the extent of their participation in the activity. For CE credit, SAM, and other credit types, participants can access this activity through the SNMMI website (http://www.snmmilearningcenter.org) through March 2019.
- © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.