Clinical Predictors of Significant Findings on Head Computed Tomographic Angiography

Background: Although head computed tomographic angiography (CTA) is a sensitive tool for the evaluation of neurological symptoms in the emergency department (ED), little is known about which clinical signs predict significant CTA findings. Objectives: To identify clinical factors that predict significant findings on head CTA in patients presenting to the ED with neurological complaints. Methods: Retrospective chart review of consecutive adult patients undergoing head CTA over a 6-month period in an urban, tertiary care ED with an annual volume of 76,000. Significant head CTA findings were defined as clinically significant neurological abnormalities undetected by previous imaging studies. Demographics, chief complaint, results of the neurological examinations (NE), and head non-contrast computed tomography (CT) results were used as predictors of significant head CTA. All predictors with a univariate p < 0.2 using Pearson's chi-squared were entered stepwise into a multivariable logistic regression including odds ratios (OR), with inclusion restricted to p < 0.05. Results: Chart review yielded 456 cases; 215 (47%) were male. Mean age was 62 (SD 20) years. There were 189 patients (41%) with abnormal CTAs. Multivariable logistic regression indicated five variables that predicted a clinically significant CTA: abnormal CT (OR 3.72), chief complaint of subarachnoid hemorrhage-type headache (OR 2.30), and motor deficit (OR 2.23), visual deficit (OR 2.23), and other focal deficit (OR 2.18) on NE. A chief complaint of trauma (OR 0.23) predicted a normal CTA. Conclusions: Specific historical and focal neurological findings are useful for predicting clinically significant findings on head CTA.