Med Phys
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Comparative Study
Evaluation of a prototype dual-energy computed tomographic apparatus. II. Determination of vertebral bone mineral content.
A prototype dual-energy computed tomographic (CT) scanner (Siemens Somatom DR3) with rapid kVp switching and prereconstruction processing has been used to measure vertebral bone mineral density. With this approach misregistration and beam hardening inaccuracies can be reduced considerably. Basis material images of aluminum- and Lucite-equivalent density enable measurements of bone mineral density that are nearly independent of the amount of marrow fat. ⋯ Dual-energy CT was compared to dual-photon absorptiometry (153Gd) for the measurement of bone mineral mass of ten excised human vertebrae. There was a high degree of correlation between the two measurements (r = 0.97). Dual-energy and single-energy CT measurements on 17 patients with suspected metabolic bone disease strongly support the conclusion that the influence of fat can lead to significant errors in single-energy determinations of the mineral density of trabecular bone.
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This vignette recites significant steps leading to the formation of the AAPM and transpiring in the developments of the first decade, approximately. Persons involved, dates, and places are recognized. A table summarizes the progression of events. This recitation ends with the term of Kereiakes, the last President to be elected by the Board of Directors from its own membership, and with the move of the annual meeting time to mid-summer.