1
|
Shirakawa M, Yamada K, Watase H, Chu B, Enomoto Y, Kojima T, Wakabayashi K, Sun J, Hippe DS, Ferguson MS, Balu N, Yoshimura S, Hatsukami TS, Yuan C. Atherosclerotic carotid plaque characteristics vary with time from ischemic event: A multicenter, prospective magnetic resonance vessel wall imaging registry study. J Neurol Sci 2023; 446:120582. [PMID: 36796273 DOI: 10.1016/j.jns.2023.120582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 01/12/2023] [Accepted: 02/05/2023] [Indexed: 02/10/2023]
Abstract
Recent studies report that the rate of recurrent stroke is highest in the stages immediately following cerebral infarction and decreases over time in patients with atherosclerotic carotid stenosis. The purpose of this study was to identify temporal differences in early stage carotid plaque components from acute cerebrovascular ischemic events using carotid MRI. Carotid plaque images were obtained on 3 T MRI from 128 patients enrolled in MR-CAS. Among the 128 subjects, 53 were symptomatic and 75 asymptomatic. The symptomatic patients were classified into three groups based on interval from onset of symptoms to the date of the carotid MRI (Group <14 days; 15-30 days; and > 30 days). The volume of each plaque component was identified and quantified from MR images. The presence of juxtaluminal loose matrix/inflammation (LM/I) was identified as a possible indicator of inflammation on the luminal side. Plaque components were compared between groups using the Wilcoxon rank-sum or the Chi-square test. Patient characteristics and carotid plaque morphology were similar among all four groups. The median volume of LM/I in Group >30 days was significantly lower than in other groups (0 mm3 vs 12.3 mm3 and 18.1 mm3; p = 0.003). In addition, the prevalence of juxtaluminal LM/I decreased over time (ptrend = 0.002). There were no statistically significant differences in other plaque components between the symptomatic groups. The volume of LM/I was significantly smaller in Group >30 days and prevalence of juxtaluminal LM/I in the atherosclerotic carotid plaque was high in the early stages after events. This suggests that carotid plaques undergo rapid evolution after an acute cerebrovascular ischemic event.
Collapse
Affiliation(s)
- Manabu Shirakawa
- Department of Radiology, University of Washington, Seattle, USA; Department of Neurosurgery, Hyogo Medical University, Nishinomiya, Japan
| | - Kiyofumi Yamada
- Department of Neurosurgery, Hyogo Medical University, Nishinomiya, Japan
| | - Hiroko Watase
- Department of Emergency and General Internal Medicine, Fujita Health University, Toyoake, Japan
| | - Baocheng Chu
- Department of Radiology, University of Washington, Seattle, USA
| | - Yukiko Enomoto
- Department of Neurosurgery, Gifu University, Gifu, Japan
| | - Takao Kojima
- Department of Neurosurgery, Fukushima Medical University, Fukushima, Japan
| | | | - Jie Sun
- Department of Radiology, University of Washington, Seattle, USA
| | - Daniel S Hippe
- Clinical Research Division, Fred Hutchinson Cancer Center, Seattle, WA
| | | | - Niranjan Balu
- Department of Radiology, University of Washington, Seattle, USA
| | - Shinichi Yoshimura
- Department of Neurosurgery, Hyogo Medical University, Nishinomiya, Japan
| | - Thomas S Hatsukami
- Department of Surgery, Division of Vascular Surgery, University of Washington, Seattle, USA
| | - Chun Yuan
- Department of Radiology, University of Washington, Seattle, USA.
| |
Collapse
|
2
|
Wei H, Zhang M, Li Y, Zhao X, Canton G, Sun J, Xu D, Zhou Z, Chen S, Ferguson MS, Hatsukami TS, Li R, Yuan C. Evaluation of 3D multi-contrast carotid vessel wall MRI: a comparative study. Quant Imaging Med Surg 2020; 10:269-282. [PMID: 31956548 DOI: 10.21037/qims.2019.09.11] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Background Conventional reference multi-contrast black-blood (BB) MRI can be used for measuring luminal stenosis severity and plaque components, and its performance has been validated by intra- and inter-reader reproducibility test and histology. Recently, a set of 3D multi-contrast BB sequences have been developed, but its accuracy and reliability have not been well investigated. In this study, we evaluated the performance of 3D multi-contrast MRI (3D-MERGE, T2-VISTA, and SNAP) by comparing it with reference multi-contrast vessel wall MRI and assessing the inter-reader reproducibility. Methods In total, 27 patients were recruited in this study. Twenty-six participants underwent reference and 3D multi-contrast imaging in a 3.0T MR scanner. One participant underwent carotid endarterectomy (CEA) after 3D MR imaging. Two trained reviewers interpreted reference and 3D datasets. Lumen area (LA), wall area (WA), normalized wall index (NWI), maximum wall thickness (MaxWT), and mean wall thickness (MWT) were measured, and the presence of lipid-rich necrotic core (LRNC), intra-plaque hemorrhage (IPH) and calcification (CA) were identified. Inter-reader reproducibility of 3D interpretation was assessed. Results 3D imaging provided comparable measurements with reference imaging in LA (43.81±25.74 vs. 43.35±24.66 mm2) and MaxWT (1.65±1.33 vs. 1.62±1.10 mm), with a lower NWI (0.40±0.15 vs. 0.43±0.11), WA (29.40±21.92 vs. 30.64±16.17 mm2) and MWT (1.09±0.69 vs. 1.14±0.47), and showed good agreement for identification of LRNC (κ=0.66, 95% CI: 0.30-1.00) and CA (κ=0.69, 95% CI: 0.42-0.97), and excellent agreement for IPH (κ=1.00, 95% CI: 1.00-1.00). Inter-reader agreement of 3D analysis was good (LRNC, κ=0.87, 95% CI: 0.61-1.00; CA, κ=0.66, 95% CI: 0.36-0.96; IPH, κ=1.00, 95% CI: 1.00-1.00). Conclusions 3D multi-contrast vessel wall imaging provides comparable performance in morphological measurements and identification of carotid plaque components as reference multi-contrast MRI, with good inter-reader reproducibility.
Collapse
Affiliation(s)
- Hanyu Wei
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing 100084, China
| | - Miaoqi Zhang
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing 100084, China
| | - Yunduo Li
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing 100084, China
| | - Xihai Zhao
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing 100084, China
| | - Gador Canton
- Department of Radiology, University of Washington, Seattle, WA, USA
| | - Jie Sun
- Department of Radiology, University of Washington, Seattle, WA, USA
| | - Dongxiang Xu
- Department of Radiology, University of Washington, Seattle, WA, USA
| | - Zechen Zhou
- Philips Research North America, Cambridge, MA, USA
| | - Shuo Chen
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing 100084, China
| | | | | | - Rui Li
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing 100084, China
| | - Chun Yuan
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing 100084, China.,Department of Radiology, University of Washington, Seattle, WA, USA
| |
Collapse
|
3
|
Liu J, Sun J, Balu N, Ferguson MS, Wang J, Kerwin WS, Hippe DS, Wang A, Hatsukami TS, Yuan C. Semiautomatic carotid intraplaque hemorrhage volume measurement using 3D carotid MRI. J Magn Reson Imaging 2019; 50:1055-1062. [PMID: 30861249 DOI: 10.1002/jmri.26698] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 02/14/2019] [Accepted: 02/15/2019] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND Presence of intraplaque hemorrhage (IPH) is a known risk factor for stroke and plaque progression. Accurate and reproducible measurement of IPH volume are required for further risk stratification. PURPOSE To develop a semiautomatic method to measure carotid IPH volume. STUDY TYPE Retrospective. POPULATION Patients scheduled for carotid endarterectomy and patients with 16-79% asymptomatic carotid stenosis by ultrasound. FIELD STRENGTH 3T. SEQUENCE Simultaneous noncontrast angiography and intraplaque hemorrhage (SNAP) MRI. ASSESSMENT A semiautomated volumetric measurement of IPH using signal intensity thresholding of 3D SNAP volume was implemented. Fourteen carotid endarterectomy patients were enrolled to determine the signal intensity threshold of IPH using histology. Thirty-three patients with 16-79% asymptomatic stenosis were scanned twice within 1 month to evaluate reproducibility. The normalized SNAP intensity with the highest Youden index for predicting IPH on histology was used for thresholding. Scan-rescan reproducibility of IPH measurement was assessed using the intraclass correlation coefficient (ICC) and coefficient of variation (CV). STATISTICAL TESTS Receiver operating characteristic curve, area under the curve, Cohen's kappa, intraclass correlation coefficient, coefficient of variance (CV), and paired t-test. RESULTS IPH detection by the algorithm had substantial agreement with manual review (kappa: 0.92; 95% confidence interval [CI]: 0.83, 1.00) and moderate agreement with histology (kappa: 0.55; 95% CI: 0.34, 0.68). IPH volume measurements by the algorithm were strongly correlated with histology (Spearman's rho = 0.76, P = 0.002). IPH measurements were also reproducible, with ICCs of 0.86 (95% CI: 0.57, 0.96), 0.77 (95% CI: 0.32, 0.94), and 0.99 (95% CI: 0.93, 1.00) for maximum/mean normalized intensity and IPH volume, respectively. The corresponding CVs were 10.6%, 5.2%, and 11.8%. DATA CONCLUSION IPH volume measurements on SNAP MRI are highly reproducible using semiautomatic measurement. Level of Evidence 2 Technical Efficacy Stage 2 J. Magn. Reson. Imaging 2019;50:1055-1062.
Collapse
Affiliation(s)
- Jin Liu
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Jie Sun
- Department of Radiology, University of Washington, Seattle, Washington, USA
| | - Niranjan Balu
- Department of Radiology, University of Washington, Seattle, Washington, USA
| | - Marina S Ferguson
- Department of Radiology, University of Washington, Seattle, Washington, USA
| | - Jinnan Wang
- Department of Radiology, University of Washington, Seattle, Washington, USA
| | - William S Kerwin
- Department of Radiology, University of Washington, Seattle, Washington, USA
| | - Daniel S Hippe
- Department of Radiology, University of Washington, Seattle, Washington, USA
| | - Amy Wang
- Department of Radiology, University of Washington, Seattle, Washington, USA
| | - Thomas S Hatsukami
- Department of Surgery, University of Washington, Seattle, Washington, USA
| | - Chun Yuan
- Department of Bioengineering, University of Washington, Seattle, Washington, USA.,Department of Radiology, University of Washington, Seattle, Washington, USA
| |
Collapse
|
4
|
Daemen MJ, Ferguson MS, Gijsen FJ, Hippe DS, Kooi ME, Demarco K, van der Wal AC, Yuan C, Hatsukami TS. Carotid plaque fissure: An underestimated source of intraplaque hemorrhage. Atherosclerosis 2016; 254:102-108. [PMID: 27718372 PMCID: PMC5533085 DOI: 10.1016/j.atherosclerosis.2016.09.069] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 09/23/2016] [Accepted: 09/27/2016] [Indexed: 01/20/2023]
Abstract
Background and aims Plaque fissuring, a phenomenon morphologically distinct from the classical rupture of a thinned fibrous cap, has not been well characterized in carotid atherosclerosis. The aim of this study was to establish the prevalence of plaque fissures in advanced carotid plaques with an otherwise intact luminal surface, and to determine whether they might be a source of intraplaque hemorrhage (IPH). Methods We evaluated 244 surgically intact, ‘en bloc’ embedded, serially sectioned carotid endarterectomy specimens and included only those plaques with a grossly intact luminal surface. Results Among the 67 plaques with grossly intact luminal surface, cap fissure was present in 39 (58%) plaques. A total of 60 individual fissures were present, and longitudinally mean fissure length was 1.3 mm. Most fissures were found distal to the bifurcation (63%), proximal to the stenosis (88%), and in the posterior (opposite the flow divider) or lateral quadrants (80%). 36% of the fissures remained in the superficial third of the plaque. 52% extended from the lumen surface to the middle third of the plaque and 12% reached the outer third of the plaque on cross section. Fissures often occurred between two tissue planes and were connected to IPH (fresh: 63%; any type: 92%) and calcifications (43%). No correlation was found with patient characteristics such as symptom status, carotid stenosis, hypertension, diabetes, smoking and medications (statins or antiplatelet agents). Conclusions Plaque fissures are common in advanced carotid plaques with an otherwise grossly intact luminal surface and are associated with fresh intraplaque hemorrhage. As they occur on the interface between plaque components with different mechanical properties, further biomechanical studies are needed to unravel the underlying failure mechanisms.
