Skeletal Applications for Flat-Panel versus Storage-Phosphor Radiography: Effect of Exposure on Detection of Low-Contrast Details

Martin Uffmann, Cornelia Schaefer-Prokop, Ulrich Neitzel, Michael Weber, Christian J. Herold, Mathias Prokop

Research output: Contribution to journalArticlepeer-review

20 Scopus citations


PURPOSE: To compare exposure requirements for similar detection performance with flat-panel detectors and the most recent generation of storage-phosphor plates in the simulated scatter of typical skeletal radiographic examinations. MATERIALS AND METHODS: A contrast-detail test object was covered with varying thicknesses of acrylic to simulate skeletal exposure conditions in the wrist, knee, and pelvis. Three series were obtained with increasing thicknesses of a simulated soft-tissue layer (5, 10, and 20 cm) and increasing tube voltage (50, 70, and 90 kVp). A fourth series was obtained with exposure conditions adapted to the phantom instructions (75 kVp). Images were acquired with a flat-panel detector (cesium iodide scintillator) and storage-phosphor plates at five exposure levels (speed class range, 100-1,600). Five readers evaluated 84 images to determine the threshold contrast of 12 lesion diameters (range, 0.25-11.1 mm). Statistical significance of differences between the two digital systems was assessed with two-way analysis of variance. RESULTS: A linear relationship was found between the number of detected lesions and the logarithm of exposure (R2 > 0.98 for all series). On average, the flat-panel system required 45% less exposure than did the phosphor plates when 20-cm-thick acrylic was superimposed on the test object. Differences in exposure requirements were smaller with decreasing thicknesses of simulated soft-tissue layers and lower tube voltages (39% at 10 cm and 70 kVp, and 17% at 5 cm and 50 kVp). All differences were statistically significant. CONCLUSION: Flat-panel radiography provides improved contrast detectability and a potential for exposure reduction compared with those with storage-phosphor radiography. The best performance was achieved with conditions comparable to those for radiography of the trunk and lowest for conditions that simulate radiography of the extremities.

Original languageEnglish (US)
Pages (from-to)506-514
Number of pages9
Issue number2
StatePublished - May 1 2004


  • Experimental study
  • Radiations, exposure to patients and personnel
  • Radiography, comparative studies
  • Radiography, flat panel
  • Radiography, storage phosphor

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging


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