Experimental evaluation of a surface charge method for computing the induced magnetic field in trabecular bone.
The magnetic field induced in the pores of trabecular bone as a result of the susceptibility difference between bone and bone marrow was computed with the aid of magnetic surface charge models generated from images of trabecular bone specimens acquired at 78 and 63 microm resolution. The predicted field was compared with the values derived from 2D and 3D field maps obtained by echo-offset imaging techniques and excellent agreement was found between the two methods. Finally, from the slopes of regression between the experimental and computed fields, the absolute susceptibility of bone was nondestructively determined as -11.0 x 10(-6) (MKS), which is in close agreement with a reported value of -11.3 x 10(-6) obtained with powdered bone by means of a spectroscopic susceptibility matching technique (J. A. Hopkins and F. W. Wehrli, Magn. Reson. Med. 37, 494-500 (1997)).
Hwang
S N
SN
Department of Radiology, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania 19104, USA.
Wehrli
F W
FW
D000818:Animals; D001842:Bone and Bones / Q000033:anatomy & histology* / Q000473:pathology; D005269:Femur / Q000033:anatomy & histology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D066298:In Vitro Techniques; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008280:Magnetics; D011817:Rabbits; D011884:Radius / Q000033:anatomy & histology