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McNally JS, Kim SE, Mendes J, Hadley JR, Sakata A, De Havenon AH, Treiman GS, Parker DL. Magnetic Resonance Imaging Detection of Intraplaque Hemorrhage. MAGNETIC RESONANCE INSIGHTS 2017; 10:1-8. [PMID: 28469441 PMCID: PMC5348123 DOI: 10.1177/1178623x17694150] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Accepted: 01/25/2017] [Indexed: 11/16/2022]
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.
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Affiliation(s)
- J Scott McNally
- Utah Center for Advanced Imaging Research, Department of Radiology and Imaging Sciences, The University of Utah, Salt Lake City, UT, USA
| | - Seong-Eun Kim
- Utah Center for Advanced Imaging Research, Department of Radiology and Imaging Sciences, The University of Utah, Salt Lake City, UT, USA
| | - Jason Mendes
- Utah Center for Advanced Imaging Research, Department of Radiology and Imaging Sciences, The University of Utah, Salt Lake City, UT, USA
| | - J Rock Hadley
- Utah Center for Advanced Imaging Research, Department of Radiology and Imaging Sciences, The University of Utah, Salt Lake City, UT, USA
| | - Akihiko Sakata
- Utah Center for Advanced Imaging Research, Department of Radiology and Imaging Sciences, The University of Utah, Salt Lake City, UT, USA
| | - Adam H De Havenon
- Department of Neurology, The University of Utah, Salt Lake City, UT, USA
| | - Gerald S Treiman
- Utah Center for Advanced Imaging Research, Department of Radiology and Imaging Sciences, The University of Utah, Salt Lake City, UT, USA
| | - Dennis L Parker
- Utah Center for Advanced Imaging Research, Department of Radiology and Imaging Sciences, The University of Utah, Salt Lake City, UT, USA
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Kurosaki Y, Yoshida K, Fukuda H, Handa A, Chin M, Yamagata S. Asymptomatic Carotid T1-High-Intense Plaque as a Risk Factor for a Subsequent Cerebrovascular Ischemic Event. Cerebrovasc Dis 2017; 43:250-256. [DOI: 10.1159/000455973] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 01/10/2017] [Indexed: 01/06/2023] Open
Abstract
Background: Intraplaque hemorrhage, detected as a high-signal intensity on carotid MRI, is also strongly associated with ischemic events in symptomatic patients. However, in asymptomatic patients, the relationship of the T1-high intense plaque and the subsequent stroke is not clear. The aim of this study is to test the hypothesis that asymptomatic carotid T1-high intense plaque is a risk factor for a subsequent cerebrovascular ischemic event. Methods: Of the 1,353 consecutive patients, who underwent head and carotid MRI as part of their annual medical check-up, the imaging quality of 13 was poor and 150 did not present for follow-up examination, thus leaving 1,190 subjects for evaluation. Of the 1,190 patients, 96 patients had findings of high-signal intensity on carotid MRI and 1,094 patients did not. Cerebrovascular events were retrospectively evaluated. Results: During a mean follow-up period of 53 months, 4 patients with high-signal intensities on carotid MRI (4%) and 3 with no findings (0.3%) had a cerebrovascular ischemic event, with the occurrences significantly higher in the high-signal-intensity group. (p < 0.01) Cox regression analysis indicated that the presence of the high-intense plaque on carotid MRI (hazard ratio [HR] 4.2; 95% CI 1.0-17.1; p = 0.04), age (HR 1.1; 95% CI 1.0-1.2; p = 0.003), and diabetes mellitus (HR 7.2; 95% CI 1.8-27.4; p = 0.004) were associated with the occurrence of subsequent ischemic cerebrovascular events. Conclusions: Asymptomatic carotid T1-high-intense plaque might be a potential high-risk factor for a subsequent cerebrovascular ischemic event.
