Cardiac catheterization can be used to do various tests, including Angiography Detection and quantification of shunts Endomyocardial biopsy Intravascular ultrasonography (IVUS) Measurement of cardiac output (CO) Measurements of myocardial metabolism These tests define coronary artery anatomy, cardiac anatomy, cardiac function, and pulmonary arterial hemodynamics to establish diagnoses and help clinicians select treatment.