Hooman Hamedani1,
Stephen J. Kadlececk1, Biao Han1, Kiarash Emami1,
Yi Xin1, Masaru Ishii2, Milton Rossman3,
Rahim Rizi1
1Department
of Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2Otolarynology,
Johns Hopkins Medical Center, Baltimore, MD, United States; 3Pulmonary,
allergy and Critical Care Division, University of Pennsylvania, Philadelphia,
PA, United States
The precision of hyperpolarized pAO2-imaging is diminished by abnormal flows that may occur during the required breath-hold, which can then result in implausible, non-physiologic values. It is shown here that a sequence of progressive breaths of hyperpolarized 3He prior to the pAO2-imaging not only improves the level of signal-to-noise, but also produces a more uniform distribution of imaging gas in parenchyma, ultimately resulting in more reasonable pAO2-maps. In addition, filling the poorly ventilated regions of the lung by progressive wash-in breaths provides information about these regions that is unavailable due to lack of signal when using the single-breath protocols.