The purpose of this study is to determine the dose of PB127 for detection and/or exclusion of coronary artery disease when used with cardiac ultrasound. This study also evaluates the safety of PB127.

Inclusion Criteria:

Stages 1 and 2

1. Men and women
2. Ages 18 30
3. Normal volunteers
4. No history (or suspicion) of CAD

Stage 3

1. Men and women with known or suspected CAD

2. Ages 18 years and older

3. Scheduled for or undergone clinically indicated coronary angiography within 28 days prior to or following Study Day 1

   1. Coronary angiography within 28 days prior to Study Day 1 and/or SPECT must have been non-interventional
   2. Coronary angiography images available in digital format (non cine) for transmission to core laboratory

4. Scheduled for or undergone SPECT within 28 days prior to or following Study Day 1

Exclusion Criteria:

1. Unable to provide written informed consent

2. Women who are pregnant or lactating

3. Known hypersensitivity or known contraindication to:

   1. Dipyridamole
   2. Ultrasound contrast agents (including PB127 and excipients)
   3. Blood, blood products, albumin, egg whites, or protein

4. Use of caffeine or xanthine containing products within the 24 hours prior to PB127 administration on Study Day 1 (Stages 2 and 3)

5. Previous exposure to PB127

6. Inadequate echocardiographic windows

7. Heart transplant

8. Known right to left shunt, including atrial septal defect

9. History of CABG

10. Current uncontrolled ventricular tachycardia, atrial fibrillation, atrial tachycardia, or atrial flutter

11. Pacemaker or defibrillator

12. Unstable angina grade CCS Class IV severity with ongoing symptoms and/or ongoing infusion of IV nitroglycerin

13. Second degree or greater heart block

14. Hypertension (SPB >200 and/or DBP >110 mmHg on two consecutive readings within 1 hour prior to PB127 administration)

15. Hypotension (SPB <90 mmHg on two consecutive readings within 1 hour prior to PB127 administration)

16. Severe aortic stenosis (>100 mmHg peak transvalvar gradient or <0.6 cm2 estimated valve area)

17. Pulmonary edema within the 7 days prior to Study Day 1

18. Resting oxygen saturation of less than 90%

19. Q wave MI or major surgery within the 7 days prior to Study Day 1

20. PTCA within the 28 days prior to Study Day 1

21. Chronic obstructive pulmonary disease or bronchospastic airway disease which, in the opinion of the Investigator, is significant enough to contraindicate dipyridamole

22. Known history of severe pulmonary hypertension characterized by estimated pulmonary artery systolic pressure of >50 mmHg

23. Liver disease, characterized by or including one or more of the following

    1. Elevated total bilirubin > upper limit of normal
    2. Currently elevated hepatic enzymes >3X upper limit of normal

24. Medical conditions or other circumstances that would significantly decrease the chances of obtaining reliable data or achieving the study objectives (i.e., drug dependence, psychiatric disorder, dementia, or associated illness); extenuating circumstances or medical conditions that make it unlikely that a patient can complete the clinical trial or follow up evaluations; or other reasons for expected poor compliance with the clinical investigator's instructions