Advances in Pulmonary Functional Imaging Research Program History

In 1995, Dr. Patz became interested in a new technology known as hyperpolarized noble gas MRI, which uses a laser polarization device to magnetize either 3He or 129Xe gas ~100,000 times larger than that produced by a traditional MRI magnet. Dr. Patz first obtained a BWH Interdisciplinary Seed Grant and then a NIH R21 grant. This work, primarily in phantoms and animals, was performed in collaboration with R. Mair from the Harvard Smithsonian Center for Astrophysics. The diffusion of hyperpolarized gas in a variety of porous media was explored and resulted in a number of important papers including one in the pre-eminent physics journal, Physical Review Letters. Together with Dr. J Butler, Dr. Patz then led the group in demonstrating a novel noninvasive MRI method to measure surface area per unit volume (S/V), which is a direct quantitative measure of the degree of emphysema.

In 2003, Dr. Patz received an NIH Bioengineering Research Partnership Grant R01. This funding allowed his group to produce ground-breaking noninvasive, regional measurements of pulmonary function including the first dynamic breathing MRI movies with hyperpolarized 129Xe, the first human MRI images of gas exchange, and demonstrated novel measurements of PaO2 and the diffusivity of 129Xe in the human lung. Based on this work, Dr. Patz received a NIH R01 in 2010 to perform ancillary studies of hyperpolarized 129Xe in the COPDGene cohort.

In 2011, Dr. Butler and colleagues published a report in NEJM on using hyperpolarized gas MRI to measure the alveolar microstructure dimensions in a pneumonectomy subject. This work was a collaboration of thoracic surgery (Dr. S. Mentzer at BWH), pulmonary physiology (Dr. J. Butler at HSPH), anaesthesia (Dr. S. Loring at BIDMC) and Radiology at Washington University (Dr. D. Yablonskiy). This Case Report demonstrated that, contrary to common belief, an adult human can regenerate lung tissue.

For the past 4 years, Dr. Patz has been working on a revolutionary MRI device. It is a very low field, portable device designed for the ICU. The device, called a Lung Density Monitor (LDM), will be used to measure regional lung mechanics in the ICU to assist a clinician in choosing optimal pressure settings for subjects on ventilator support. A second version of the low field portable device, called a Ventilation Stethoscope (VS), will use hyperpolarized gas and is designed for the Neonatal Intensive Care Unit. Dr. Patz has received four research grants to further develop the LDM and VS. A patent on this technology has been filed and there is commercial interest.

For the past 4 years, Dr. Ritu Gill, a board certified thoracic radiologist, has been working with our group. Dr. Gill has demonstrated the ability to differentiate between different types of mesothelioma using both Apparent Diffusion Coefficient (ADC) MRI as well as dynamic contrast enhanced (DCE) MRI. Beginning in 2013, the group has developed a number of novel approaches to looking at the pulmonary vasculature using endogenous proton MRI.

The group has recently completed participation in a NIH CADET I study directed by Dr. J. Loscalzo in which hyperpolarized gas MRI was developed for rat imaging to provide an imaging biomarker for regeneration of lung tissue. Further collaborations are underway with Bruce Levy, Chair of Pulmonary and Critical Care to establish HypX MRI for non-invasive assessment of mice pathology and treatment.