Radiology, Vol 198, 213-218, Copyright © 1996 by Radiological Society of North America
Distal radius: in vivo assessment with quantitative MR imaging, peripheral quantitative CT, and dual X-ray absorptiometry
S Grampp, S Majumdar, M Jergas, D Newitt, P Lang and HK Genant
Department of Radiology, University of California, San Francisco 94143, USA.
PURPOSE: To evaluate in vivo the relationship between magnetic resonance
(MR) imaging relaxation time and bone mineral density (BMD) at the distal
radius. MATERIALS AND METHODS: The 1/T2* MR imaging relaxation rates and
dual X-ray absorptiometry (DXA) measurements were evaluated in the
trabecular bone of the distal 5 cm of the radius in 14 healthy
premenopausal women and 11 healthy postmenopausal women and in 11 women
with osteoporosis. Trabecular and total BMD were measured with peripheral
quantitative computed tomography (CT). RESULTS: In healthy women, 1/T2*
values and trabecular BMD at peripheral quantitative CT were significantly
correlated but 1/T2* and total BMD were not. Statistically significant (P =
.03) correlations between 1/T2* and DXA were found only in the most distal
area covered with DXA. The 1/T2* values were more closely correlated with
age and showed higher relative annual decreases (0.47%-0.81%) than
peripheral quantitative CT (0.20%- 0.59%) or DXA (0.10%-0.39%). Pre- and
postmenopausal healthy subjects could be distinguished only with MR
imaging, and postmenopausal healthy and osteoporotic subjects only with CT
and DXA. CONCLUSION: MR imaging relaxation rates correlate well with
trabecular BMD in vivo.