Collapse
Affiliation(s)
- Mat J Daemen
- Department of Pathology, Academic Medical Center, Meibergdreef 9, 1105AZ, Amsterdam, The Netherlands.
| | - Marina S Ferguson
- Department of Radiology, University of Washington, 1959 NE Pacific Street, SS-202, Seattle, WA 98195-7117, USA
| | - Frank J Gijsen
- Biochemical Engineering, Thoraxcenter, Erasmus Medical Center, Rotterdam, PO Box 2040, 3000 CA, Rotterdam, The Netherlands
| | - Daniel S Hippe
- Department of Radiology, University of Washington, 1959 NE Pacific Street, SS-202, Seattle, WA 98195-7117, USA
| | - M Eline Kooi
- Department of Radiology, Maastricht University Medical Center, PO Box 5800, 6202 AZ, Maastricht, The Netherlands
| | - Kevin Demarco
- Walter Reed National Military Medical Center, 8901 Wisconsin Avenue, Department of Radiology, Building 9, Room 1799, Bethesda, MD 20889, USA
| | - Allard C van der Wal
- Department of Pathology, Academic Medical Center, Meibergdreef 9, 1105AZ, Amsterdam, The Netherlands
| | - Chun Yuan
- Department of Radiology, University of Washington, 1959 NE Pacific Street, SS-202, Seattle, WA 98195-7117, USA
| | - Thomas S Hatsukami
- Department of Surgery, Division of Vascular Surgery, University of Washington, Vascular Imaging Laboratory, 850 Republican Street, Brotman Building Room 124, Seattle, WA 98019, USA
| |
Collapse
|
5
|
Liu J, Balu N, Hippe DS, Ferguson MS, Martinez-Malo V, DeMarco JK, Zhu DC, Ota H, Sun J, Xu D, Kerwin WS, Hatsukami TS, Yuan C. Semi-automatic carotid intraplaque hemorrhage detection and quantification on Magnetization-Prepared Rapid Acquisition Gradient-Echo (MP-RAGE) with optimized threshold selection. J Cardiovasc Magn Reson 2016; 18:41. [PMID: 27430263 PMCID: PMC4950626 DOI: 10.1186/s12968-016-0260-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 06/25/2016] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Intraplaque hemorrhage (IPH) is associated with atherosclerosis progression and subsequent cardiovascular events. We sought to develop a semi-automatic method with an optimized threshold for carotid IPH detection and quantification on MP-RAGE images using matched histology as the gold standard. METHODS Fourteen patients scheduled for carotid endarterectomy underwent 3D MP-RAGE cardiovascular magnetic resonance (CMR) preoperatively. Presence and area of IPH were recorded using histology. Presence and area of IPH were also recorded on CMR based on intensity thresholding using three references for intensity normalization: the sternocleidomastoid muscle (SCM), the adjacent muscle and the automatically generated local median value. The optimized intensity thresholds were obtained by maximizing the Youden's index for IPH detection. Using leave-one-out cross validation, the sensitivity and specificity for IPH detection based on our proposed semi-automatic method and the agreement with histology on IPH area quantification were evaluated. RESULTS The optimized intensity thresholds for IPH detection were 1.0 times the SCM intensity, 1.6 times the adjacent muscle intensity and 2.2 times the median intensity. Using the semi-automatic method with the optimized intensity threshold, the following IPH detection and quantification performance was obtained: sensitivities up to 59, 68 and 80 %; specificities up to 85, 74 and 79 %; Pearson's correlation coefficients (IPH area measurement) up to 0.76, 0.93 and 0.90, respectively, using SCM, the adjacent muscle and the local median value for intensity normalization, after heavily calcified and small IPH were excluded. CONCLUSIONS A semi-automatic method with good performance on IPH detection and quantification can be obtained in MP-RAGE CMR, using an optimized intensity threshold comparing to the adjacent muscle. The automatically generated reference of local median value provides comparable performance and may be particularly useful for developing automatic classifiers. Use of the SCM intensity as reference is not recommended without coil sensitivity correction when surface coils are used.
Collapse
Affiliation(s)
- Jin Liu
- />University of Washington, Seattle, WA USA
| | | | | | | | | | - J. Kevin DeMarco
- />Walter Reed National Military Medical Center, Bethesda, MD USA
| | - David C. Zhu
- />Michigan State University, East Lansing, MI USA
| | | | - Jie Sun
- />University of Washington, Seattle, WA USA
| | | | | | | | - Chun Yuan
- />University of Washington, Seattle, WA USA
| |
Collapse
|
6
|
Wang J, Börnert P, Zhao H, Hippe DS, Zhao X, Balu N, Ferguson MS, Hatsukami TS, Xu J, Yuan C, Kerwin WS. Simultaneous noncontrast angiography and intraplaque hemorrhage (SNAP) imaging for carotid atherosclerotic disease evaluation. Magn Reson Med 2013; 69:337-45. [PMID: 22442116 PMCID: PMC3418400 DOI: 10.1002/mrm.24254] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2011] [Revised: 02/20/2012] [Accepted: 02/23/2012] [Indexed: 12/24/2022]
Abstract
A simultaneous noncontrast angiography and intraplaque hemorrhage (SNAP) MR imaging technique is proposed to detect both luminal stenosis and hemorrhage in atherosclerosis patients in a single scan. Thirteen patients with diagnosed carotid atherosclerotic plaque were admitted after informed consent. All scans were performed on a 3T MR imaging system with SNAP, 2D time-of-flight and magnetization-prepared 3D rapid acquisition gradient echo sequences. The SNAP sequence utilized a phase sensitive acquisition, and was designed to provide positive signals corresponding to intraplaque hemorrhage and negative signals corresponding to lumen. SNAP images were compared to time-of-flight images to evaluate lumen size measurements using linear mixed models and the intraclass correlation coefficient. Intraplaque hemorrhage identification accuracy was evaluated by comparing to magnetization-prepared 3D rapid acquisition gradient echo images using Cohen's Kappa. Diagnostic quality SNAP images were generated from all subjects. Quantitatively, the lumen size measurements by SNAP were strongly correlated (intraclass correlation coefficient = 0.96, P < 0.001) with those measured by time-of-flight. For intraplaque hemorrhage detection, strong agreement (κ = 0.82, P < 0.001) was also identified between SNAP and magnetization-prepared 3D rapid acquisition gradient echo images. In conclusion, a SNAP imaging technique was proposed and shows great promise for imaging both lumen size and carotid intraplaque hemorrhage with a single scan.
Collapse
Affiliation(s)
- Jinnan Wang
- Clinical Sites Research Program, Philips Research North America, Briarcliff Manor, New York, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Yamada K, Song Y, Sun J, Dong L, Xu D, Hippe DS, Ferguson MS, Chu B, Hatsukami TS, Chen M, Zhou C, Yuan C. High intensity signal on MIP images from routine TOF-MRA of carotid atherosclerotic plaque indicates higher volume of intraplaque hemorrhage and lipid rich necrotic core. J Cardiovasc Magn Reson 2012. [PMCID: PMC3304856 DOI: 10.1186/1532-429x-14-s1-p133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
8
|
Yamada K, Song Y, Hippe DS, Sun J, Dong L, Xu D, Ferguson MS, Chu B, Hatsukami TS, Chen M, Zhou C, Yuan C. Quantitative evaluation of high intensity signal on MIP images of carotid atherosclerotic plaques from routine TOF-MRA reveals elevated volumes of intraplaque hemorrhage and lipid rich necrotic core. J Cardiovasc Magn Reson 2012; 14:81. [PMID: 23194180 PMCID: PMC3552725 DOI: 10.1186/1532-429x-14-81] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 11/16/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Carotid intraplaque hemorrhage (IPH) and lipid rich necrotic core (LRNC) have been associated with accelerated plaque growth, luminal narrowing, future surface disruption and development of symptomatic events. The aim of this study was to evaluate the quantitative relationships between high intensity signals (HIS) in the plaque on TOF-MRA and IPH or LRNC volumes as measured by multicontrast weighted CMR. METHODS Seventy six patients with a suspected carotid artery stenosis or carotid plaque by ultrasonography underwent multicontrast carotid CMR. HIS presence and volume were measured from TOF-MRA MIP images while IPH and LRNC volumes were separately measured from multicontrast CMR. RESULTS For detecting IPH, HIS on MIP images overall had high specificity (100.0%, 95% CI: 93.0 - 100.0%) but relatively low sensitivity (32%, 95% CI: 20.8 - 47.9%). However, the sensitivity had a significant increasing relationship with underlying IPH volume (p = 0.033) and degree of stenosis (p = 0.022). Mean IPH volume was 2.7 times larger in those with presence of HIS than in those without (142.8 ± 97.7 mm(3) vs. 53.4 ± 56.3 mm(3), p = 0.014). Similarly, mean LRNC volume was 3.4 times larger in those with HIS present (379.8 ± 203.4 mm(3) vs. 111.3 ± 122.7 mm(3), p = 0.001). There was a strong correlation between the volume of the HIS region and the IPH volume measured from multicontrast CMR (r = 0.96, p < 0.001). CONCLUSION MIP images are easily reformatted from three minute, routine, clinical TOF sequences. High intensity signals in carotid plaque on TOF-MRA MIP images are associated with increased intraplaque hemorrhage and lipid-rich necrotic core volumes. The technique is most sensitive in patients with moderate to severe stenosis.
