[Assessment of the various image display systems affected to the visual analysis using 99mTc-GSA liver scintigraphy]

The aim of this study was to evaluate the physical performance for the gray-scale monitor and the image display system of the color monitor with the films using the visual analysis of the liver scintigraphy by 99mTc-DTPA-galactosyl-human serum albumin (GSA). The seven kinds of calibration curves (CC) were applied to convert into both the counts of the density of the films and the intensity of the monitors. The relationship between the intensity and density was evaluated in the 123 patients suspected with hepatic dysfunction. The liver scintigraphy images of 1-minute duration from five to six minutes after administration of 99mTc-GSA were converted according to the seven kinds of CC (861 images per image display system). These images were visually classified by the 16 observers following the five-point scoring system arranged beforehand. The intensity of monitors and the density of films showed positive correlation. Thus the CC for both the intensity and the density was centralized. The CC obtained by the present study was suitable for both monitors and films, respectively. The CC, which had the slope of approximately 4.8 for the monitor and 4.2 for the film, showed a good correlation between the indices of liver functions obtained from the biochemical liver function tests and from the 99mTc-GSA liver scintigraphy. Data suggest that the suitable CC in the three sets of image display system may contribute to the other scintigraphy as well as 99mTc-GSA liver scintigraphy, evaluating the scintigraphy using the visual analysis.