Variation of visual image quality using CR technology, relationship with E

Abstract

We would like to point out some observations we have found in an experiment involving a computed radiography system (Wolverson Acoma X-ray unit). Recently we completed a study to determine how visual image quality and lesion visibility vary when mAs, kVp and SID are manipulated. Images were generated from an anthropomorphic chest phantom (Kyotokagaku N1 “LUNGMAN”), with two simulated lesions. Fig. 1 shows how perceptual image quality and lesion visibility (Y Axis) vary with increasing mA at 180 cm SID. Y axis data was derived from a two alternative forced choice (2AFC) method from 5 highly experienced clinicians, the image quality scoring was partly based on European chest X-ray criteria. 1 Carmichael J.H.E. Maccia C. Moores B.M. Oestmann J.W. Schibilla H. Teunen D. et al. Commission of the European CommunitiesEuropean guidelines on quality criteria for diagnostic radiographic images. Office of Official Publications of the European Communities, Luxembourg1996 Google Scholar The X axis represents an increase in mA; by using Monte Carlo modeling effective dose 2 Tapiovaara M. Lakkisto M. Servomaa A. PCXMC: a PC-based Monte Carlo program for calculating patient doses in medical X-ray examinations. Finnish Centre for Radiation and Nuclear Safety, Helsinki1997 Google Scholar (E) is indicated onto the X axis. The graphs demonstrate how perceptual image quality varies for the indicated kVp range at various E levels.