Hepatic magnetic resonance imaging with T2* mapping of ovariectomized rats: correlation between iron overload and postmenopausal osteoporosis.
OBJECTIVE
To explore the correlation between liver iron overload and bone mineral density (BMD) in an ovariectomy (OVX) rat model, using liver magnetic resonance (MR)-T2* and dual-energy X-ray absorptiometry (DEXA).


METHODS
Sprague-Dawley rats received deferoxamine (DFO) or phosphate-buffered saline 3 months after bilateral OVX. MRI and DEXA were performed pre- and postoperatively. Five rats per group were killed every month for micro-CT, histopathology and biochemical examinations. Statistical analysis was performed with independent-samples t tests, box plots and Pearson's correlation analysis.


RESULTS
At 2 months postoperatively, BMD was significantly lower in the OVX group than in the control group (P < 0.01), corresponding to the increased serum ferritin concentration (SFC; P < 0.01) and liver iron concentration (LIC; P < 0.01). Liver T2* values significantly differed between the two groups at 1 month postoperatively (P < 0.001) and improved 1 month after DFO injection (P < 0.05). These values were significantly and positively correlated with BMD in the control (r = 0.527, P < 0.001) and OVX (r = 0.456, P < 0.001) groups.


CONCLUSIONS
Liver MRI T2* changed markedly earlier than BMD, LIC and SFC, and correlated well with osteoporosis; it may thus be a valuable early indicator of osteoporosis.


CONCLUSIONS
• Iron overload plays a vital role in the pathogenesis of postmenopausal osteoporosis. • Liver T2* relaxation time is a sensitive value in reflecting iron overload. • Liver T2* mapping elucidates changes in postmenopausal osteoporosis earlier than BMD. • Iron chelation increases BMD in ovariectomized rats. • Liver T2* has a moderate positive correlation with BMD.
Department of Radiology, Zhongda Hospital of Southeast University, Nanjing, China.
Lingshan
L
Chen
Zhengqiu
Z
Zhu
Xingui
X
Peng
Yuancheng
Y
Wang
Yaling
Y
Wang
Min
M
Chen
Qi
Q
Wang
Jiyang
J
Jin
D015502:Absorptiometry, Photon; D000818:Animals; D015519:Bone Density; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D019190:Iron Overload / Q000175:diagnosis*; D008099:Liver / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015663:Osteoporosis, Postmenopausal / Q000175:diagnosis*; D010052:Ovariectomy; D051381:Rats; D017207:Rats, Sprague-Dawley