Background and purpose: Magnetic resonance (MR) and contrast-enhanced ultrasound assess characteristics and neovascularization, respectively, of the carotid plaque. The purpose of the present study was to clarify how findings of contrast-enhanced ultrasound plaque imaging are related to those of 3-dimensional (3D) fast spin echo (FSE) T1-weighted MR plaque imaging (WI) in severe stenosis (≥70%) of the cervical carotid artery.
Methods: Fifty-three patients underwent 3D FSE T1-WI and contrast-enhanced ultrasound. For each patient, the averaged contrast ratio on MR (CRMR) was calculated by dividing the averaged internal carotid artery plaque signal intensity by the sternocleidomastoid muscle signal intensity; maximally enhanced intensities on the intraplaque and lumen time-intensity curves were obtained from contrast-enhanced ultrasound data, and the ratio of the maximal intensity of the intraplaque curve to that of the lumen curve was calculated and defined as contrast effect (CEUS).
Results: A linear correlation (r = .702; P <.0001) was observed between CRMR and CEUS. Receiver operating characteristic curve analyses to evaluate the ability of the CEUS to differentiate each category of CRMR from the other 2 categories showed that the sensitivity was significantly lower for category II (1.30 ≤ CRMR ≤ 1.60) than for category I (CRMR < 1.30) or III (1.60 < CRMR). The CEUS was lower in plaques with higher CRMR than in those with lower CRMR in a subgroup of category III (P = .0196).
Conclusion: Findings of contrast-enhanced ultrasound plaque imaging are related to those of 3D FSE T1-WI MR plaque imaging according to the life history of arterial plaque and its neovascularization.
Keywords: Carotid plaque; T1-weighted image; contrast-enhanced ultrasound; magnetic resonance imaging.
Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.