title: Serial magnetic resonance imaging in a non-traumatic rabbit osteonecrosis model: an experimental longitudinal study.
abstract: We investigated the time-dependent natural course of experimental osteonecrosis (ON), including initial changes in ON and the reparative process, using in vivo serial repetitive magnetic resonance imaging (MRI) in a non-traumatic rabbit serum sickness ON model. Some necrotic lesions were detected at 1 week (3 of 16 femora with necrotic lesions) and some in the metaphysis were detected by 12 weeks (2 of 6 femora with lesions) on T(1)-weighted, T(2)-weighted, and fat suppression T(1)-weighted images. On contrast-enhanced MRI, extravasation of the erythrocytes was detected at 72 h (7 of 26 femora with lesions) as a small, focal enhanced area. Necrotic lesions were detected in all abnormal femora by 6 weeks (16 of 16 femora with lesions) as focal, homogeneously or inhomogeneously enhanced areas. Reparative tissue replaced with new vascular and trabecular formation in necrotic areas was detected as an extended marginal enhanced area at 12 weeks. These results suggest that the enhancement patterns on contrast-enhanced MRI may provide helpful information about the developmental and reparative process of clinical ON.
authors.affiliation: Department of Orthopedic Surgery, Osaka University Medical School, Osaka, Japan. tsakai@ort.med.osaka-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Sakaia
authors.forename: N
authors.initials: N
authors.lastname: Sugano
authors.forename: T
authors.initials: T
authors.lastname: Tsuji
authors.forename: T
authors.initials: T
authors.lastname: Nishii
authors.forename: H
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: K
authors.initials: K
authors.lastname: Ohzono
mesh_terms: D000818:Animals; D003287:Contrast Media; D004195:Disease Models, Animal; D005269:Femur / Q000473:pathology*; D007089:Image Enhancement / Q000379:methods*; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010020:Osteonecrosis / Q000175:diagnosis*; D011817:Rabbits; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media