Diagnosing pneumonia in rural Thailand: Digital cameras versus film digitizers for chest radiograph teleradiology

Background: Accurate surveillance for pneumonia requires standardized classification of chest radiographs. Digital imaging permits rapid electronic transfer of data to radiologists, and recent improvements in digital camera technology present high quality, yet cheaper, options. Methods: We evaluated the comparative utility of digital camera versus film digitizer in capturing chest radiographs in a pneumonia surveillance system in rural Thailand using a panel of radiologists; the gold standard was the hard-copy radiograph. We calculated sensitivity and specificity and conducted a receiver operator characteristics (ROC) analysis. Results: Of the 192 radiographs from patients with clinical pneumonia, 166 (86%) were classified as pneumonia on the hard copies. Sensitivity and specificity for identifying pneumonia were 89% and 73% for the camera and 90% and 65% for the digitizer. In the ROC analysis, there was no statistically significant difference in the area under the curve (camera, 0.86; film digitizer, 0.91, p = 0.29). The digital camera set cost $965 compared to $3000 for the film digitizer. Conclusion: Detection of pneumonia was not measurably compromised by using digital cameras compared with film digitizers. The 3-fold lower cost of the digital camera makes this technology an affordable and widely accessible alternative for surveillance systems, vaccine trials, and perhaps clinical use. (c) 2005 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.