The influence of CT and dual-energy X-ray absorptiometry (DXA) bone density on quantitative 18F sodium fluoride PET

摘要

Background[¹⁸F] sodium fluoride PET/CT provides quantitative measures of bone metabolic activity expressed by the parameters standardised uptake value (SUV) and bone plasma clearance (Ki) that correlate with measurements of bone formation rate obtained by bone biopsy with double tetracycline labelling. Both SUV and Ki relate to the tracer uptake in each millilitre of tissue. In general, the bone region of interest (ROI) includes both mineralised bone {generally with a high concentration of [¹⁸F]NaF} and bone marrow (with a much lower concentration), suggesting that correcting SUV and Ki for volumetric bone mineral density (vBMD) and measuring them with respect to the tracer uptake in each gram of bone mineral might improve the correlation with the findings of bone biopsy. As a first test of this hypothesis, we looked for positive correlations between SUV and Ki values with CT and DXA bone mineral density (BMD) parameters measured in the same ROI.