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3
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Axisa B, Naylor AR, London N, Bell PRF, Thompson MM. The Influence of Carotid Plaque Morphology on the Development of Cerebral Symptoms. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/153857440003400405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background: Large randomized trials such as the European Carotid Surgery Trial (ECST) and North American Symptomatic Carotid Endarterectomy Trial (NASCET) have defined a role for carotid endarterectomy in symptomatic patients with severe carotid artery stenosis. Data from the same trials also shows that a subgroup of patients with less severe stenosis with a higher risk of stroke might benefit form carotid endarterectomy. In recent years, it has become apparent that besides the degree of stenosis, the morphology of the plaque itself plays a significant role in its potential for development of symptoms, and noninvasive methods of assessing plaque morphology are currently being developed. This paper reviews the literature regarding the relationship between carotid plaque morphology and the potential for development of clinical symptoms. Methods: A Medline search and a meta-analysis of the literature was carried out. Intraplaque hemorrhage and plaque ulceration were both found to be associated with a higher risk of stroke development (p = 0.001 and 0.0001, respectively). Intraluminal thrombus was not found to be associated with an increased risk of symptom development in the data analyzed. A possible explanation for this incongruous finding is discussed. In addition, the paper also discusses the role of noninvasive plaque characterization as a method of identifying unstable plaques in the future. Conclusion: Certain characteristics of plaque morphology correlate with a higher risk of development of symptoms and better noninvasive identification of plaque characterization will lead to better patient selection and may be especially useful identifying patients with lower degrees of stenosis but with potentially unstable plaques who might benefit from carotid endarterectomy but do not qualify for surgery using currently accepted criteria.
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Affiliation(s)
| | | | | | | | - M. M. Thompson
- Department of Surgery, Leicester Royal Infirmary, United Kingdom
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4
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Kurosaki Y, Yoshida K, Fukumitsu R, Sadamasa N, Handa A, Chin M, Yamagata S. Carotid artery plaque assessment using quantitative expansive remodeling evaluation and MRI plaque signal intensity. J Neurosurg 2016; 124:736-42. [DOI: 10.3171/2015.2.jns142783] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT
Plaque characteristics and morphology are important indicators of plaque vulnerability. MRI-detected intraplaque hemorrhage has a great effect on plaque vulnerability. Expansive remodeling, which has been considered compensatory enlargement of the arterial wall in the progression of atherosclerosis, is one of the criteria of vulnerable plaque in the coronary circulation. The purpose of this study was risk stratification of carotid artery plaque through the evaluation of quantitative expansive remodeling and MRI plaque signal intensity.
METHODS
Both preoperative carotid artery T1-weighted axial and long-axis MR images of 70 patients who underwent carotid endarterectomy (CEA) or carotid artery stenting (CAS) were studied. The expansive remodeling ratio (ERR) was calculated from the ratio of the linear diameter of the artery at the thickest segment of the plaque to the diameter of the artery on the long-axis image. Relative plaque signal intensity (rSI) was also calculated from the axial image, and the patients were grouped as follows: Group A = rSI ≥ 1.40 and ERR ≥ 1.66; Group B = rSI< 1.40 and ERR ≥ 1.66; Group C = rSI ≥ 1.40 and ERR < 1.66; and Group D = rSI < 1.40 and ERR < 1.66. Ischemic events within 6 months were retrospectively evaluated in each group.
RESULTS
Of the 70 patients, 17 (74%) in Group A, 6 (43%) in Group B, 7 (44%) in Group C, and 6 (35%) in Group D had ischemic events. Ischemic events were significantly more common in Group A than in Group D (p = 0.01).
CONCLUSIONS
In the present series of patients with carotid artery stenosis scheduled for CEA or CAS, patients with plaque with a high degree of expansion of the vessel and T1 high signal intensity were at higher risk of ischemic events. The combined assessment of plaque characterization with MRI and morphological evaluation using ERR might be useful in risk stratification for carotid lesions, which should be validated by a prospective, randomized study of asymptomatic patients.
