"It's for IVUS." Shim Youhuan slammed his fist into the palm of his hand, finally recalling there was such a specialized examination, he said, "I initially thought she wanted to do esophageal ultrasound, thinking this wouldn't have been done already, unless it's done again during surgery?"
IVUS is intravascular ultrasound, which can also be used to examine the intravascular condition of the coronary arteries. Unlike coronary angiography, it doesn't require the use of contrast agent for visualizing the thickness of the blood vessels. Instead, a miniature ultrasound probe is directly inserted into the blood vessel to detect the internal condition of the vessel. Further examination can be carried out with future OCT, utilizing infrared to measure blood vessels, which offers higher precision than IVUS.
Why aren't these latter two technologies commonly used in clinical practice? The main reason is just one: cost.
