Pulmonary nodule detection and visual search: P45 and p104 monochrome versus color monitor displays

Rationale and Objectives. The faceplate of a cathode-ray tube (CRT) display monitor is covered on the vacuum side with a phosphor screen. The different phosphors that can be used for this screen have distinctly different physical properties that can affect the noise properties of the display. Differences in noise affect the signal-to-noise ratio and, hence, may affect diagnostic performance. This study evaluated observer performance and visual search parameters in the detection of pulmonary nodules, comparing two monochrome CRT monitors with different phosphors (P45 and P104) and a color CRT monitor. Materials and Methods. The receiver operating characteristic paradigm was used to evaluate observer performance with a series of radiographic chest images containing solitary pulmonary nodules. Eye position was recorded as the observers searched the images on each type of monitor. Results. Observer performance, as indicated by the area under the receiver operating characteristic curve and compared by means of an analysis of variance test, was best for the P45 monitor, next best for the P104 monitor, and worst for the color monitor. All differences were statistically significant. Eye-position parameters were also affected by monitor type. The time required to fixate the lesion and overall search times were longest with the color monitor. Conclusion. The type of phosphor used in the CRT monitor faceplate can affect diagnostic performance and visual search parameters. Care should be taken in the selection of monitors for use in clinical radiology.