Perfusion Angiography in reperfused ischemic stroke patients: differentiating between favorable and unfavorable outcome.

Background and purpose: The Thrombolysis in Cerebral Infarction (TICI) score determines the reperfusion grade on digital subtraction angiography (DSA) after endovascular treatment (EVT) in acute ischemic stroke patients. Despite successful macrovascular reperfusion, almost half of patients have poor clinical outcome. 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 (TICs) 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 (eTICI ≥2B) were selected. Perfusion parameters of the capillary pixels were computed on post-EVT DSA by deconvolving the TIC with the arterial input function obtained from the internal carotid artery. Four perfusion parameters were extracted: cerebral blood volume (CBV), cerebral blood flow (CBF), time to maximum CBF (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 odds ratio, 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 in differentiating between favorable and unfavorable functional outcome. The code for producing the quantitative digital subtraction perfusion angiography is publicly available at: https://github.com/RuishengSu/perfDSAABBREVIATIONS: EVT＝ Endovascular thrombectomy.