Phase-I Study of Radiolabeled DFH-12 (PulmoBind) for Molecular Imaging of the Pulmonary Circulation

Inclusion Criteria: * male or female greater than 18 years of age. Female subjects must be post-menopausal (defined as two years after menstrual cycle) * within normal range for the following: BP systolic 100-140 mmHg and diastolic 50-90 mmHg; * HR 60-100 beats per minute; * oral temperature less than 37.6 degrees Centigrade; * respiratory rate 12-20 breaths per minute; * normal lung function tests; * normal echocardiogram including estimation of pulmonary artery systolic pressure; * normal chest x-ray; Normal electrocardiogram Exclusion Criteria: * any known chronic or acute medical condition with or without the need for chronic pharmacologic therapy or any condition that may interfere with normal biodistribution of DFH-12. Includes but not limited to: * lung parenchymal or lung vascular diseases such as chronic obstructive pulmonary disease, * bronchitis, * lung cancer, * pleural effusion, * emphysema, * asthma, * pulmonary fibrosis, * occupational lung disease, * pulmonary hypertension (primary or secondary), * systemic hypertension, * diabetes, * cancer, * kidney disease, * liver disease, * heart failure or previous myocardial infarction, * coronary artery disease, * peripheral vascular disease or inflammatory disease; * subjects requiring chronic administration of any substance for a medical condition, active smoking or history of smoking for more than one year in the past 10 years, known self-reported alcoholism (active or abstinent); * unable to tolerate study procedures ex.(venipuncture, movement restrictions during imaging); * previous nuclear study since one week (to avoid cross-contamination)