title: Simultaneous measurement of pulmonary partial pressure of oxygen and apparent diffusion coefficient by hyperpolarized 3He MRI.
abstract: Hyperpolarized (3)He (HP (3)He) MRI shows promise to assess structural and functional pulmonary parameters in a sensitive, regional, and noninvasive way. Structural HP (3)He MRI has applied the apparent diffusion coefficient (ADC) for the detection of disease-induced lung microstructure changes at the alveolar level, and HP (3)He pulmonary partial pressure of oxygen (pO(2)) imaging measures the oxygen transfer efficiency between the lung and blood stream. Although both parameters are affected in chronic obstructive pulmonary disease (COPD), a quantitative assessment of the regional correlation of the two parameters has not been reported in the literature. In this work, a single acquisition technique for the simultaneous measurement of ADC and pO(2) is presented. This technique is based on the multiple regression method, in which a general linear estimator is used to retrieve the values of ADC and pO(2) from a series of measurements. The measurement uncertainties are also analytically derived and used to find an optimal measurement scheme. The technique was first tested on a phantom model, and then on an in vivo normal pig experiment. A case study was performed on a COPD patient, which showed that in a region of interest ADC was 29% higher while oxygen depletion rate was 61% lower than the corresponding global average values.
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
authors.forename: Jiangsheng
authors.initials: J
authors.lastname: Yu
authors.forename: Michelle
authors.initials: M
authors.lastname: Law
authors.forename: Stephen
authors.initials: S
authors.lastname: Kadlecek
authors.forename: Kiarash
authors.initials: K
authors.lastname: Emami
authors.forename: Masaru
authors.initials: M
authors.lastname: Ishii
authors.forename: Michael
authors.initials: M
authors.lastname: Stephen
authors.forename: John M
authors.initials: JM
authors.lastname: Woodburn
authors.forename: Vahid
authors.initials: V
authors.lastname: Vahdat
authors.forename: Rahim R
authors.initials: RR
authors.lastname: Rizi
mesh_terms: D000818:Animals; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006371:Helium; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008168:Lung / Q000378:metabolism* / Q000473:pathology*; D008875:Middle Aged; D010100:Oxygen / Q000032:analysis / Q000378:metabolism*; D019047:Phantoms, Imaging; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000378:metabolism*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013552:Swine
chemical_list: D003287:Contrast Media; D019275:Radiopharmaceuticals; D006371:Helium; D010100:Oxygen