The foramen magnum and its contents : a magnetic resonance imaging study of the normal spatial relationships

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dc.contributor.advisorEls, W Jen_ZA
dc.contributor.authorLotz, Jan Willemen_ZA
dc.date.accessioned2017-12-13T14:17:25Z
dc.date.available2017-12-13T14:17:25Z
dc.date.issued1994en_ZA
dc.description.abstractThe well-known neurological disturbances associated with caudal displacement of the cerebellar tonsils through the fora men magnum (Chiari malformation) have lead to many radiological studies of the region. With MRI, routine sagittal and parasagittal views of the craniovertebral junction have shown that the position of the cerebellar tonsils is variable, and in many otherwise healthy individuals, the inferior tonsillar margins lie within the fora men magnum itself. In some cases, this topography is associated with little signal from the surrounding cerebra-spinal fluid (CSF), indicating reduction of the cerebellomedullary cistern and, therefore, crowding of neural structures within the confines of the fora men. The objective of this study has been to examine the spatial relationship between the contents of the foramen magnum ie. the medulla and cerebellar tonsils, using a normal sample comprising 120 volunteers. Instead of the conventional measurements of distance, a ratio, the Foramen Magnum Index (FMI), has been determined, derived from the relative surface areas (pixels) of neural parenchyma and CSF, over axially and sagittaly-defined boundaries of the fora men. The FMI, with a 95th centile of 0.77, exhibits appropriate statistical correlation with tonsillar position below the level of the foramen, and is therefore considered specific. As a quantitative means of assessing the cerebellomedullary cistern, the FMI also identifies certain subjects whose tonsils are at the foramen, in whom the cistern is small with resultant neural crowding.en_ZA
dc.identifier.apacitationLotz, J. W. (1994). <i>The foramen magnum and its contents : a magnetic resonance imaging study of the normal spatial relationships</i>. (Thesis). University of Cape Town ,Faculty of Health Sciences ,Division of Anatomical Pathology. Retrieved from http://hdl.handle.net/11427/26605en_ZA
dc.identifier.chicagocitationLotz, Jan Willem. <i>"The foramen magnum and its contents : a magnetic resonance imaging study of the normal spatial relationships."</i> Thesis., University of Cape Town ,Faculty of Health Sciences ,Division of Anatomical Pathology, 1994. http://hdl.handle.net/11427/26605en_ZA
dc.identifier.citationLotz, J. 1994. The foramen magnum and its contents : a magnetic resonance imaging study of the normal spatial relationships. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Lotz, Jan Willem AB - The well-known neurological disturbances associated with caudal displacement of the cerebellar tonsils through the fora men magnum (Chiari malformation) have lead to many radiological studies of the region. With MRI, routine sagittal and parasagittal views of the craniovertebral junction have shown that the position of the cerebellar tonsils is variable, and in many otherwise healthy individuals, the inferior tonsillar margins lie within the fora men magnum itself. In some cases, this topography is associated with little signal from the surrounding cerebra-spinal fluid (CSF), indicating reduction of the cerebellomedullary cistern and, therefore, crowding of neural structures within the confines of the fora men. The objective of this study has been to examine the spatial relationship between the contents of the foramen magnum ie. the medulla and cerebellar tonsils, using a normal sample comprising 120 volunteers. Instead of the conventional measurements of distance, a ratio, the Foramen Magnum Index (FMI), has been determined, derived from the relative surface areas (pixels) of neural parenchyma and CSF, over axially and sagittaly-defined boundaries of the fora men. The FMI, with a 95th centile of 0.77, exhibits appropriate statistical correlation with tonsillar position below the level of the foramen, and is therefore considered specific. As a quantitative means of assessing the cerebellomedullary cistern, the FMI also identifies certain subjects whose tonsils are at the foramen, in whom the cistern is small with resultant neural crowding. DA - 1994 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1994 T1 - The foramen magnum and its contents : a magnetic resonance imaging study of the normal spatial relationships TI - The foramen magnum and its contents : a magnetic resonance imaging study of the normal spatial relationships UR - http://hdl.handle.net/11427/26605 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/26605
dc.identifier.vancouvercitationLotz JW. The foramen magnum and its contents : a magnetic resonance imaging study of the normal spatial relationships. [Thesis]. University of Cape Town ,Faculty of Health Sciences ,Division of Anatomical Pathology, 1994 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/26605en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDivision of Anatomical Pathologyen_ZA
dc.publisher.facultyFaculty of Health Sciencesen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherForamen Magnum - anatomy and histologyen_ZA
dc.subject.otherForamen Magnum - radionuclide imagingen_ZA
dc.subject.otherAnatomyen_ZA
dc.titleThe foramen magnum and its contents : a magnetic resonance imaging study of the normal spatial relationshipsen_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMSc (Med)en_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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