Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Aug 10;17(8):e0272725.
doi: 10.1371/journal.pone.0272725. eCollection 2022.

The importance of precise plane selection for female adult Chiari Type I malformation midsagittal morphometrics

Mark Morkos  1 , Maggie Eppelheimer  1 , Blaise Simplice Talla Nwotchouang  1 , Seyed Amir Ebrahimzadeh  2 , Rafeeque A Bhadelia  2 , Dorothy Loth  3 , Philip A Allen  3 , Francis Loth  4
Affiliations

The importance of precise plane selection for female adult Chiari Type I malformation midsagittal morphometrics

Mark Morkos et al. PLoS One. .

Abstract

Introduction: Morphometric assessment of Chiari malformation type I (CMI) is typically performed on a midsagittal MRI. However, errors arising from an imprecise selection of the midsagittal plane are unknown. We define absolute parasagittal error as the absolute difference between morphometric measurements at the midsagittal and parasagittal planes. Our objective was to determine the absolute parasagittal error at various lateral distances for morphometric parameters commonly used in CMI research.

Methods: Sagittal T1-weighted MRI scans of 30 CMI adult female subjects were included. Image sets were evaluated to assess 14 CMI morphometric parameters in the midsagittal plane and four parasagittal planes located 1 and 2 mm lateral (left and right). Comparisons between measurements at the midsagittal and parasagittal planes were conducted to determine the mean individual absolute and mean group parasagittal errors for all 14 parameters.

Results: The mean individual absolute parasagittal error was > 1 unit (1 mm for lengths and 1 degree for angles) for 9/14 parameters within a lateral distance of 2 mm. No significant group parasagittal errors were seen in 14/14 parameters, including tonsillar position within a lateral distance of 2 mm.

Conclusion: Our results show that the absolute errors for imprecise midsagittal plane selection may impact the clinical assessment of an individual patient. However, the impact on group measurements, such as in a research setting, will be minimal.

PubMed Disclaimer

Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. Representation of midsagittal and parasagittal planes.
Reproduced from [11] (CC BY-SA 4.0).
Fig 2
Fig 2. Coronal view of the locations of midsagittal, left and right parasagittal planes.
Fig 3
Fig 3. Fourteen morphometric measurements taken on a midsagittal T1-weighted MRI.
A: 2-Posterior cranial fossa height, 7-pons height, 10- McRae line length, 11-tonsillar position, 12- fastigium height, 13- clivus length, 14-corpus callosum height. B: 1-Basal angle, 3-odontoid angle, 4-Wackenheim angle, 6- Boogard angle. C: 5-intracranial diameter, 8- intracranial height, 9-anteroposterior diameter dura-opisthion.
Fig 4
Fig 4. The average lateral distance from midsagittal plane (mm) at which the parasagittal error (difference between morphometric measurement at the parasagittal and midsagittal planes) exceeds 1 unit (mm/deg).
Fig 5
Fig 5. Symmetry plots showing parameters that maintain lateral symmetry up to 4 mm from the midsagittal plane.
Fig 6
Fig 6. Symmetry plots showing parameters that maintain lateral symmetry up to 3 mm from the midsagittal plane.
Fig 7
Fig 7. Symmetry plots showing parameters that demonstrate large lateral asymmetry from the midsagittal plane.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Allen PA, Houston JR, Pollock JW, Buzzelli C, Li X, Harrington AK, et al.. (2014) Task-specific and general cognitive effects in Chiari malformation type I. PLoS One. 9(4): p. e94844. doi: 10.1371/journal.pone.0094844 - DOI - PMC - PubMed
    1. Ebrahimzadeh SA, Loth F, Ibrahimy A, Nwotchouang BST, and Bhadelia RA (2021) Diagnostic utility of parasagittal measurements of tonsillar herniation in Chiari I malformation. Neuroradiol J: p. 19714009211041524. doi: 10.1177/19714009211041524 - DOI - PMC - PubMed
    1. Garcia MA, Allen PA, Li X, Houston JR, Loth F, Labuda R, et al.. (2019) An examination of pain, disability, and the psychological correlates of Chiari Malformation pre- and post-surgical correction. Disabil Health J. 12(4): p. 649–656. doi: 10.1016/j.dhjo.2019.05.004 - DOI - PubMed
    1. Houston JR, Allen PA, Rogers JM, Lien MC, Allen NJ, Hughes ML, et al.. (2019) Type I Chiari malformation, RBANS performance, and brain morphology: Connecting the dots on cognition and macrolevel brain structure. Neuropsychology. 33(5): p. 725–738. doi: 10.1037/neu0000547 - DOI - PubMed
    1. Milhorat TH, Chou MW, Trinidad EM, Kula RW, Mandell M, Wolpert C, et al.. (1999) Chiari I malformation redefined: clinical and radiographic findings for 364 symptomatic patients. Neurosurgery. 44(5): p. 1005–17. doi: 10.1097/00006123-199905000-00042 - DOI - PubMed

Publication types