Abstract

Objective: This study compared pharyngeal airway measurements (volume, linear, area) made using whole head Cone-Beam Computed Tomography (CBCT) and 3T Magnetic Resonance Imaging (MRI) methods.

Methods: Eleven subjects (mean age 15y11m) received whole head CBCT (NewTom5G, AFP Imaging, USA) and 3T MRI (Siemens Medical Solutions, DE). Each subject received both scans within a one-month period of time. CBCT images were made with an 18x16 inch field of view, exposure time of 5.4s, and resolution of 0.3x0.3x0.3mm. 3T MR images were captured as contiguous sagittal images of the whole head with a T1- weighted 3D imaging sequence (Magnetization Prepared Rapid Acquisition by Gradient Echo (MP-RAGE), TP/TE = 1950/2.26ms) and resolution of 1.0x1.0x1.0mm. Simpleware Scan IP (v.M-2018.03) imaging software was used to process the images in the following order: 1) registration 2) airway segmentation, 3) volume measurement, 4) linear measurement, and 5) cross-section area measurement. Agreement between CBCT and MRI measurements was evaluated with an Intraclass Correlation Coefficient (ICC). Intra-rater reliability (after a 1-week washout period) was also evaluated with an ICC. A Bland-Altman test was used to determine whether systematic or proportional bias was present. Results: Excellent agreement between CBCT and MRI measurements of the pharyngeal airway was observed. Mean ICC was 0.982 (CI 0.975 - 0.986). Reliability was demonstrated with an ICC of 0.999 (CI 0.998 - 0.999) for MRI and an ICC of 0.998 (CI 0.997 - 0.999) for CBCT measurements. The degree of bias ranged from -0.16-0.96mm. No statistically significant systematic (p>0.05) or proportional (p>0.05) bias was observed. Conclusion: MRI and CBCT give similar linear, cross-section area, and volumetric measurements of the pharyngeal airway. These results indicate that further studies are warranted to characterize the interchangeability of CBCT and MRI for the purpose of airway analysis.

LLU Discipline

Orthodontics and Dentofacial Orthopedics

Department

Orthodontics and Dentofacial Orthopedics

School

School of Dentistry

First Advisor

V. Leroy Leggitt

Second Advisor

James Farrage

Third Advisor

Roland Neufeld

Fourth Advisor

R. David Rynearson

Fifth Advisor

Gina Roque-Torres

Degree Name

Master of Science in Orthodontics and Dentofacial Orthopedics (MSODO)

Degree Level

M.S.

Year Degree Awarded

2019

Date (Title Page)

9-2019

Language

English

Library of Congress/MESH Subject Headings

Magnetic Resonance Imaging; Cone-Beam Computed Tomography

Type

Thesis

Page Count

xii, 49 p.

Digital Format

PDF

Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

Loma Linda University. Del E. Webb Memorial Library. University Archives

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