Identification of “vulnerable plaque” using virtual histology in angiographically benign looking lesion of proximal left anterior descending artery

Virtual Histology Intravascular Ultrasound in Carotid Interventions

Purpose:

To report early clinical experience with virtual histology intravascular ultrasound (VH IVUS) in carotid endoluminal repair.

Technique:

A 2.9-F, 20-MHz catheter that utilizes computer software to demonstrate the histological components of arteriosclerotic plaque was evaluated during carotid angioplasty and stenting. VH IVUS images were created following a pullback through the carotid stenosis and produced a color-coded map of the different histological constituents of the disease (dark green: fibrous, yellow/green: fibrofatty, white: calcified, and red: necrotic lipid core plaque).

Conclusion:

VH IVUS produces a color-coded map of the different histological components of artery plaque. It has the potential to predict how the plaque is likely to behave at the moment of endoluminal treatment.

Intravascular ultrasound: principles and cerebrovascular applications

Intravascular sonography is a valuable tool for the morphologic assessment of coronary atherosclerosis and the effect of pharmacologic and nonpharmacologic interventions on the progression or stabilization of atherosclerosis. An analysis of the different modes, applications, and limitations is provided on the basis of review of existing data from multiple clinical case studies, trials, and mechanistic studies. Intravascular sonography has been used to assess the outcomes of different percutaneous interventions, including angioplasty and stent implantation, and to provide detailed characterization of atherosclerotic lesions, aneurysms, and dissections within the cerebrovascular circulation. Evolution of intravascular sonographic technology has led to the development of more sophisticated diagnostic tools such as color-flow, virtual histology, and integrated backscatter intravascular sonography. The technologic advancement in intravascular sonography has the potential of providing more accurate information prior, during, and after a medical or endovascular intervention. Continued assessment of this diagnostic technique in both the intracranial and extracranial circulation will lead to increased use in clinical practice with the intent to improve outcomes.

Virtual Histology and Color Flow Intravascular Ultrasound in Peripheral Interventions

The quality and interpretation of intravascular ultrasound (IVUS) imaging has been revolutionized in recent years by two new and major advances: virtual histology and color flow IVUS. Virtual histology intravascular ultrasound (VHIVUS) is a catheter-based technology where IVUS is generated from the transducer on the catheter tip and the reflected signals from the artery wall produce a color-coded map of the arterial disease. Different histological constituents of the plaque produce different reflected signals and these are assigned different colors (dark green, fibrous; yellow/green, fibrofatty; white, calcified; red, necrotic lipid core plaque). This color-coded map assists the interventionalist in understanding more fully how the lesion will behave at the moment of treatment, whether it will resist complete stent deployment or be liable to embolization. Originally introduced for coronary interventions, VHIVUS is now being applied to peripheral situations. Because it provides a detailed and close-proximity view of plaque, its potential to improve the safety and efficacy of carotid endoluminal repair is stimulating substantial interest. Similarly, color flow IVUS provides greater understanding for the operator of blood flow, and the interface between the vessel wall and the blood stream, lumen size, and success of treatment. Color flow IVUS does not use the Doppler effect, but creates real-time images that resemble color flow Doppler ultrasound. These two technological advances in IVUS have greatly improved the ability of the endovascular specialist to understand the arterial disease they are treating and to assess the completion of treatment.