Angiography gives a detailed 2 dimension view of the artery however it suffers from a lot of drawbacks. The percentage of blockage might vary from cardiologist to cardiologist as a visual estimate is used to identify it. Intravascular Ultrasound (IVUS) and Optical Coherence Tomography (OCT) overcome many of the drawbacks.
An angiography is a lumenography where the artery is visualised from the outside whereas Intravascular Ultrasound (IVUS) and Optical Coherence Tomography (OCT) visualize the vessel from the inside. Intravascular Ultrasound uses ultrasound waves and Optical Coherence Tomography uses infrared waves.