ARRS 2022 Abstracts


E1733. Non-Oncologic Joint-Related Musculoskeletal Findings on 18F-FDG PET/CT: A Case-Based Pictorial Review and Its Multi-Modality Correlation
  1. Pokhraj Suthar; Rush University Medical Center
  2. Sumeet Virmani; Rush University Medical Center
18F-FDG PET/CT is routinely performed to detect, stage, and evaluate treatment response for many solid cancers. Many nonmalignant pathologies in the musculoskeletal system may demonstrate FDG uptake on 18F-FDG PET/CT, many of which may be confused with metastatic disease by those unfamiliar with these entities. This case-based educational exhibit highlights the various non-oncological musculoskeletal findings on 18F-FDG PET/CT and their correlation with other imaging modalities.

Educational Goals / Teaching Points
The goals of this exhibit are to evaluate the spectrum of characteristic non-oncological, joint-related, musculoskeletal findings and patterns of FDG uptake on 18F-FDG PET/CT and correlate those findings with other imaging modalities.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
There is no absolute SUV cut off to reliably differentiate benign from malignant lesions. Additional MRI correlation is helpful in clinical management. Alternatively, attention should be given on follow-up PET/CT examination, as the FDG activity from some benign lesions should normalize over several months. We present a case-based pictorial review highlighting the spectrum of non-oncological, joint-related FDG uptake and its multimodality correlation, focusing on shoulder and hip joints and the spine. The spectrum of cases include: muscle strain, post-traumatic FDG uptake such as in Hill Sachs lesion, rotator cuff abnormalities of the shoulder, adhesive capsulitis, various degree of degenerative changes involving articular surface and synovium, joint effusions, ligament injuries, myositis ossification, hypertrophic bone, peri-prosthetic complications, post-radiation changes, rheumatoid arthritis, bursitis, enthesitis, kissing spine, and facet and disc abnormalities.

18F-FDG PET/CT is prone to many pitfalls and incidental findings, largely related to whole body imaging and the nonspecific mechanism of FDG. Nonspecific nature of articular and periarticular FDG uptake in the shoulder, hip, and spine is usually associated with painful joint disease. This presented PET/CT case-based pictorial review with multimodality correlation raises awareness and strengthens the judgment of the reading physician.