title: Differentiation between paraclinoid and cavernous sinus aneurysms with contrast-enhanced 3D constructive interference in steady- state MR imaging.
abstract: OBJECTIVE
  Differentiation between paraclinoid and cavernous sinus aneurysms of the internal carotid artery (ICA) is critical when considering treatment options. The purpose of this study was to determine whether contrast-enhanced (CE) 3D constructive interference in steady state (CISS) MR imaging is useful to differentiate between paraclinoid and cavernous sinus aneurysms.
  
  
  METHODS
  This study included 11 aneurysms in 10 consecutive female patients, ranging from 52 to 66 years of age. All aneurysms were adjacent to the anterior clinoid process. After conventional and CE 3D-CISS imaging on a 1.5T MR imaging unit, all patients underwent surgery, and the relationship between the aneurysms and the dura was confirmed. Two neuroradiologists evaluated the location of the aneurysms on CE 3D-CISS images and classified them as intradural, partially intradural, and extradural aneurysms. Operative findings were used as a reference standard. To understand the imaging characteristics, we assessed the boundary and signal intensity of the cavernous sinus, CSF, and carotid artery on the side contralateral to the lesion.
  
  
  RESULTS
  Operative findings disclosed that 5 aneurysms were intradural and 6 were extradural. All except 2 were accurately assessed with CE 3D-CISS imaging. One intradural aneurysm adjacent to a large cavernous aneurysm and 1 cavernous giant aneurysm were assessed as partially intradural. On CE 3D-CISS images, the boundary between the CSF, cavernous sinus, and carotid artery was identified by high signal-intensity contrast in all cases.
  
  
  CONCLUSIONS
  CE 3D-CISS MR imaging is useful for the differentiation between paraclinoid and cavernous sinus aneurysms.
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan. t-hirai@kumamoto-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Hirai
authors.forename: Y
authors.initials: Y
authors.lastname: Kai
authors.forename: M
authors.initials: M
authors.lastname: Morioka
authors.forename: S
authors.initials: S
authors.lastname: Yano
authors.forename: M
authors.initials: M
authors.lastname: Kitajima
authors.forename: H
authors.initials: H
authors.lastname: Fukuoka
authors.forename: A
authors.initials: A
authors.lastname: Sasao
authors.forename: R
authors.initials: R
authors.lastname: Murakami
authors.forename: Y
authors.initials: Y
authors.lastname: Nakayama
authors.forename: K
authors.initials: K
authors.lastname: Awai
authors.forename: R
authors.initials: R
authors.lastname: Toya
authors.forename: M
authors.initials: M
authors.lastname: Akter
authors.forename: Y
authors.initials: Y
authors.lastname: Korogi
authors.forename: J
authors.initials: J
authors.lastname: Kuratsu
authors.forename: Y
authors.initials: Y
authors.lastname: Yamashita
mesh_terms: D000368:Aged; D002339:Carotid Arteries / Q000473:pathology*; D002426:Cavernous Sinus / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D002532:Intracranial Aneurysm / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity