title: Prominent Inferior Intercavernous Sinus on Sagittal T1-Weighted Images: A Sign of Intracranial Hypotension.
abstract: OBJECTIVE
  The purpose of this study is to describe the diagnostic accuracy of the dilatation of the inferior intercavernous sinus as a sign of intracranial hypotension and to raise awareness of this anatomic structure, which can be mistaken for a focal pituitary lesion.
  
  
  METHODS
  Sagittal T1-weighted images of 26 patients with intracranial hypotension and 28 control subjects were evaluated to determine the presence of a distended inferior intercavernous sinus. Information about the shape, size, and signal of the inferior intercavernous sinus was also collected. The chi-square test was used to compare both groups. Sensitivity and specificity of the dilatation of the inferior intercavernous sinus as a sign of intracranial hypotension were calculated.
  
  
  RESULTS
  A visible inferior intercavernous sinus was found in 13 of 26 patients with intracranial hypotension (50%) and in four of 28 control subjects (14.3%). These percentages were significantly different (p = 0.005). There was no significant difference in size of the inferior intercavernous sinus in the intracranial hypotension group (median, 5.86 mm(2); interquartile range, 6.28 mm(2)) compared with the control group (median, 8.25 mm(2); interquartile range, 16.69 mm(2)). Changes in the size of the inferior intercavernous sinus were detected in congruence with the appearance or resolution of intracranial hypotension.
  
  
  CONCLUSIONS
  Dilatation of the inferior intercavernous sinus is frequently associated with intracranial hypotension, although it can also be found in the healthy adult as a normal anatomic variant. Recognition of this anatomic structure is important to avoid mistaking it for a focal pituitary lesion.
authors.affiliation: 1 Department of Medical Imaging, St. Michael's Hospital, 30 Bond St, Toronto, ON, M5B 1W8, Canada.
authors.forename: Paula
authors.initials: P
authors.lastname: Alcaide-Leon
authors.affiliation: 2 Department of Radiodiagnóstico, Hospital Clinic, Barcelona, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: López-Rueda
authors.affiliation: 1 Department of Medical Imaging, St. Michael's Hospital, 30 Bond St, Toronto, ON, M5B 1W8, Canada.
authors.forename: Ailish
authors.initials: A
authors.lastname: Coblentz
authors.affiliation: 3 Department of Medical Imaging, University of Toronto, Toronto, ON, Canada.
authors.forename: Walter
authors.initials: W
authors.lastname: Kucharczyk
authors.affiliation: 1 Department of Medical Imaging, St. Michael's Hospital, 30 Bond St, Toronto, ON, M5B 1W8, Canada.
authors.forename: Aditya
authors.initials: A
authors.lastname: Bharatha
authors.affiliation: 1 Department of Medical Imaging, St. Michael's Hospital, 30 Bond St, Toronto, ON, M5B 1W8, Canada.
authors.forename: Lyne Noël
authors.initials: LN
authors.lastname: de Tilly
mesh_terms: D016022:Case-Control Studies; D002426:Cavernous Sinus / Q000473:pathology*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D019585:Intracranial Hypotension / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity
keywords: T1-weighted MRI; intercavernous sinus; intracranial hypotension