Automatic Recognition of Bone for X-Ray Bone Densitometry

We described a method for automatically identifying and separating pixels representing bone from those representing soft tissue in a dual- energy point-scanned projection radiograph of the abdomen. In order to achieve stable quantitative measurement of projected bone mineral density, a calibration using sample bone in regions containing only soft tissue must be performed. In addition, the projected area of bone must be measured. We show that, using an image with a realistically low noise, the histogram of pixel values exhibits a well-defined peak corresponding to the soft tissue region. A threshold at a fixed multiple of the calibration segment value readily separates bone from soft tissue in a wide variety of patient studies. Our technique, which is employed in the Hologic QDR-1000 Bone Densitometer, is rapid, robust, and significantly simpler than a conventional artificial intelligence approach using edge-detection to define objects and expert systems to recognize them

Progress report no. 4

Statement of responsibility on title-page reads: editors: M.J. Driscoll, D.D. Lanning, I. Kaplan, A.T. Supple ; contributors: A. Alvim, G.J. Brown, J.K. Chan, T.P. Choong, M.J. Driscoll, G. A. Ducat, I.A. Forbes, M.V. Gregory, S.Y. Ho, C.M. Hove, O. K. Kadiroglu, R.J. Kennerley, D.D. Lanning, J.L. Lazewatsky, L. Lederman, A.S. Leveckis, V.A. Miethe, P. A. Scheinert, A.M. Thompson, N.E. Todreas, C.P. Tzanos, and P.J. WoodIncludes bibliographical referencesProgress report; June 30, 1973U.S. Atomic Energy Commission contract: AT(11-1)225

Progress report no. 3

Statement of responsibility on title-page reads: editors: M.J. Driscoll, D.D. Lanning, I. Kaplan; contributors: S. T. Brewer, G.J. Brown, P. Delaquil, M.J. Driscoll, G.A. Ducat, I.A. Forbes, M. V. Gregory, S.Y. Ho, M.S. Kalra, C.S. Kang, L.T. Kim, D.D. Lanning, J.L. Lazewatsky, T.C. Leung, E.A. Mason, N.R. Ortiz, N.C. Rasmussen, I.C. Rickard, K.D. Roberson, A.T. Supple, A.M. Thompson, and C.P. TzanosIncludes bibliographical referencesProgress report ; June 30, 1972U.S. Atomic Energy Commission contracts: AT(11-1)306