RT Journal Article SR Electronic T1 Perfusion Collateral Index versus Hypoperfusion Intensity Ratio in Assessment of Collaterals in Patients with Acute Ischemic Stroke JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 1249 OP 1255 DO 10.3174/ajnr.A8002 VO 44 IS 11 A1 Tsui, Brian A1 Chen, Iris E. A1 Nour, May A1 Kihira, Shingo A1 Tavakkol, Elham A1 Polson, Jennifer A1 Zhang, Haoyue A1 Qiao, Joe A1 Bahr-Hosseini, Mersedeh A1 Arnold, Corey A1 Tateshima, Satoshi A1 Salamon, Noriko A1 Villablanca, J. Pablo A1 Colby, Geoffrey P. A1 Jahan, Reza A1 Duckwiler, Gary A1 Saver, Jeffrey L. A1 Liebeskind, David S. A1 Nael, Kambiz YR 2023 UL http://www.ajnr.org/content/44/11/1249.abstract AB BACKGROUND AND PURPOSE: Perfusion-based collateral indices such as the perfusion collateral index and the hypoperfusion intensity ratio have shown promise in the assessment of collaterals in patients with acute ischemic stroke. We aimed to compare the diagnostic performance of the perfusion collateral index and the hypoperfusion intensity ratio in collateral assessment compared with angiographic collaterals and outcome measures, including final infarct volume, infarct growth, and functional independence.MATERIALS AND METHODS: Consecutive patients with acute ischemic stroke with anterior circulation proximal arterial occlusion who underwent endovascular thrombectomy and had pre- and posttreatment MRI were included. Using pretreatment MR perfusion, we calculated the perfusion collateral index and the hypoperfusion intensity ratio for each patient. The angiographic collaterals obtained from DSA were dichotomized to sufficient (American Society of Interventional and Therapeutic Neuroradiology [ASITN] scale 3–4) versus insufficient (ASITN scale 0–2). The association of collateral status determined by the perfusion collateral index and the hypoperfusion intensity ratio was assessed against angiographic collaterals and outcome measures.RESULTS: A total of 98 patients met the inclusion criteria. Perfusion collateral index values were significantly higher in patients with sufficient angiographic collaterals (P < .001), while there was no significant (P = .46) difference in hypoperfusion intensity ratio values. Among patients with good (mRS 0–2) versus poor (mRS 3–6) functional outcome, the perfusion collateral index of ≥ 62 was present in 72% versus 31% (P = .003), while the hypoperfusion intensity ratio of ≤0.4 was present in 69% versus 56% (P = .52). The perfusion collateral index and the hypoperfusion intensity ratio were both significantly predictive of final infarct volume, but only the perfusion collateral index was significantly (P = .03) associated with infarct growth.CONCLUSIONS: Results show that the perfusion collateral index outperforms the hypoperfusion intensity ratio in the assessment of collateral status, infarct growth, and determination of functional outcomes.AISacute ischemic strokeASITNAmerican Society of Interventional and Therapeutic NeuroradiologyAUCarea under the curveHIRhypoperfusion intensity ratioIQRinterquartile rangemTICImodified TICIPCIperfusion collateral indexROCreceiver operating characteristicTmaxtime-to-maximum