Choice Of Initial Brain Imaging In Patients With Suspected Acute Stroke: Stroke69, A Population-Based Study

Background: In patients with suspected stroke, brain imaging is recommended in the acute phase for appropriate management and treatment. Both computed tomography (CT) and magnetic resonance imaging (MRI) are considered reasonable choices for initial brain imaging. When both techniques are available, choosing one or the other might be associated with specific factors related either to patients, stroke symptoms, and severity or management organization. Methods: The study was performed within the STROKE 69 database, a population-based cohort of all adult patients with suspected stroke admitted in one of the emergency departments (ED), primary stroke center, or stroke center of the Rhone County, from November 2015 to December 2016. Patients were included if they were admitted within 24 h following either symptom onset or last known normal. To identify factors potentially associated with the choice of initial brain imaging, a multivariate logistic regression was performed. Results: Among the 3,244 patients with suspected stroke enrolled in the STROKE69 cohort, 3,107 (95.8%) underwent brain imaging within the first 24 h after admission. Among those 74.6% underwent CT as initial imaging while 25.4% had an MRI. In multivariate analyses, several factors were associated with a lower probability of having an MRI as initial brain imaging versus CT. These were either patient characteristics: older age (>80 years old, OR 0.39 [95% CI 0.28-0.54]), preexisting disability (OR 0.55 [95% CI 0.36-0.84]), use of anticoagulants (OR 0.52 [95% CI 0.33-0.81]), stroke characteristics: stroke of unknown onset (OR 0.42 [95% CI 0.31-0.58]) or factors associated with overall management: onset-to-door time (>6 h, OR 0.38 [95% CI 0.23-0.60]), initial admission to ED (OR 0.02 [95% CI 0.02-0.04]) or intensive care unit (OR 0.01 [95% CI 0.001-0.08]), personal transport (OR 0.66 [95% CI 0.45-0.96]), and admission during working hours (OR 0.65 [95% CI 0.51-0.84]). Conclusions: Besides CT or MRI availability, a number of other parameters could influence the choice of first imaging in case of stroke suspicion. These are related to patient characteristics, type of stroke symptoms, and type of organization.