Collapse
Affiliation(s)
- Kiyofumi Yamada
- Department of Radiology, University of Washington, 815 Mercer St, Seattle, WA 98109-4325, USA
| | - Yan Song
- Department of Radiology, Beijing Hospital, Beijing, China
| | - Daniel S Hippe
- Department of Radiology, University of Washington, 815 Mercer St, Seattle, WA 98109-4325, USA
| | - Jie Sun
- Department of Radiology, University of Washington, 815 Mercer St, Seattle, WA 98109-4325, USA
| | - Li Dong
- Department of Radiology, University of Washington, 815 Mercer St, Seattle, WA 98109-4325, USA
| | - Dongxiang Xu
- Department of Radiology, University of Washington, 815 Mercer St, Seattle, WA 98109-4325, USA
| | - Marina S Ferguson
- Department of Radiology, University of Washington, 815 Mercer St, Seattle, WA 98109-4325, USA
| | - Baocheng Chu
- Department of Radiology, University of Washington, 815 Mercer St, Seattle, WA 98109-4325, USA
| | | | - Min Chen
- Department of Radiology, Beijing Hospital, Beijing, China
| | - Cheng Zhou
- Department of Radiology, Beijing Hospital, Beijing, China
| | - Chun Yuan
- Department of Radiology, University of Washington, 815 Mercer St, Seattle, WA 98109-4325, USA
| |
Collapse
|
9
|
Yamada K, Hippe DS, Underhill HR, Ferguson MS, Sun J, Chu B, Yuan C, Hatsukami TS. Abstract 429: High-Risk Features of Carotid Atherosclerotic Disease Occur Bilaterally: A Cross-Sectional, High-Resolution MRI Investigation. Arterioscler Thromb Vasc Biol 2012. [DOI: 10.1161/atvb.32.suppl_1.a429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background:
The presence of intraplaque hemorrhage (IPH), large lipid rich necrotic core (LRNC), and fibrous cap rupture (FCR) in the carotid plaque as detected by magnetic resonance imaging (MRI) has been associated with future cerebrovascular events. This study sought to determine whether these high-risk features occur symmetrically in the carotid arteries.
Methods:
Multi-contrast MR images of both carotids from 119 patients with 50- 79 % stenosis in at least one carotid artery were reviewed. Images from each artery were interpreted independent from results of the contralateral artery. Images were reviewed for presence/absence of LRNC, IPH and FCR. The maximum size of LRNC relative to the wall (%LRNC) was also recorded.
Results:
Table 1 shows the significantly increased probability of having IPH and LRNC on the contralateral side when present on one side while FCR was nearly significant. In patients with LRNC present, there was a strong correlation in size of %LRNC between sides (Pearson’s r = 0.60, p<0.001). However, there was a significant difference in mean size of %LRNC between the two sides (30.0 vs. 12.8 %, p<0.001; paired t-test).
Conclusion:
These results provide compelling evidence that high-risk features of atherosclerotic disease are prone to develop bilaterally, although not concurrently, in patients with carotid disease. Presence of unstable features in one artery appears to herald the development of similar features in the contralateral artery which suggests that the pathophysiology of the high risk plaque is governed by systemic factors.
Collapse
Affiliation(s)
| | | | | | | | - Jie Sun
- Dept of Radiology, Univ of Washington, Seattle, WA
| | - Baocheng Chu
- Dept of Radiology, Univ of Washington, Seattle, WA
| | - Chun Yuan
- Dept of Radiology, Univ of Washington, Seattle, WA
| | | |
Collapse
|
10
|
Wang J, Ferguson MS, Balu N, Yuan C, Hatsukami TS, Börnert P. Improved carotid intraplaque hemorrhage imaging using a slab-selective phase-sensitive inversion-recovery (SPI) sequence. Magn Reson Med 2011; 64:1332-40. [PMID: 20597120 DOI: 10.1002/mrm.22539] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Intraplaque hemorrhage in atherosclerotic plaques has been associated with accelerated plaque growth as well as exacerbation of clinical symptoms. The identification of intraplaque hemorrhage using magnetic resonance imaging primarily relies on the detection of methemoglobin on T(1) weighted images. Current techniques are limited by insufficient intraplaque hemorrhage-wall contrast and poor blood suppression. In this study, a slab-selective phase-sensitive inversion-recovery (SPI) technique is proposed by combining a phase-sensitive reconstruction with a T(1) weighted sequence specifically designed to achieve improved intraplaque hemorrhage imaging. The SPI sequence was optimized and then used on ex vivo plaque specimens for histology based validation and intraplaque hemorrhage-wall contrast-to-noise ratio comparison with magnetization-prepared 3D rapid acquisition gradient echo MP-RAGE. SPI and MP-RAGE were also tested on a group of atherosclerosis patients to compare in vivo intraplaque hemorrhage-wall contrast-to-noise ratio and blood suppression effectiveness. On ex vivo specimens SPI had better intraplaque hemorrhage identification accuracy and a significantly higher intraplaque hemorrhage-wall contrast-to-noise ratio (P = 0.01) than MP-RAGE. Similar results were found in the in vivo test: Slab-selective phase-sensitive inversion-recovery provided a significantly improved intraplaque hemorrhage-wall contrast-to-noise ratio (P < 0.01) and blood suppression efficiency (P < 0.01). In conclusion, SPI is a novel technique optimized for intraplaque hemorrhage detection and validated against histology. It has demonstrated its capability for improved in vivo intraplaque hemorrhage identification and blood suppression in atherosclerosis patients.
Collapse
Affiliation(s)
- Jinnan Wang
- Clinical Sites Research Program, Philips Research North America, Briarcliff Manor, Seattle, WA 98109, USA.
| | | | | | | | | | | |
Collapse
|
11
|
Ota H, Yarnykh VL, Ferguson MS, Underhill HR, Demarco JK, Zhu DC, Oikawa M, Dong L, Zhao X, Collar A, Hatsukami TS, Yuan C. Carotid intraplaque hemorrhage imaging at 3.0-T MR imaging: comparison of the diagnostic performance of three T1-weighted sequences. Radiology 2010; 254:551-63. [PMID: 20093526 DOI: 10.1148/radiol.09090535] [Citation(s) in RCA: 165] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To compare the diagnostic performances of three T1-weighted 3.0-T magnetic resonance (MR) sequences at carotid intraplaque hemorrhage (IPH) imaging, with histo logic analysis as the reference standard. MATERIALS AND METHODS Institutional review board approval and informed consent were obtained for this HIPAA-compliant study. Twenty patients scheduled for carotid endarterectomy underwent 3.0-T carotid MR imaging, including two-dimensional fast spin-echo, three-dimensional time-of-flight (TOF), and three-dimensional magnetization-prepared rapid acquisition gradient-echo (RAGE) sequences. Two reviewers blinded to the histologic findings assessed the presence, area, and signal intensity of IPH with each sequence. Detection statistics (sensitivity, specificity, and Cohen kappa values) and agreement between area measurements (Pearson correlation coefficient [r] values) were calculated for each sequence. RESULTS When all 231 available MR sections were included for analysis, the magnetization-prepared RAGE (kappa = 0.53) and fast spin-echo (kappa = 0.42) sequences yielded moderate agreement between MR and histologic measurements, while the TOF sequence yielded fair agreement (k = 0.33). However, when 47 sections with either small IPHs or heavily calcified IPHs were excluded, sensitivity, specificity, and kappa values, respectively, were 80%, 97%, and 0.80 for magnetization-prepared RAGE imaging; 70%, 92%, and 0.63 for fast spin-echo imaging; and 56%, 96%, and 0.57 for TOF imaging. MR imaging-histologic analysis correlation for IPH area was highest with magnetization-prepared RAGE imaging (r = 0.813), followed by TOF (r = 0.745) and fast spin-echo (r = 0.497) imaging. The capability of these three sequences for IPH detection appeared to be in good agreement with the quantitative contrast of IPH versus background plaque tissue. CONCLUSION The magnetization-prepared RAGE sequence, as compared with the fast spin-echo and TOF sequences, demonstrated higher diagnostic capability for the detection and quantification of IPH. Potential limitations of 3.0-T IPH MR imaging are related to hemorrhage size and coexisting calcification.
Collapse
Affiliation(s)
- Hideki Ota
- Department of Radiology, University of Washington, 815 Mercer St, Box 358050, Room 124, Seattle, WA 98109, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Li R, Zhao X, Ferguson MS, Yuan C. Distinguishing type I and type II hemorrhage by gradient echo based MR sequence in carotid atherosclerotic plaques. J Cardiovasc Magn Reson 2010. [DOI: 10.1186/1532-429x-12-s1-t12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
13
|
Dong L, Kerwin WS, Ferguson MS, Li R, Wang J, Chen H, Canton G, Hatsukami TS, Yuan C. Cardiovascular magnetic resonance in carotid atherosclerotic disease. J Cardiovasc Magn Reson 2009; 11:53. [PMID: 20003520 PMCID: PMC2806867 DOI: 10.1186/1532-429x-11-53] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Accepted: 12/15/2009] [Indexed: 11/13/2022] Open
Abstract
Atherosclerosis is a chronic, progressive, inflammatory disease affecting many vascular beds. Disease progression leads to acute cardiovascular events such as myocardial infarction, stroke and death. The diseased carotid alone is responsible for one third of the 700,000 new or recurrent strokes occurring yearly in the United States. Imaging plays an important role in the management of atherosclerosis, and cardiovascular magnetic resonance (CMR) of the carotid vessel wall is one promising modality in the evaluation of patients with carotid atherosclerotic disease. Advances in carotid vessel wall CMR allow comprehensive assessment of morphology inside the wall, contributing substantial disease-specific information beyond luminal stenosis. Although carotid vessel wall CMR has not been widely used to screen for carotid atherosclerotic disease, many trials support its potential for this indication. This review summarizes the current state of knowledge regarding carotid vessel wall CMR and its potential clinical application for management of carotid atherosclerotic disease.
Collapse
Affiliation(s)
- Li Dong
- Department of Radiology, University of Washington, Seattle, WA, USA
| | - William S Kerwin
- Department of Radiology, University of Washington, Seattle, WA, USA
| | | | - Rui Li
- Department of Radiology, University of Washington, Seattle, WA, USA
| | - Jinnan Wang
- Clinical Sites Research Program, Philips Research North America, Briarcliff Manor, NY, USA
| | - Huijun Chen
- Department of Radiology, University of Washington, Seattle, WA, USA
| | - Gador Canton
- Department of Radiology, University of Washington, Seattle, WA, USA
| | | | - Chun Yuan
- Department of Radiology, University of Washington, Seattle, WA, USA
| |
Collapse
|
14
|
Yu W, Underhill HR, Ferguson MS, Hippe DS, Hatsukami TS, Yuan C, Chu B. The added value of longitudinal black-blood cardiovascular magnetic resonance angiography in the cross sectional identification of carotid atherosclerotic ulceration. J Cardiovasc Magn Reson 2009; 11:31. [PMID: 19689816 PMCID: PMC2737539 DOI: 10.1186/1532-429x-11-31] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Accepted: 08/18/2009] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Carotid atherosclerotic ulceration is a significant source of stroke. This study evaluates the efficacy of adding longitudinal black-blood (BB) cardiovascular magnetic resonance (CMR) angiography to cross-sectional CMR images in the identification of carotid atherosclerotic ulceration. METHODS Thirty-two subjects (30 males and two females with ages between 48 and 83 years) scheduled for carotid endarterectomy were imaged on a 1.5T GE Signa scanner using multisequence [3D time-of-flight, T1, proton density, T2, contrast enhanced T1], cross-sectional CMR images and longitudinal BB CMR angiography (0.625 x 0.625 mm/pixel). Two rounds of review (round 1: cross-sectional CMR images alone and round 2: cross-sectional CMR images plus longitudinal BB CMR angiography) were conducted for the presence and volume measurements of ulceration. Ulceration was defined as a distinct depression into the plaque containing blood flow signal on cross-sectional CMR and longitudinal BB CMR angiography. RESULTS Of the 32 plaques examined by histology, 17 contained 21 ulcers. Using the longitudinal BB CMR angiography sequence in addition to the cross-sectional CMR images in round 2, the sensitivity improved to 80% for ulcers of at least 6 mm3 in volume by histology and 52.4% for all ulcers, compared to 30% and 23.8% in round 1, respectively. There was a slight decline in specificity from 88.2% to 82.3%, though both the positive and negative predictive values increased modestly from 71.4% to 78.6% and from 48.4% to 58.3%, respectively. CONCLUSION The addition of longitudinal BB CMR angiography to multisequence cross-sectional CMR images increases accuracy in the identification of carotid atherosclerotic ulceration.
