Pretreatment CT perfusion collateral parameters correlate with penumbra salvage in middle cerebral artery occlusion

Abstract

Background and PurposeAcute ischemic stroke due to large vessel occlusion (AIS‐LVO) is a major cause of functional dependence. Collateral status (CS) is an important determinant of functional outcomes. Pretreatment CT perfusion (CTP) parameters serve as reliable surrogates of CS. Penumbra Salvage Index (PSI) is another parameter predictive of functional outcomes in AIS‐LVO. The aim of this study is to assess the relationship of pretreatment CTP parameters with PSI.MethodsIn this prospectively collected, retrospectively reviewed multicenter analysis, inclusion criteria were as follows: (1) CT angiography confirmed middle cerebral artery (MCA) M1‐segment and proximal M2‐segment occlusion from 9/1/2017 to 9/22/2022; (2) diagnostic CTP; and (3) available diagnostic Magnetic resonance Imaging (MRI) diffusion‐weighted images. Pearson correlation analysis was performed to assess the association between cerebral blood volume (CBV) index and hypoperfusion intensity ratio (HIR) with PSI. p value ≤.05 was considered statistically significant.ResultsIn total, 131 patients (n = 86, M1 and n = 45, proximal M2 occlusion) met our inclusion criteria. CBV index showed a modest positive correlation with PSI (r = 0.34, p<.001) in patients with proximal MCA occlusion. Similar trends were noted in subgroup analysis of patients with M1 occlusion, and proximal M2 occlusion. Whereas, HIR did not have a strong trend or correlation with PSI.ConclusionCBV index correlates with PSI, whereas HIR does not. Future studies are needed to expand our understanding of the adjunct role of CBV index with other similar pretreatment CTP‐based markers in clinical evaluation and decision‐making in patients with MCA occlusion.

The Relative Cerebral Blood Volume (rCBV) < 42% Is Independently Associated with Collateral Status in Anterior Circulation Large Vessel Occlusion

“…The multiphase CTA-based mCTA scoring system is a six-point scoring system which takes into account dynamic filling of the collateral vessels during different contrast phases [ 28 ]. There are several CTP-based CS markers which are being validated, which include the Hypoperfusion Intensity Ratio (HIR), defined as the ratio of the Tmax >10 s lesion volume to the Tmax > 6 s lesion volume [ 8 ]; the CBV Index, defined as the relative CBV in the Tmax > 6 s region [ 8 ]; the compensation index, defined as the ratio of the Tmax > 4 s lesion volume to the Tmax > 6 s lesion volume [ 6 ]; and the relative cerebral blood flow (rCBF) < 38% lesion volume.…”

“…The cerebral blood volume (CBV) is an excellent quantitative marker for estimations of the collateral blood flow in the affected territory of acute ischemic stroke secondary to large vessel occlusion (AIS-LVO). There are a number of factors that impact the outcomes of AIS-LVOs, one of these is the robust collateral blood flow [referred to as collateral status (CS)] in the affected territories via pial arterial collateralization, hereby referred to as the collateral status [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. A robust CS has been associated with better functional outcomes, a smaller infarct growth rate and better recanalization following mechanical thrombectomy (MT).…”

CT Perfusion Derived rCBV < 42% Lesion Volume Is Independently Associated with Followup FLAIR Infarct Volume in Anterior Circulation Large Vessel Occlusion

“…In several automated software platforms, the cerebral blood volume is quantified relative to the non-affected hemisphere [1][2][3][4][5][6][7][8]. RapidAI (IschemaView, Menlo Park, CA, USA) is one such software platform with the capability of quantifying cerebral blood volume where the relative cerebral blood volume (rCBV) is derived from the cerebral blood volume values in the region of time to maximum (Tmax) > 6 second lesion area within the affected hemisphere.…”