title: 2D time-of-flight MR venography in neonates: anatomy and pitfalls.
abstract: OBJECTIVE
  The dural venous sinuses in neonates differ from those in adults or older children in that the caliber of venous sinuses is smaller and there is skull molding. The aim of this retrospective study is to evaluate the presence of flow gaps in venous sinuses in neonates on 2D time-of-flight (TOF) MR venography (MRV).
  
  
  METHODS
  Fifty-one neonates underwent coronal 2D TOF MRV. Nine also had CT venography (CTV) for comparison. In 1 neonate, a further 2D TOF MRV was performed in the sagittal plane; in another neonate, images were captured in the axial plane; and in another, a further coronal TOF MRV with shorter echo time was performed.
  
  
  RESULTS
  Flow gap was seen in the posterior aspect of the superior sagittal sinus in 35 of 51 (69%). Focal narrowing of the superior sagittal sinus, in the region of convergence of lambdoid sutures, was detected in 7 of 51 (14%). The right and left transverse sinuses demonstrated flow gap in 13 of 51 (25%) and 32 of 51 (63%) respectively. There was normal filling of contrast on CTV in the superior sagittal sinus, transverse sinus and sigmoid sinus in those cases with flow gap detected on coronal 2D TOF MRV. Right, left, and codominance of the transverse sinuses are as follows: 32 of 51 (63%), 5 of 51 (10%), and 14 of 51 (27%), respectively. The right and left sigmoid sinuses demonstrated flow gap in 7 of 51 (14%) and 8 of 51 (16%), respectively, and the left sigmoid sinus was absent in 1 of 51 (2%).
  
  
  CONCLUSIONS
  The high proportion of flow gap in the venous sinuses of neonates, particularly of the superior sagittal sinus, could be attributed to the smaller caliber venous sinuses, slower venous flow, and skull molding.
authors.affiliation: Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: E
authors.initials: E
authors.lastname: Widjaja
authors.forename: M
authors.initials: M
authors.lastname: Shroff
authors.forename: S
authors.initials: S
authors.lastname: Blaser
authors.forename: S
authors.initials: S
authors.lastname: Laughlin
authors.forename: C
authors.initials: C
authors.lastname: Raybaud
mesh_terms: D015901:Angiography, Digital Subtraction; D016477:Artifacts; D002533:Cerebral Angiography / Q000379:methods*; D002550:Cerebral Veins / Q000033:anatomy & histology*; D003287:Contrast Media / Q000008:administration & dosage; D003392:Cranial Sinuses / Q000033:anatomy & histology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007231:Infant, Newborn; D007234:Infant, Premature; D007472:Iohexol; D018810:Magnetic Resonance Angiography / Q000379:methods*; D012016:Reference Values; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed
chemical_list: D003287:Contrast Media; D007472:Iohexol