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Affiliation(s)
| | - Kazumichi Yoshida
- 2Department of Neurosurgery, Kyoto University School of Medicine, Kyoto, Japan
| | - Ryu Fukumitsu
- 2Department of Neurosurgery, Kyoto University School of Medicine, Kyoto, Japan
| | - Nobutake Sadamasa
- 1Department of Neurosurgery, Kurashiki Central Hospital, Okayama; and
| | - Akira Handa
- 1Department of Neurosurgery, Kurashiki Central Hospital, Okayama; and
| | - Masaki Chin
- 1Department of Neurosurgery, Kurashiki Central Hospital, Okayama; and
| | - Sen Yamagata
- 1Department of Neurosurgery, Kurashiki Central Hospital, Okayama; and
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Makris GC, Teng Z, Patterson AJ, Lin JM, Young V, Graves MJ, Gillard JH. Advances in MRI for the evaluation of carotid atherosclerosis. Br J Radiol 2015; 88:20140282. [PMID: 25826233 DOI: 10.1259/bjr.20140282] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Carotid artery atherosclerosis is an important source of mortality and morbidity in the Western world with significant socioeconomic implications. The quest for the early identification of the vulnerable carotid plaque is already in its third decade and traditional measures, such as the sonographic degree of stenosis, are not selective enough to distinguish those who would really benefit from a carotid endarterectomy. MRI of the carotid plaque enables the visualization of plaque composition and specific plaque components that have been linked to a higher risk of subsequent embolic events. Blood suppressed T1 and T2 weighted and proton density-weighted fast spin echo, gradient echo and time-of-flight sequences are typically used to quantify plaque components such as lipid-rich necrotic core, intraplaque haemorrhage, calcification and surface defects including erosion, disruption and ulceration. The purpose of this article is to review the most important recent advances in MRI technology to enable better diagnostic carotid imaging.
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Affiliation(s)
- G C Makris
- Department of Radiology, University of Cambridge, Cambridge, UK
| | - Z Teng
- Department of Radiology, University of Cambridge, Cambridge, UK
| | - A J Patterson
- Department of Radiology, University of Cambridge, Cambridge, UK
| | - J-M Lin
- Department of Radiology, University of Cambridge, Cambridge, UK
| | - V Young
- Department of Radiology, University of Cambridge, Cambridge, UK
| | - M J Graves
- Department of Radiology, University of Cambridge, Cambridge, UK
| | - J H Gillard
- Department of Radiology, University of Cambridge, Cambridge, UK
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Teng Z, Sadat U, Brown AJ, Gillard JH. Plaque hemorrhage in carotid artery disease: pathogenesis, clinical and biomechanical considerations. J Biomech 2014; 47:847-58. [PMID: 24485514 PMCID: PMC3994507 DOI: 10.1016/j.jbiomech.2014.01.013] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2014] [Indexed: 12/21/2022]
Abstract
Stroke remains the most prevalent disabling illness today, with internal carotid artery luminal stenosis due to atheroma formation responsible for the majority of ischemic cerebrovascular events. Severity of luminal stenosis continues to dictate both patient risk stratification and the likelihood of surgical intervention. But there is growing evidence to suggest that plaque morphology may help improve pre-existing risk stratification criteria. Plaque components such a fibrous tissue, lipid rich necrotic core and calcium have been well investigated but plaque hemorrhage (PH) has been somewhat overlooked. In this review we discuss the pathogenesis of PH, its role in dictating plaque vulnerability, PH imaging techniques, marterial properties of atherosclerotic tissues, in particular, those obtained based on in vivo measurements and effect of PH in modulating local biomechanics.
