title: Tracer accumulation in femoral head during early phase of bone scintigraphy after renal transplantation.
abstract: Nontraumatic osteonecrosis of the femoral head (ONF) is a complication of renal transplantation. The pathogenic mechanism of ONF is thought to be an ischemic event. The purpose of this study was to investigate whether 3-phase bone scintigraphy can reveal early hemodynamic changes associated with ONF after renal transplantation.
  
  
  METHODS
  We performed 3-phase bone scintigraphy on 19 renal allograft recipients between 3 and 9 wk after they underwent renal transplantation. Regions of interest (ROI) were assigned bilaterally in the femoral heads, diaphyses, and soft tissue. The head-to-diaphysis ratio (HD) in each phase was then calculated.
  
  
  RESULTS
  ONF occurred in 8 femoral heads of 4 patients. Three of the 4 ONF patients had no abnormal MRI findings at the time of bone scintigraphy. In phase 1, no significant difference in HDs was observed between the ONF patients (mean HD +/- SD, 0.62 +/- 0.44) and the non-ONF patients (0.31 +/- 1.40). The difference between the mean counts for bone and soft tissue was small in both instances, and the HD had a large dispersion. In phase 2, the HDs for the ONF patients (0.70 +/- 0.27) and the non-ONF patients (1.31 +/- 0.43) were significantly different (P = 0.0005). The HD was <1.00 in all femoral heads of the ONF patients, whereas 9 non-ONF heads had an HD that was <1.00. In phase 3, the HD of the ONF patients was significantly lower than that of the non-ONF patients (ONF patients, 0.92 +/- 0.17; non-ONF patients, 1.62 +/- 0.46; P = 0.0002).
  
  
  CONCLUSIONS
  All ONF patients were in the group with a low HD in phase 2, suggesting a reduction in blood flow or blood pool. Phase 2 accumulation in 3-phase bone scintigraphy can be used to estimate early hemodynamic changes in patients with ONF after renal transplantation.
authors.affiliation: Department of Radiology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kubota
authors.forename: Y
authors.initials: Y
authors.lastname: Ushijima
authors.forename: C
authors.initials: C
authors.lastname: Okuyama
authors.forename: T
authors.initials: T
authors.lastname: Kubo
authors.forename: T
authors.initials: T
authors.lastname: Nishimura
mesh_terms: D000328:Adult; D001842:Bone and Bones / Q000000981:diagnostic imaging*; D005260:Female; D005270:Femur Head / Q000098:blood supply / Q000000981:diagnostic imaging; D005271:Femur Head Necrosis / Q000000981:diagnostic imaging*; D006801:Humans; D016030:Kidney Transplantation; D008297:Male; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D013669:Technetium Tc 99m Medronate / Q000031:analogs & derivatives*
chemical_list: D019275:Radiopharmaceuticals; C024226:technetium Tc 99m hydroxymethylene diphosphonate; D013669:Technetium Tc 99m Medronate