ABSTRACT
An investigation of light diffusion in x-ray intensifying screens and the prospects for improvement by confining light spread with a special structure are reported. Light diffusion in CaWO4 screens was studied theoretically using computer simulation. The proportion and spatial distribution of light emerging from different depths in the screen were calculated. The introduction of narrow gaps in the screens made it possible to improve these proportions and distributions. The gaps improved the line spread functions, the screen efficiencies, and the average contribution of the absorbed quanta to the light output.
Subject(s)
Radiographic Image Enhancement , X-Ray Intensifying Screens , Light , Radiographic Image Enhancement/instrumentation , Scattering, RadiationABSTRACT
A method for quantitative estimation of split renal function using a computerized gamma camera system is described. 42 children and adolescents with existing or preexisting vesicoureteric reflux and recurrent urinary tract infection were investigated. Total renal clearance of DTPA was calculated with a disappearance curve derived from the largest extrarenal area in the field of view of a gamma camera with diverging collimator. Split renal function was estimated with the slopes of second phase renograms. The plasma disappearance clearance of DTPA, calculated using one compartment model with two late blood samples, gave similar results with the clearance estimated from the body disappearance curves. The proportional planimetric renal parenchymal areas had good correlation with the split clearance estimated from renogram slopes. The method offers data on renal function and urinary tract dynamics which is very valuable in the follow-up of children with recurrent urinary tract infection and vesicoureteric reflux.