Perfusion Angiography in Reperfused Patients with Ischemic Stroke: Differentiating between Favorable and Unfavorable Outcome

BACKGROUND AND PURPOSE: The TICI score determines the reperfusion grade on DSA after endovascular treatment (EVT) in patients with acute ischemic stroke. Despite successful macrovascular reperfusion, almost one-half of patients have poor clinical outcomes. In addition to the large vessels, DSA also depicts the passage of contrast in the capillaries. We aim to study differences in DSA perfusion parameters generated from the time-intensity curves that might differentiate between good and poor clinical outcome in patients who achieved successful reperfusion. MATERIALS AND METHODS: Patients from the MR CLEAN Registry with an ICA, M1, and M2 occlusion, and successful reperfusion extended TICI (eTICI ≥2b) were selected. Perfusion parameters of the capillary pixels were computed on post-EVT DSA by deconvolving the time-intensity curve with the arterial input function obtained from the ICA. We extracted 4 perfusion parameters: CBV, CBF, time-to-maximum (Tmax), and mean transit time (MTT). The association between the perfusion parameters and favorable functional outcome at 90 days (0-2 mRS) was analyzed using logistic regression with adjustments for prognostic patient characteristics including eTICI. RESULTS: In total, 743 of 5768 patients were included. There was no association between eTICI scores and favorable functional outcome. In contrast, a shorter MTT and Tmax were associated with favorable functional outcome (adjusted OR, 1.25 [95% CI, 1.03-1.51], 1.39 [95% CI, 1.06-1,82]). DSA-CBV and DSA-CBF were not significantly associated with mRS. CONCLUSIONS: Quantifying DSA perfusion parameters provides additional information about reperfusion status and could contribute to differentiating between favorable and unfavorable functional outcomes. The code for producing the quantitative digital subtraction perfusion angiography is publicly available at: https://github.com/RuishengSu/perfDSA.