title: Investigation of the calcification at the petroclival region through Multi-slice Computed Tomography of the skull base.
abstract: OBJECTIVE
  The aim of this paper was a retrospective investigation of calcification at the petroclival region using Multi-slice Computed Tomography (MSCT).
  
  
  METHODS
  One hundred thirty skull bases were reviewed. The images were acquired with a 64 slice CT (MSCT). At first images were taken at the axial plane; and then coronal and sagittal reconstructions of raw data were performed. Later investigations were carried out on these 3-dimensional images (3-D imaging). Petrosphenoidal ligament (PSL) (Gruber's ligament) and posterior petroclinoid ligament (PPCL) calcifications were evaluated as "none, partial or complete calcification" for the right and left sides.
  
  
  RESULTS
  In the right PSL, there were partial calcifications in 9.8% and complete calcifications in 2.3%. Calcification ratio was 9.8% partial and 2.9% complete in the left PSL. In the right side, there were 26.6% partial and 5.2% complete calcifications of PPCL. In the left side, there were 29.5% partial and 4.6% complete PPCL calcifications. PPCL calcification was detected more in males compared to females in the right and left sides. In older patients, left PSL; right and left PPCL calcification were detected more.
  
  
  CONCLUSIONS
  PPCL calcifications cannot be differentiated from PSL calcifications in MSCT slices. The distinction can be easily done in 3-D views. The presence of ossified ligaments may make surgeries in this region difficult, and special care has to be taken to avoid injuries to structures which pass under these ossified ligaments. Particularly in elderly patients, the appropriate surgical instrument for the PSL calcifications should be prepared preoperatively. If PSL is calcified, 6th cranial nerve palsy may not occur even though increased intracranial pressure syndrome is present. Whereas, in lateral trans-tentorial herniations, 3rd cranial nerve palsy occurs in earlier periods when PSL is calcified. Moreover, in subtemporal and transtentorial petrosal approaches, knowing the PSL calcification preoperatively is important to avoid damaging the 6th cranial nerve during surgery.
authors.affiliation: Kirikkale University, School of Medicine, Department of Radiodiagnostics, Kirikkale, Turkey.
authors.forename: Mikail
authors.initials: M
authors.lastname: Inal
authors.affiliation: Kirikkale University, School of Medicine, Department of Otolaryngology, Kirikkale, Turkey. Electronic address: nbayarmuluk@yahoo.com.
authors.forename: Nuray Bayar
authors.initials: NB
authors.lastname: Muluk
authors.affiliation: Kirikkale University, School of Medicine, Department of Radiodiagnostics, Kirikkale, Turkey.
authors.forename: Veysel
authors.initials: V
authors.lastname: Burulday
authors.affiliation: Kirikkale University, School of Medicine, Department of Neurosurgery, Kirikkale, Turkey.
authors.forename: Mehmet Hüseyin
authors.initials: MH
authors.lastname: Akgül
authors.affiliation: Kirikkale University, School of Medicine, Department of Neurosurgery, Kirikkale, Turkey.
authors.forename: Mehmet Faik
authors.initials: MF
authors.lastname: Ozveren
authors.affiliation: Kirikkale University, School of Medicine, Department of Radiodiagnostics, Kirikkale, Turkey.
authors.forename: Umut Orkun
authors.initials: UO
authors.lastname: Çelebi
authors.affiliation: Kirikkale University, School of Medicine, Department of Otolaryngology, Kirikkale, Turkey.
authors.forename: Gökçe
authors.initials: G
authors.lastname: Şimşek
authors.affiliation: Kirikkale University, School of Medicine, Department of Radiodiagnostics, Kirikkale, Turkey.
authors.forename: Birsen Ünal
authors.initials: BÜ
authors.lastname: Daphan
mesh_terms: D002113:Calcification, Physiologic; D002114:Calcinosis / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D061330:Multidetector Computed Tomography / Q000379:methods*; D010579:Petrous Bone; D012189:Retrospective Studies; D019291:Skull Base
keywords: 3-Dimensional images; Calcification; Multi-slice computed tomography (MSCT); Petrosphenoidal ligament (PSL); Posterior petroclinoid ligament (PPCL)