Collapse
Affiliation(s)
- Wei Yu
- Department of Radiology, University of Washington, Seattle, WA, USA
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, PR China
| | | | | | - Daniel S Hippe
- Department of Radiology, University of Washington, Seattle, WA, USA
| | - Thomas S Hatsukami
- Department of Surgery, Vascular Surgery Division, University of Washington, Seattle, WA, USA
| | - Chun Yuan
- Department of Radiology, University of Washington, Seattle, WA, USA
| | - Baocheng Chu
- Department of Radiology, University of Washington, Seattle, WA, USA
| |
Collapse
|
15
|
Groen HC, Gijsen FJH, van der Lugt A, Ferguson MS, Hatsukami TS, Yuan C, van der Steen AFW, Wentzel JJ. High shear stress influences plaque vulnerability Part of the data presented in this paper were published in Stroke 2007;38:2379-81. Neth Heart J 2008; 16:280-3. [PMID: 18711619 PMCID: PMC2516295 DOI: 10.1007/bf03086163] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Shear stress of the blood at the vessel wall plays an important role in many processes in the cardiovascular system primarily focused on the regulation of vessel lumen and wall dimensions. There is ample evidence that atherosclerotic plaques are generated at low shear stress regions in the cardiovascular system, while high shear stress regions are protected. In the course of plaque progression, advanced plaques start to encroach into the lumen, and thereby start to experience high shear stress at the endothelium. Until now the consequences of high shear stress working at the endothelium of an advanced plaque are unknown. As high shear stress influences tissue regression, we hypothesised that high shear stress can destabilise the plaque by cap weakening leading to ulceration. We investigated this hypothesis in a magnetic resonance imaging (MRI) dataset of a 67-year-old woman with a plaque in the carotid artery at baseline and an ulcer at ten-month follow-up. The lumen, plaque components (lipid/necrotic core, intraplaque haemorrhage) and ulcer were reconstructed three dimensionally and the geometry at baseline was used for shear stress calculation using computational fluid dynamics. Correlation of the change in plaque composition with the shear stress at baseline showed that the ulcer was generated exclusively at the high shear stress location. In this serial MRI study we found plaque ulceration at the high shear stress location of a protruding plaque in the carotid artery. Our data suggest that high shear stress influences plaque vulnerability and therefore may become a potential parameter for predicting future events. (Neth Heart J 2008;16:280-3.).
Collapse
Affiliation(s)
- H C Groen
- Departments of Biomedical Engineering and Radiology, Erasmus MC, Rotterdam, and Interuniversity Cardiology Institute of the Netherlands, Utrecht, the Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
16
|
Saam T, Hatsukami TS, Takaya N, Chu B, Underhill H, Kerwin WS, Cai J, Ferguson MS, Yuan C. The vulnerable, or high-risk, atherosclerotic plaque: noninvasive MR imaging for characterization and assessment. Radiology 2007; 244:64-77. [PMID: 17581895 DOI: 10.1148/radiol.2441051769] [Citation(s) in RCA: 276] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
"Vulnerable" plaques are atherosclerotic plaques that have a high likelihood to cause thrombotic complications, such as myocardial infarction or stroke. Plaques that tend to progress rapidly are also considered to be vulnerable. Besides luminal stenosis, plaque composition and morphology are key determinants of the likelihood that a plaque will cause cardiovascular events. Noninvasive magnetic resonance (MR) imaging has great potential to enable characterization of atherosclerotic plaque composition and morphology and thus to help assess plaque vulnerability. A classification for clinical, as well as pathologic, evaluation of vulnerable plaques was recently put forward in which five major and five minor criteria to define vulnerable plaques were proposed. The purpose of this review is to summarize the status of MR imaging with regard to depiction of the criteria that define vulnerable plaques by using existing MR techniques. The use of MR imaging in animal models and in human disease in various vascular beds, particularly the carotid arteries, is presented.
Collapse
Affiliation(s)
- Tobias Saam
- Department of Radiology, University of Washington, Seattle, Washington, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Groen HC, Gijsen FJH, van der Lugt A, Ferguson MS, Hatsukami TS, van der Steen AFW, Yuan C, Wentzel JJ. Plaque rupture in the carotid artery is localized at the high shear stress region: a case report. Stroke 2007; 38:2379-81. [PMID: 17615365 DOI: 10.1161/strokeaha.107.484766] [Citation(s) in RCA: 160] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND PURPOSE Cerebrovascular events are related to atherosclerotic disease in the carotid arteries and are frequently caused by rupture of a vulnerable plaque. These ruptures are often observed at the upstream region of the plaque, where the wall shear stress (WSS) is considered to be highest. High WSS is known for its influence on many processes affecting tissue regression. Until now, there have been no serial studies showing the relationship between plaque rupture and WSS. Summary of Case- We investigated a serial MRI data set of a 67-year-old woman with a plaque in the carotid artery at baseline and an ulcer at 10-month follow up. The lumen, plaque components (lipid/necrotic core, intraplaque hemorrhage), and ulcer were segmented and the lumen contours at baseline were used for WSS calculation. Correlation of the change in plaque composition with the WSS at baseline showed that the ulcer was generated exclusively at the high WSS location. CONCLUSIONS In this serial MRI study, we found plaque ulceration at the high WSS location of a protruding plaque in the carotid artery. Our data suggest that high WSS influences plaque vulnerability and therefore may become a potential parameter for predicting future events.
Collapse
Affiliation(s)
- Harald C Groen
- Biomedical Engineering, Biomechanics Laboratory, Erasmus MC, CA Rotterdam, The Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Takaya N, Cai J, Ferguson MS, Yarnykh VL, Chu B, Saam T, Polissar NL, Sherwood J, Cury RC, Anders RJ, Broschat KO, Hinton D, Furie KL, Hatsukami TS, Yuan C. Intra- and interreader reproducibility of magnetic resonance imaging for quantifying the lipid-rich necrotic core is improved with gadolinium contrast enhancement. J Magn Reson Imaging 2006; 24:203-10. [PMID: 16739123 DOI: 10.1002/jmri.20599] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To test the hypothesis that intra- and interreader reproducibility for measuring the lipid-rich necrotic core (LR-NC) size is significantly improved with gadolinium (Gd) contrast-enhanced magnetic resonance imaging (CEMRI) compared to non-CEMRI. MATERIALS AND METHODS Thirty-seven individuals with >50% carotid artery stenosis underwent carotid MRI at 1.5T (pre- and postcontrast T1-weighted (T1W), T2-weighted (T2W), proton density-weighted (PDW), and three-dimensional time-of-flight (TOF) sequences). Two independent readers measured the mean area of the LR-NC from the precontrast images only, followed by a second measurement using the additional postcontrast images. One reader repeated the measurements after an interval of five months. Intra- and interreader reproducibility was analyzed by means of the intraclass correlation coefficient (ICC), coefficient of variation (CV), and standard deviation (SD). RESULTS The CV decreased from 33.7% to 8.8% for intrareader measurements of the LR-NC, and from 33.5% to 17.6% for interreader measurements. The SD was significantly smaller with CEMRI than with non-CEMRI (P = 0.003 and P = 0.006, respectively). The ICC increased from 0.94 to 0.99 and from 0.85 to 0.93 for the intra- and interreader measurements, respectively. CONCLUSION Reader reproducibility for in vivo MRI quantification of LR-NC size is significantly improved by the addition of Gd contrast in individuals with >50% carotid stenosis.
Collapse
Affiliation(s)
- Norihide Takaya
- Department of Radiology, University of Washington, Seattle, Washington, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Yuan C, Kerwin WS, Yarnykh VL, Cai J, Saam T, Chu B, Takaya N, Ferguson MS, Underhill H, Xu D, Liu F, Hatsukami TS. MRI of atherosclerosis in clinical trials. NMR Biomed 2006; 19:636-54. [PMID: 16986119 DOI: 10.1002/nbm.1065] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Magnetic resonance imaging (MRI) of the arterial wall has emerged as a viable technology for characterizing atherosclerotic lesions in vivo, especially within carotid arteries and other large vessels. This capability has facilitated the use of carotid MRI in clinical trials to evaluate therapeutic effects on atherosclerotic lesions themselves. MRI is specifically able to characterize three important aspects of the lesion: size, composition and biological activity. Lesion size, expressed as a total wall volume, may be more sensitive than maximal vessel narrowing (stenosis) as a measure of therapeutic effects, as it reflects changes along the entire length of the lesion and accounts for vessel remodeling. Lesion composition (e.g. lipid, fibrous and calcified content) may reflect therapeutic effects that do not alter lesion size or stenosis, but cause a transition from a vulnerable plaque composition to a more stable one. Biological activity, most notably inflammation, is an emerging target for imaging that is thought to destabilize plaque and which may be a systemic marker of vulnerability. The ability of MRI to characterize each of these features in carotid atherosclerotic lesions gives it the potential, under certain circumstances, to replace traditional trials involving large numbers of subjects and hard end-points--heart attacks and strokes--with smaller, shorter trials involving imaging end-points. In this review, the state of the art in MRI of atherosclerosis is presented in terms of hardware, image acquisition protocols and post-processing. Also, the results of validation studies for measuring lesion size, composition and inflammation will be summarized. Finally, the status of several clinical trials involving MRI of atherosclerosis will be reviewed.
