Radiology, Vol 138, 195-201, Copyright © 1981 by Radiological Society of North America
Quantitative and qualitative comparison of two microfocus-tube imaging systems
RG Gould and HK Genant
Two microfocus-tube magnification systems were compared: one used an RSI
tube (stationary anode, Pierce-gun cathode) and the other used a GE tube
(rotating anode, biased cathode). Imaging parameters for body parts of
three thicknesses, the hand (low), knee (medium), and hip (high), were
considered at a magnification of 2. The focal-spot MTF was measured on and
off the central ray of the beam, as well as beam quality and the intensity
of scatter in the image plane. Patient exposures were also determined.
While both systems gave high-quality images at acceptable exposure levels,
the RSI unit was judged superior for body parts up to 15 cm thick. For
thicker parts, scatter degraded contrast with the RSI unit, making the GE
unit superior.
