Advanced Carotid Plaque Imaging

Hermus, Linda; Dam, van Gooitzen; Zeebregts, Clark J.

doi:10.1016/j.ejvs.2009.11.020

Cited by 60 publications

(41 citation statements)

References 51 publications

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“…Although many investigators have reported that magnetic resonance imaging (MRI) is a useful tool to predict the components of carotid plaque, its validity is not established [10,11,12,13,14,15,16,17,18]. On the other hand, 18 F-fluorodeoxyglucose (FDG) positron emission tomography (PET) may be an alternative modality to directly identify the inflamed plaque in carotid artery stenosis [9,19,20,21,22,23,24,25]. Therefore, this study was aimed at evaluating the validity of dual imaging with MRI and FDG-PET to predict the vulnerable components of carotid plaques.…”

Section: Introductionmentioning

confidence: 99%

Validity of Dual MRI and <sup>18</sup>F-FDG PET Imaging in Predicting Vulnerable and Inflamed Carotid Plaque

Saito

Kuroda

Hirata³

et al. 2013

Cerebrovasc Dis

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Background: Vulnerable and inflamed plaques in the carotid artery are at high risk of ischemic stroke, suggesting the importance of diagnostic modalities to detect them in patients with carotid stenosis with high sensitivity and specificity. Although many investigators have reported that magnetic resonance imaging (MRI) is a useful tool to predict the vulnerable components of carotid plaque, its validity is not established. On the other hand, ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET) may be an alternative modality to directly identify the inflamed plaque in carotid artery stenosis. Therefore, this study aimed at evaluating the validity of MRI and FDG-PET to predict vulnerable and inflamed carotid plaque. Methods: This prospective study totally included 25 patients who underwent carotid endarterectomy (CEA) for carotid artery stenosis at our institute between January 2009 and January 2012. Prior to CEA, FDG-PET, black-blood T1-weighted imaging (BB-T1WI), and 3-dimensional time-of-flight (TOF) imaging were performed. The specimens were stained with hematoxylin-eosin to assess the different plaque components (lipid, hemorrhage, calcification, and fibrous tissue). In addition, they were stained with primary antibodies against CD68 (activated macrophages) and matrix metalloproteinase (MMP)-9. Results: High FDG uptake was detected in 13 (52.0%) of 25 patients. All of them had lipid-rich plaque. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) to identify the lipid-rich plaques were all 100% for FDG-PET. More importantly, all of the FDG-positive plaques had strong immunoreactivity against both CD68 and MMP-9. There was a significant correlation between the findings on FDG-PET and those on immunohistochemistry against CD68 and MMP-9 (p = 0.006 and 0.004, respectively). On the other hand, 16 (64.0%) of 25 patients had high signal intensity plaque on BB-T1WI. In 7 of these 16 patients, the lesions also showed high signal intensity on TOF imaging. All of them had a large intraplaque hemorrhage. The sensitivity, specificity, PPV, and NPV to identify a large intraplaque hemorrhage were 70, 100, 100, and 83%, respectively, for MRI. Conclusions: These findings suggest that FDG-PET and MRI are complementary to predict high-risk carotid plaque, such as lipid-rich or hemorrhagic plaque. FDG-PET can accurately predict the lipid-rich and inflamed plaque. MRI is valuable to identify unstable plaque with a large intraplaque hemorrhage. The combination of these two modalities may play an important role in predicting carotid plaque at high risk of ischemic stroke.

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Section: Introductionmentioning

confidence: 99%

Validity of Dual MRI and <sup>18</sup>F-FDG PET Imaging in Predicting Vulnerable and Inflamed Carotid Plaque

Saito

Kuroda

Hirata³

et al. 2013

Cerebrovasc Dis

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“…They therefore cannot distinguish between stable and unstable plaques. Because plaque composition rather than stenosis is important in detecting an unstable plaque, new imaging modalities are needed (5). 18 F-FDG PET can be used to identify vulnerable plaques in atherosclerotic disease, because 18 F-FDG accumulates in activated macrophages.…”

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confidence: 99%

Folate Receptor-β Imaging Using ^99mTc-Folate to Explore Distribution of Polarized Macrophage Populations in Human Atherosclerotic Plaque