Collapse
Affiliation(s)
- Chun Yuan
- Department of Radiology, University of Washington, Seattle, WA 98195, USA.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Kerwin WS, O'Brien KD, Ferguson MS, Polissar N, Hatsukami TS, Yuan C. Inflammation in carotid atherosclerotic plaque: a dynamic contrast-enhanced MR imaging study. Radiology 2006; 241:459-68. [PMID: 16966482 PMCID: PMC1820770 DOI: 10.1148/radiol.2412051336] [Citation(s) in RCA: 208] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
PURPOSE To prospectively evaluate if there is an association between plaque enhancement at magnetic resonance (MR) imaging and proinflammatory cardiovascular risk factors and plaque content. MATERIALS AND METHODS This study was performed with informed consent, HIPAA compliance, and institutional review board approval. Contrast agent dynamics within carotid plaques were measured in 30 patients (29 men, one woman; mean age, 67.7 years +/- 10.7 [standard deviation]) who were scheduled to undergo carotid endarterectomy. Measurements were based on kinetic modeling of images obtained at 15-second intervals during which a gadolinium-based contrast agent was injected. The time-varying signal intensities within the plaques were used to estimate the fractional plasma volume (vp) and transfer constant (Ktrans) of contrast material into the extracellular space. Pearson correlation coefficients were computed between blinded MR measurements and histologic measurements of plaque composition, including macrophages, neovasculature, necrotic core, calcification, loose matrix, and dense fibrous tissue. Correlation coefficients or mean differences were computed regarding clinical markers of cardiovascular risk. RESULTS Analyzable MR images and histologic results were obtained in 27 patients. Measurements of Ktrans correlated with macrophage (r = 0.75, P < .001), neovasculature (r = 0.71, P < .001), and loose matrix (r = 0.50, P = .01) content. Measurements of v(p) correlated with macrophage (r = 0.54, P = .004), neovasculature (r = 0.68, P < .001), and loose matrix (r = 0.42, P = .03) content. For clinical parameters, significant associations were correlated with Ktrans only, with decreased high-density lipoprotein levels (r = -0.66, P < .001) and elevated Ktrans measurements in smokers compared with nonsmokers (mean, 0.134 min(-1) vs 0.074 min(-1), respectively; P = .01). CONCLUSION The correlations between Ktrans and histologic markers of inflammation suggest that Ktrans is a quantitative and noninvasive marker of plaque inflammation, which is further supported by the correlation of Ktrans with proinflammatory cardiovascular risk factors, decreased high-density lipoprotein levels, and smoking.
Collapse
Affiliation(s)
- William S Kerwin
- Department of Radiology, Division of Cardiology, and Department of Surgery, University of Washington, 815 Mercer St, Seattle, WA 98109, USA.
| | | | | | | | | | | |
Collapse
|
21
|
Saam T, Cai J, Ma L, Cai YQ, Ferguson MS, Polissar NL, Hatsukami TS, Yuan C. Comparison of symptomatic and asymptomatic atherosclerotic carotid plaque features with in vivo MR imaging. Radiology 2006; 240:464-72. [PMID: 16864672 PMCID: PMC1797417 DOI: 10.1148/radiol.2402050390] [Citation(s) in RCA: 169] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To retrospectively determine if in vivo magnetic resonance (MR) imaging can simultaneously depict differences between symptomatic and asymptomatic carotid atherosclerotic plaque. MATERIALS AND METHODS Institutional review board approval and informed consent were obtained for this HIPAA-compliant study. Twenty-three patients (21 men, two women; mean age, 66.1 years +/- 11.0 [standard deviation]) with unilateral symptomatic carotid disease underwent 1.5-T time-of-flight MR angiography and 1.5-T T1-, intermediate-, and T2-weighted MR imaging. Both carotid arteries were reviewed. One observer recorded quantitative and morphologic information, which included measurement of the area of the lumen, artery wall, and main plaque components; fibrous cap status (thick, thin, or ruptured); American Heart Association (AHA) lesion type (types I-VIII); and location (juxtaluminal vs intraplaque) and type of hemorrhage. Plaques associated with neurologic symptoms and asymptomatic plaques were compared with Wilcoxon signed rank and McNemar tests. RESULTS Compared with asymptomatic plaques, symptomatic plaques had a higher incidence of fibrous cap rupture (P = .007), juxtaluminal hemorrhage or thrombus (P = .039), type I hemorrhage (P = .021), and complicated AHA type VI lesions (P = .004) and a lower incidence of uncomplicated AHA type IV and V lesions (P = .005). Symptomatic plaques also had larger hemorrhage (P = .003) and loose matrix (P = .014) areas and a smaller lumen area (P = .008). No significant differences between symptomatic and asymptomatic plaques were found for quantitative measurements of the lipid-rich necrotic core, calcification, and the vessel wall or for the occurrence of intraplaque hemorrhage or type II hemorrhage. CONCLUSION This study revealed significant differences between symptomatic and asymptomatic plaques in the same patient.
Collapse
Affiliation(s)
- Tobias Saam
- Department of Radiology, University of Washington, 815 Mercer St, Box 358050, Seattle, WA 98109, USA.
| | | | | | | | | | | | | | | |
Collapse
|
22
|
Abstract
OBJECTIVE To address questions about the etiology, behavior, optimal treatment, and prognosis of metastasizing pleomorphic adenoma (MPA), we undertook a review of the literature (1953-2005) and constructed a virtual series of all identified cases of MPA, metastatic lesions that are very occasionally identified in patients with a history of pleomorphic salivary adenoma and, on detailed pathological evaluation, found to exhibit all the histological hallmarks of the preceding benign lesions. DATA SOURCES A review of the English-language literature between 1953 and 2005 using MEDLINE, secondary references identified from bibliographies of pertinent articles, and a further case from one of our institutions. DATA SYNTHESIS A virtual case series was constructed and quantitatively analyzed. Forty-two patients with an average age of 33 years were identified. There were 20 male and 22 female patients. There was an overwhelming history of incomplete surgery for pleomorphic salivary adenoma. Most patients had locoregional recurrences before metastasis, and the mean presentation-to-metastasis latency was 16 years. Bone was the most common site for metastases (45%), followed by the head and neck (43%) and lung (36%). There was significant morbidity and mortality from distant disease, with 5-year disease-specific and disease-free survival of 58% and 50%, respectively. Developing distant lesions within 10 years of the primary tumor and presence of metastases in multiple sites were independent predictors of survival on Cox regression analysis. Metastasectomy conferred significant survival advantage over nonoperative treatment (log-rank analysis, P<.02). Chemotherapy and radiotherapy were of limited value. CONCLUSIONS Meticulous surgery is crucial in preventing MPA. Metastatic disease carries significant morbidity and mortality and should be treated surgically when feasible.
Collapse
Affiliation(s)
- S A R Nouraei
- Department of Otolaryngology-Head and Neck Surgery, Charing Cross Hospital, London, England.
| | | | | | | | | | | | | |
Collapse
|
23
|
Takaya N, Yuan C, Chu B, Saam T, Underhill H, Cai J, Tran N, Polissar NL, Isaac C, Ferguson MS, Garden GA, Cramer SC, Maravilla KR, Hashimoto B, Hatsukami TS. Association Between Carotid Plaque Characteristics and Subsequent Ischemic Cerebrovascular Events. Stroke 2006; 37:818-23. [PMID: 16469957 DOI: 10.1161/01.str.0000204638.91099.91] [Citation(s) in RCA: 566] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose—
MRI is able to quantify carotid plaque size and composition with good accuracy and reproducibility and provides an opportunity to prospectively examine the relationship between plaque features and subsequent cerebrovascular events. We tested the hypothesis that the characteristics of carotid plaque, as assessed by MRI, are possible predictors of future ipsilateral cerebrovascular events.
Methods—
A total of 154 consecutive subjects who initially had an asymptomatic 50% to 79% carotid stenosis by ultrasound with ≥12 months of follow-up were included in this study. Multicontrast-weighted carotid MRIs were performed at baseline, and participants were followed clinically every 3 months to identify symptoms of cerebrovascular events.
Results—
Over a mean follow-up period of 38.2 months, 12 carotid cerebrovascular events occurred ipsilateral to the index carotid artery. Cox regression analysis demonstrated a significant association between baseline MRI identification of the following plaque characteristics and subsequent symptoms during follow-up: presence of a thin or ruptured fibrous cap (hazard ratio, 17.0;
P
≤0.001), intraplaque hemorrhage (hazard ratio, 5.2;
P
=0.005), larger mean intraplaque hemorrhage area (hazard ratio for 10 mm
2
increase, 2.6;
P
=0.006), larger maximum %lipid-rich/necrotic core (hazard ratio for 10% increase, 1.6;
P
=0.004), and larger maximum wall thickness (hazard ratio for a 1-mm increase, 1.6;
P
=0.008).
Conclusions—
Among patients who initially had an asymptomatic 50% to 79% carotid stenosis, arteries with thinned or ruptured fibrous caps, intraplaque hemorrhage, larger maximum %lipid-rich/necrotic cores, and larger maximum wall thickness by MRI were associated with the occurrence of subsequent cerebrovascular events. Findings from this prospective study provide a basis for larger multicenter studies to assess the risk of plaque features for subsequent ischemic events.
Collapse
Affiliation(s)
- Norihide Takaya
- Department of Radiology, University of Washington, Seattle, WA, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Chu B, Ferguson MS, Underhill H, Takaya N, Cai J, Kliot M, Yuan C, Hatsukami TS. Images in cardiovascular medicine. Detection of carotid atherosclerotic plaque ulceration, calcification, and thrombosis by multicontrast weighted magnetic resonance imaging. Circulation 2006; 112:e3-4. [PMID: 15998688 DOI: 10.1161/circulationaha.104.494419] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Baocheng Chu
- Department of Radiology, University of Washington, 1959 NE Pacific St, Seattle, WA 98195, USA.
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Liu F, Xu D, Ferguson MS, Chu B, Saam T, Takaya N, Hatsukami TS, Yuan C, Kerwin WS. Automated in vivo segmentation of carotid plaque MRI with Morphology-Enhanced probability maps. Magn Reson Med 2006; 55:659-68. [PMID: 16470594 DOI: 10.1002/mrm.20814] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
MRI is a promising noninvasive technique for characterizing atherosclerotic plaque composition in vivo, with an end-goal of assessing plaque vulnerability. Because of limitations arising from acquisition time, achievable resolution, contrast-to-noise ratio, patient motion, and the effects of blood flow, automatically identifying plaque composition remains a challenging task in vivo. In this article, a segmentation method using maximum a posteriori probability Bayesian theory is presented that divides axial, multi-contrast-weighted images into regions of necrotic core, calcification, loose matrix, and fibrous tissue. Key advantages of the method are that it utilizes morphologic information, such as local wall thickness, and coupled active contours to limit the impact from noise and artifacts associated with in vivo imaging. In experiments involving 142 sets of multi-contrast images from 26 subjects undergoing carotid endarterectomy, segmented areas of each of these tissues per slice agreed with histologically confirmed areas with correlations (R(2)) of 0.78, 0.83, 0.41, and 0.82, respectively. In comparison, manually identifying areas blinded to histology yielded correlations of 0.71, 0.76, 0.33, and 0.78, respectively. These results show that in vivo automatic segmentation of carotid MRI is feasible and comparable to or possibly more accurate than manual review for quantifying plaque composition.
