Date of Award

Spring 1985

Document Type

Thesis - Restricted

Degree Name

Master of Science (MS)


Biomedical Engineering

First Advisor

Jeutter, Dean C.


The development of Digital Radiology has made practical the quantitative measurement of anatomical and physiological quantities. However, before these measurements can be made accurate, it is necessary to remove some of the effects the scatter radiation created by the photons of the x-ray beam interacting with the imaging system, as the scatter reduces the dynamic range and contrast of the images. A study was conducted on the current state of conventional radiology and techniques to reduce scatter, and including some of the recent experimental scatter reduction techniques. One post-processing technique to reduce scatter is presented in this paper. Using the classical set of equations to characterize an x-ray beam and its interactions with the patient and imaging system, a formula was derived to arrive at a group of images that could be acquired on a Digital Fluorographic System and manipulated to calculate the scatter distribution for a given patient and geometry. Various anthropomorphic phantoms were used to simulate the patient anatomy. A software package was integrated into the General Electric Medical Systems Digital Fluoricon 3000 Application Software to allow for the acquisition and the processing of the appropriate set of images to form the scatter distribution. Due to certain limitations of the Digital Fluoricon 3000, the final portion of the image processing was performed on the General Electric Medical Systems Independent Physician's Display Console (IPDC), an image processor with floating point arithmetic capabilities. To determine the success of the technique, additional images of the anthropomorphic phantoms containing a bar simulating an artery of known attenuation were acquired. The scatter distribution was calculated from the set of test images and subsequently subtracted from the images used to form the ''artery" difference image Comparisons were made between the measurement of the corrected contrast of the artery material, the measurement of the uncorrected contrast of the artery material and the known contrast of the artery material. The results proved to be very promising, with the exception of areas of low intensities where correction was not possible. On the average, the improvement of the contrast measurement of the artery material was 75%.



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