TY - JOUR
T1 - Relationship between cancellous bone induced magnetic field and ultrastructure in a rat ovariectomy model
AU - Takahashi, Masaya
AU - Wehrli, Felix W.
AU - Hwang, Scott N.
AU - Wehrli, Suzanne L.
N1 - Funding Information:
The authors are indebted to Maria Fernandez-Seara for helpful discussions. This work was supported by Procter & Gamble, and National Institute of Health Grants RO1 41443 and RO1 45196.
PY - 2000/1
Y1 - 2000/1
N2 - The site-dependent variations in trabecular bone morphology were studied in the rat tibia by magnitude and phase difference three-dimensional nuclear magnetic resonance microscopy and image processing, and the implications of ovariectomy were evaluated. Specimens excised from the proximal tibial metaphysis in ovariectomized (n = 7) and intact control (n = 4) rats were imaged at 9.4T with their anatomic axes parallel to the direction of the magnetic field. An echo-offset 3D rapid spin-echo excitation pulse sequence was used to generate phase difference maps, from which the standard deviation of the phase difference, σ(Δφ), was calculated. In addition, a fictitious rate constant, R2/', was calculated from the slope of the exponential portion of the Fourier transform of the phase difference histogram. Trabecular bone volume fraction was also determined in the same volume of interest. The results show strong correlations between bone volume fraction and both σ(Δφ) and R2/', suggesting that these parameters could be useful for nondestructive assessment of trabecular bone volume.
AB - The site-dependent variations in trabecular bone morphology were studied in the rat tibia by magnitude and phase difference three-dimensional nuclear magnetic resonance microscopy and image processing, and the implications of ovariectomy were evaluated. Specimens excised from the proximal tibial metaphysis in ovariectomized (n = 7) and intact control (n = 4) rats were imaged at 9.4T with their anatomic axes parallel to the direction of the magnetic field. An echo-offset 3D rapid spin-echo excitation pulse sequence was used to generate phase difference maps, from which the standard deviation of the phase difference, σ(Δφ), was calculated. In addition, a fictitious rate constant, R2/', was calculated from the slope of the exponential portion of the Fourier transform of the phase difference histogram. Trabecular bone volume fraction was also determined in the same volume of interest. The results show strong correlations between bone volume fraction and both σ(Δφ) and R2/', suggesting that these parameters could be useful for nondestructive assessment of trabecular bone volume.
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U2 - 10.1016/S0730-725X(99)00107-1
DO - 10.1016/S0730-725X(99)00107-1
M3 - Article
C2 - 10642100
AN - SCOPUS:0033987963
VL - 18
SP - 33
EP - 39
JO - Magnetic Resonance Imaging
JF - Magnetic Resonance Imaging
SN - 0730-725X
IS - 1
ER -