Collapse
Affiliation(s)
- Fei Liu
- Department of Radiology, University of Washington, Seattle, WA 98109, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Cai J, Hatsukami TS, Ferguson MS, Kerwin WS, Saam T, Chu B, Takaya N, Polissar NL, Yuan C. In vivo quantitative measurement of intact fibrous cap and lipid-rich necrotic core size in atherosclerotic carotid plaque: comparison of high-resolution, contrast-enhanced magnetic resonance imaging and histology. Circulation 2005; 112:3437-44. [PMID: 16301346 DOI: 10.1161/circulationaha.104.528174] [Citation(s) in RCA: 383] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND Previous studies with contrast-enhanced magnetic resonance imaging (CEMRI) have shown that the fibrous cap (FC) in atherosclerotic carotid plaques enhances with gadolinium-based contrast agents. Conversely, the lipid-rich necrotic core (LR-NC), lacking both vasculature and matrix, shows no or only slight enhancement. The goal of this study was to assess whether CEMRI can be used to accurately measure the dimensions of the intact FC and LR-NC. METHODS AND RESULTS Twenty-one patients scheduled for carotid endarterectomy were imaged with a 1.5-T scanner. Precontrast images and CEMRI were obtained. One hundred eight locations with an intact FC were matched between MRI and the excised histology specimens. Quantitative measurements of FC length along the lumen circumference, FC area, and LR-NC area were collected from CEMRI images and histology sections. Blinded comparison of corresponding MR images and histology slices showed moderate to good correlation for length (r=0.73, P<0.001) and area (r=0.80, P<0.001) of the intact FC. The mean percentage LR-NC areas (LR-NC area/wall area) measured by CEMRI and histology were 30.1% and 32.7%, respectively, and were strongly correlated across locations (r=0.87, P<0.001). CONCLUSIONS In vivo high-resolution CEMRI is capable of quantitatively measuring the dimensions of the intact FC and LR-NC. These new parameters may be useful to evaluate plaque vulnerability and provide continuous variables for characterizing the intact FC and LR-NC in progression and regression studies.
Collapse
Affiliation(s)
- Jianming Cai
- Department of Radiology, University of Washington, Seattle, WA, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Takaya N, Yuan C, Chu B, Saam T, Polissar NL, Jarvik GP, Isaac C, McDonough J, Natiello C, Small R, Ferguson MS, Hatsukami TS. Presence of Intraplaque Hemorrhage Stimulates Progression of Carotid Atherosclerotic Plaques. Circulation 2005; 111:2768-75. [PMID: 15911695 DOI: 10.1161/circulationaha.104.504167] [Citation(s) in RCA: 413] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Previous studies suggest that erythrocyte membranes from intraplaque hemorrhage into the necrotic core are a source of free cholesterol and may become a driving force in the progression of atherosclerosis. We have shown that MRI can accurately identify carotid intraplaque hemorrhage and precisely measure plaque volume. We tested the hypothesis that hemorrhage into carotid atheroma stimulates plaque progression.
Methods and Results—
Twenty-nine subjects (14 cases with intraplaque hemorrhage and 15 controls with comparably sized plaques without intraplaque hemorrhage at baseline) underwent serial carotid MRI examination with a multicontrast weighted protocol (T1, T2, proton density, and 3D time of flight) over a period of 18 months. The volumes of wall, lumen, lipid-rich necrotic core, calcification, and intraplaque hemorrhage were measured with a custom-designed image analysis tool. The percent change in wall volume (6.8% versus −0.15%;
P
=0.009) and lipid-rich necrotic core volume (28.4% versus −5.2%;
P
=0.001) was significantly higher in the hemorrhage group than in controls over the course of the study. Furthermore, those with intraplaque hemorrhage at baseline were much more likely to have new plaque hemorrhages at 18 months compared with controls (43% versus 0%;
P
=0.006).
Conclusions—
Hemorrhage into the carotid atherosclerotic plaque accelerated plaque progression in an 18-month period. Repeated bleeding into the plaque may produce a stimulus for the progression of atherosclerosis by increasing lipid core and plaque volume and creating new destabilizing factors.
Collapse
Affiliation(s)
- Norihide Takaya
- Department of Radiology, University of Washington, Seattle, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Saam TS, Ferguson MS, Yarnykh VL, Xu D, Polissar NL, Hatsukami TS, Yuan C. Identifizierung und Quantifizierung von arteriosklerotischen Plaquekomponenten der Arteria carotis mittels nichtinvasiver MRT. ROFO-FORTSCHR RONTG 2005. [DOI: 10.1055/s-2005-867756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
29
|
Saam TS, Cai JM, Cai YQ, Ma L, Ferguson MS, Polissar NL, Hatsukami TS, Yuan C. Nichtinvasives MRT differenziert zwischen symptomatischen und asymptomatischen arteriosklerotischen Plaques der Karotiden. ROFO-FORTSCHR RONTG 2005. [DOI: 10.1055/s-2005-867935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
30
|
Kampschulte A, Ferguson MS, Kerwin WS, Polissar NL, Chu B, Saam T, Hatsukami TS, Yuan C. Differentiation of Intraplaque Versus Juxtaluminal Hemorrhage/Thrombus in Advanced Human Carotid Atherosclerotic Lesions by In Vivo Magnetic Resonance Imaging. Circulation 2004; 110:3239-44. [PMID: 15533871 DOI: 10.1161/01.cir.0000147287.23741.9a] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Intraplaque hemorrhage and juxtaluminal hemorrhage/thrombus may differ in cause and clinical implications. This study tested the hypothesis that MRI can distinguish between intraplaque hemorrhage and juxtaluminal hemorrhage/thrombus and investigated the association between hemorrhage and underlying lesion types.
Methods and Results—
Twenty-six patients scheduled for carotid endarterectomy were imaged with a 1.5-T GE scanner by a multicontrast-weighted MRI technique. Hemorrhages were identified with previously established MRI criteria, and differentiations were made between intraplaque and juxtaluminal hemorrhage/thrombus. Corresponding histology was used to confirm the magnetic resonance findings. Tissues underlying areas of hemorrhage/thrombus were histologically categorized according to modified American Heart Association criteria. Of 190 matched sections, 140 contained areas of hemorrhage by histology, of which MRI correctly detected 134. The sensitivity and specificity for MRI to correctly identify cross sections that contained hemorrhage were 96% and 82%, respectively. Furthermore, MRI was able to distinguish juxtaluminal hemorrhage/thrombus from intraplaque hemorrhage with an accuracy of 96%. The distribution of lesion types underlying hemorrhages differed significantly (
P
=0.004). Intraplaque hemorrhage had an underlying lipid-rich type IV/V lesion in 55% of histological sections, whereas juxtaluminal hemorrhage/thrombus had an underlying calcified lesion type VII in 70% of sections.
Conclusions—
In vivo high-resolution MRI can detect and differentiate intraplaque hemorrhage from juxtaluminal hemorrhage/thrombus with good accuracy. The association of hemorrhage and lesion types suggests potential differences in origin. Noninvasive MRI therefore provides a possible tool for prospectively studying differences in origin of plaque hemorrhage and the association of plaque progression and instability.
Collapse
Affiliation(s)
- A Kampschulte
- Department of Radiology, University of Washington, Seattle, Wash 98195, USA
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Saam T, Ferguson MS, Yarnykh VL, Takaya N, Xu D, Polissar NL, Hatsukami TS, Yuan C. Quantitative evaluation of carotid plaque composition by in vivo MRI. Arterioscler Thromb Vasc Biol 2004; 25:234-9. [PMID: 15528475 DOI: 10.1161/01.atv.0000149867.61851.31] [Citation(s) in RCA: 459] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE This study evaluates the ability of MRI to quantify all major carotid atherosclerotic plaque components in vivo. METHODS AND RESULTS Thirty-one subjects scheduled for carotid endarterectomy were imaged with a 1.5T scanner using time-of-flight-, T1-, proton density-, and T2-weighted images. A total of 214 MR imaging locations were matched to corresponding histology sections. For MRI and histology, area measurements of the major plaque components such as lipid-rich/necrotic core (LR/NC), calcification, loose matrix, and dense (fibrous) tissue were recorded as percentages of the total wall area. Intraclass correlation coefficients (ICCs) were computed to determine intrareader and inter-reader reproducibility. MRI measurements of plaque composition were statistically equivalent to those of histology for the LR/NC (23.7 versus 20.3%; P=0.1), loose matrix (5.1 versus 6.3%; P=0.1), and dense (fibrous) tissue (66.3% versus 64%; P=0.4). Calcification differed significantly when measured as a percentage of wall area (9.4 versus 5%; P<0.001). Intrareader and inter-reader reproducibility was good to excellent for all tissue components, with ICCs ranging from 0.73 to 0.95. CONCLUSIONS MRI-based tissue quantification is accurate and reproducible. This application can be used in therapeutic clinical trials and in prospective longitudinal studies to examine carotid atherosclerotic plaque progression and regression.
Collapse
Affiliation(s)
- T Saam
- Department of Radiology, University of Washington, Seattle, Wash, USA
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Chu B, Kampschulte A, Ferguson MS, Kerwin WS, Yarnykh VL, O'Brien KD, Polissar NL, Hatsukami TS, Yuan C. Hemorrhage in the atherosclerotic carotid plaque: a high-resolution MRI study. Stroke 2004; 35:1079-84. [PMID: 15060318 DOI: 10.1161/01.str.0000125856.25309.86] [Citation(s) in RCA: 347] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE High-resolution, multicontrast magnetic resonance imaging (MRI) has developed into an effective tool for the identification of carotid atherosclerotic plaque components, such as necrotic core, fibrous matrix, and hemorrhage/thrombus. Factors that may lead to plaque instability are lipid content, thin fibrous cap, and intraplaque hemorrhage. Determining the age of intraplaque hemorrhage can give insight to the history and current condition of the biologically active plaque. The aim of this study was to develop criteria for the identification of the stages of intraplaque hemorrhage using high-resolution MRI. METHODS Twenty-seven patients, scheduled for carotid endarterectomy (CEA), were imaged on a 1.5-T GE SIGNA scanner (sequences: 3-dimensional time of flight, double-inversion recovery, T1-weighted (T1W), PDW and T2W). Two readers, blinded to histology, reviewed MR images and grouped hemorrhage into fresh, recent, and old categories using a modified cerebral hemorrhage criteria. The CEA specimens were serially sectioned and graded as to presence and stage of hemorrhage. RESULTS Hemorrhage was histologically identified and staged in 145/189 (77%) of carotid artery plaque locations. MRI detected intraplaque hemorrhage with high sensitivity (90%) but moderate specificity (74%). Moderate agreement in classifying stages occurred between MRI and histology (Cohen kappa=0.7, 95% CI: 0.5 to 0.8 for reviewer 1 and 0.4, 95% CI: 0.2 to 0.6 for reviewer 2), with moderate agreement between the 2 MRI readers (kappa=0.4, 95% CI: 0.3 to 0.6). CONCLUSIONS Multicontrast MRI can detect and classify carotid intraplaque hemorrhage with high sensitivity and moderate specificity.
Collapse
Affiliation(s)
- Baocheng Chu
- Department of Radiology, University of Washington, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Mitsumori LM, Hatsukami TS, Ferguson MS, Kerwin WS, Cai J, Yuan C. In vivo accuracy of multisequence MR imaging for identifying unstable fibrous caps in advanced human carotid plaques. J Magn Reson Imaging 2003; 17:410-20. [PMID: 12655579 DOI: 10.1002/jmri.10264] [Citation(s) in RCA: 176] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To evaluate the in vivo accuracy of a multisequence MRI technique for prospectively identifying one feature of the vulnerable plaque-an unstable fibrous cap-in human carotid atherosclerosis. MATERIALS AND METHODS The carotid arteries of 18 endarterectomy patients were preoperatively imaged in a 1.5 T scanner using a multisequence protocol that generated four contrast weightings (3D time of flight (ToF), T1, proton density (PD), and T2) at each slice location. With the use of previously published MR criteria, the images of the vessel wall were first examined for evidence of an unstable fibrous cap. The imaging findings were then correlated with the histology from the surgical specimens. RESULTS A blinded review of the MR findings with the histologic state of the fibrous cap revealed that 1). assessing the preoperative appearance of the fibrous cap has a high test sensitivity (0.81) and specificity (0.90) for identifying an unstable cap in vivo; and 2). the availability of different contrast weightings facilitated image interpretation when intimal calcifications or flow artifacts obscured the lumen surface. CONCLUSION Multisequence MRI can accurately characterize the in vivo state of the fibrous cap. This finding supports the use of these noninvasive techniques to prospectively identify vulnerable plaques.
