1 Division of Pulmonary, Critical Care, and Sleep Medicine, University of Florida College of Medicine, Gainesville, FL. Electronic address: hiren.mehta@medicine.ufl.edu.
2 Department of Public Health Sciences, Charleston, SC.
3 Division of Pulmonary, Critical Care, Allergy and Sleep Medicine, Charleston, SC.
4 Department of Radiology and Radiological Sciences, Medical University of South Carolina, Charleston, SC.