Conspicuity of FDG-Avid Osseous Lesions on PET/MRI Versus PET/CT: a Quantitative and Visual Analysis

Expert Panel on Neurological Imaging, Eldaya RW, Parsons MS, Hutchins TA, Avery R, Burns J, Griffith B, Hassankhani A, Khan MA, Ng H, Raizman NM, Reitman C, Shah VN, Sliker C, Soliman H, Timpone VM, Tomaszewski CA, Yahyavi-Firouz-Abadi N, Policeni B. ACR Appropriateness Criteria® Cervical Pain or Cervical Radiculopathy: 2024 Update

Cervical spine pain is one of the most common reasons for seeking medical care as it ranks in the top 5 causes of global years lost to disability. The economic burden of cervical pain is also significant. Imaging is at the center of diagnosis of cervical pain and its causes. However, different symptoms and potential causes of cervical pain require different initial imaging to maximize the benefit of diagnostic usefulness of imaging. In this document we address different cervical pain variants with detailed assessment of the strengths and weaknesses of different modalities for addressing each specific variant. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Neuroendocrine Tumor Diagnosis: PET/MR Imaging

Imaging plays a critical role in the diagnosis and management of neuroendocrine tumors (NETs). The initial workup of the primary tumor, including its characterization, local and distant staging, defines subsequent treatment decisions. Functional imaging using hybrid systems, such as PET combined with computed tomography, has become the gold standard. As NETs majorly arise from the gastrointestinal system and metastasize primarily to the liver, simultaneous PET and MR imaging with its high soft tissue contrast might be a valuable clinical one-stop-shop whole-body imaging tool. This review presents the current status and challenges of PET/MR imaging for diagnosis of NETs.

Clinical Applications of PET/MR Imaging

PET/MR imaging is in routine clinical use and is at least as effective as PET/CT for oncologic and neurologic studies with advantages with certain PET radiopharmaceuticals and applications. In addition, whole body PET/MR imaging substantially reduces radiation dosages compared with PET/CT which is particularly relevant to pediatric and young adult population. For cancer imaging, assessment of hepatic, pelvic, and soft-tissue malignancies may benefit from PET/MR imaging. For neurologic imaging, volumetric brain MR imaging can detect regional volume loss relevant to cognitive impairment and epilepsy. In addition, the single-bed position acquisition enables dynamic brain PET imaging without extending the total study length which has the potential to enhance the diagnostic information from PET.

Practical Considerations for Clinical PET/MR Imaging

Clinical PET/MR imaging is currently performed at a number of centers around the world as part of routine standard of care. This article focuses on issues and considerations for a clinical PET/MR imaging program, focusing on routine standard-of-care studies. Although local factors influence how clinical PET/MR imaging is implemented, the approaches and considerations described here intend to apply to most clinical programs. PET/MR imaging provides many more options than PET/computed tomography with diagnostic advantages for certain clinical applications but with added complexity. A recurring theme is matching the PET/MR imaging protocol to the clinical application to balance diagnostic accuracy with efficiency.