Simultaneous measurement of pulmonary partial pressure of oxygen and apparent diffusion coefficient by hyperpolarized 3He MRI

• Published in: Magnetic resonance in medicine 2009-05, Vol.61 (5), p.1015-1021
• Main Authors: Yu, Jiangsheng, Law, Michelle, Kadlecek, Stephen, Emami, Kiarash, Ishii, Masaru, Stephen, Michael, Woodburn, John M., Vahdat, Vahid, Rizi, Rahim R.
• Format: Article
• Language: English
• Subjects: Animals; apparent diffusion coefficient; Contrast Media; Diffusion Magnetic Resonance Imaging - instrumentation; Diffusion Magnetic Resonance Imaging - methods; Female; Helium; Humans; hyperpolarized 3He MRI; Image Interpretation, Computer-Assisted - methods; Lung - metabolism; Lung - pathology; Middle Aged; Oxygen - analysis; Oxygen - metabolism; partial pressure of oxygenl multiple regression method; Phantoms, Imaging; Pulmonary Disease, Chronic Obstructive - diagnosis; Pulmonary Disease, Chronic Obstructive - metabolism; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Swine
• ISSN: 0740-3194; 1522-2594
• DOI: 10.1002/mrm.21854

Hyperpolarized 3He (HP 3He) MRI shows promise to assess structural and functional pulmonary parameters in a sensitive, regional, and noninvasive way. Structural HP 3He MRI has applied the apparent diffusion coefficient (ADC) for the detection of disease‐induced lung microstructure changes at the alveolar level, and HP 3He pulmonary partial pressure of oxygen (pO2) 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 pO2 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 pO2 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. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.