Head and Neck CTA Utilization: Analysis of Ordering Frequency and Nonroutine Results Communication, With Focus on the Fifty Most Common Emergency Department Clinical Presentations.

Background: Utilization of head and neck CTA in the emergency department (ED) has grown disproportionately to other neuroimaging examinations. Objective: To characterize utilization of head and neck CTA in the ED, comparing utilization and frequency of nonroutine results communication among patients' chief concerns. Methods: All adult ED visits for a single healthcare system from January 2014 to December 2017 were retrospectively reviewed. Variables recorded included chief concerns, whether head and neck CTA was performed, and, if so, whether the report documented nonroutine results communication. The fifty chief concerns resulting in the highest number of head and neck CTA examinations were identified. Frequencies of head and neck CTA ordering and of nonroutine results communication were calculated. A subset of reports documenting nonroutine communication were manually reviewed. Results: Head and neck CTA was ordered in 2.5% (17,903) of 708,145 ED visits in 236,476 patients (mean age 48.9±20.5 years; 110,952 male, 125,521 female, 3 unknown sex). Head and neck CTA was ordered for 833 distinct chief concerns. Nonroutine results communication was documented for 17.6% (31,55/17,903) of examinations. Among the fifty chief concerns associated with the highest number of examinations, frequency of ordering head and neck CTA ranged from <0.5% (five concerns) to 55.2% (stroke code), and frequency of nonroutine communication ranged from 5.6% (transient ischemic attack) to 67.5% (unresponsive). Chief concerns not among the fifty most common accounted for 50.0% (8956/17903) of examinations; these exhibited a collective frequency of nonroutine communication of 4.8% (429/8956). Manual review of 11.1% (350/3155) of reports with a nonroutine communication indicated an acute finding related to the indication in 51.1%, non-emergent but potentially explanatory finding in 28.0%, incidental finding in 28.0%, and communication of negative results in 6.9%. Conclusion: Head and neck CTA is ordered in 2.5% of ED visits for a wide range of chief concerns. Frequencies of ordering and of nonroutine results communication are highly variable among chief concerns. Acute indication-related findings account for half of nonroutine radiologist communications. Clinical Impact: Insight into patterns regarding head and neck CTA ordering and nonroutine results may help optimize patient selection and radiologist communications in the ED setting.