PT - JOURNAL ARTICLE AU - Morand Piert AU - Tilman T. Zittel AU - Michael Jahn AU - Anke Stahlschmidt AU - Georg A. Becker AU - Hans-Jürgen Machulla TI - Increased Sensitivity in Detection of a Porcine High-Turnover Osteopenia After Total Gastrectomy by Dynamic <sup>18</sup>F-Fluoride Ion PET and Quantitative CT DP - 2003 Jan 01 TA - Journal of Nuclear Medicine PG - 117--124 VI - 44 IP - 1 4099 - http://jnm.snmjournals.org/content/44/1/117.short 4100 - http://jnm.snmjournals.org/content/44/1/117.full SO - J Nucl Med2003 Jan 01; 44 AB - High-resolution 18F-fluoride ion PET in combination with quantitative CT (QCT) allows the assessment of bone metabolism in relation to bone mass. This combined imaging approach was used to elucidate porcine bone metabolic changes after gastrectomy, which are frequently associated with osteopenia or osteomalacia. Methods: Six months after total gastrectomy (n = 7) or sham operation (n = 6), bone blood flow and bone metabolic activity (Ki, Kflux) were calculated from dynamic PET measurements from vertebral bodies and compared with corresponding QCT bone mineral density (BMD) measurements. Results: Total gastrectomy resulted in a significant reduction of the BMD (−21%; P &lt; 0.005), whereas 1,25-(OH)2-vitamin D, serum phosphate, and parathyroid hormone were significantly increased compared with that of sham-operated animals. Because of the significant increase of the rate constant k3 (+325%; P &lt; 0.05), describing chemisorption and incorporation of 18F-fluoride onto or into the bone matrix, Ki (+36%) and Kflux (+37%) were significantly elevated after total gastrectomy compared with that of control animals (P &lt; 0.01), whereas bone blood flow was not significantly different between groups. The normalization of Ki and Kflux values by the specific bone mass (Ki/BMD; Kflux/BMD) largely increased the differences between groups (Ki/BMD, +74%; Kflux, +76%; P &lt; 0.001). Conclusion: Dynamic 18F-fluoride ion PET revealed that porcine bone loss after total gastrectomy is related to a high-turnover bone disease without significant changes in bone blood flow. In mini pigs, the increased bone metabolism is probably related to an elevated parathyroid hormone secretion, thus maintaining serum calcium homeostasis at the expense of the bone mineral content. Normalizing bone metabolic activity by the specific bone mass increases the sensitivity in the detection of osteopenic high-turnover bone diseases. Therefore, the combination of QCT and 18F-fluoride ion PET seems to be the method of choice for the classification of metabolic bone diseases and for monitoring treatment effects quantitatively.