This study is designed to evaluate the technical performance and clinical handling of a coronary catheter that includes two imaging techniques. The catheter being evaluated performs near infrared spectroscopy and ultrasound imaging of the coronary arteries. Near infrared spectroscopy is used to identify lipid or cholesterol deposits in the vessel wall and the ultrasound component provides structural information about the vessel. Combining multiple imaging techniques into a single catheter can reduce the total number of catheters required during treatment and the overall duration of cardiac catheterization. Both of these results may lead to safer procedures.

Inclusion Criteria:

• >=18yrs of age.
• diagnosed with stable angina pectoris or documented silent ischemia
• scheduled for elective, non-emergent cardiac catheterization
• able to read, understand, and provide written informed consent
• >=1 obstructive stenosis (>50%DS by visual estimate)in a major native coronary artery
• clinically indicated treatment plan includes placement of a guidewire into the target artery.
• target artery has a >=30mm segment with a reference vessel diameter >=2.5mm
• target artery has a >50%DS luminal narrowing

Exclusion Criteria:

• Subject unwilling or unable to provide written informed consent.
• Subject unwilling to comply with protocol
• Subject is pregnant
• Subject is of childbearing potential without negative pregnancy test.
• Subject received prolonged CPR within 2 weeks of enrollment procedure
• Subject is intubated.
• Subject is diagnosed with an acute coronary syndrome.
• Subject has severe persistent hypertension.
• Subject has renal dysfunction or insufficiency.
• Subject has an abnormal platelet count.
• Subject has low hemoglobin levels.
• Subject has active liver disease or dysfunction.
• subject diagnosed with acute pulmonary edema or congestive heart failure.
• Subject diagnosed or suspected to have acute myo-, peri-, or endo- carditis, cardiac tamponade, or dissected aortic aneurysm.
• Subject has significant valvular heart disease, cardiomyopathy, or congenital heart disease.
• Subject has history of intracranial bleeding or aneurysm.
• Subject has a history of stroke that precludes the use of routine antithrombotic agents during PCI?
• Subject has known hypercoagulable state, coagulopathy, or abnormal bleeding.
• subject has family history of coagulopathy or bleeding diathesis.
• subject has undergone PCI in the last 30days.
• subject enrolled or participating in pharmaceutical study in last 30 days.
• subject enrolled or participating in medical device treatment study in last 30 days.
• subject has obstructive LMCA disease.
• subject has multivessel CAD that requires additional treatment in a separate procedure with 30days of enrollment.
• subject has unprotected left main disease.
• three vessel intervention is required during enrollment procedure.
• target artery is the left circumflex artery.
• target artery is accessed through a vein or arterial graft.
• target artery is tortuous
• target artery contains segments of severe calcification
• target artery has >2 serial obstructions exceeding 50%DS.
• target artery has an aneurysm or suspected aneurysm.
• target artery has <=1 TIMI flow.
• target lesion is >99% DS.
• target lesion is severely calcified
• target lesion has angiographic characteristics of thrombus.
• target lesion has angiographic characteristics of ulceration.
• target lesion has inclusion of a side branch greater than 1mm.
• target lesion is located in a vessel segment with >4.0mm reference vessel diameter.

Subjects will be recruited from the patients presenting to the cardiac catheterization laboratory for elective cardiac catheterization.