Ahsan Samiee1, Stephen J. Kadlecek2,
Kiarash Emami2, Yinan Xu2, Hooman Hamedani3,
Yi Xin2, Puttisarn Mongkolwisetwara2, Nicholas N. Kuzma2,
Peter Magnusson4, Lise Vejby Sgaard4, Sandra Diaz5,
Wilson Miller6, Milton D. Rossman7, Masaru Ishii8,
Rahim R. Rizi2
1Mechanical & Aerospace
Engineering, University of California, San Diego, San Diego, CA, United
States; 2Radiology, University of Pennsylvania, Philadelphia, PA,
United States; 3Radiology, University of Pennsylvania,
Philadelphia, United States; 4Danish Research Centre for Magnetic
Resonance, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; 5Department
of Clinical Sciences, Malm University Hospital, Malm, Sweden; 6Department
of Radiology, University of Virginia, Charlottesville, VA, United States; 7Pulmonary,
Allergy & Critical Care Division, University of Pennsylvania,
Philadelphia, PA, United States; 8OtolaryngologyHead & Neck
Surgery, Johns Hopkins University, Baltimore, MD, United States
Early diagnosis of emphysema is not a possibility with standard clinical tests. Noting the heterogeneity of the disease, CT and increasingly MRI-based imaging techniques have been proposed for this purpose, including measurements of Apparent Diffusion Coefficient (ADC) of respiratory gas. It has been shown that the mean ADC is fairly reproducible marker, which can clearly differentiate emphysematous lungs from healthy lungs. This approach can undesirably mask regional distribution and heterogeneity of abnormalities. This work presents a scalar metric sensitive to regional distributions of gas diffusion in airways while retaining as much of the heterogeneity information as possible.