et al. 2014

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In atherosclerotic plaques, the risk of rupture is increased at sites of macrophage accumulation. Activated macrophages express folate receptor-β (FR-β), which can be targeted by folate coupled to radioactive ligands to visualize vulnerability. The aim of this study was to explore the presence of activated macrophages in human atherosclerotic plaques by 99m Tc-folate imaging and to evaluate whether this technique can discriminate between an M1-like and M2-like macrophage phenotype. Methods: Carotid endarterectomy specimens of 20 patients were incubated with 99m Tc-folate, imaged using micro-SPECT, and divided into 3-mm slices. The mean accumulation was calculated per slice, and the distribution of M1-like and M2-like macrophages per slice was quantified by immunohistochemical staining for CD86 as well as inducible nitric oxide synthase (iNOS) for M1 and CD163 and FR-β for M2 macrophages. Monocytes from healthy donors were differentiated toward M1-like or M2-like phenotype by in vitro culturing. Messenger RNA levels of specific M1 and M2 markers were measured by reversetranscription polymerase chain reaction and expression of FR-β, CD86, and CD163 by flow cytometry. Results: There was a heterogeneous accumulation of 99m Tc-folate in plaques (median, 2.45 [0.77-6.40] MBq/g). Slices with the highest 99m Tc-folate accumulation of each plaque showed significantly more expression of FR-β and CD163, compared with slices with the lowest 99m Tc-folate accumulation, which showed significantly more expression of iNOS. In in vitro polarized macrophages, messenger RNA expression of FR-β, mannose receptor, IL-10, and matrix metalloproteinase-9 was significantly increased in M2-like macrophages, compared with M1-like macrophages. On a receptor level, CD86 was shown to be overexpressed on M1-like macrophages whereas FR-β and CD163 were overexpressed on M2-like macrophages measured by flow cytometry. Conclusion: Higher numbers of M2-like macrophages were present in areas of high 99m Tc-folate accumulation than areas with low accumulation. It is anticipated that 99m Tcfolate imaging using SPECT as a marker for M2-like macrophages in atherosclerosis might be a good indicator for plaque vulnerability.

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“…In contrast, a high amount of fibrous contents and greater calcification may be associated with a lower risk of stroke (stable plaques). Therefore, plaque morphology and composition should be included in the evaluation of atherosclerotic diseases, which will further contribute to the knowledge about lumen narrowing 3,13,16,17 .…”

Section: Introductionmentioning

confidence: 99%

“…Currently, the characteristics of carotid stenosis are described using imaging methods, such as duplex ultrasound (US), digital subtraction angiography (DSA), CT angiography (CT-angio) and magnetic resonance angiography (MRA). The content of the atheroma may be analyzed using several of these imaging techniques, but most authors use them only to define the characteristics of anatomic plaque stenosis, while plaque morphology and composition are often not investigated 3,5 . Other complementary imaging tests, such as positron emission tomography (PET) and single photon emission CT (SPECT), may play an adjuvant role in follow-up.…”

Section: Introductionmentioning

confidence: 99%

“…About 50% to 80% of all strokes are ischemic 1,3 , and of all ischemic strokes, 15% to 50% result from emboli and thrombi produced by the atherosclerotic plaque in the extracranial carotid artery bifurcation [1][2][3][4][5][6] . However, not all plaque with marked stenosis becomes symptomatic and leads to a stroke or transient ischemic attack (TIA), which raises questions about whether surgery should be indicated for asymptomatic patients 7 .…”

Section: Introductionmentioning

confidence: 99%

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Comparacoes preliminares entre a histologia virtual ultrassonografica in vivo e os achados histopatologicos da placa carotidea produto de endarterectomia

Menezes

Silveira

et al. 2013

J. vasc. bras.

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Background: Extracranial carotid artery atherosclerosis is a major preventable cause of strokes, the second most common cause of death in developed countries. The degree of arterial lumen stenosis is the basis for surgical indications, but does not provide information about other plaque aspects. Studies in the literature suggest that the morphological characteristics of the plaque and its composition should also be included in the assessment of this disease. Objective: Investigate the correlation between atherosclerotic plaque composition defined by computer-assisted analysis of ultrasound images (virtual histology -USVH) and conventional histology. Method: The images of twelve plaques, obtained during preoperative ultrasound scanning, were analyzed by computer, and the grey scale images were correlated with the plaque components and subsequently compared with the histological findings of the analysis of the endarterectomy specimens. Results: The amount of lipids and fibromuscular tissue were strongly correlated in the two tests (R=0.83 and 0.91). There were no significant correlations with amount of blood or calcium (R=0.05 and 0.19). Conclusion: This study confirmed the usefulness of noninvasive USVH. Further technical improvements and software developments may promote the clinical application of this method.

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Advanced Carotid Plaque Imaging

Cited by 60 publications

References 51 publications

Validity of Dual MRI and <sup>18</sup>F-FDG PET Imaging in Predicting Vulnerable and Inflamed Carotid Plaque

Validity of Dual MRI and <sup>18</sup>F-FDG PET Imaging in Predicting Vulnerable and Inflamed Carotid Plaque

Folate Receptor-β Imaging Using ^99mTc-Folate to Explore Distribution of Polarized Macrophage Populations in Human Atherosclerotic Plaque

Comparacoes preliminares entre a histologia virtual ultrassonografica in vivo e os achados histopatologicos da placa carotidea produto de endarterectomia

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Advanced Carotid Plaque Imaging

Cited by 60 publications

References 51 publications

Validity of Dual MRI and <sup>18</sup>F-FDG PET Imaging in Predicting Vulnerable and Inflamed Carotid Plaque

Validity of Dual MRI and <sup>18</sup>F-FDG PET Imaging in Predicting Vulnerable and Inflamed Carotid Plaque

Folate Receptor-β Imaging Using 99mTc-Folate to Explore Distribution of Polarized Macrophage Populations in Human Atherosclerotic Plaque

Comparacoes preliminares entre a histologia virtual ultrassonografica in vivo e os achados histopatologicos da placa carotidea produto de endarterectomia

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Folate Receptor-β Imaging Using ^99mTc-Folate to Explore Distribution of Polarized Macrophage Populations in Human Atherosclerotic Plaque