Screening for self-plagiarism in a subspecialty-versus-general imaging journal using iThenticate

Self-plagiarism is a form of research misconduct that can dilute the credibility and reputation of a scientific journal, as well as the represented specialty. Journal editors are aware of this problem when reviewing submissions and use on-line plagiarism-analysis programs to facilitate detection. The American Journal of Neuroradiology (AJNR) uses iThenticate to screen several submitted original research manuscripts selected for review per issue and retrospectively assesses 3 issues per year. The prevalence of self-plagiarism in AJNR was compared with that in Radiology; the necessity and cost of more extensive screening in AJNR were evaluated. The self-duplication rate in AJNR original research articles was compared with that in Radiology, a general imaging journal that screens all submitted original research manuscripts selected for review by using iThenticate. The rate of self-duplication in original research articles from 2 randomly selected 2012 AJNR issues was compared with the rate in the prior year to gauge the need for more extensive screening. A cost analysis of screening all submitted original research manuscripts selected for review by using iThenticate was performed. Using an empiric 15% single-source duplication threshold, we found that the rate of significant self-plagiarism in original research articles was low for both journals. While AJNR had more articles exceeding this threshold, most instances were insignificant. Analyzing 2 randomly chosen issues of AJNR for single-source duplication of >15% in original research articles yielded no significant differences compared with an entire year. The approximate annual cost of screening all submitted original research manuscripts selected for review was US $6800.00. While the rate of self-plagiarism was low in AJNR and similar to that in Radiology, its potential cost in negative impact on AJNR and the subspecialty of neuroradiology justifies the costs of broader screening.