Automated Measurement of Net Water Uptake From Baseline and Follow-Up CTs in Patients With Large Vessel Occlusion Stroke
Open Access
- 27 June 2022
- journal article
- research article
- Published by Frontiers Media SA in Frontiers in Neurology
- Vol. 13, 898728
- https://doi.org/10.3389/fneur.2022.898728
Abstract
Quantifying the extent and evolution of cerebral edema developing after stroke is an important but challenging goal. Lesional net water uptake (NWU) is a promising CT-based biomarker of edema, but its measurement requires manually delineating infarcted tissue and mirrored regions in the contralateral hemisphere. We implement an imaging pipeline capable of automatically segmenting the infarct region and calculating NWU from both baseline and follow-up CTs of large-vessel occlusion (LVO) patients. Infarct core is extracted from CT perfusion images using a deconvolution algorithm while infarcts on follow-up CTs were segmented from non-contrast CT (NCCT) using a deep-learning algorithm. These infarct masks were flipped along the brain midline to generate mirrored regions in the contralateral hemisphere of NCCT; NWU was calculated as one minus the ratio of densities between regions, removing voxels segmented as CSF and with HU outside thresholds of 20–80 (normal hemisphere and baseline CT) and 0–40 (infarct region on follow-up). Automated results were compared with those obtained using manually-drawn infarcts and an ASPECTS region-of-interest based method that samples densities within the infarct and normal hemisphere, using intraclass correlation coefficient (ρ). This was tested on serial CTs from 55 patients with anterior circulation LVO (including 66 follow-up CTs). Baseline NWU using automated core was 4.3% (IQR 2.6–7.3) and correlated with manual measurement (ρ = 0.80, p < 0.0001) and ASPECTS (r = −0.60, p = 0.0001). Automatically segmented infarct volumes (median 110-ml) correlated to manually-drawn volumes (ρ = 0.96, p < 0.0001) with median Dice similarity coefficient of 0.83 (IQR 0.72–0.90). Automated NWU was 24.6% (IQR 20–27) and highly correlated to NWU from manually-drawn infarcts (ρ = 0.98) and the sampling-based method (ρ = 0.68, both p < 0.0001). We conclude that this automated imaging pipeline is able to accurately quantify region of infarction and NWU from serial CTs and could be leveraged to study the evolution and impact of edema in large cohorts of stroke patients.Keywords
Funding Information
- National Institute of Neurological Disorders and Stroke (K23NS099440, K23NS099487, R01NS085419)
- Foundation of the American Society of Neuroradiology
This publication has 44 references indexed in Scilit:
- U-Net: Convolutional Networks for Biomedical Image SegmentationPublished by Springer Science and Business Media LLC ,2015
- Brain Edema Predicts Outcome After Nonlacunar Ischemic StrokeStroke, 2014
- Contrast Staining on CT after DSA in Ischemic Stroke Patients Progresses to Infarction and Rarely HemorrhagesInterventional Neuroradiology, 2014
- Automated Cerebral Infarct Volume Measurement in Follow-up Noncontrast CT Scans of Patients with Acute Ischemic StrokeAmerican Journal of Neuroradiology, 2013
- Age-specific CT and MRI templates for spatial normalizationNeuroImage, 2012
- Validating Imaging Biomarkers of Cerebral Edema in Patients With Severe Ischemic StrokeJournal of Stroke and Cerebrovascular Diseases, 2012
- Improved Optimization for the Robust and Accurate Linear Registration and Motion Correction of Brain ImagesNeuroImage, 2002
- 'Malignant' Middle Cerebral Artery Territory InfarctionArchives of Neurology, 1996
- Intraclass correlations: Uses in assessing rater reliability.Psychological Bulletin, 1979
- Experimental regional cerebral ischemia in the middle cerebral artery territory in primates. Part 2: Effects on brain water and electrolytes in the early phase of MCA stroke.Stroke, 1977