High-resolution three-dimensional micro-computed tomography detects bone loss and changes in trabecular architecture early: comparison with DEXA and bone histomorphometry in a rat model of disuse osteoporosis.
OBJECTIVE
The ability of three-dimensional micro-computed tomography (3D-microCT) to detect changes in a rat model of disuse osteoporosis was evaluated and compared with two reference techniques: dual x-ray absorptiometry (DEXA) for bone mass, and bone histomorphometry (BHM) for bone mass and trabecular micro-architecture.


METHODS
Forty-two rats were divided into controls or were hindlimb unloaded for 7, 13, and 23 days. DEXA bone mineral density measurements were performed on right tibiae. Then, after plastic embedding, bone volume (BV/TV) and trabecular (Tb)-derived parameters of trabecular bone architecture (Tb Th, thickness; Tb N, number) were measured with BHM. 3D-microCT measurements of BV/TV, Tb Th, and Tb N were carried out on left tibiae.


RESULTS
Unloaded rats lost bone in a time-dependent manner. DEXA and 3D-microCT detected bone loss earlier than BHM. The decreases in Tb Th and Tb N were observed at day 13 only with 3D-microCT (P < 0.05 and P < 0.01, respectively). All bone mass and architectural parameters measured with the three techniques correlated significantly (0.59, 0.89, P < 0.001), except Tb Th.


CONCLUSIONS
3D-microCT is a valid technique for bone mass and micro-architecture measurements in this rat model of disuse osteoporosis.
Barou
Odile
O
Laboratoire de Biologie et de Biochimie du Tissu Osseux, Equipe Mixte INSERM 9901, Faculté de Médecine, Saint-Etienne, France.
Valentin
David
D
Vico
Laurence
L
Tirode
Cathrine
C
Barbier
Alain
A
Alexandre
Christian
C
Lafage-Proust
Marie-Hélène
MH
D015502:Absorptiometry, Photon; D000818:Animals; D019417:Hindlimb Suspension; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008297:Male; D008852:Microradiography; D010024:Osteoporosis / Q000000981:diagnostic imaging* / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D013977:Tibia / Q000000981:diagnostic imaging* / Q000473:pathology; D014057:Tomography, X-Ray Computed / Q000379:methods*