Evolving role of FDG PET imaging in assessing joint disorders: a systematic review

Abstract

Assessing joint disorders has been a relatively recent and evolving application of 18F-2-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) imaging. FDG is taken up by inflammatory cells, particularly when they are active as part of an ongoing inflammatory process. Hence FDG PET has been employed to assess a wide array of arthritic disorders. FDG PET imaging has been investigated in various joint diseases for diagnostic purposes, treatment monitoring, and as a prognostic indicator as in other disorders. In some of the diseases the ancillary findings in FDG PET have provided important clues about the underlying pathophysiology and pathogenesis processes. While substantial promise has been demonstrated in a number of studies, it is clear that the potential utility of PET in this clinical realm far outweighs that which has been established to date.

Fluorine‐18‐fluoro‐2‐deoxy‐d‐glucose PET‐CT aids in detection of soft‐tissue injuries for dogs with thoracic or pelvic limb lameness

“…Unlike PET, ultrasound and MRI are available in most referral veterinary hospitals and frequently performed for the detection of soft tissue pathologies. Contrast‐enhanced MRI is generally considered the “gold standard” for the detection of musculoskeletal lesions . Both ultrasound and MRI introduce no radiation burden to the patient or the veterinary personnel.…”

“…Positron emission tomography‐CT can diagnose soft tissue pathologies and provides objective morphological lesion localization. In humans, PET‐CT is used for the clinical investigation of exercise physiology as well as to detect various musculoskeletal pathologies . The most common way to quantify PET tracer accumulation is by standardized uptake values (SUV), the tissue activity concentration normalized by the fraction of the injected dose/unit weight .…”

Increased 18F-FDG uptake suggests synovial inflammatory reaction with osteoarthritis

“…PET imaging with FDG as a surrogate marker for glucose utilization allows for the measurement of cellular metabolism in normal and pathological states. Increased FDG uptake in painful joints represents ongoing tissue inflammation, as has been demonstrated in studies of similar disease states [15, 16]. …”

Non-FDG PET in oncology

“…First, it is of rather limited use in several tumours that have a low metabolic rate, such as prostate cancer or [2], that are well differentiated malignancies, as is the case with many hepatocellular carcinomas, and in very mucinous tumours. Moreover, there can be prominent FDG uptake in infl ammatory and infectious diseases, which could potentially cause false positive interpretations, but at the same time constitutes a source of new indications for FDG PET/CT imaging in benign conditions [3,4].…”