title: The posterior cranial fossa: a comparative MRI-based anatomic study of linear dimensions and volumetry in a homogeneous South Indian population.
abstract: OBJECTIVE
  The posterior fossa contains structures that are vital to life. In this study, we aimed at establishing normal linear dimensions and volume data of the posterior fossa in a homogeneous south Indian population. We also evaluated the influence of large tumors on these parameters. We evaluated the accuracy of different techniques of measuring these dimensions and compared them with literature.
  
  
  METHODS
  Control and tumor MRIs were selected from an imaging database. Linear posterior fossa dimensions as well as volumes were measured using Image J and Fiji. The volume data were compared with similar data from literature. The effect of the presence of a tumor on posterior fossa volume was measured.
  
  
  RESULTS
  The posterior fossa volume was higher in men than in women, irrespective of whether the volume was estimated on axial, sagittal or coronal MR images. Despite the wide variation in the techniques used, there was no significant difference between the volumes reported in literature and the volumes calculated in the current series. The presence of large tumors did not affect linear dimensions or posterior fossa volumes. Among the techniques based on linear measurements that were assessed for concordance with manual segmentation, the technique using the formula for volume of an ellipsoid had the best agreement.
  
  
  CONCLUSIONS
  Posterior fossa volume is higher in men than in women, Posterior fossa dimensions were not affected by the presence of large tumors. Manual segmentation remains the most accurate method to measure posterior fossa volume.
authors: Department of Neurosurgery, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Pondicherry, 605006, India.
authors: Awalpreet Singh
authors: AS
authors: Chadha
authors: Department of Neurosurgery, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Pondicherry, 605006, India. vensmad@gmail.com.
authors: Venkatesh S
authors: VS
authors: Madhugiri
authors: Department of Neurosurgery, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Pondicherry, 605006, India.
authors: M N
authors: MN
authors: Tejus
authors: Department of Neurosurgery, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Pondicherry, 605006, India.
authors: V R Roopesh
authors: VR
authors: Kumar
mesh_terms: D003388:Cranial Fossa, Posterior / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007194:India; D008279:Magnetic Resonance Imaging; D008297:Male; D012016:Reference Values
keywords: Fiji; Image J; Morphometry; Posterior fossa; Posterior fossa volume; Supratentorial tumor
references: Neurol Res. 2010 Jul;32(6):587-92
references: 20092676
references: J Neuroimaging. 2014 May-Jun;24(3):250-6
references: 23324118
references: J Ultrasound Med. 2011 Oct;30(10 ):1403-10
references: 21968492
references: J Neurosurg. 2007 Nov;107(5):932-6
references: 17977263
references: Acta Neurochir (Wien). 2010 Feb;152(2):221-7; discussion 227
references: 19672553
references: AJNR Am J Neuroradiol. 2013 Sep;34(9):1758-63
references: 23493894
references: J Neurol Sci. 1990 Nov;99(2-3):137-45
references: 2086722
references: Neurosci Lett. 2012 Oct 31;529(1):92-6
references: 22982148
references: Turk Neurosurg. 2011;21(4):504-15
references: 22194108
references: Eur Radiol. 2014 Oct;24(10):2427-34
references: 25038855
references: J Anat. 1991 Oct;178:133-44
references: 1810922
references: Neuroradiology. 1993;35(2):113-8
references: 8433785
references: Childs Nerv Syst. 2008 Mar;24(3):329-36
references: 17657497
references: Lancet. 1995 Oct 21;346(8982):1085-7
references: 7564793
references: Nat Methods. 2012 Jul;9(7):671-5
references: 22930834
references: AJR Am J Roentgenol. 2014 Mar;202(3):614-8
references: 24555599
references: J Med Imaging Radiat Oncol. 2014 Oct;58(5):595-600
references: 25124316
references: J Neurosurg. 2008 Jan;108(1):66-73
references: 18173312
references: J Neurosci Rural Pract. 2012 Sep;3(3):261-6
references: 23188974
references: Acta Neurochir Suppl. 2003;86:529-32
references: 14753500
references: Nat Methods. 2012 Jun 28;9(7):676-82
references: 22743772
references: IEEE J Biomed Health Inform. 2014 Jul;18(4):1317-27
references: 25014936
references: Prenat Diagn. 2012 May;32(5):440-3
references: 22495736
references: J Clin Neurosci. 2009 Nov;16(11):1449-54
references: 19736012
references: J Neurosurg Pediatr. 2011 Apr;7(4):362-8
references: 21456906
references: Clin Neurol Neurosurg. 2011 Jun;113(5):399-403
references: 21333437
references: J Neurosurg. 2006 Aug;105(2 Suppl):101-6
references: 16922070
references: Adv Exp Med Biol. 2013;789:345-51
references: 23852514
references: Acta Neurochir (Wien). 2009 Jun;151(6):669-75
references: 19350204
references: NMR Biomed. 2014 Sep;27(9):1112-22
references: 25066601
references: Acta Neurochir Suppl. 2002;81:31-3
references: 12171062
references: Acta Neurochir (Wien). 2010 Jul;152(7):1117-27
references: 20440631
references: ScientificWorldJournal. 2012;2012:616934
references: 22629166
references: Acta Neurochir Suppl. 2002;81:271-3
references: 12168324