title: Interhemispheric characterization of small vessel disease imaging markers after subcortical infarct.
abstract: In structural Magnetic Resonance Imaging (MRI) of patients with a recent small subcortical infarct (RSSI) and small vessel disease (SVD) imaging markers coexist. However, their spatial distribution and prevalence with respect to the hemisphere of the RSSI remain unknown.
  
  
  
  From brain MRI in 187 patients with an acute lacunar ischemic stroke clinical syndrome and a relevant diffusion weighted imaging (DWI)-positive lesion, we semiautomatically extracted the RSSI, microbleeds, lacunes, old cortical infarcts, and white matter hyperintensities (WMH) using optimized thresholding in the relevant sequences, and rated the load of perivascular spaces. We registered all images to an age-relevant brain template and calculated the probability distribution of all SVD markers mentioned for patients who had the RSSI in each hemisphere separately. We used the Wilcoxon and chi-squared tests to compare the volumes and frequencies of occurrence, respectively, of the SVD markers between hemispheres throughout the sample.
  
  
  
  Fifty-two percent patients (n= 97) had the RSSI in the left hemisphere, 42% (n= 78) in the right, 2.7% (n= 5) in both, and 3.7% (n= 7) in the cerebellum or brainstem. There was no significant difference in RSSI frequency between left and right hemispheres (p= .10) in the sample. The median volume of the RSSI (expressed as a percentage of the total intracranial volume) was 0.05% (IQR = 0.06). There was no difference in median percent volume of the right RSSIs versus left (p= .16). Neither was there a significant interhemispheric difference in the volume of any of the SVD markers regardless of the location of the RSSI and they were equally distributed in both hemispheres.
  
  
  
  Assessment of SVD imaging markers in the contralateral hemisphere could be used as a proxy for the SVD load in the whole brain to avoid contamination by the RSSI of the measurements, especially of WMH.
authors.affiliation: Department of Neuroimaging Sciences Centre for Clinical Brain Sciences University of Edinburgh Edinburgh UK.
authors.forename: Maria Del C
authors.identifier: 0000-0003-2771-6546
authors.initials: MD
authors.lastname: Valdés Hernández
authors.affiliation: College of Medicine and Veterinary Medicine University of Edinburgh Edinburgh UK.
authors.forename: Xinyi
authors.initials: X
authors.lastname: Qiu
authors.affiliation: Department of Neuroimaging Sciences Centre for Clinical Brain Sciences University of Edinburgh Edinburgh UK.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Neuroimaging Sciences Centre for Clinical Brain Sciences University of Edinburgh Edinburgh UK.
authors.forename: Stewart
authors.initials: S
authors.lastname: Wiseman
authors.affiliation: Department of Neuroimaging Sciences Centre for Clinical Brain Sciences University of Edinburgh Edinburgh UK.
authors.forename: Eleni
authors.initials: E
authors.lastname: Sakka
authors.affiliation: Buckinghamshire Healthcare NHS Trust Buckinghamshire UK.
authors.forename: Lucy C
authors.initials: LC
authors.lastname: Maconick
authors.affiliation: Department of Neuroimaging Sciences Centre for Clinical Brain Sciences University of Edinburgh Edinburgh UK.
authors.forename: Fergus
authors.initials: F
authors.lastname: Doubal
authors.affiliation: Department of Neuroimaging Sciences Centre for Clinical Brain Sciences University of Edinburgh Edinburgh UK.
authors.forename: Cathie L M
authors.initials: CL
authors.lastname: Sudlow
authors.affiliation: Department of Neuroimaging Sciences Centre for Clinical Brain Sciences University of Edinburgh Edinburgh UK.
authors.forename: Joanna M
authors.initials: JM
authors.lastname: Wardlaw
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D020520:Brain Infarction / Q000000981:diagnostic imaging / Q000473:pathology*; D020526:Brain Stem Infarctions / Q000000981:diagnostic imaging / Q000473:pathology; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000473:pathology*; D002543:Cerebral Hemorrhage / Q000000981:diagnostic imaging / Q000473:pathology*; D002544:Cerebral Infarction / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D059409:Stroke, Lacunar / Q000000981:diagnostic imaging / Q000473:pathology*; D066127:White Matter / Q000000981:diagnostic imaging / Q000473:pathology*
chemical_list: D015415:Biomarkers
keywords: magnetic resonance images; neuroimaging; small vessel disease; stroke; white matter hyperintensities