Session Title: Imaging of Rheumatic Diseases - Poster II: XR/CT/PET/MRI
Session Type: ACR Poster Session B
Session Time: 9:00AM-11:00AM
Background/Purpose: Polymyositis/dermatomyositis (PM/DM) are systemic inflammatory disorders predominantly affecting skeletal muscles and skin respectively. Although muscle biopsy is the most important to the diagnosis of PM/DM, some cases may not have inflammatory lesion in biopsy site. There are some reports that enhanced magnetic resonance imaging (MRI) is useful for decision of biopsy site. However, enhanced MRI could not detect inflammatory lesion of whole body easily.The purpose of this study was to investigate the usefulness of volumetric parameters of the whole-body FDG PET/CT for evaluating disease activity in patients with PM/DM.
Methods: A total of 21 patients with previously untreated PM/DM were examined with whole-body FDG PET/CT. The same number of age- and sex-matched control patients with non-muscular diseases were also identified. The FDG uptake was visually evaluated in 22 regions of the whole-body. Regions with FDG uptake greater than that of the mediastinum blood vessels were considered positive. The semi-quantitative analysis was also performed using a maximum standardized uptake value (SUVmax), metabolic volume (MTV), and total lesion glycolysis (TLG). PET results were compared with those of serum levels of creatine kinase (CK) and aldolase.
Results: On visual analysis, the mean ± SD of number of positive regions in patients with PM/DM was 11 ± 7. The mean value of SUVmax in patients with PM/DM was significantly higher than that in control patients (p<0.001). There was a significant correlation between number of positive regions and TLG (p<0.04). There was a significant correlation between MTV and aldolase (p<0.04) and between TLG and CK (p<0.009) and aldolase (p<0.006). There was no significant correlation between number of positive regions and CK or aldolase and between SUVmax and CK or aldolase.
Conclusion: These preliminary results suggest that volumetric parameters such as MTV and TLG of whole-body FDG PET/CT may be useful for evaluating disease activity in patients with PM/DM.
To cite this abstract in AMA style:Kondo A, Dobashi H, Kameda T, Izumikawa M, Nakashima S, Shimada H, Ozaki H, Wakiya R, Yamamoto Y, Nishiyama Y, Kadowaki N. The Usefulness of Volumetric Parameters of FDG PET/CT for Reflecting Disease Activity in Polymyositis/Dermatomyositis Patients [abstract]. Arthritis Rheumatol. 2016; 68 (suppl 10). https://acrabstracts.org/abstract/the-usefulness-of-volumetric-parameters-of-fdg-petct-for-reflecting-disease-activity-in-polymyositisdermatomyositis-patients/. Accessed November 28, 2020.
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