de-Lacerda99m Tc-MDP bone uptake in secondary hyperparathyroidism: comparison of the mandible, cranium, radius, and femur Abstract Objectives. To evaluate the bone involvement of the mandible, cranium, radius, and femur in secondary hyperparathyroidism (SHPT) using 99m Tc-MDP uptake correlated with the serum intact parathyroid hormone (PTHi). Methods. In a prospective study of 54 patients with SHPT due to chronic renal disease and 15 normal individuals (control group), all patients had elevated serum PTHi and positive 99m Tc-MDP bone scintigraphy. Bone uptake was measured in regions of interest (ROIs) in the mandible, posterior cranium, distal radius, and proximal femur. In addition, soft tissue uptake was measured in one ROI in the soft tissues of the medial thigh (BG). The ROI-BG ratio was used as an index of the normalized bone uptake. Results. The uptake differences in the SHPT and control groups were statistically signifi cant for the mandible (P = 0.001) and cranium (P = 0.002). When the SHPT group was subclassifi ed according to serum PTHi levels, the bone uptake increased with the serum PTHi level. All mandibles of the patients with SHPT were abnormal, and 33% had focal lesions. Conclusions. The bone uptake in the SHPT group was abnormal in all areas evaluated, and a high uptake of 99m Tc-MDP was correlated with an increased serum PTHi.