In vitro perception of low-contrast features in digital, film, and digitized dental radiographs: a receiver operating characteristic analysis

Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2007 May;103(5):694-701. doi: 10.1016/j.tripleo.2006.04.005. Epub 2006 Aug 2.

Abstract

Objective: To compare experimentally the image quality of charged-coupled device (CCD)-based digital, flatbed scanner digitized, and dental film radiographs.

Study design: High-contrast standardized radiographs of an aluminum step wedge containing boreholes were obtained on dental radiographic film (F) and a CCD receptor (D). Digitization (S) was done with a flatbed scanner. Each radiograph was separated into 23 single images, 18 of which showed a dark spot. Thirty observers indicated their confidence on the visibility of the spots for a receiver operating characteristic (ROC) analysis.

Results: Mean Az values (area beneath the ROC curves) differed significantly (P < .05), being highest for D (Az = 0.76), followed by F (Az = 0.71) and S (Az = 0.60). Mean sensitivity of S (0.45) was significantly (P = .000) lower than for D (0.66) and F (0.67).

Conclusion: The difference between modality D and F was small. However, the inferior performance of S images, particularly in dark regions, could be clinically relevant.

Publication types

  • Comparative Study
  • Evaluation Study

MeSH terms

  • Contrast Media
  • Phantoms, Imaging
  • ROC Curve
  • Radiographic Image Enhancement
  • Radiography, Dental / instrumentation*
  • Radiography, Dental / methods*
  • Radiography, Dental, Digital
  • Semiconductors
  • Sensitivity and Specificity
  • X-Ray Film
  • X-Ray Intensifying Screens

Substances

  • Contrast Media