December 29, 2014 — Manufacturers have introduced hybrid imaging systems that combine positron emission tomography (PET) with magnetic resonance imaging (MRI). The purported benefit is improved detail in organ and soft-tissue images without the ionizing radiation inherent with systems that combine PET with computed tomography (CT), the gold-standard hybrid imaging modality.
Utilization is affected by the uncertain reimbursement environment for integrated PET/MRI scans. Some private, third-party payers (Aetna, Anthem, Humana) deny coverage for the hybrid imaging exams. Clinical trials comparing PET/MRI to PET/CT imaging have generally not demonstrated a substantial difference in diagnostic accuracy between PET/MRI and PET/CT, affecting anticipated utilization.
ECRI Institute’s expert panel thought that the possible development of new PET radiotracers targeting brain structures and soft tissue tumors might increase PET/MRI utilization for certain indications, especially if evidence demonstrates a benefit in diagnostic accuracy and if reimbursement becomes available.
Potential Health Impact
Most clinical trials of PET/MRI underway are comparing it with PET/CT. Heusch et al. (2014) found no significant differences in tumor detection between the two modalities. Quick et al. (2013) reported that PET/MRI detected more tumors than PET/CT. However, other trials (Chandarana et al. 2013, Gaertner et al. 2013, Wiesmuller et al. 2013) found that PET/MRI detected most tumors identified by PET/CT. Afshar-Oromieh et al. (2014) and Beiderwellen et al. (2013) concluded that PET/MRI may have better contrast and tumor conspicuity than PET/CT, but Gaertner et al. (2013) found better tumor conspicuity with PET/CT.
Potential Financial Impact
Hospitals face substantial costs to acquire integrated PET/MRI technology, including construction or renovation required to accommodate the combined system’s physical requirements and to install MRI-compatible (nonmagnetic) ancillary medical equipment needed during imaging procedures. As changes in healthcare coverage place a greater financial burden on healthcare consumers, some patients may forgo expensive procedures or diagnostic tests, thereby reducing demand for some technologies.
For more information: www.ecri.org
March 31, 2017 
