Intravascular ultrasound (IVUS)
Intravascular ultrasound (IVUS) is an imaging technology platform that aids cardiologists in the diagnosis and treatment of cardiovascular disease. IVUS is performed during coronary angiography and angioplasty (stenting). IVUS intravascular imaging technology utilises ultrasound waves to create images to assess coronary artery disease.
During IVUS assessment, an IVUS catheter is inserted into a guiding catheter through a puncture site in the skin either at the wrist or the groin and threaded over a guidewire to the area of interest within the coronary artery. Ultrasound waves are transmitted from a miniaturized ultrasound probe on the catheter which bounces back from the vessel wall, and the information is collected and analysed to form a greyscale image of the coronary artery and its walls.
Benefits of IVUS Technology
IVUS aids the cardiologist in the assessment of lesion morphology (calcium, lipid, fibrous tissue or presence of blood clot), optimising stent selection and evaluating stent apposition, beyond what is appreciated with coronary angiography alone.
The imaging capabilities of IVUS assist cardiologists in selecting the best stent option for each patient. The system provides precise measurements of lesion dimensions and vessel size and structure, optimising treatment and follow-up strategies.
In addition to guiding stent selection, IVUS offers cardiologists post-stenting information, potentially minimising the risk of repeat revascularization will mean that the patient would have to undergo another procedure or surgery to restore blood flow to the heart. IVUS technology can provide detailed information regarding the inner lining of the coronary artery and whether there is a reoccurrence of the blood vessel narrowing.
Unlike OCT, IVUS imaging does not require contrast injection during the imaging, and this makes it more applicable for most patients.
Further advances in IVUS technology allow even greater differentiation of the composition of the plaque (using VH-IVUS – ‘virtual histology’), and even using objective assessment of how much lipid there is in the plaque (using NIRS – ‘near infrared spectroscopy’).
Is IVUS Safe?
IVUS has been used together with coronary angiography and angioplasty for about 30 years and has minimal risk to patients. Complications are rare (occurring in less than 1% of patients), which may include arrhythmias (abnormal heartbeats), hypotension (low blood pressure), or blockage, dissection, or spasm of the artery; these are related to the procedure risk of coronary angiography and angioplasty.