Huyen T Nguyen1, Ulysses Magalang2, Amir Abduljalil3, Saba Elias4, Petra Schmalbrock5, Preethi Chandrasekaran6, Samantha Rojas7, Kirsten Emmons8, David Ribble8, Michael V Knopp9. 1. Wright Center of Innovation in Biomedical Imaging, Department of Radiology, The Ohio State University, 395 W 12(th), Columbus, OH 43210, United States. Electronic address: nguyen.837@buckeyemail.osu.edu. 2. Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, The Ohio State University, 473 W. 12th St., Columbus, OH 43210, United States. Electronic address: ulysses.magalang@osumc.edu. 3. Wright Center of Innovation in Biomedical Imaging, Department of Radiology, The Ohio State University, 395 W 12(th), Columbus, OH 43210, United States. Electronic address: abduljalil.1@osu.edu. 4. Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, The Ohio State University, 473 W. 12th St., Columbus, OH 43210, United States. 5. Wright Center of Innovation in Biomedical Imaging, Department of Radiology, The Ohio State University, 395 W 12(th), Columbus, OH 43210, United States. Electronic address: schmalbrock.1@osu.edu. 6. Wright Center of Innovation in Biomedical Imaging, Department of Radiology, The Ohio State University, 395 W 12(th), Columbus, OH 43210, United States. Electronic address: subramanian.100@osu.edu. 7. Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, The Ohio State University, 473 W. 12th St., Columbus, OH 43210, United States. Electronic address: samantha.rojas@osumc.edu. 8. Hill-Rom, 130 E. Randolph St., Suite 1000, Chicago, IL 60601, United States. 9. Wright Center of Innovation in Biomedical Imaging, Department of Radiology, The Ohio State University, 395 W 12(th), Columbus, OH 43210, United States. Electronic address: knopp.16@osu.edu.
Abstract
PURPOSE: To develop a non-invasive MRI-based methodology to visually and quantitatively assess the impact of head and chest rotations on the airway caliber. METHODS: An MRI table set-up was developed for independent rotations of the head and chest along B0 field and tested for feasibility using phantom scans. The accuracy of the head and chest rotations was validated with ten volunteer scans. A 3T MRI protocol was optimized to image the regions of interest (ROIs) that were the retropalatal (RP) and retroglossal (RG) sections of the upper airway. A workflow for data analysis was developed to assess the changes of the airway caliber following the independent head and chest rotations. RESULTS: A prototype MRI table setup was established with two separate plates each supporting and rotating the head or chest independently. Subject positioning and image acquisition were finished within seven minutes for each position. Thus, each subject MRI was set up with seven positions and completed for less than one hour. The implemented angles were within 0.3-degree deviation from the targeted angles. The data analysis workflow provided 2D and 3D visualization and quantification with the measurements of cross-sectional area, lateral and anterior-posterior distances of the ROIs. Sharp contrast of the airway and its surrounding tissues facilitated an automatic approach to ROI placement to minimize subjectivity. CONCLUSIONS: The 3T MRI data acquisition and analysis methodology could reliably assess the impact of head and chest rotations on the upper airway caliber to identify the optimal position for obstructive sleep apnea patients.
PURPOSE: To develop a non-invasive MRI-based methodology to visually and quantitatively assess the impact of head and chest rotations on the airway caliber. METHODS: An MRI table set-up was developed for independent rotations of the head and chest along B0 field and tested for feasibility using phantom scans. The accuracy of the head and chest rotations was validated with ten volunteer scans. A 3T MRI protocol was optimized to image the regions of interest (ROIs) that were the retropalatal (RP) and retroglossal (RG) sections of the upper airway. A workflow for data analysis was developed to assess the changes of the airway caliber following the independent head and chest rotations. RESULTS: A prototype MRI table setup was established with two separate plates each supporting and rotating the head or chest independently. Subject positioning and image acquisition were finished within seven minutes for each position. Thus, each subject MRI was set up with seven positions and completed for less than one hour. The implemented angles were within 0.3-degree deviation from the targeted angles. The data analysis workflow provided 2D and 3D visualization and quantification with the measurements of cross-sectional area, lateral and anterior-posterior distances of the ROIs. Sharp contrast of the airway and its surrounding tissues facilitated an automatic approach to ROI placement to minimize subjectivity. CONCLUSIONS: The 3T MRI data acquisition and analysis methodology could reliably assess the impact of head and chest rotations on the upper airway caliber to identify the optimal position for obstructive sleep apneapatients.