title: Pathophysiological consideration of medullary streaks on FLAIR imaging in pediatric moyamoya disease.
abstract: OBJECTIVE Medullary streaks detected on fluid-attenuated inversion recovery (FLAIR) imaging have been considered to be reflected ischemic regions in pediatric moyamoya disease. The purpose of this study was to evaluate these medullary streaks both clinically and radiologically and to discuss associated pathophysiological concerns. METHODS The authors retrospectively reviewed data from 14 consecutive pediatric patients with moyamoya disease treated between April 2009 and June 2016. Clinical and radiological features and postoperative imaging changes were analyzed. In 4 patients, hyperintense medullary streaks on FLAIR imaging (HMSF) at the level of the centrum semiovale were detected. RESULTS The HMSF were coincident with hyperintense medullary streaks on a T2-weighted image, though they were not completely coincident with the vasculature on either a T2*-weighted image or contrast-enhanced CT. Analysis revealed significantly higher values in terms of MR angiography scores, number of flow voids of the basal ganglia, and the presence of the medullary artery in the group with HMSF than in those without. In contrast, the presence of white matter damage was significantly less frequent in the HMSF group. All HMSF disappeared after surgery, and the mean apparent diffusion coefficient at the same level was significantly reduced postoperatively. CONCLUSIONS Although HMSF should be associated with collateral circulation in moyamoya disease, other factors may be involved, including stagnated cerebrospinal fluid or vasogenic edema that is relevant to the impaired state of the white matter. Findings in this study provide insight into the pathophysiological basis of the perivascular space in moyamoya disease.
authors.affiliation: Departments of 1 Neurosurgery and.
authors.forename: Hime
authors.initials: H
authors.lastname: Suzuki
authors.affiliation: Departments of 1 Neurosurgery and.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Mikami
authors.affiliation: Departments of 1 Neurosurgery and.
authors.forename: Tomoyoshi
authors.initials: T
authors.lastname: Kuribara
authors.affiliation: Department of Neurosurgery, Hokkaido Medical Center for Child Health and Rehabilitation; and.
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Yoshifuji
authors.affiliation: Departments of 1 Neurosurgery and.
authors.forename: Katsuya
authors.initials: K
authors.lastname: Komatsu
authors.affiliation: Departments of 1 Neurosurgery and.
authors.forename: Yukinori
authors.initials: Y
authors.lastname: Akiyama
authors.affiliation: Public Health, Sapporo Medical University.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Ohnishi
authors.affiliation: Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Kiyohiro
authors.initials: K
authors.lastname: Houkin
authors.affiliation: Departments of 1 Neurosurgery and.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Mikuni
mesh_terms: D000293:Adolescent; D002533:Cerebral Angiography; D002536:Cerebral Arteries / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D002548:Cerebral Revascularization; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008526:Medulla Oblongata / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000503:physiopathology* / Q000601:surgery; D009072:Moyamoya Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology* / Q000601:surgery; D012189:Retrospective Studies
keywords: ACA = anterior cerebral artery; ADC = apparent diffusion coefficient; CSF = cerebrospinal fluid; CTA = CT angiography; DWI = diffusion-weighted imaging; FLAIR = fluid-attenuated inversion recovery; HMSF = hypointense medullary streaks on FLAIR imaging; ICA = internal carotid artery; IMSF = isointense medullary streaks on FLAIR imaging; MCA = middle cerebral artery; MRA = MR angiography; MRI; PCA = posterior cerebral artery; ROI = region of interest; STA = superficial temporal artery; medullary streaks; moyamoya disease; vascular disorders