title: Carotid artery stenosis with a high-intensity signal plaque on time-of-flight magnetic resonance angiography and association with evidence of intraplaque hypoxia.
abstract: OBJECTIVE Hypoxia induces angiogenesis and plays a major role in the progression of carotid plaques. During carotid intervention, plaques with high-intensity signals on time-of-flight (TOF) magnetic resonance angiography (MRA) often cause ischemic stroke and embolic complications. However, the role of intraplaque hypoxia before carotid endarterectomy (CEA) and carotid artery stenting is not presently understood. In this study the authors aimed to investigate the relationship between intraplaque hypoxia and MRA findings. METHODS Nineteen consecutive patients with 20 carotid artery stenoses who underwent CEA at Saga University Hospital between August 2008 and December 2014 were enrolled in the study. The expressions of hypoxia-inducible transcription factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) were analyzed by immunohistochemical analysis. In addition, the relationship between the findings on TOF MRA and pathology for the carotid plaques was analyzed. RESULTS High-intensity plaques on TOF MRA showed higher expression levels of HIF-1α (p = 0.015) and VEGF (p = 0.007) compared with isointensity plaques. The rate of intraplaque hemorrhage (IPH) on TOF MRA was also significantly higher in the high-intensity plaques than in the isointensity plaques (p = 0.024). Finally, the mean number of neovessels was significantly higher in those without plaque hemorrhage than in those with plaque hemorrhage (p = 0.010). CONCLUSIONS Plaques with high-intensity signals on TOF MRA were associated with IPH and evidence of intraplaque hypoxia. This fact may represent an opportunity to establish novel therapeutic agents targeting intraplaque hypoxia.
authors.affiliation: Departments of 1 Neurosurgery and.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ogata
authors.affiliation: Departments of 1 Neurosurgery and.
authors.forename: Masatou
authors.initials: M
authors.lastname: Kawashima
authors.affiliation: Departments of 1 Neurosurgery and.
authors.forename: Tomihiro
authors.initials: T
authors.lastname: Wakamiya
authors.affiliation: Radiology, School of Medicine, Saga University, Saga, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Nishihara
authors.affiliation: Departments of 1 Neurosurgery and.
authors.forename: Jun
authors.initials: J
authors.lastname: Masuoka
authors.affiliation: Departments of 1 Neurosurgery and.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Nakahara
authors.affiliation: Departments of 1 Neurosurgery and.
authors.forename: Ryo
authors.initials: R
authors.lastname: Ebashi
authors.affiliation: Departments of 1 Neurosurgery and.
authors.forename: Kohei
authors.initials: K
authors.lastname: Inoue
authors.affiliation: Departments of 1 Neurosurgery and.
authors.forename: Yukinori
authors.initials: Y
authors.lastname: Takase
authors.affiliation: Radiology, School of Medicine, Saga University, Saga, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Irie
authors.affiliation: Departments of 1 Neurosurgery and.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Abe
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000601:surgery; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000000981:diagnostic imaging*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000601:surgery; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D042461:Vascular Endothelial Growth Factor A
keywords: CAS = carotid artery stenting; CEA = carotid endarterectomy; HIF = hypoxia-inducible transcription factor; IPH = intraplaque hemorrhage; MRA = MR angiography; TOF = time of flight; VEGF = vascular endothelial growth factor; carotid artery; carotid stenosis; hypoxia; vascular disorders