[en] A number of image-processing techniques have been applied to a digital ionographic chest image in order to evaluate their possible effects on this type of image. In order to quantify any effect, a simulated lesion was superimposed on the image at a variety of locations representing different types of structural detail. Visualization of these lesions was evaluated by a number of observers both pre- and post-processing operations. The operations employed included grey-scale transformations, histogram operations, edge-enhancement and smoothing functions. The resulting effects of these operations on the visualization of the simulated lesions are discussed. (author)

[en] A method of measuring relative blood flow through at least a part of the body using penetrating radiation comprises transmitting a plurality of rays at an initial angle or initial mean angle through a planar slice of the body to define a first set of rays, transmitting a plurality of further sets of rays at angles or mean angles different from each other and from the initial angle or initial mean angle through the same planar slice of the body to define by the intersection of all such rays a two-dimensional matrix of elements of the body in the slice, measuring for each ray emerging from the body a number of over the period of time at least equal to a pulse interval representing the momentary sum of the transmissions or absorptions of the element of the body intersected by the ray, determining from the momentary signals momentary signals a difference signal representing the maximum difference between the momentary signals for each ray over the period of time, deriving sets of discrete difference signals corresponding to the sets of rays, the difference signals being indicative of the transmission or absorption of blood flowing through each element of the body in the matrix, and calculating from the difference signals resultant signals representing the transmissions or absorptions due to blood flow in the elements of the matrix. These resultant signals may be visually depicted on a cathode ray tube display, as a digital print-out, or as a photograph. 30 claims, 8 figures

[en] This book is written to assist the operator when performing an organized and directed ultrasound examination. It provides, in outline form, a sequential approach to the scanning of abdominal organs and regions by; indicating the structures within the organ or region that should be scanned; suggesting other regions for examination if abnormalities within the initially imaged structures are detected and; suggesting differential diagnostic possibilities when abnormalities are seen

[en] Abstract only45

[en] This book contains 13 chapters. The first two chapters include a review of the principles of CT image formation and quality and provide coverage of normal cross-sectional anatomy of the chest, abdomen, and pelvis. Ten chapters cover the major disease processes of these anatomic regions. The last chapter describes CT-guided interventional techniques. Some correlation with other imaging modalities is included in the study of the mediastinum, lungs, and gastrointestinal tract

[en] This self-study guide recognizes that evaluation and interpretation of CT-images demands a firm understanding of both cross-sectional anatomy and the principles of computed tomography. The objectives of this book are: to discuss the basic principles of CT, to stress the importance of cross-sectional anatomy to CT through study of selected cardinal transverse sections of head, neck, and trunk, to explain orientation and interpretation of CT-images with the aid of corresponding cross-sectional preparations

[en] The authors present the evaluation of a new image compression technique, subband coding using vector quantization, on 44 CT examinations of the upper abdomen. Three independent radiologists reviewed the original images and compressed versions. The compression ratios used were 16:1 and 20:1. Receiver operating characteristic analysis showed no difference in the diagnostic contents between originals and their compressed versions. Subjective visibility of anatomic structures was equal. Except for a few 20:1 compressed images, the observers could not distinguish compressed versions from original images. They conclude that subband coding using vector quantization is a valuable method for data compression in CT scans of the abdomen

[en] This paper reports on techniques employed in abdominal computed tomography, chosen to maximize delineation of normal anatomic structures, accurately identify pathologic processes, and ensure optimal scanner utilization and operational efficiency. A particular technique is selected after careful consideration of the individual clinical question; the available equipment; the condition, status, and special requirements of the patient; and the logistics unique to the hospital or clinic. There is no one technique that will prove optimal for all CT examinations. There are, however, general principles of the abdominal CT examination that, if followed, will ensure a high degree of sensitivity and specificity. Undoubtedly, CT examination techniques will continue to evolve as scanner technology, contrast agents, and pharmacologic enhancement of abdominal CT are developed

[en] Purpose: To compare the X-ray images made by the Kodak InSight Pediatric Imaging System (InSight P) with conventional film-screen systems in pediatric chest radiography. Material and methods: The comparison involved chest radiographs made using Quanta-Fast-Detail/Cronex 4 (DuPont), Trimax 16/XDA (3 M) and DuPont UVR/UVL systems. The image quality of critical structures and the physical parameters of quantum interference, contrast and resolution were assessed. The energy path of the system was assessed by preparing density curves. Test conditions were in accordance with the latest guidelines of the Bundesaerztekammer (German Physicians' Association). Results: The mediastinal area, retrocardiac and paravertebral spaces and the peripheral vessels of the lung were all displayed more distinctly using InSight P. The reason for this seems to be a lower degree of quantum interference associated with this system. With tube voltages between 60 and 80 kV, InSight P displayed a relatively low degree of sensitivity. Conclusion: InSight P can be used to produce predominantly high quality chest radiographs on infants between one and five years of age. However, this system has limited sensitivity in the tube voltage range recommended by the German Physicians' Association. (orig.)

[en] The principle impetus behind the development of new rapid imaging techniques is to improve clinical efficiency, i.e., to increase the effectiveness of the examination per unit time. A further motivation is to minimize patient discomfort as the tolerance for a particular examination increases with decreasing scan time. An additional incentive is to minimize the adveres effects of involuntary physiologic patient motion on image quality. Notably, breathing motion has thus far severly impaired the quality of upper abdominal images. Hence, a substantial reduction in scan time permits patients to be scanned with suspended respiration during data acquisition. Finally, a shortening of scan time opens new avenues for dynamic scanning, such as functional imaging of the cardiovascular system and for performing time-course studies