Energy deposition in microscopic volumes by high-energy protons

Microscopic energy deposition from passing protons in tissue spher

Simple computer method provides contours for radiological images

Computer is provided with information concerning boundaries in total image. Gradient of each point in digitized image is calculated with aid of threshold technique; then there is invoked set of algorithms designed to reduce number of gradient elements and to retain only major ones for definition of contour

Space radiation hazards in man Annual report, 1 Oct. 1968 - 30 Sep. 1969

Space radiation hazards and proton energy deposition in ma

Changes in the frequency distribution of energy deposited in short pathlengths as a function of energy degradation of the primary beam

Frequency distributions of event size in deposition of energy over small pathlengths measured after penetration of 44.3 MeV protons through thicknesses of tissue-like materia

Research progress in radiation detectors, pattern recognition programs, and radiation damage determination in DNA

The radiological implications of statistical variations in energy deposition by ionizing radiation were investigated in the conduct of the following experiments: (1) study of the production of secondary particles generated by the passage of the primary radiation through bone and muscle; (2) the study of the ratio of nonreparable to reparable damage in DNA as a function of different energy deposition patterns generated by X rays versus heavy fast charged particles; (3) the use of electronic radiography systems for direct fluoroscopic tomography and for the synthesis of multiple planes and; (4) the determination of the characteristics of systems response to split fields having different contrast levels, and of minimum detectable contrast levels between the halves under realistic clinical situations

Radiation measurement of radiobiological hazards of man in space Semiannual report, 1 Oct. 1967 - 31 Mar. 1968

Isodose patterns, microdosimetric distributions, and energy event frequency distributions in relation to radiobiological hazards in spac

Development and investigation of single-scan TV radiography for the acquisition of dynamic physiologic data

Research data obtained by the low dose electronic radiography system are reported. Data cover: (1) localization and tracking of Ta screws implanted in the inner wall of the right ventrical of the heart, (2) use of cross hairs to outline inner or outer heart wall contours, (3) quantitative measure of anatomical components which are stationary in size or change size dynamically, and (4) study of dynamic quantitative data from roentenologic or fluoroscopic procedures

Microdosimetry and radiology Annual report, 1 Oct. 1969 - 30 Sep. 1970

Investigating experimental and theoretical approaches to microdosimetry, radiobiology, and single-scan television system

Development and investigation of single-scan TV radiography for the acquisition of dynamic physiologic data

A light amplifier for large flat screen fluoroscopy was investigated which will decrease both its size and weight. The work on organ contouring was extended to yield volumes. This is a simple extension since the fluoroscopic image contains density (gray scale) information which can be translated as tissue thickness, integrated, yielding accurate volume data in an on-line situation. A number of devices were developed for analog image processing of video signals, operating on-line in real time, and with simple selection mechanisms. The results show that this approach is feasible and produces are improvement in image quality which should make diagnostic error significantly lower. These are all low cost devices, small and light in weight, thereby making them usable in a space environment, on the Ames centrifuge, and in a typical clinical situation

Radiation measurement of radiobiological hazards of men in space Annual report, 1 Oct. 1967 - 30 Sep. 1968

Cyclotron radiation experiments to test Blunck-Leisegang theory of statistical distributions of small energy losses for pathlengths of biological interes