Collapse
Affiliation(s)
- Lee M Mitsumori
- Department of Radiology, University of Washington, Seattle, Washington 98195, USA
| | | | | | | | | | | |
Collapse
|
34
|
Abstract
BACKGROUND Recent studies demonstrated that in vivo and ex vivo MRI can characterize the components of the carotid atherosclerotic plaque, such as fibrous tissue, lipid/necrotic core, calcium, hemorrhage, and thrombus. The purpose of this study was to determine whether in vivo high-resolution multicontrast MRI could accurately classify human carotid atherosclerotic plaque according to the American Heart Association classification. METHODS AND RESULTS Sixty consecutive patients (mean age 70 years; 54 males) scheduled for carotid endarterectomy were imaged with a 1.5-T scanner after informed consent was obtained. A standardized protocol was used to obtain 4 different contrast-weighted images (time of flight and T1-, PD-, and T2-weighted) of the carotid arteries. Best voxel size was 0.25x0.25x1 mm3. Carotid plaques were removed intact and processed for histological examination. Both MR images and histological sections were independently reviewed, categorized, and compared. Overall, the classification obtained by MRI and the American Heart Association classifications showed good agreement, with Cohen's kappa (95% CI) of 0.74 (0.67 to 0.82) and weighted kappa of 0.79. The sensitivity and specificity, respectively, of MRI classification were as follows: type I-II lesions, 67% and 100%; type III lesions, 81% and 98%; type IV-V lesions, 84% and 90%; type VI lesions, 82% and 91%; type VII lesions, 80% and 94%; and type VIII lesions, 56% and 100%. CONCLUSIONS In vivo high-resolution multicontrast MRI is capable of classifying intermediate to advanced atherosclerotic lesions in the human carotid artery and is also capable of distinguishing advanced lesions from early and intermediate atherosclerotic plaque.
Collapse
Affiliation(s)
- Jian-Ming Cai
- Department of Radiology, University of Washington, Seattle, Wash 98195-7115, USA
| | | | | | | | | | | |
Collapse
|
35
|
Yuan C, Zhang SX, Polissar NL, Echelard D, Ortiz G, Davis JW, Ellington E, Ferguson MS, Hatsukami TS. Identification of fibrous cap rupture with magnetic resonance imaging is highly associated with recent transient ischemic attack or stroke. Circulation 2002; 105:181-5. [PMID: 11790698 DOI: 10.1161/hc0202.102121] [Citation(s) in RCA: 272] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND High-resolution MRI has been shown to be capable of distinguishing intact, thick fibrous caps from thin and ruptured caps in human carotid atherosclerosis in vivo. The aim of this study was to determine whether MRI identification of fibrous cap thinning or rupture is associated with a history of recent transient ischemic attack (TIA) or stroke. METHODS AND RESULTS Fifty-three consecutive patients (mean age, 71 years; 49 male) scheduled for carotid endarterectomy were recruited after obtaining informed consent. Twenty-eight subjects had a recent history of TIA or stroke on the side appropriate to the index carotid lesion, and 25 were asymptomatic. Preoperative carotid MRI was performed in a 1.5-T GE Signa scanner that generated T(1)-, PD-, and T(2)-weighted and three-dimensional time-of-flight images. Using previously reported MRI criteria, the fibrous cap was categorized as intact-thick, intact-thin, or ruptured for each carotid plaque by blinded review. There was a strong and statistically significant trend showing a higher percentage of symptomatic patients for ruptured caps (70%) compared with thick caps (9%) (P=0.001 Mann-Whitney test for cap status versus symptoms). Compared with patients with thick fibrous caps, patients with ruptured caps were 23 times more likely to have had a recent TIA or stroke (95% CI=3, 210). CONCLUSIONS MRI identification of a ruptured fibrous cap is highly associated with a recent history of TIA or stroke. Ongoing prospective studies will determine the predictive value fibrous cap characteristics, as visualized by MRI, for risk of subsequent ischemic events.
Collapse
Affiliation(s)
- Chun Yuan
- Department of Radiology, University of Washington, Seattle 98195, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Yuan C, Kerwin WS, Ferguson MS, Polissar N, Zhang S, Cai J, Hatsukami TS. Contrast-enhanced high resolution MRI for atherosclerotic carotid artery tissue characterization. J Magn Reson Imaging 2002; 15:62-7. [PMID: 11793458 DOI: 10.1002/jmri.10030] [Citation(s) in RCA: 336] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
PURPOSE To determine if a gadolinium-based contrast agent provides additional information for characterization of human plaque tissues, particularly neovasculature. Although high-resolution magnetic resonance imaging (MRI) has been used to identify plaque constituents in advanced atherosclerosis, some constituents, such as neovascularized tissue, defy detection. MATERIALS AND METHODS Non-contrast-enhanced carotid artery images from 18 patients scheduled for carotid endarterectomy and two normal volunteers were used to identify regions of fibrous tissue, necrotic core, or calcification, using established criteria. Then, the percent change in T1-weighted images after contrast enhancement was calculated for each region. RESULTS There were statistically significant differences in mean intensity change between tissues, with the largest increase for fibrous tissue (79.5%) and the smallest for necrotic core (28.6%). Additionally, histological analysis showed that a subset of fibrous regions rich in plaque neovascularization could be identified using a threshold of 80% enhancement (sensitivity = 76%, specificity = 79%). CONCLUSION The ability of contrast-enhanced MRI to identify neovascularization and potentially improve differentiation of necrotic core from fibrous tissue further establishes MRI as a viable tool for in vivo study of atherosclerotic plaque.
Collapse
Affiliation(s)
- Chun Yuan
- University of Washington, School of Medicine, Seattle, Washington 98195-7115, USA.
| | | | | | | | | | | | | |
Collapse
|
37
|
Yuan C, Mitsumori LM, Ferguson MS, Polissar NL, Echelard D, Ortiz G, Small R, Davies JW, Kerwin WS, Hatsukami TS. In vivo accuracy of multispectral magnetic resonance imaging for identifying lipid-rich necrotic cores and intraplaque hemorrhage in advanced human carotid plaques. Circulation 2001; 104:2051-6. [PMID: 11673345 DOI: 10.1161/hc4201.097839] [Citation(s) in RCA: 528] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND High-resolution MRI has been shown to be capable of identifying plaque constituents, such as the necrotic core and intraplaque hemorrhage, in human carotid atherosclerosis. The purpose of this study was to evaluate differential contrast-weighted images, specifically a multispectral MR technique, to improve the accuracy of identifying the lipid-rich necrotic core and acute intraplaque hemorrhage in vivo. METHODS AND RESULTS Eighteen patients scheduled for carotid endarterectomy underwent a preoperative carotid MRI examination in a 1.5-T GE Signa scanner using a protocol that generated 4 contrast weightings (T1, T2, proton density, and 3D time of flight). MR images of the vessel wall were examined for the presence of a lipid-rich necrotic core and/or intraplaque hemorrhage. Ninety cross sections were compared with matched histological sections of the excised specimen in a double-blinded fashion. Overall accuracy (95% CI) of multispectral MRI was 87% (80% to 94%), sensitivity was 85% (78% to 92%), and specificity was 92% (86% to 98%). There was good agreement between MRI and histological findings, with a value of kappa=0.69 (0.53 to 0.85). CONCLUSIONS Multispectral MRI can identify the lipid-rich necrotic core in human carotid atherosclerosis in vivo with high sensitivity and specificity. This MRI technique provides a noninvasive tool to study the pathogenesis and natural history of carotid atherosclerosis. Furthermore, it will permit a direct assessment of the effect of pharmacological therapy, such as aggressive lipid lowering, on plaque lipid composition.
Collapse
Affiliation(s)
- C Yuan
- Department of Radiology, University of Washington, Seattle, WA 98195, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Abstract
Columbia-Rambouillet cross-bred sheep were used to study the revascularization and ligamentization process of anterior cruciate ligament (ACL) reconstruction over a 6-month period using basic histology, immunohistochemistry, and electron microscopy. The reconstruction technique studied was a quadruple-hamstring, interference screw fixation technique. Further, these specimens, after retrieval at 6, 12, and 26 weeks, were compared with human arthroscopic 'second looks' and with 10 en bloc specimens obtained when a cruciate-sacrificing total knee replacement was performed. The study showed that, with this reconstruction technique, Sharpey's fibers were seen at 6 weeks in both sheep and human specimens. The intratunnel specimens showed proliferative chondrification, then ossification of the matrix. Intra-articular neovascularization, ligamentization, and junction ossification occurred. Myoblasts or smooth muscle cells appear to mediate the ligamentization as evidenced in electron microscopy by proliferate collagen manufacture. These myoblasts were seen in both the healing sheep and human second looks, but not seen in mature ACL grafts or in normal ACLs. At 6 months postoperatively, the sheep ACL reconstruction appeared clinically, histologically, and immunohistochemically indistinguishable from the normal sheep ACL. A correlation of this work with published animal studies in which biomechanical testing was performed and with human 'second looks' would imply that an ACL reconstruction may be vulnerable during this period of neovascularization and ligamentization.
Collapse
|
39
|
von Ingersleben G, Schmiedl UP, Hatsukami TS, Nelson JA, Subramaniam DS, Ferguson MS, Yuan C. Characterization of atherosclerotic plaques at the carotid bifurcation: correlation of high-resolution MR imaging with histologic analysis--preliminary study. Radiographics 1997; 17:1417-23. [PMID: 9397455 DOI: 10.1148/radiographics.17.6.9397455] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The clinical symptoms and morbidity that result from carotid artery disease, the primary cause of stroke, are mainly due to plaque ulceration, thrombosis, intraplaque hemorrhage, and thinned fibrous caps. The contents of atherosclerotic plaques of the carotid artery can be determined with in vivo high-resolution magnetic resonance imaging with flow suppression. Eight patients scheduled to undergo endarterectomy and four healthy volunteers were imaged with a 1.5-T imager and custom-made carotid phased-array coils. T1-weighted spin-echo images and cardiac-gated proton-density--weighted fast spin-echo images were acquired. In vivo imaging findings as determined by three radiologists were correlated with ex vivo imaging and histologic findings. Among the eight plaque specimens, regions of hemorrhage, calcium, lipid deposits, and fibrous plaques were identified on T1- and proton-density-weighted images. Calcium and lipid deposits were detectable on both T1- and proton-density--weighted images. Hemorrhage and fibrous plaques were better demonstrated on proton-density--weighted images.