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Affiliation(s)
- Zhongzhao Teng
- University Department of Radiology, University of Cambridge, UK; Department of Engineering, University of Cambridge, UK.
| | - Umar Sadat
- Department of Surgery, Cambridge University Hospitals NHS Foundation Trust, UK
| | - Adam J Brown
- Department of Cardiovascular Medicine, University of Cambridge, UK
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7
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Kim SE, Treiman GS, Roberts JA, Jeong EK, Shi X, Hadley JR, Parker DL. In vivo and ex vivo measurements of the mean ADC values of lipid necrotic core and hemorrhage obtained from diffusion weighted imaging in human atherosclerotic plaques. J Magn Reson Imaging 2011; 34:1167-75. [DOI: 10.1002/jmri.22736] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Accepted: 07/15/2011] [Indexed: 11/10/2022] Open
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8
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Miura T, Matsukawa N, Sakurai K, Katano H, Ueki Y, Okita K, Yamada K, Ojika K. Plaque vulnerability in internal carotid arteries with positive remodeling. Cerebrovasc Dis Extra 2011; 1:54-65. [PMID: 22566983 PMCID: PMC3343763 DOI: 10.1159/000328645] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND This study aimed to evaluate the efficacy of assessing positive remodeling for predicting future stroke events in the internal carotid artery. We therefore assessed narrowing of the carotid artery lumen using multidetector-row computer tomography (MDCT) angiography and carotid plaque characteristics using black-blood (BB) magnetic resonance (MR). METHODS We retrospectively selected 17 symptomatic and 11 asymptomatic lesions with luminal narrowing >50%. We compared remodeling parameters of luminal stenosis (remodeling ratio, RR/remodeling index, RI) using MDCT and MR intensities of atherosclerotic plaque contents using the BB technique (relative signal intensity, rSI). We also confirmed the validity of the relationship between MR intensity and atherosclerotic plaque contents by histology. The levels of biological markers related to vessel atherosclerosis were measured. RESULTS Plaque lesions with positive remodeling in carotid arteries were associated with a significantly higher prevalence of stroke compared with plaques with negative remodeling (p < 0.05). Radiologic and histologic analyses determined that plaques with positive remodeling had higher signal intensities (with respect to their lipid-rich content or to hemorrhage) compared with negative remodeling (correlation coefficients: RI and rSI, r = 0.41, p < 0.05; RR and rSI, r = 0.50, p < 0.05). Levels of biological markers, including high-sensitivity C-reactive protein, hemoglobin A1C, total cholesterol, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol, were not useful for predicting stroke events. CONCLUSIONS The results of this study suggest that the combined analysis of RR, RI and rSI could potentially help to predict future stroke events.
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Affiliation(s)
- Toshiyasu Miura
- Department of Neurology, Nagoya City University, Nagoya, Japan
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9
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Kurosaki Y, Yoshida K, Endo H, Chin M, Yamagata S. Association between carotid atherosclerosis plaque with high signal intensity on T1-weighted imaging and subsequent ipsilateral ischemic events. Neurosurgery 2011; 68:62-7; discussion 67. [PMID: 21099723 DOI: 10.1227/neu.0b013e3181fc60a8] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND An association between magnetic resonance imaging detection of intraplaque hemorrhage and the risk of cerebral ischemic events has been described. However, few studies have followed patients with intraplaque hemorrhage. OBJECTIVE We used 3-dimensional gradient-echo black-blood T1-weighted imaging (screening BB [S-BB]) as a magnetic resonance imaging sequence to evaluate acute cerebrovascular stroke. The association between S-BB high signal plaques and the risk of subsequent ipsilateral ischemic events was investigated. METHODS A total of 928 consecutive patients hospitalized for a stroke or transient ischemic attack according to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification were evaluated. Recurrence was retrospectively evaluated in S-BB-positive patients and patients with severe stenosis (SS) (≥70%) by magnetic resonance angiography. Based on clinical and imaging findings, recurrence was defined as a carotid artery stroke or transient ischemic attack that developed after hospital discharge as an initial event. RESULTS Sixty-six patients were S-BB positive and 62 patients had severe stenosis (S-BB positive with SS, 32 patients; S-BB negative with SS, 30 patients; S-BB positive without SS, 34 patients). During a mean follow-up period of 9.1 months, 7 S-BB-positive patients with SS (18.7%) and 1 S-BB-negative patient with SS (3%) had a recurrent event (P = .051). In the S-BB-positive group, in 34 patients without SS, the recurrence rate was 14.7% (5/34); the difference in the recurrence rate between S-BB-positive group with and without SS was not significant (P = .34). CONCLUSION Patients with carotid artery lesions and intraplaque hemorrhage tend to be at higher risk of a subsequent ipsilateral ischemic event. Risk evaluation of carotid artery disease should include plaque characteristics.
