Objective: This study compared the agreement between whole head Cone-Beam Computed Tomography (CBCT) and 3T Magnetic Resonance Imaging (MRI) methods to assess the cross-sectional area of the internal nasal valve.

Methods: Thirteen human subjects (mean age 15y11m) were used in this study. All scans were preformed [sic] within two weeks of one another. CBCT images were made with an 18x16 inch field of view, exposure time of 5.4 s, and resolution of 0.3x0.3x0.3 mm. 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 = 1950/2.26 ms) and resolution of 1.0x1.0x1.0 mm. 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) cross-sectional area measurement. Agreement between CBCT and MRI measurements was evaluated with an Intraclass Correlation Coefficient (ICC). Intra-rater reliability (after a 1-month 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 cross-sectional area measurements of the internal nasal valve was observed. Mean ICC was 0.876 (CI 0.833 – 0.908). Reliability was demonstrated with an ICC of 0.999 (CI 0.998 – 1.00) for MRI and an ICC of 1.00 (CI 1.00 – 1.00) for CBCT measurements. The degree of bias ranged from -0.068 - 0.123 cm2. No statistically significant systematic (p>0.05) or proportional (p>0.05) bias was observed.

Conclusion: MRI and CBCT give similar cross-sectional area measurements of the internal nasal valve. These results indicate that further studies are necessary to evaluate the interchangeability of CBCT and MRI for the purpose of nasal airway analysis.


Orthodontics and Dentofacial Orthopedics


School of Dentistry

First Advisor

V. Leroy Leggitt

Second Advisor

James Farrage

Third Advisor

Gina Roque-Torres

Degree Name

Master of Science in Orthodontics and Dentofacial Orthopedics (MSODO)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Spiral Cone-Beam Computed Tomography; Reproducibility of Results; Magnetic Resonance Imaging



Page Count

xi; 40 p.

Digital Format


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.


Loma Linda University Electronic Theses and Dissertations

Collection Website



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