Prediction of Hemorrhage after Successful Recanalization in Patients with Acute Ischemic Stroke: Improved Risk Stratification Using Dual-Energy CT Parenchymal Iodine Concentration Ratio Relative to the Superior Sagittal Sinus

Abstract

BACKGROUND AND PURPOSE: Brain parenchymal hyperdensity on postthrombectomy CT in patients with acute stroke can be due to hemorrhage and/or contrast staining. We aimed to determine whether iodine concentration within contrast-stained parenchyma compared with an internal reference in the superior sagittal sinus on dual-energy CT could predict subsequent intracerebral hemorrhage.MATERIALS AND METHODS: Seventy-one patients with small infarct cores (ASPECTS $ 7) and good endovascular recanalization (modified TICI 2b or 3) for anterior circulation large-vessel occlusion were included. Brain parenchymal iodine concentration as per dual-energy CT and the percentage of contrast staining relative to the superior sagittal sinus were recorded and correlated with the development of intracerebral hemorrhage using Mann-Whitney U and Fisher exact tests.RESULTS: Forty-three of 71 patients had parenchymal hyperdensity on initial dual-energy CT. The median relative iodine concentration compared with the superior sagittal sinus was significantly higher in those with subsequent intracerebral hemorrhage (137.9% versus 109.2%, P 4 .007). By means of receiver operating characteristic analysis, a cutoff value of 100% (iodine concentration relative to the superior sagittal sinus) enabled identification of patients going on to develop intracerebral hemorrhage with 94.75% sensitivity, 43.4% specificity, and a likelihood ratio of 1.71.CONCLUSIONS: Within our cohort of patients, the relative percentage of iodine concentration at dual-energy CT compared with the superior sagittal sinus was a reliable predictor of intracerebral hemorrhage development and may be a useful imaging biomarker for risk stratification after endovascular treatment. ABBREVIATIONS: DECT 4 dual-energy CT; ICH 4 intracerebral hemorrhage; SSS 4 superior sagittal sinus

A Review of the Applications of Dual-Energy CT in Acute Neuroimaging

“…This method was thought to account for variability in iodine concentration depending on factors such as patient size, cardiac output, renal function, and volume of contrast medium administered. 42 However, while contrast staining predicts intracranial hemorrhage, in another study it was not found to be associated with symptomatic hemorrhage or functional outcomes. 35…”

“…This method was thought to account for variability in iodine concentration depending on factors such as patient size, cardiac output, renal function, and volume of contrast medium administered. 42 However, while contrast staining predicts intracranial hemorrhage, in another study it was not found to be associated with symptomatic hemorrhage or functional outcomes. 35 Postprocedural DECT may help to guide antiplatelet therapy in patients who have EVT and stenting of carotid occlusions to balance the risks of bleeding and stent thrombosis based on risk factors seen on DECT such as infarct size, contrast staining, and hemorrhage.…”

Imaging for Predicting Hemorrhagic Transformation of Acute Ischemic Stroke—A Narrative Review

“…A study measuring relative iodine density between the superior sagittal sinus and the ischemic region in patients with contrast staining, demonstrated that a relative iodine value of 100% was associated with a 94.7% sensitivity, 43.4% specificity, and a likelihood ratio of 1.7 for HT. 23…”

Dual-Energy Computed Tomography Quantification of Extravasated Iodine and Hemorrhagic Transformation after Thrombectomy

“…1 Parenchymal hyperdense lesions, commonly observed on brain computed tomography scans after EVT, are caused by ischemic disruption of the blood-brain barrier and may be seen with secondary contrast staining or hemorrhage. [2][3][4] Dual-energy computed tomography (DECT) can accurately differentiate hemorrhage from contrast staining, and parenchymal contrast staining has been associated with the development of future HT. 2-4 However, whether the predictability may be improved when both imaging and clinical markers are simultaneously considered and the imaging marker associated with HT volume remain unclear.Hence, we aimed to identify quantified markers for iodine extravasation on early DECT for the occurrence and volume of HT and investigate whether the simultaneous consideration of clinical markers could improve predictability.This single-center retrospective study included patients with acute ischemic stroke with large artery occlusion of the anterior circulation, who underwent EVT and DECT within 60 minutes after EVT between May 2019 and October 2020 (Supplementary Figure 1).…”

“…The details of the study design and imaging analysis are described in the Supplementary methods and Supplementary results. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] Briefly, the volume of interest (VOI) was manually drawn by two independent readers. The VOIs covered § Volume of iodine extravasation was defined as the voxel volume with an iodine concentration >0.7 mg/mL.…”