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Affiliation(s)
- Yoshitaka Kurosaki
- Department of Neurosurgery, The Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka, Japan.
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10
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Kim SE, Jeong EK, Shi XF, Morrell G, Treiman GS, Parker DL. Diffusion-weighted imaging of human carotid artery using 2D single-shot interleaved multislice inner volume diffusion-weighted echo planar imaging (2D ss-IMIV-DWEPI) at 3T: diffusion measurement in atherosclerotic plaque. J Magn Reson Imaging 2010; 30:1068-77. [PMID: 19856440 DOI: 10.1002/jmri.21944] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To determine if 2D single-shot interleaved multislice inner volume diffusion-weighted echo planar imaging (ss-IMIV-DWEPI) can be used to obtain quantitative diffusion measurements that can assist in the identification of plaque components in the cervical carotid artery. MATERIALS AND METHODS The 2D ss-DWEPI sequence was combined with interleaved multislice inner volume region localization to obtain diffusion weighted images with 1 mm in-plane resolution and 2 mm slice thickness. Eleven subjects, six of whom have carotid plaque, were studied with this technique. The apparent diffusion coefficient (ADC) images were calculated using DW images with b = 10 s/mm(2) and b = 300 s/mm(2). RESULTS The mean ADC measurement in normal vessel wall of the 11 subjects was 1.28 +/- 0.09 x 10(-3) mm(2)/s. Six of the 11 subjects had carotid plaque and ADC measurements in plaque ranged from 0.29 to 0.87 x 10(-3) mm(2)/s. Of the 11 common carotid artery walls studied (33 images), at least partial visualization of the wall was obtained in all ADC images, more than 50% visualization in 82% (27/33 images), and full visualization in 18% (6/33 images). CONCLUSION 2D ss-IMIV-DWEPI can perform diffusion-weighted carotid magnetic resonance imaging (MRI) in vivo with reasonably high spatial resolution (1 x 1 x 2 mm(3)). ADC values of the carotid wall and plaque are consistent with similar values obtained from ex vivo endarterectomy specimens. The spread in ADC values obtained from plaque indicate that this technique could form a basis for plaque component identification in conjunction with other MRI/MRA techniques.
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Affiliation(s)
- Seong-Eun Kim
- Department of Radiology, Utah Center for Advanced Imaging Research, Salt Lake City, Utah 84108, USA.
