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Biomedical subjects

S Rudin

Publications and source records attributed to S Rudin.

At least 55 records · Page 3Linked to original sources
PubMed1983

Artifacts produced by moving grids.

Anti-scatter grids reduce the amount of secondary radiation contributing to the image and improve the signal-to-noise ratio. However, they may also lead to the creation of linear artifacts representing the shadows of the radiopaque septa. Grid motion perpendicular to the septa during the exposure can cause blurring of the artifacts; however, the wider septa of recently proposed grids increase the difficulty of suppressing the artifacts entirely. Physical characteristics which affect perceptibility of grid-line artifacts and the conditions needed for their elimination are analyzed. Sufficient grid movement can eliminate overlap artifacts, while synchronization of linear grid motion with exposure time can suppress artifacts for relatively small grid movements.

Technology, Radiologic↗
PubMed1983

Reduction of fluoroscopic exposure for the air-contrast barium enema.

In a fluoroscopic imaging system, image quality and patient dose are both affected by the optical system linking the image intensifier with the video camera. The effect on patient exposure of increasing the optical iris aperture size over that required for other procedures performed on the same imaging system was investigated for the air-contrast barium enema examination. Using a large-area transmission ionisation chamber to monitor the Roentgen-area-product of entrance exposure, a decrease in fluoroscopic radiation of greater than 50% was clinically documented for a fluoroscopic system utilising kVp and mA variable automatic brightness control. For this iris change, the video image was of acceptable quality for positioning and monitoring the patient, and no deleterious effect was detected in the conduct of the air-contrast exam. The availability of a variable-sized operator-selectable iris diaphragm would permit this dose-reduction approach to be extended to other fluoroscopic procedures.

Air↗
PubMed1981

Computed tomography of the orbit.

In less than a decade computed tomography (CT scanning) had a profound impact on diagnostic radiology. Radiology of the orbit is no exception. As early as 1973, reports published in the radiological literature indicated that this new noninvasive imaging method was a highly effective way of demonstrating intraorbital mass lesions. As CT scanners became widely available, computed tomography became a significant adjunct to ophthalmological diagnosis. Today the main indications for CT scanning of the orbit are (1) suspected mass lesions, most frequently presenting as exophthalmos, (2) orbital trauma, including foreign bodies, (3) some congenital anomalies, and (4) suspicion of extension into the orbit of extraorbital disease processes. Along with ultrasonography, another new noninvasive imaging technique, CT has replaced a number of more invasive and often less effective diagnostic methods, such as orbital pneumography, venography, and arteriography as major imaging techniques in orbital pathology. The paper discusses current practices in the technique of CT scanning of the orbit including the important aspect of radiation dosimetry and the clinical applications, using a number of cases to illustrate its use.

Eye Foreign Bodies↗
PubMed1980

Improved contrast in special procedures using a rotating aperture wheel (RAW) device.

A new scatter control technology consisting of multiple rotating aperture wheels (RAWs) is being developed to provide improved radiographic contrast and/or reduced patient dose in both single frame and dynamic procedures. The unique geometry of this system allows the conventional source-patient-image receptor geometric relationship to remain unchanged so that the device can be added to existing radiographic, fluoroscopic, and conventional tomographic installations. A prototype RAW device has been used with a rapid film changer for simulated abdominal angiography. The resulting images show improved contrast over those obtained with a standard 12:1 fixed grid.

Angiography↗