Quantification of Cerebellar Crowding in Type I Chiari Malformation

• Published in: Annals of biomedical engineering Vol. 47; no. 3; pp. 731 - 743
• Main Authors: Biswas, Dipankar, Eppelheimer, Maggie S., Houston, James R., Ibrahimy, Alaaddin, Bapuraj, J. Rajiv, Labuda, Richard, Allen, Philip A., Frim, David, Loth, Francis
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.03.2019; Springer Nature B.V
• Subjects: Adult; Arnold-Chiari Malformation - diagnostic imaging; Arnold-Chiari Malformation - pathology; Biochemistry; Biological and Medical Physics; Biomedical and Life Sciences; Biomedical Engineering and Bioengineering; Biomedicine; Biophysics; Brain; Brain - diagnostic imaging; Brain - pathology; Brain stem; Cerebellum; Cerebrospinal fluid; Classical Mechanics; Congenital defects; Crowding; Elongation; Female; Humans; Magnetic resonance imaging; Middle Aged; Morphometry; Neural tube defects; Parameters; Patients; Skull; Tonsil; Young Adult; Posterior cranial fossa; Cerebrospinal fluid; MRI; Morphology; Tonsillar position
• ISSN: 0090-6964; 1573-9686
• DOI: 10.1007/s10439-018-02175-z

This study was focused on a semi-automated morphometric analysis of the cerebellum in the mid-sagittal plane as an alternative to tonsillar descent alone in the evaluation of Chiari malformation type 1 (CMI) patients. Morphometric analyses of posterior fossa structures were performed on mid-sagittal MRI images of 375 individuals (females, > 18 years, 235 CMI and 140 healthy controls). Twenty-six parameters including linear, angular and area measurements together with non-dimensional ratios were calculated. Eighteen parameters were found to be significantly different between CMI and control subjects. Smaller posterior cranial fossa (PCF) area in CMI subjects was attributed to a smaller PCF area anterior to the brainstem. The cerebellar area was found to be larger in CMI subjects as compared to controls (15.1%), even without inclusion of the tonsillar area below the foramen magnum (FM) (8.4%). The larger cerebellar area in CMI subjects was due to cranial–caudal elongation of the cerebellum, predominately below the fastigium. The cerebrospinal fluid spaces below the FM were smaller in CMI subjects as compared to controls. Overall, greater cerebellar crowding was identified in CMI subjects relative to healthy controls. These observations may improve our understanding of the pathophysiology of CMI in adult female patients.