title: Comparison of airway diameter measurements from an anthropomorphic airway tree phantom using hyperpolarized 3He MRI and high-resolution computed tomography.
abstract: An anthropomorphic airway tree phantom was imaged with both hyperpolarized (HP) 3He MRI using a dynamic projection scan and computed tomography (CT). Airway diameter measurements from the HP 3He MR images obtained using a newly developed model-based algorithm were compared against their corresponding CT values quantified with a well-established method. Of the 45 airway segments that could be evaluated with CT, only 14 airway segments (31%) could be evaluated using HP 3He MRI. No airway segments smaller than approximately 4 mm in diameter and distal to the fourth generation were adequate for analysis in MRI. For the 14 airway segments measured, only two airway segments yielded a non-equivalent comparison between the two imaging modalities, while eight more had inconclusive comparison results, leaving only four airway segments (29%) that satisfied the designed equivalence criteria. Some of the potential problems in airway diameter quantification described in the formulation of the model-based algorithm were observed in this study. These results suggest that dynamic projection HP 3He MRI may have limited utility for measuring airway segment diameters, particularly those of the central airways.
authors.affiliation: Department of Radiology, Brigham and Women's Hospital, and Department of Biomedical Engineering, Boston University, Massachusetts, USA.
authors.forename: Yang-Sheng
authors.initials: YS
authors.lastname: Tzeng
authors.forename: Eric
authors.initials: E
authors.lastname: Hoffman
authors.forename: Janice
authors.initials: J
authors.lastname: Cook-Granroth
authors.forename: Rie
authors.initials: R
authors.lastname: Maurer
authors.forename: Niral
authors.initials: N
authors.lastname: Shah
authors.forename: Joey
authors.initials: J
authors.lastname: Mansour
authors.forename: Juerg
authors.initials: J
authors.lastname: Tschirren
authors.forename: Mitchell
authors.initials: M
authors.lastname: Albert
mesh_terms: D000465:Algorithms; D001980:Bronchi / Q000033:anatomy & histology; D003196:Computer Graphics; D006371:Helium; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007554:Isotopes; D008168:Lung / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019047:Phantoms, Imaging; D011650:Pulmonary Alveoli / Q000033:anatomy & histology; D011856:Radiographic Image Enhancement / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014132:Trachea / Q000033:anatomy & histology
chemical_list: D007554:Isotopes; D006371:Helium