Quantitative 3D scintigraphy shows increased muscular uptake of pyrophosphate in idiopathic inflammatory myopathy

• DOI: 10.1186/s13550-017-0348-2
• Publication Date: 2017-12-08T07:27:57Z
• Authors: Karin Folmer Thøg...; Jane Angel Simonsen; Svend Hvidsten; Oke Gerke; Søren Jacobsen; Poul Flemming Høi...; Karen Middelbo Bu...; Louise Pyndt Died...
• Keywords: Medical physics. Medical radiology. Nuclear medicine; 03 medical and health sciences; 0302 clinical medicine; Myositis; R895-920; Quantitative SPECT; PYP; SPECT/CT; Original Research

Nuclear imaging is increasingly being used in the diagnostic work-up of idiopathic inflammatory myopathy (IIM). Increased muscular uptake technetium-99m-pyrophosphate (99mTc-PYP) has hitherto been assessed qualitatively by planar scintigraphy. We set out to perform quantitative tomographic scintigraphy IIM. Ninety IIM patients and 48 control subjects underwent 99mTc-PYP single-photon emission computed tomography (SPECT)/CT upper lower body. Scans were evaluated visually an intensity score (1–4) quantitatively mean standardized value (SUVmean) thigh muscles after semi-automated segmentation these. Furthermore, a SUVmean gradient down along thighs was determined linear regression slice-by-slice activity. Interobserver analyses performed on qualitative evaluations. Compared controls, more often had high (p < 0.0001), but interobserver revealed only moderate agreement. The activity 60% higher than p 0.0001, albeit with wide range. There muscle, proximal tracer highest, this steeper controls; decreased 0.00024 0.00010 mm−1, respectively, thighs. significantly healthy controls assessment. distal part gradients differed between groups. Hence, nuclear allowing for quantification might contribute diagnosis IIM, SPECT/CT body suffice.