title: Retrograde flow in the dural sinuses detected by three-dimensional time-of-flight MR angiography.
abstract: BACKGROUND
  Retrograde flow in the left dural sinuses is sometimes detected by three-dimensional time-of-flight (3D-TOF) magnetic resonance (MR) angiography. The purpose of this study was to evaluate the incidence of this phenomenon and its characteristic features on 3D-TOF MR angiograms.
  
  
  METHODS
  We retrospectively reviewed cranial MR angiography images of 1,078 patients examined at our institution. All images were obtained by the 3D-TOF technique with one of two 1.5-T scanners. Maximum intensity projection (MIP) images in the horizontal rotation view were displayed stereoscopically. We reviewed the source images, inferosuperior MIP images, and horizontal MIP images and identified retrograde flow in the dural sinuses.
  
  
  RESULTS
  We found retrograde flow in the dural sinuses of 67 patients on the source images from 3D-TOF MR angiography; the incidence was 6.2%. In 47 of the 67 patients, retrograde flow was identified in the left inferior petrosal sinus, in 13, it was seen in the left sigmoid sinus, and in 6, it was seen in the left inferior petrosal and left sigmoid sinuses. The remaining patient had retrograde flow in the left inferior petrosal and left and right sigmoid sinuses. The mean age of the patients with retrograde flow was slightly greater than that of the patients without this phenomenon (70 years vs 63 years).
  
  
  CONCLUSIONS
  Retrograde flow in the dural sinuses frequently occurs on the left side in middle-aged and elderly patients during 3D-TOF MR angiography performed with the patient in the supine position. This phenomenon should not be misdiagnosed as a dural arteriovenous fistula.
authors.affiliation: Department of Radiology, Saga Medical School, 5-1-1 Nabeshima, Saga, 849-8501, Japan. uchino@med.saga-u.ac.jp
authors.forename: Akira
authors.initials: A
authors.lastname: Uchino
authors.forename: Keita
authors.initials: K
authors.lastname: Nomiyama
authors.forename: Yukinori
authors.initials: Y
authors.lastname: Takase
authors.forename: Takahiko
authors.initials: T
authors.lastname: Nakazono
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Tominaga
authors.forename: Takeshi
authors.initials: T
authors.lastname: Imaizumi
authors.forename: Sho
authors.initials: S
authors.lastname: Kudo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016121:Brachiocephalic Veins / Q000503:physiopathology*; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D003392:Cranial Sinuses / Q000503:physiopathology*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies