Magnetic Resonance Imaging Detection of Intraplaque Hemorrhage

Abstract

Carotid artery atherosclerosis is a major cause of ischemic stroke. For more than 30 years, future stroke risk and carotid stroke etiology have been determined using percent diameter stenosis based on clinical trials in the 1990s. In the past 10 years, magnetic resonance imaging (MRI) sequences have been developed to detect carotid intraplaque hemorrhage. By detecting carotid intraplaque hemorrhage, MRI identifies potential stroke sources that are often overlooked by lumen imaging. In addition, MRI can dramatically improve assessment of future stroke risk beyond lumen stenosis alone. In this review, we discuss the use of heavily T1-weighted MRI sequences used to detect carotid intraplaque hemorrhage. In addition, advances in ciné imaging, motion robust techniques, and specialized neck coils will be reviewed. Finally, the clinical use and future impact of MRI plaque hemorrhage imaging will be discussed.

Pathogenesis regarding development and structure of unstable atherosclerotic plaque in internal carotid artery in relation to high risk factors of an ischaemic stroke. Current status of knowledge

“…Furthermore, it is a factor predisposing for a recurrent cerebral ischaemic episode [48]. Upon MRI imaging [49] IPH is more often revealed in symptomatic patients [47,50]. Abnormal vessels formed during neovascularization may rupture spontaneously or may lead to chronic intraplaque haemorrhage.…”

Non-invasive imaging techniques and assessment of carotid vasa vasorum neovascularization: Promises and pitfalls

“…Furthermore,Kerwin et al showed that K trans in the carotid adventitia in the presence of plaques provides a quantitative proxy for the extent of VVn(55,56). DCE-MRI can be used to estimate arterial and plaque calcification, loosening of the matrix, or haemorrhages, by measuring the response to a variety of magnetic pulses(53,54,69,70). The ability of DCE-MRI to measure these characteristics of the atherosclerotic plaque allows the identification of high-risk plaques (71-73) and opened new uses for the technique.…”

Magnetic Resonance Imaging of Carotid Intraplaque Hemorrhage and Microvasculature

“…10,50 Scoring of IPH using MR imaging has proven to be an accurate method to identify IPH and has been validated with histopathology by us and others (specificity >86%, sensitivity ≥80%). 51,52 Although manual quantification of IPH is a laborious procedure, we have demonstrated high inter-observer agreement values (ĸ=0.95). 34 The degradation of hemorrhage into methemoglobin results in T1 shortening and, correspondingly, causes a high signal intensity on T1-weighted (T1w) MR images.…”

“…50 Thirdly, computational models have shown IPH to be associated with higher structural wall stress. 51 Finally, a recent study from Lin et al showed an association between IPH and plaque surface calcification, 52 that has been shown to lead to a local increase in biomechanical stress. 53 Apart from a lower vessel wall K trans , presence of IPH was positively associated with NWI (indicative for plaque burden).…”

“…51 Scoring of IPH presence on T1w inversion recovery-turbo field echo MR images, also known as MP-RAGE images, has been validated with histopathology. 52 Us and others have shown that MRI can identify IPH with a high sensitivity and specificity (specificity >86%, sensitivity ≥80%). 47,53 The presence of a LRNC can be identified as a region within the bulk of the plaque that does not show contrast enhancement on post-contrast T1-weighted black blood MR images.…”