Table II.

Comparison of the characteristics of OCT and IVUS.

A, IVUS modality
Advantages	Limitations
The development of IVUS and the recognition of images are relatively mature	The currently developed IVUS imaging catheter has poor passing ability for more severe stenosis or twisted angular lesions
IVUS is able to clearly display the intravascular structure and evaluate the plaque composition	As different tissues may have the same acoustic properties, the same density value may be reflected in IVUS images
It may optimize and guide the treatment of coronary intervention	The current IVUS on the market has a low resolution and is not able to make accurate judgments for small structures and lesions in blood vessels, and corresponding changes in the lumen after stent implantation
It may be used to study the mechanism of plaque progression or regression prior to and after treatment, vascular remodeling and restenosis after stent implantation
B, OCT modality
Advantages	Limitations
It has an ultra-high resolution comparable to histology, allowing real-time observation of small structures and lesions in blood vessels	The OCT imaging process requires blocking or removal of the blood in the corresponding detection vessel, which increases the difficulty of the operation and limits its application in severe coronary ischemic diseases
It is able to accurately measure coronary luminal parameters, observe the morphological characteristics of arterial intima and plaques, and identify vulnerable plaques and macrophage infiltration prior to surgery	OCT has a weak penetrating ability and is not able to accurately analyze the whole picture of the lesion. It is also difficult to measure the diameter of larger blood vessels and evaluate vascular remodeling
It is able to make the percutaneous coronary intervention process more refined and optimize the immediate effect after stent implantation. It may accurately observe the postoperative situation of various types of stent implantation at the cross-sectional level	OCT is not able to clearly identify the internal tissue covered by the thrombus (particularly red thrombus) inside the blood vessel
	In the detection after stent implantation, although OCT may clearly detect the stent intima, it is still unable to distinguish the histological characteristics of the stent surface covering the intima

OCT, optical coherence tomography; IVUS, intravascular ultrasound.