Association of Regional Bone Synthetic Activities of Vertebral Corners and Vertebral Bodies Quantified Using 18F-Fluoride Positron Emission Tomography with Bone Mineral Density on Dual Energy X-ray Absorptiometry in Patients with Ankylosing Spondylitis

Keunyoung Kim; Kyoungjune Pak; In-Joo Kim; Seong-Jang Kim; Dong Hyun Sohn; Aran Kim; Seung-Geun Lee

doi:10.3390/jcm9082656

Association of Regional Bone Synthetic Activities of Vertebral Corners and Vertebral Bodies Quantified Using ¹⁸F-Fluoride Positron Emission Tomography with Bone Mineral Density on Dual Energy X-ray Absorptiometry in Patients with Ankylosing Spondylitis

J Clin Med. 2020 Aug 17;9(8):2656. doi: 10.3390/jcm9082656.

Authors

Keunyoung Kim^{1

2}, Kyoungjune Pak^{1

2}, In-Joo Kim^{1

2}, Seong-Jang Kim³, Dong Hyun Sohn⁴, Aran Kim^{2

5}, Seung-Geun Lee^{2

5}

Affiliations

¹ Department of Nuclear Medicine, Pusan National University Hospital, Busan 49241, Korea.
² Biomedical Research Institute, Pusan National University Hospital, Busan 49241, Korea.
³ Department of Nuclear Medicine and Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan 50612, Korea.
⁴ Department of Microbiology and Immunology, Pusan National University School of Medicine, Yangsan 50612, Korea.
⁵ Divsion of Rheumatology, Department of Internal Medicine, Pusan National University School of Medicine, Pusan National University Hospital, Busan 49241, Korea.

Abstract

We investigated whether the bone-synthetic activities of vertebral bodies or vertebral corners quantified using ¹⁸F-fluoride positron emission tomography (PET) was associated with bone mineral density (BMD) at the corresponding lumbar vertebrae in ankylosing spondylitis (AS) at each vertebra level. We analyzed 48 lumbar vertebrae in 12 AS patients who underwent ¹⁸F-fluoride PET and dual energy X-ray absorptiometry (DXA). The mean standardized uptake values (SUVmean) of the vertebral body and corners from L1 to L4 were measured using the spatially separated region of interest (ROI). The L1-L4 BMDs were calculated based on the DXA ("conventional BMD"). The BMD of the internal vertebral bodies was measured by manually drawing ROIs to represent the trabecular BMD ("alternative BMD"). After adjusting the within-patient correlation, the ¹⁸F-fluoride SUVmean of the vertebral corners but not that of vertebral bodies was significantly related with the conventional BMD of the vertebra. Otherwise, the ¹⁸F-fluoride uptake of both the vertebral and vertebral bodies was significantly related with the alternative BMD. The bone-synthetic activities of the vertebral corners may be more closely related with BMD than those of the vertebral bodies, suggesting that the effects of regional bone metabolism at the vertebral corners and bodies on BMD differ in AS.

Keywords: ankylosing spondylitis; bone density; cancellous bone; cortical bone; positron emission tomography.