Interpretation of Bone Scans Using a Video Display

Abstract

Digital processing, storing, and interpretation of scintigraphic images from a PACS system has been postulated as an efficient, cost-saving measure that may obviate the need for analog film. In order to replace analog film, documentation that images can be interpreted from a digital video display with accuracy at least equal to film must be obtained. Analog film was compared with video images in 28 patients with cancer suspected to be metastatic to bone. Images were acquired with a gamma camera and processed in 256 x 256 word mode by the use of the Medical Data Systems A3 computer. Adjustment of gray scales provided operator-controlled digital contrast enhancement. Video and film images were independently interpreted by two experienced nuclear medicine physicians, each blinded to the other modality. A linear four-color scale was then substituted for the gray scale, and images again interpreted. Lesions were interpreted as positive or equivocal and verified through follow-up scans over a minimum of six months. Of the 28 patients, 22 proved to have metastases, in whom 129 lesions were confirmed by follow-up scintigrams. 124 of these lesions (96.1%) were detectable on both analog film and video images. An additional three proven metastatic lesions on video images were absent or equivocal on analog studies, increasing sensitivity for video images to 98.4%. Five further lesions seen on the video screen represented rib fractures and regressed on follow-up examination. All lesions seen on black-and-white video were also seen when the color scale was applied.(ABSTRACT TRUNCATED AT 250 WORDS)