title: Scintigraphic assessments of the reparative process in osteonecrosis of the femoral head using SPECT/CT with 99mTc hydroxymethylene diphosphonate.
abstract: OBJECTIVE
  The aim of the study was to assess the degree and location of the reparative process in early osteonecrosis of the femoral head on the basis of single-photon emission computed tomography/computed tomography (SPECT/CT) with technetium-99m hydroxymethylene diphosphonate.
  
  
  METHODS
  This study was approved by the institutional review board. We retrospectively evaluated SPECT/CT scans of 23 consecutive hips. On the basis of the classification system used, 12 hips were classified as stage 1 (no radiographic abnormality), six hips as stage 2 (demarcating sclerosis without femoral head collapse), and five hips as stage 3A (<3 mm femoral head collapse). In each femoral head, the area with the maximum uptake count was defined as the region of maximum uptake. The degree of maximum uptake was assessed by the count ratio, which was defined as the maximum count within the femoral head divided by the mean uptake count of the cross-sectional region of the ipsilateral femur at the level of the distal end of the lesser trochanter.
  
  
  RESULTS
  In stage 1, the maximum uptake count tended to occur in the anterior region of the femoral head. Meanwhile, in both stage 2 and stage 3A, the maximum uptake count was more likely to be observed in the lateral region. The mean count ratio of stage 2 was significantly higher than that of stage 1.
  
  
  CONCLUSIONS
  We speculate that osteoblastic activity in the precollapsed stage may gradually increase around the necrotic lesion, with a tendency to advance toward the lateral region of the femoral head.
authors: Departments of aOrthopaedic Surgery bClinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka cDepartment of Orthopaedic Surgery, Kyushu University Beppu Hospital, Oita, Japan.
authors: Goro
authors: G
authors: Motomura
authors: Takuaki
authors: T
authors: Yamamoto
authors: Koichiro
authors: K
authors: Abe
authors: Yasuharu
authors: Y
authors: Nakashima
authors: Masanobu
authors: M
authors: Ohishi
authors: Satoshi
authors: S
authors: Hamai
authors: Toshio
authors: T
authors: Doi
authors: Hiroshi
authors: H
authors: Honda
authors: Yukihide
authors: Y
authors: Iwamoto
mesh_terms: D000328:Adult; D001842:Bone and Bones / Q000000981:diagnostic imaging* / Q000378:metabolism; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging* / Q000378:metabolism; D005271:Femur Head Necrosis / Q000000981:diagnostic imaging* / Q000378:metabolism; D006615:Hip / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D010027:Osteotomy; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012189:Retrospective Studies; D013669:Technetium Tc 99m Medronate / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D014055:Tomography, Emission-Computed / Q000379:methods*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D019275:Radiopharmaceuticals; C024226:technetium Tc 99m hydroxymethylene diphosphonate; D013669:Technetium Tc 99m Medronate