[Detection of small bone lesions with digital radiography using storage phosphors]

To date, the skeletal imaging capabilities of digital radiography with storage phosphors have been poorly investigated, and the diagnostic accuracy of this technique has not been thoroughly assessed. To evaluate the performance of storage phosphor digital radiography we compared 66 conventional and 66 digital radiographs of small abnormalities of the extremities (fractures, erosions, calcifications). Conventional images were obtained with a low-speed screen-film system while digital ones were acquired with high-resolution (5 lp/mm max) phosphors and laser-printed on a 8" x 10" film. Two experienced radiologists defined the gold standard (389 abnormalities) and four radiologists scored the findings (1,556 observations) on a five-point discrete scale. ROC analysis indicated film and storage radiography to be equally effective in the overall detection of abnormalities. No difference was found in the individual performances of the four readers, in the site subclasses (wrist, hand), and in the specific detection of fractures and erosions. Digital radiography proved to be superior to conventional radiography in the detection of calcifications in all sites and particularly in the wrist (p less than 0.05). Storage phosphor radiography may replace conventional radiography of the extremities without causing any significant decrease in diagnostic accuracy.