AUTHOR=Noto Yu-ichi , Kondo Masaki , Tsuji Yukiko , Matsushima Shigenori , Mizuno Toshiki , Tokuda Takahiko , Nakagawa Masanori 

TITLE=Diagnostic Value of Muscle [11C] PIB-PET in Inclusion Body Myositis

JOURNAL=Frontiers in Neurology

VOLUME=10

YEAR=2020

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2019.01386

DOI=10.3389/fneur.2019.01386

ISSN=1664-2295

ABSTRACT=<p><bold>Background:</bold> The accumulation of multiple-protein aggregates within muscle fibers is a pathological hallmark of sporadic inclusion body myositis (s-IBM) with the presence of inclusion bodies. Amyloid-beta is one of the accumulated proteins in s-IBM. The aim of this study was to elucidate the utility of Pittsburgh compound B-positron emission tomography (PIB-PET) for diagnosing s-IBM.</p><p><bold>Methods:</bold> Nine patients with s-IBM and four patients with idiopathic inflammatory myopathy (IIM) were included. Patients underwent PIB-PET of body muscles. Standardized uptake values (SUVs) were measured in 16 muscles. A comparison of SUVs was made between s-IBM and IIM groups. The correlation between PIB-PET and clinical parameters was analyzed.</p><p><bold>Results:</bold> The mean SUV of all muscles in s-IBM patients was higher than in IIM patients (0.32 vs. 0.25, respectively; <italic>p</italic> = 0.031). Subgroup analysis identified a clear difference in SUVs of the forearm and lower-leg muscle groups (<italic>p</italic> = 0.021 and <italic>p</italic> = 0.045, respectively). There was no correlation between SUVs and clinical parameters in s-IBM patients.</p><p><bold>Conclusions:</bold> Muscle PIB-PET may help to make a diagnosis of s-IBM.</p>