Which of the following diagnostic tools is used to measure ejection fraction in heart failure?

A. Electroencephalogram (EEG) measures electrical activity of the brain, not cardiac function. B. KUB (Kidneys, Ureters, Bladder) is an X-ray used to assess the urinary tract, not heart function. C. Dexascan (DEXA) is used to measure bone density, unrelated to heart function. D. Cardiac catheterization is an invasive diagnostic procedure that allows direct measurement of cardiac pressures and evaluation of coronary arteries. It can be used to assess cardiac function including ejection fraction, either directly or with adjunctive imaging like ventriculography. Additionally, echocardiography is commonly used non-invasively to measure ejection fraction but among the given options, cardiac catheterization is the correct answer