Biomedical subjects
Publications and source records attributed to G T Herman.
We survey some of the literature on three-dimensional medical imaging. We report both on technical developments and on medical applications, with a concentration on material that has been published within the years 1990-1992.
Three-dimensional (3D) imaging on a CT or magnetic resonance scanner by the use of software that runs on the scanner's computer is one of a number of approaches to 3D imaging that have become available in recent years. It is shown that this particular approach can be made very inexpensive, provided that it is used in an appropriate manner in the clinical environment. The proposed methodology for the clinical use of 3D imaging on the scanner is illustrated by a discussion of the use of 3D98 (software designed for the GE CT/T 9800 scanner) for the 3D imaging of craniofacial surgical cases.
Rotation of a system consisting of a single x-ray source and a linear detector array allows rapid collection of x-ray projection data from which transaxial cross sections can be reconstructed. In this paper, we present an algorithm which makes possible rapid computerized reconstruction from such data. We describe some experiments aimed at investigating the optimal choice of some of the parameters associated with the algorithm. We report on reconstructions using our algorithm of the intact thorax of a dog and also of cross sections of the human female breast from x-ray data obtained by a computerized mammography machine.
In a joint project between the Department of Computer and Information Sciences and the Department of Radiology, we are applying techniques of artificial intelligence to improve clinical performance in coronary arteries. Specifically, we are investigating how images from intravenous digital subtraction angiography (DSA) can be enhanced so that their efficacy for lesion detection and quantitation becomes comparable with that of the more dangerous procedure of selective coronary arteriography. The enhancement techniques (which include algorithms for 3-dimensional vessel detection, reconstruction and display, as well as for accurate lumen-size estimation) are based on models of (i) the 3-dimensional topological structure of the coronary arterial tree, (ii) myocardial dynamics, and (iii) the X-ray imaging process involved in producing digital subtraction angiograms. The evaluation of these model-driven visualization techniques is done by the standard psychophysical method of Receiver Operating Characteristic (ROC) analysis applied to observer performance tests on images from an animal coronary atherosclerosis model.