Diagnostic value of 3D arterial spin labeling plus diffusion-weighted imaging for transient ischemic attack and short-term stroke prognosis: A retrospective cohort study.

Transient ischemic attack (TIA) carries substantial short-term stroke risk, yet current diagnostics lack adequate sensitivity. Diffusion-weighted imaging (DWI) detects only 30% to 50% of TIA-related lesions, while 3-dimensional arterial spin labeling (3D-ASL) offers complementary hemodynamic assessment. We performed a retrospective cohort study of 106 TIA patients and 58 healthy controls undergoing 3.0T MRI within 72 hours of symptom onset. Imaging included DWI (b = 0,1000 seconds/mm2), 3D-ASL with dual post-labeling delays, and MR angiography. Clinical data and ABCD2 scores were collected, with 90-day stroke follow-up. Diagnostic performance and prognostic factors were analyzed using ROC curves and Cox regression. DWI detected acute lesions in 37 patients (34.9%), while 3D-ASL revealed cerebral hypoperfusion in 64 (60.4%), including 35 DWI-negative cases. Combined imaging improved 90-day stroke prediction (AUC 0.854; sensitivity 93.8%, specificity 71.1%) versus DWI alone (AUC 0.761) or 3D-ASL alone (AUC 0.790) (P <.05). During follow-up, 16 patients (15.1%) experienced stroke. Multivariate analysis identified DWI positivity (HR 3.24, 95% CI: 1.18-8.91), hypoperfusion volume >15 mL (HR 2.87, 95% CI: 1.06-7.78), and ABCD2 score ≥4 (HR 3.01, 95% CI: 1.09-8.31) as independent predictors. Symptom duration ≥1 hour correlated with higher DWI positivity (47.7% vs 25.8%, P = .012) and larger hypoperfusion volumes (16.8 vs 9.2 mL, P = .004). Combining 3D-ASL with DWI significantly improves cerebrovascular pathology detection and 90-day stroke risk prediction beyond clinical scoring, identifying high-risk TIA patients for intensified secondary prevention.