T. Sakai et al., Serial magnetic resonance imaging in a non-traumatic rabbit osteonecrosis model: an experimental longitudinal study, MAGN RES IM, 18(7), 2000, pp. 897-905
We investigated the time-dependent natural course of experimental osteonecr
osis (ON), including initial changes in ON and the reparative process, usin
g in vivo serial repetitive magnetic resonance imaging (MRI) in a non-traum
atic 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 w
ere detected by 12 weeks (2 of 6 femora with lesions) on T-1-weighted. T-2-
weighted, and far suppression T-1-weighted images. On contrast-enhanced MRI
, extravasation of the erythrocytes was detected at 72 h (7 of 26 femora wi
th 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 replace
d with new vascular and trabecular formation in necrotic areas was detected
as an extended marginal enhanced area at 12 weeks. These results suggest t
hat the enhancement patterns on contrast-enhanced MRI may provide helpful i
nformation about the developmental and reparative process of clinical ON. (
C) 2000 Elsevier Science Inc. All rights reserved.