Collapse
Affiliation(s)
- G von Ingersleben
- Department of Radiology, University of Washington, Seattle 98195-7115, USA
| | | | | | | | | | | | | |
Collapse
|
40
|
Abstract
BACKGROUND AND PURPOSE Studies have suggested that B-mode ultrasonography can be used to determine carotid plaque composition and that specific plaque characteristics are associated with a worse clinical outcome. However, histological studies examining the relationship between carotid plaque morphology and clinical outcome have reported conflicting findings. Furthermore, few investigators have described plaque morphology in quantifiable terms. This study examines the association between the volume of carotid plaque constituents and preoperative ischemic neurological symptoms. Constituents examined were chosen based on their potential for identification by current diagnostic imaging modalities such as ultrasound or MRI. METHODS Atherosclerotic plaques from 43 patients undergoing carotid endarterectomy were examined histologically, with sections obtained every 0.5 to 1 mm. The lesions were examined for the presence and quantity of fibrous intimal tissue, intraplaque hemorrhage, lipid core, necrotic plaque core, and calcification. The quantity of each constituent was compared in plaques removed from symptomatic patients with those excised from asymptomatic individuals. Differences were analyzed with a Kolmogorov-Smirnov statistic. RESULTS There was no difference between plaques removed from asymptomatic and symptomatic patients with regard to the presence and volume of fibrous intimal tissue, intraplaque hemorrhage, the lipid core, the necrotic core, or calcification. CONCLUSIONS In patients with highly stenotic carotid lesions who are undergoing carotid endarterectomy, gross plaque composition is similar regardless of preoperative symptom status. Given this similarity, it is unlikely that differences in the volume of intraplaque hemorrhage, lipid core, necrotic core, or calcification in atherosclerotic carotid plaques explain their embolic history.
Collapse
Affiliation(s)
- T S Hatsukami
- Seattle Veterans Affairs Medical Center, WA 98108, USA.
| | | | | | | | | | | | | | | |
Collapse
|
41
|
Wildy KS, Yuan C, Tsuruda JS, Ferguson MS, Wen N, Subramaniam DS, Strandness DE. Atherosclerosis of the carotid artery: evaluation by magnetic resonance angiography. J Magn Reson Imaging 1996; 6:726-32. [PMID: 8890010 DOI: 10.1002/jmri.1880060505] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Carotid artery atherosclerotic plaques (APs) can lead to brain ischemia, an event shown to correlate with both the degree of stenosis and the composition of the AP. Currently, accurate estimates of stenosis can be obtained by either x-ray angiography or three-dimensional time-of-flight (TOF) magnetic resonance angiography (MRA). Our purpose was to determine whether three-dimensional TOF MRA images could also provide information on plaque location, morphology, and composition. Seven pre-endarterectomy patients underwent three-dimensional TOF MRA. After endarterectomy, plaque histology was evaluated. Three-dimensional TOF MRA images contained sufficient soft tissue contrast to differentiate the plaques from the surrounding tissues in all cases. Estimation of plaque morphology had 80% correlation with histology. Finally, intraplaque hemorrhage and calcification were deplicted as regions of moderately high and very low intensity, respectively. These preliminary results suggest that three-dimensional TOF MRA may be useful in studying the development and progression of carotid atherosclerosis.
Collapse
Affiliation(s)
- K S Wildy
- Department of Radiology, University of Washington School of Medicine, Seattle 98195, USA
| | | | | | | | | | | | | |
Collapse
|
42
|
Yuan C, Murakami JW, Hayes CE, Tsuruda JS, Hatsukami TS, Wildy KS, Ferguson MS, Strandness DE. Phased-array magnetic resonance imaging of the carotid artery bifurcation: preliminary results in healthy volunteers and a patient with atherosclerotic disease. J Magn Reson Imaging 1995; 5:561-5. [PMID: 8574042 DOI: 10.1002/jmri.1880050515] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
A high resolution MR imaging technique using a custom designed flexible phased-array surface coil was developed to examine the wall of the carotid artery bifurcation in vivo. The phased-array consisted of two overlapping coils which increased the image signal-to-noise ratio at the depth of the carotid artery by approximately 70%, relative to a similarly sized single loop coil. The imaging protocol included a 2D T1-weighted (T1W) spin-echo scan and cardiac gated T2-weighted and proton density-weighted (PDW) fast spin-echo (FSE) scans. Images were obtained of six healthy volunteers and of one patient with known atherosclerotic disease several days before carotid endarterectomy. On T1W and PDW images of the healthy volunteers, the carotid arterial wall appeared to be comprised of two concentric rings; a high signal inner ring and a lower signal outer ring. The MR images of the patient revealed a calcified carotid bifurcation plaque which was confirmed during surgery. The endarterectomy specimen was imaged in vitro with MR and then sectioned histologically for correlation with the patients in vivo images. Our preliminary findings indicate that a high resolution technique may provide a noninvasive technique to study atherosclerosis of the carotid bifurcation.
Collapse
Affiliation(s)
- C Yuan
- Department of Radiology, University of Washington, Seattle 98195, USA
| | | | | | | | | | | | | | | |
Collapse
|
43
|
Thackray BD, Burns DH, Ferguson MS, Gordon D, Beach KW, Hatsukami T, Detmer PR, Primozich JF, Strandness DE. A new method for studying plaque morphology. Am J Card Imaging 1995; 9:149-56. [PMID: 7549354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A histologic method was developed for three-dimensional (3-D) analysis of atherosclerotic plaques removed from the carotid bifurcation during endarterectomy. By sectioning the plaque at frequent intervals (0.5 to 1.0 mm), it is possible to obtain important information on plaque constituents with regard to their volume and distribution within the lesion. These data from each section are combined with those from other sections and displayed in a 3-D format for the entire length of the lesion. The tissues making up each of the 10 carotid plaques were outlined and digitized for each histologic section by position along the lesion. From the areas outlined a 3-D model was created by a computer-aided design program. Quantitative information on tissue distribution within the plaque was measured. Fibrous tissue constituted between 35% and 70% of plaque volume; loose necrosis from 0.5% to 30% of the plaque and thrombus occupied, at a maximum, 10% even though if was present in six of the 10 plaques. To investigate the distribution of constituents about the long axis, measurements were also made from each of the four quadrants of each section. The reproducibility of the measurements of three sets of sections at 10-mm separation showed that estimates of the amount of some constituents were very reproducible whereas others had considerable variation related to the small volume they occupied within the lesion. By generating a complete 3-D reproduction of the contents of atherosclerotic plaques, it may be possible to identify those features of the plaque that are most responsible for the development of ischemic events.
Collapse
Affiliation(s)
- B D Thackray
- Department of Bioengineering, University of Washington School of Medicine, Seattle 98195, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Yuan C, Tsuruda JS, Beach KN, Hayes CE, Ferguson MS, Alpers CE, Foo TK, Strandness DE. Techniques for high-resolution MR imaging of atherosclerotic plaque. J Magn Reson Imaging 1994; 4:43-9. [PMID: 8148555 DOI: 10.1002/jmri.1880040111] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Atherosclerotic cardiovascular disease is the most common cause of death in the United States. Investigation of atherosclerotic plaque morphology and composition is important because the findings may be useful in predicting prognosis or response to therapy. This study presents high-resolution magnetic resonance (MR) imaging techniques developed on a 1.5-T whole-body imager with a custom-built surface coil, for characterizing the composition and morphology of plaque removed at carotid endarterectomy. The initial comparison of MR imaging and histologic results showed good correlation. In conjunction with MR angiography, these techniques could be used in in vivo imaging to define the size, location, and contents of atherosclerotic plaque at the carotid bifurcation.
Collapse
Affiliation(s)
- C Yuan
- Department of Radiology, University of Washington, Seattle 98195
| | | | | | | | | | | | | | | |
Collapse
|
45
|
Hatsukami TS, Thackray BD, Primozich JF, Ferguson MS, Burns DH, Beach KW, Detmer PR, Alpers C, Gordon D, Strandness DE. Echolucent regions in carotid plaque: preliminary analysis comparing three-dimensional histologic reconstructions to sonographic findings. Ultrasound Med Biol 1994; 20:743-749. [PMID: 7863563 DOI: 10.1016/0301-5629(94)90031-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
This study compares sonographic and histologic findings within defined spatial regions in carotid artery plaque, using computer generated three-dimensional reconstructions. Twenty-four patients (14 asymptomatic, 10 symptomatic) with angiographically documented 70% to 99% carotid artery stenosis were examined with ultrasonic B-mode imaging prior to endarterectomy. Using a standardized protocol for instrument set-up and scanning technique, echolucent regions in the plaque were identified. After endarterectomy, each plaque was sectioned at 0.5 to 1.0 millimeter increments throughout its length. Sites containing intraplaque hemorrhage, cholesterol clefts, foam cells, necrotic cores, dense calcification and speckled calcification were identified. These areas were outlined on a template, digitized and imported into a computer program that created three-dimensional reconstructions of the histologic findings. Each carotid plaque was divided into quadrants for analysis: (1) lateral wall proximal to the common carotid bifurcation (flow divider); (2) medial wall proximal to the flow divider; (3) lateral wall distal to the flow divider; and (4) medial wall distal to the flow divider. The odds of finding intraplaque hemorrhage, foam cells, necrotic cores and speckled calcification were significantly higher in quadrants with an echolucent region identified by ultrasonography (odds ratio (95% confidence interval) for intraplaque hemorrhage = 3.5 (1.4-8.6); foam cells = 4.0 (1.6-9.9); necrotic cores = 3.2 (1.2-8.4); speckled calcification = 4.0 (1.6-9.8). This preliminary analysis demonstrates the potential of these newly developed techniques for comparing ultrasonic imaging to histology.
Collapse
Affiliation(s)
- T S Hatsukami
- Department of Surgery, University of Washington, Seattle
| | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Beach KW, Hatsukami T, Detmer PR, Primozich JF, Ferguson MS, Gordon D, Alpers CE, Burns DH, Thackray BD, Strandness DE. Carotid artery intraplaque hemorrhage and stenotic velocity. Stroke 1993; 24:314-9. [PMID: 8421835 DOI: 10.1161/01.str.24.2.314] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND AND PURPOSE One of the proposed mechanisms for sudden expansion of a carotid bifurcation plaque is hemorrhage within the lesion. It has been postulated that the sudden increase in plaque size will acutely reduce blood flow to the ipsilateral hemisphere and induce either a transient ischemic attack or a stroke. In this study, the relation between peak systolic velocity at the site of narrowing and its potential role in the development of intraplaque hemorrhage were investigated. METHODS Ten patients who had carotid endarterectomy were examined by duplex Doppler sonography before surgery to determine the peak systolic velocity at the site of maximal narrowing. The excised carotid plaques were sectioned at 1-mm intervals and examined for histological evidence of intraplaque hemorrhage. The recorded peak systolic velocities in patients with intraplaque hemorrhage were compared with the velocities in cases in which no hemorrhage was identified. RESULTS Five of the ten patients had intraplaque hemorrhage. Four of the five patients with intraplaque hemorrhage had a peak systolic velocity of > 420 cm/sec and diastolic velocities of > 160 cm/sec; none of the patients without intraplaque hemorrhage had such high values. CONCLUSIONS Peak systolic velocity is significantly higher in patients with intraplaque hemorrhage. The specificity and sensitivity of a peak systolic velocity of > 420 cm/sec in predicting intraplaque hemorrhage remains to be determined.
Collapse
Affiliation(s)
- K W Beach
- Department of Surgery, University of Washington, Seattle 98195
| | | | | | | | | | | | | | | | | | | |
Collapse
|