Intravascular ultrasound imaging of the coronary arteries: an in vitro evaluation of measurement of area of the lumen and atheroma characterisation

Abstract

Objective-To assess the accuracy of measurement of area of the lumen, and sensitivity, and specificity of detection of atheroma in coronary arteries in vitro with a commercially available 20 MHz intravascular ultrasound system.Setting-A teaching hospital department of cardiology with the support of the department of cardiovascular pathology.Procedure-10 segments of coronary artery were removed from cadaver hearts. Intravascular ultrasound imaging was performed at fixed levels and the vessels were then sectioned and photographed before histological preparation. An independent blinded observer measured luminal area and assessed the presence of atheroma on the intravascular ultrasound images of 76 vessel sections (304 quadrants). The sensitivity and specificity of detection of atheroma was assessed in comparison with the histologically prepared sections. Luminal areas from intravascular ultrasound, photographs of cross sections of the vessels and histological sections were compared with the technique of limits of agreement.Results-Overall 36% of the 304 quadrants studied histologically had identifiable atheroma. Intravascular ultrasound sensitivity for atheroma was 0 593 and the specificity was 0-839. The positive predictive value was 0-674, and the relative risk 3X139. Values for area of the vessel lumen were on average 9-4 mm2 (confidence interval (CI) 8-6-10-2 mm2) larger than those measured from photographs and 10-7 (CI 9-8-11-6 mm2) larger than those measured from the histological sections.Conclusions-The intravascular ultrasound system assessed in this study significantly overestimated coronary vessel luminal area and had low sensitivity and specificity for detection of atheroma. Improvements in image resolution are required before this system can provide useful information on coronary artery size and morphology. (Br Heart J 1992;48:276-8 1)The concept of imaging the coronary arteries from within the lumen with ultrasound is not new but early attempts were limited by catheter technology.' The development over the last 15 years of intravascular interventional procedures such as angioplasty and atherectomy has renewed interest in intravascular imaging. The realisation that the distribution and structure of the atheromatous plaque are important factors affecting the success of these strategies spurred interest in intravascular ultrasound and angioscopy. Imaging of the vessel after the intervention would enable assessment of the response of the atheroma to the treatment and identification of features associated with satisfactory long-term outcome. Although angioscopy can achieve imaging in front of the catheter tip it provides information on surface appearance only whereas intravascular ultrasound has the potential advantage of providing information on the deeper composition of the vessel wall including atheromatous plaques. This tantalising prospect is responsible for the current explosion of interest in intravascular ultrasound techniques.Recently published studies have shown excellent correlation of v...

Adjunctive intra-coronary imaging for the assessment of coronary artery disease

“…19,20 IVUS is able to assess vessel wall composition and identify any abnormalities such as inadequate stent apposition or expansion, as well as the presence of dissections following PCI, thus guiding the operator to optimise intervention. [21][22][23] The distribution and structure of the atheromatous plaque are important factors affecting the success of PCI, brachytherapy as well as atherectomy 24 and by facilitating more precise plaque assessment, IVUS has become increasingly invaluable to the interventional cardiologist. 25,26 In the era of drug eluting stents, IVUS-guided PCI has been shown to reduce major adverse cardiovascular events (MACE) when compared with angiographically guided PCI.…”