title: MR imaging findings in colloid cysts of the sellar region: comparison with colloid cysts of the third ventricle and Rathke's cleft cysts.
abstract: OBJECTIVE
  To identify magnetic resonance (MR) imaging characteristics allowing specific preoperative discrimination between colloid cysts (CCs) of the sellar region and third ventricle (CC3rdv) versus Rathke's cleft cysts (RCCs).
  
  
  METHODS
  MR imaging data of 38 patients with histologically proven CCs/CC3rdv and RCC underwent retrospective analysis with respect to signal intensity and heterogeneity on T1- and T2-weighted images, presence of the dot sign, enhancement, size, location, and accompanying infundibular stalk abnormalities.
  
  
  RESULTS
  Thirteen patients had CCs, 12 had CC3rdv, and 13 had RCCs. Signal intensity on T1-weighted images was partly or entirely hyperintense (n = 8), iso- or mixed iso/hypointense (n = 5) in CCs; hyperintense (n = 8), isointense, or mixed hypo/isointense (n = 3) in CC3rdv and hyperintense (n = 9); or mixed (n = 4) in RCCs. On T2-weighted images, signal intensity was hypointense (n = 12) or hyperintense (n = 1) in CCs, hypointense (n = 9) or hyperintense (n = 2) in CC3rdv, and hypointense (n = 5) or iso/hyperintense (n = 8) in RCCs. T2-weighted images were unavailable in two patients. Only one questionable enhancement was found in CCs, whereas an enhancing rim was consistently seen in RCCs. The dot sign was present in 7 CCs, 8 CC3rdv, and 4 RCCs. Mean cyst diameters were 12.6 mm for CCs and 14.5 mm for RCCs. RCCs showed more frequent and even solely suprasellar extent contrary to CCs.
  
  
  CONCLUSIONS
  Cyst wall enhancement was found in all RCCs but in none of the CCs, making this feature a reliable discriminator between the two. Complementary, suprasellar extension was more frequent in RCCs, whereas signal hypointensity on T2w was more common in colloid cysts.
authors.affiliation: Department of Diagnostic and Interventional Neuroradiology, Eberhard-Karls-University, Hoppe-Seyler-Str. 3, 72076 Tübingen, Germany. Electronic address: Benjamin.bender@med.uni-tuebingen.de.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Bender
authors.forename: Jürgen B
authors.initials: JB
authors.lastname: Honegger
authors.forename: Rudi
authors.initials: R
authors.lastname: Beschorner
authors.forename: Ulrike
authors.initials: U
authors.lastname: Ernemann
authors.forename: Marius
authors.initials: M
authors.lastname: Horger
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D020863:Central Nervous System Cysts / Q000175:diagnosis* / Q000473:pathology; D002552:Cerebral Ventricles / Q000473:pathology*; D002648:Child; D003287:Contrast Media; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012658:Sella Turcica / Q000473:pathology*
chemical_list: D003287:Contrast Media
keywords: Colloid cyst (CC); Rathke's cleft cyst (RCC); magnetic resonance imaging