COMPARISON OF HARD-COPY AND SOFT-COPY DIGITAL CHEST IMAGES WITH DIFFERENT MATRIX SIZES FOR MANAGING CORONARY-CARE UNIT PATIENTS

OBJECTIVE. This study was to determine whether different digital displ ay formats for portable chest radiographs of coronary care unit patien ts would provide comparable information for clinical care, In particul ar, we tried to ascertain whether 1024 x 1024 pixel (1K) images on a p icture archiving and communication system (PACS) workstation would be comparable to 1760 x 2140 pixel (2K) images on workstations or to digi tal films, If comparability could be proved, we hypothesized that 1K w orkstations could considerably lower equipment and film costs and faci litate image transmission from point to point. MATERIALS AND METHODS. Four chest radiologists read a panel of chest studies assembled from 9 8 coronary care unit patients, comparing 1K and 2K soft-copy images wi th digital hard copies. For all three image types for the 98 patients, the readers evaluated nine image parameters that the cardiologists de emed essential for clinical decision making, Two other chest radiologi sts reviewed each patient's three image types, historical chest images , current and prior radiologic reports, and medical record to determin e the consensus, or ''truth findings.'' RESULTS. With one exception (s mall pleural effusions), the receiver operating characteristic analysi s showed no significant differences in the clinical information derive d from the three image types. CONCLUSION. For clinical management in a coronary care unit, comparable information can be obtained from digit al radiologic chest studies using a 1K x 1K soft-copy format, a 2K x 2 K soft-copy format, or a hard copy (film). Substantial savings in cost and time are therefore possible by using soft-copy images and lower r esolution (1K x 1K) workstations and, when necessary, by transmitting images on regular telephone lines.