Cecil Charles PhD, Presenter: Research Grant, Merck & Co, Inc

Ahmed Halaweish PhD, Abstract Co-Author: Employee, Siemens AG

H. Page McAdams MD, Abstract Co-Author: Research Grant, General Electric Company Consultant, MedQIA Author, Reed Elsevier Author, UpToDate, Inc

Niel R. MacIntyre MD, Abstract Co-Author: Nothing to Disclose

Richard D. Moon MD, Abstract Co-Author: Nothing to Disclose

Maureen D. Ainslie MS, RT, Abstract Co-Author: Nothing to Disclose

William M. Foster PhD, Abstract Co-Author: Nothing to Disclose

19Fluorine Gas MRI provides a dynamic assessment of pulmonary ventilatory function. The purpose of this work is the demonstrate extraction and generation of image based biomarkers of pulmonary ventilation for utilization in clinical trial and clinical settings.

Imaging [45 Normals (28 Non smokers, 9 exsmokers, 8 smokers), 7 COPD] was performed on a Siemens TIM Trio 3T MRI scanner and consisted of conventional localizing scout and inspiratory/expiratory breath-held scans (1H) and 3D GRE-VIBE functional scans using Perfluoropropane/Oxygen gas mixtures (19F, TR/TE ,15/1.62 ms, NEX=2, Matrix=64x64, slice=15mm, pixel size=6.25x6.25 mm, flip angle= 70°). All acquisitions were performed at total lung capacity to facilitate anatomical correlation utilizing an in house developed gas delivery and subject monitoring apparatus. A total of at least 7 sequential breath holds were performed, interleaved with 3-4 breaths of the O2/PFP mixture (wash-in), or room air (wash-out).  Using an in house developed python based script, all 3D masked [masked using Slicer (www.slicer.org)] lung volumetric image datasets were reduced to a single table representing the x,y and z coordinates and pixel value then concatenated to a 4D x,y,z,t,value table. Data analysis was accomplished using standard features of JMP (SAS Institute).

Image reduction facilitated the use of established statistical algorithms and functions to evaluate biomarkers. Each imaging session provides an array of ventilation assessments throughout the wash-in and wash-out times (seconds) of PFP gas  including static and dynamic ventilation distribution, gas trapping, ventilation heterogeneity, ventilation defect persistence and clearance and regional efficiency of ventilation.

Dynamic evaluation of the pulmonary airspaces using PFP enhanced MRI provides a straight-forward and relatively inexpensive means for evaluating ventilatory heterogeneity and providing a spatio-temporal descriptor of ‘slow to fast filling compartments’ in pulmonary disorders. Simplification of data reduction presents many avenues for generation of pulmonary ventilation based biomarkers to evaluate the integrity and functional status of the pulmonary airspaces.

19F-Enhanced MRI of Pulmonary function using PFP gas facilitates dynamic quantitative and qualitative assessments of pulmonary ventilation and the generation of clinically viable imaging biomarkers.

Charles, C, Halaweish, A, McAdams, H, MacIntyre, N, Moon, R, Ainslie, M, Foster, W, 19F Perfluoropropane/Oxygen Gas Contrast Enhanced MRI of Pulmonary Ventilation: Image Reduction, Analysis and Resulting Physiological Biomarkers.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14014782.html