Key Performance Indicators for Comparing the Performance of Portable Radiography: Direct Digital Radiography versus Conventional Machine Computed Radiography-A Study in a Nonacute Hospital.

Introduction: Portable radiography traditionally has been performed with a conventional portable x-ray unit with computed radiography (CR) system (conventional-CR combo), and off-site processing of the exposed CR cassettes was time-consuming. The direct digital radiography (DDR) portable x-ray system, with the digital image immediately available for review and wireless transmission as the key merits, is newly installed for portable radiography. Thus, the work flow of portable radiography is changed. This study was performed to quantitatively investigate the performance of portable radiography using the DDR portable x-ray system and conventional-CR combo in terms of efficiency and work flow enhancement.

Methods: One hundred ninety portable x-ray examinations were timed for each procedural step using conventional-CR combo (n=97) and the DDR portable x-ray system. The following key performance indicators were designed for measuring the performance of portable radiography quantitatively: "examination duration," "time for image becoming available in PACS," "postacquisition processing time," and "manpower deployment time."

Results: Productivity was raised by 96% using the DDR portable x-ray system. "Examination duration" using the DDR portable system was significantly faster (P < .0001), with a mean calculated time of 13.4 ± 7.6 minutes for the DDR portable system and 25.2 ± 10.9 minutes for conventional-CR combo. The "time for image becoming available in PACS" was significantly shorter than that of conventional-CR combo (P < .0001), with a mean time of 6.8 ± 2.6 minutes for the DDR portable system and 19.2 ± 9.7 minutes for conventional-CR combo. The "postacquisition processing time" was measured with slight differences, with a mean time of 2.2 ± 1.1 minutes for the DDR portable system and 1.9 ± 1.0 minutes for conventional-CR combo (P = .1064). Because more portable x-ray examinations could be performed when using the DDR portable x-ray system in each round of service, the mean "manpower deployment time" when using the DDR portable x-ray system was longer (ie, 82.6 ± 46.8 minutes for the DDR portable system and 24.5 ± 11.9 minutes for conventional-CR combo).

Conclusions: By using the new DDR portable x-ray system with work flow changes, the performance of portable radiography was improved in efficiency and work flow was enhanced. Furthermore, the four defined key performance indicators in this study may help provide a framework for measuring the performance of portable radiography in other institutions.