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11
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Yoshida K, Narumi O, Chin M, Inoue K, Tabuchi T, Oda K, Nagayama M, Egawa N, Hojo M, Goto Y, Watanabe Y, Yamagata S. Characterization of carotid atherosclerosis and detection of soft plaque with use of black-blood MR imaging. AJNR Am J Neuroradiol 2008; 29:868-74. [PMID: 18296548 DOI: 10.3174/ajnr.a1015] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE In the treatment of carotid atherosclerosis, the rate of stenosis and characteristics of plaque should be assessed to diagnose vulnerable plaques that increase the risk for cerebral infarction. We performed carotid black-blood (BB) MR imaging to diagnose plaque components and assess plaque hardness based on MR signals. MATERIALS AND METHODS Three images of BB-MR imaging per plaque were obtained from 70 consecutive patients who underwent carotid endarterectomy (CEA) to generate T1- and T2-weighted images. To evaluate the relative signal intensity (rSI) of plaque components and the relationship between histologic findings and symptoms, we prepared sections at 2-mm intervals from 34 intact plaques. We then calculated the relative overall signal intensity (roSI) of 70 plaques to assess the relationship between MR signal intensity and plaque hardness and symptoms. RESULTS The characteristics of rSI values on T1- and T2-weighted images of fibrous cap (FC), fibrosis, calcification, myxomatous tissue, lipid core (LC) with intraplaque hemorrhage (IPH), and LC without IPH differed. Symptomatic plaques were associated with FC disruption (P < .001) and LC with IPH (P < .05). The roSI on T1-weighted images was significantly higher for soft than nonsoft plaques. When the roSI cutoff value was set at 1.25 (mean of the roSI), soft plaques were diagnosed with 79.4% sensitivity and 84.4% specificity. The roSI was also significantly higher for symptomatic than for asymptomatic plaques. Soft and nonsoft plaques as well as symptomatic and asymptomatic plaques did not significantly differ on T2-weighted images. CONCLUSION BB-MR imaging can diagnose plaque components and predict plaque hardness. This procedure provides useful information for planning therapeutic strategies of carotid atherosclerosis.
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Affiliation(s)
- K Yoshida
- Department of Neurosurgery, Kurashiki Central Hospital, Okayama, Japan.
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12
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Gao P, Chen ZQ, Bao YH, Jiao LQ, Ling F. Correlation between carotid intraplaque hemorrhage and clinical symptoms: systematic review of observational studies. Stroke 2007; 38:2382-90. [PMID: 17600232 DOI: 10.1161/strokeaha.107.482760] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE We sought to investigate the association between carotid intraplaque hemorrhage (IPH) and ipsilateral symptoms of cerebral ischemia. METHODS A search was performed for clinical observational studies comparing the incidence of IPH between symptomatic and asymptomatic patients. Odds ratios (ORs) for IPH as a factor in the pathogenesis of neurologic events were calculated and combined by a meta-analysis. Interstudy heterogeneity, estimated effects, and methodologic quality of the studies were assessed. RESULTS Thirty-one studies were included for analysis. The reported ORs varied widely. Overall, the incidence of IPH in the symptomatic groups was significantly higher than in the asymptomatic group. However, there was an apparent trend for heterogeneity (P<0.00001) between studies. The random-effects summary estimator of ORs was 2.25 (95% CI, 1.57 to 3.22; P<0.00001). To identify potential sources of heterogeneity, subgroup analyses were performed. The pooled ORs varied greatly by stratification. Major heterogeneity was found among studies with low quality, microscopic methods of examination, significant effects, small sizes, early publication, and unequal severity of carotid stenosis in both groups. Large, recent, macroscopic, or high-quality studies, as well as studies with equal degrees of stenosis, tended to yield insignificant associations. The methods in defining and evaluating hemorrhage were very heterogeneous. Characterizations of the age, size, number, and location of hemorrhages were poorly reported and highly variable. In addition, a lack of control of confounders and selection bias were frequently identified among studies. CONCLUSIONS Statistical inferences have suggested a plausible role in the production of cerebral ischemia; however, reliable interpretation was strongly undermined by poor methodologic quality, substantial heterogeneity, and suspicious publication bias. To preciously estimate the underlying correlation, a well-designed study with uniformity in definition and evaluation for IPH might be warranted.
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Affiliation(s)
- Peng Gao
- 389 Xincun Rd, Putuo District, Shanghai 200065, China.
