Re: Polymyalgia rheumatica
As highlighted in this review, the diagnosis of polymyalgia rheumatic (PMR) can be challenging and dependent on clinical experience and expertise, underscoring the need for better diagnostic algorithms. Given the array of differential diagnoses including occult infection, malignancy or myositis, patients are often subjected to an array of investigations before the diagnosis of PMR is established, often as a diagnosis of exclusion, resulting in delayed diagnostic and costs associated with misdirected investigations.
18-F fluorodeoxyglucose (FDG) PET/CT enables whole body imaging of glycolytic metabolism and has been widely adopted for cancer imaging . Acute and chronic inflammatory processes also use glycolytic metabolism making FDG PET/CT an outstanding modality for imaging inflammatory diseases. It essentially enables “imaging of ESR” defining the location, pattern and degree of inflammation. Patients with PMR have a characteristic scan appearance (see image), with visualization of distinctive interspinous bursitis, widespread enthesopathies, synovitis and background large or medium large vessel vasculitis . PET/CT has discrepant and specific patterns for the differential diagnoses including infection, malignancy or myositis providing a one-stop shop for diagnosis. FDG PET/CT is perceived as an expensive test but performing an accurate and high yield test up-front can be cost effective by enabling better direction of appropriate investigations rather than performing an array of non-specific tests which in totally can more expensive and lead to incorrect diagnosis and misdirected patient management. PET also provides more accurate and earlier response assessment as glycolytic activity dissipates rapidly with effective treatment. The time has come for rheumatologists to embrace this technology to improve patient outcomes.
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Competing interests: No competing interests