Emerging trends in the volume and format of outside examinations submitted for secondary interpretation.

OBJECTIVE: The purpose of this article is to describe the trends of secondary interpretations, including the total volume and format of cases. MATERIALS AND METHODS: This retrospective study involved all outside neuroradiology examinations submitted for secondary interpretation from November 2006 through December 2010. This practice utilizes consistent criteria and includes all images that cover the brain, neck, and spine. For each month, the total number of outside examinations and their format (i.e., hard-copy film, DICOM CD-ROM, or non-DICOM CD-ROM) were recorded. RESULTS: There was no significant change in the volume of cases (1043 ± 131 cases/month; p = 0.46, two-sided Student t test). There was a significant decrease in the volume of hard-copy films submitted, with the mean number of examinations submitted per month on hard-copy film declining from 297 in 2007 to 57 in 2010 (p < 0.0001, Student t test). This decrease was mirrored by an increase in the mean number of cases submitted on CD-ROM (753 cases/month in 2007 and 1036 cases/month in 2010; p < 0.0001). Although most were submitted in DICOM format, there was almost a doubling of the volume of cases submitted on non-DICOM CD-ROM (mean number of non-DICOM CD-ROMs, nine cases/month in 2007 and 17 cases/month in 2010; p < 0.001). CONCLUSION: There has been a significant decrease in the number of hard-copy films submitted for secondary interpretation. There has been almost a doubling of the volume of cases submitted in non-DICOM formats, which is unfortunate, given the many advantages of the internationally derived DICOM standard, including ease of archiving, standardized display, efficient review, improved interpretation, and quality of patient care.