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13
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Sailer J, Rand T, Berg A, Sulzbacher I, Peloschek P, Hölzenbein T, Lammer J. High-Resolution 3 T MR Microscopy Imaging of Arterial Walls. Cardiovasc Intervent Radiol 2006; 29:771-7. [PMID: 16755347 DOI: 10.1007/s00270-005-0051-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
PURPOSE To achieve a high spatial resolution in MR imaging that allows for clear visualization of anatomy and even histology and documentation of plaque morphology in in vitro samples from patients with advanced atherosclerosis. A further objective of our study was to evaluate whether T2-weighted high-resolution MR imaging can provide accurate classification of atherosclerotic plaque according to a modified American Heart Association classification. METHODS T2-weighted images of arteries were obtained in 13 in vitro specimens using a 3 T MR unit (Medspec 300 Avance/Bruker, Ettlingen, Germany) combined with a dedicated MR microscopy system. Measurement parameters were: T2-weighted sequences with TR 3.5 sec, TE 15-120 msec; field of view (FOV) 1.4 x 1.4; NEX 8; matrix 192; and slice thickness 600 microm. MR measurements were compared with corresponding histologic sections. RESULTS We achieved excellent spatial and contrast resolution in all specimens. We found high agreement between MR images and histology with regard to the morphology and extent of intimal proliferations in all but 2 specimens. We could differentiate fibrous caps and calcifications from lipid plaque components based on differences in signal intensity in order to differentiate hard and soft atheromatous plaques. Hard plaques with predominantly intimal calcifications were found in 7 specimens, and soft plaques with a cholesterol/lipid content in 5 cases. In all specimens, hemorrhage or thrombus formation, and fibrotic and hyalinized tissue could be detected on both MR imaging and histopathology. CONCLUSION High-resolution, high-field MR imaging of arterial walls demonstrates the morphologic features, volume, and extent of intimal proliferations with high spatial and contrast resolution in in vitro specimens and can differentiate hard and soft plaques.
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Affiliation(s)
- Johannes Sailer
- Department of Angiography and Interventional Radiology, University of Vienna, Vienna, Austria.
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14
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Lovett JK, Redgrave JNE, Rothwell PM. A Critical Appraisal of the Performance, Reporting, and Interpretation of Studies Comparing Carotid Plaque Imaging With Histology. Stroke 2005; 36:1091-7. [PMID: 15774817 DOI: 10.1161/01.str.0000160749.61763.95] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose—
Carotid plaque instability is an important determinant of stroke risk. There are now a number of different imaging techniques that provide information on carotid plaque morphology. However, it is unclear how they compare with one another or whether they can reliably assess plaque instability. Studies comparing imaging with pathology have shown highly variable results, even for similar imaging techniques. This may be because of variable pathology techniques rather than differences in imaging.
Methods—
We performed a systematic review of studies that compared carotid imaging with histology of the excised plaque published between January 1995 and September 2004. We assessed the quality and comparability of these studies. In particular, we determined which histology methods were used and whether observer reproducibility of the histology assessment was reported.
Results—
Among 73 eligible studies, histological methods were poorly reported and highly variable; 23% reported reproducibility data for imaging and only 12% reported reproducibility data for histology. Of 29 studies that reported quantitative results of blinded comparisons, there were methodological deficiencies and the results were highly variable. No study considered the extent to which the lack of reproducibility influenced the imaging-pathological correlations reported.
Conclusions—
Pathological correlation in studies of carotid plaque imaging cannot be reliably interpreted or compared because of incomparable and poorly reported histology methods. We make recommendations for the performance, reporting, and interpretation of imaging–pathological correlation studies and highlight the need for consensus guidelines.
