Intravascular ultrasound (IVUS) has become an extremely invaluable endovascular evaluation tool that offers comprehensive assessments of vascular conditions and perivascular anatomy, providing critical information that enhances clinical decision-making. The benefits include improved visualization of vascular and extravascular anatomy leading to reduced procedure times, complication rates, and enhanced accuracy during catheter-based interventions. There are 2 types of IVUS available currently—radial and side-firing. The radial IVUS provides a 360-degree view of the vessel lumen, whereas the side-firing IVUS allows visualization of vascular and extravascular structures in a plane parallel to the vessel wall.

Radial IVUS is primarily used to determine the vessel size, severity and length of stenosis and plaque composition, as well as to detect pathological processes such as plaque rupture and dissections. Another significant advantage is its ability to confirm the position of intravascular devices, ensuring true lumen access versus a false lumen during endovascular interventions. It also allows identifying the origins of side branches without needing contrast materials, which can be critical for therapeutic interventions. Moreover, it can be utilized to assess extrinsic venous compression, identifying potential impacts from surrounding structures. Finally, IVUS is instrumental in evaluating the completeness and response to treatment, allowing proceduralists to verify the effectiveness of procedures such as stenting or angioplasty, thereby ensuring optimal treatment outcomes. The side-firing IVUS has been historically used for intracardiac echocardiography for trans-septal puncture, left atrial appendage closure, and intracardiac biopsies1 but has recently gained popularity for interventional radiological procedures such as trans jugular intrahepatic portosystemic shunt placement (TIPS), transvenous biopsies and transcaval abdominal aortic aneurysm endoleak embolizations.2,3

Overall, the insights gained from IVUS are invaluable in guiding and optimizing endovascular interventions. In the current review, we will compare the different IVUS modalities, discuss their different clinical applications and review basic techniques.