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Rapid Small‐Animal Dual‐Energy X‐Ray Absorptiometry Using Digital Radiography
Author(s) -
Holdsworth D. W.,
Thornton M. M.,
Drost D.,
Watson P. H.,
Fraher L. J.,
Hodsman A. B.
Publication year - 2000
Publication title -
journal of bone and mineral research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.882
H-Index - 241
eISSN - 1523-4681
pISSN - 0884-0431
DOI - 10.1359/jbmr.2000.15.12.2451
Subject(s) - bone mineral , ovariectomized rat , medicine , nuclear medicine , radiography , dual energy x ray absorptiometry , femur , bone density , digital radiography , pelvis , dual energy , densitometry , osteoporosis , radiology , biomedical engineering , pathology , surgery , estrogen
Although dual‐energy X‐ray absorptiometry (DEXA) is an established technique for clinical assessment of areal bone mineral density (BMD), the spatial resolution, signal‐to‐noise ratio, scan time, and availability of clinical DEXA systems may be limiting factors for small‐animal investigations using a large number of specimens. To avoid these limitations, we have implemented a clinical digital radiography system to perform rapid area DEXA analysis on in vitro rat bone specimens. A crossed step‐wedge (comprised of epoxy‐based materials that mimic the radiographic properties of tissue and bone) was used to calibrate the system. Digital radiographs of bone specimens (pelvis, spine, femur, and tibia from sham‐ovariectomized [SHAM] and ovariectomized [OVX] rats) were obtained at 40 kilovolt peak (kVp) and 125 kVp, and the resulting areal BMD values were compared with those obtained with a clinical fan‐beam DEXA system (Hologics QDR 4500). Our investigation indicates that the cross‐wedge calibrated (CWC) DEXA technique provides high‐precision measurements of bone mineral content (BMC; CV = 0.6%) and BMD (CV = 0.8%) within a short acquisition time (<30 s). Areal BMD measurements reported by the CWC‐DEXA system are within 8.5% of those reported by a clinical fan‐beam scanner, and BMC values are within 5% of the known value of test specimens. In an in vivo application, the CWC‐DEXA system is capable of reporting significant differences between study groups (SHAM and OVX) that are not reported by a clinical fan‐beam DEXA system, because of the reduced variance and improved object segmentation provided by the CWC‐DEXA system.