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Affiliation(s)
- J K Lovett
- Stroke Prevention Research Unit, Department of Clinical Neurology, Radcliffe Infirmary, Oxford
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15
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Manninen HI, Vanninen RL, Laitinen M, Räsänen H, Vainio P, Luoma JS, Pakkanen T, Tulla H, Ylä-Herttuala S. Intravascular ultrasound and magnetic resonance imaging in the assessment of atherosclerotic lesions in rabbit aorta. Correlation to histopathologic findings. Invest Radiol 1998; 33:464-71. [PMID: 9704286 DOI: 10.1097/00004424-199808000-00007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
RATIONALE AND OBJECTIVES The authors compare the usefulness of intravascular ultrasound (IVUS) and magnetic resonance imaging (MRI) for quantitation of atherosclerosis in hyperlipidemic rabbits, correlated with histopathology. METHODS Magnetic resonance imaging with T1- and T2-weighted spin echo sequences and three-dimensional time-of-flight MR angiography of the abdominal aorta was performed on seven rabbits using a 1.5 T MR imager and a standard head coil. X-ray angiography and IVUS examination (3.5 F/30 MHz imaging catheter) was performed via carotid artery access. RESULTS Time-of-flight MR angiography source images provided the best resolution and plaque-lumen contrast in visual comparison between the different MRI sequences. Intra- and interobserver reproducibilities of the lesion thickness and area measurements were similar in IVUS and MRI (Pearson correlations 0.52-0.97; P < 0.01). The measurements from IVUS and MRI correlated closely with each other as well as with those made from histopathologic specimens (Pearson correlations 0.50-0.79; P < 0.001). The measurements from IVUS were somewhat more accurate than those made from MRI. CONCLUSIONS Both MRI and IVUS with clinically available imaging equipments are feasible and accurate for the quantitation of experimental atherosclerosis of rabbit aorta.
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Affiliation(s)
- H I Manninen
- Department of Clinical Radiology, Kuopio University Hospital, University of Kuopio, Finland
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16
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Bridal SL, Toussaint JF, Raynaud JS, Fornes P, Leroy-Willig A, Berger G. US backscatter and attenuation 30 to 50 MHz and MR T2 at 3 Tesla for differentiation of atherosclerotic artery constituents in vitro. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 1998; 45:1517-1525. [PMID: 18249999 DOI: 10.1109/58.738291] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
This study compares quantitative characterization of atherosclerotic artery constituents by high resolution estimates of ultrasonic attenuation, ultrasonic attenuation-compensated backscatter, and magnetic resonance transverse relaxation time. Atherosclerotic human arteries were studied in vitro at 37°C. Backscattered radio frequency signals were acquired with a 50 MHz backscatter acoustic microscope. Ultrasonic parametric images were constructed from the integrated (30 to 50 MHz) backscatter and attenuation obtained using FFT methods with diffraction correction and a multinarrow-band attenuation algorithm. Parametric magnetic resonance images were constructed from calculated values of the transverse relaxation time T2 determined from an 8 echo-single-slice sequence at 3 Tesla. In a total of 54 regions of interest, average values of integrated attenuation, integrated backscatter compensated for the attenuation between the artery surface and the scattering volume, and the transverse relaxation time were correlated with local tissue composition as assessed by histology. Results show that ultrasound and magnetic resonance techniques offer complementary approaches for characterization of plaque composition.
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Affiliation(s)
- S L Bridal
- Lab. d'Imagerie Parametrique, CNRS, Paris
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17
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Ko PT, Lin SK, Chang YJ, Ryu SJ, Chu CC. Carotid floating plaques associated with multiple cerebral embolic strokes. Case reports. Angiology 1997; 48:255-61. [PMID: 9071202 DOI: 10.1177/000331979704800309] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The authors describe 2 patients with multiple cerebral infarcts and hemorrhagic transformation caused by artery-to-artery emboli. Ulcerated plaques with free-floating thrombus adherent to the plaque were detected at the carotid bifurcation by duplex sonography. No other embolic source could be found. One patient developed an occipital infarction due to carotid emboli passing through a fetal-type posterior communicating artery. Both patients recovered well without recurrence of stroke or transient ischemic attack with antiplatelet treatment only. Follow-up carotid duplex sonography showed disappearance of floating thrombus in 1 patient and consolidation of the lesion in the other.
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Affiliation(s)
- P T Ko
- Department of Neurology, Chang Gung Memorial Hospital, Taipei, Taiwan
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