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Zhu C, Wang X, Chen S, Teng Z, Bai C, Huang X, Xia M, Shao Z, Gu Z, Sun P. Complex carotid artery segmentation in multi-contrast MR sequences by improved optimal surface graph cuts based on flow line learning. Med Biol Eng Comput 2022; 60:2693-2706. [DOI: 10.1007/s11517-022-02622-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 04/28/2022] [Indexed: 11/30/2022]
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Zhu C, Wang X, Teng Z, Chen S, Huang X, Xia M, Mao L, Bai C. Cascaded residual U-net for fully automatic segmentation of 3D carotid artery in high-resolution multi-contrast MR images. Phys Med Biol 2021; 66:045033. [PMID: 33333499 DOI: 10.1088/1361-6560/abd4bb] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Accurate and automatic carotid artery segmentation for magnetic resonance (MR) images is eagerly expected, which can greatly assist a comprehensive study of atherosclerosis and accelerate the translation. Although many efforts have been made, identification of the inner lumen and outer wall in diseased vessels is still a challenging task due to complex vascular deformation, blurred wall boundary, and confusing componential expression. In this paper, we introduce a novel fully automatic 3D framework for simultaneously segmenting the carotid artery from high-resolution multi-contrast MR sequences based on deep learning. First, an optimal channel fitting structure is designed for identity mapping, and a novel 3D residual U-net is used as a basic network. Second, high-resolution MR images are trained using both patch-level and global-level strategies, and the two pre-segmentation results are optimized based on structural characteristics. Third, the optimized pre-segmentation results are cascaded with the patch-cropped MR volume data and trained to segment the carotid lumen and wall. Extensive experiments demonstrate the proposed method outperforms the state-of-the-art 3D Unet-based segmentation models.
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Affiliation(s)
- Chenglu Zhu
- College of Computer Science and Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 310023 People's Republic of China
| | - Xiaoyan Wang
- College of Computer Science and Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 310023 People's Republic of China
| | - Zhongzhao Teng
- University Department of Radiology, University of Cambridge, Cambridge, CB2 0QQ, United Kingdom
| | - Shengyong Chen
- Computer Science and Engineering, Tianjin University of Technology, Tianjin 300384, People's Republic of China
| | - Xiaojie Huang
- The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, People's Republic of China
| | - Ming Xia
- College of Computer Science and Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 310023 People's Republic of China
| | - Lizhao Mao
- College of Computer Science and Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 310023 People's Republic of China
| | - Cong Bai
- College of Computer Science and Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 310023 People's Republic of China
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Kok AM, van der Lugt A, Verhagen HJM, van der Steen AFW, Wentzel JJ, Gijsen FJH. Model-based cap thickness and peak cap stress prediction for carotid MRI. J Biomech 2017; 60:175-180. [PMID: 28736079 PMCID: PMC5754323 DOI: 10.1016/j.jbiomech.2017.06.034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 06/07/2017] [Accepted: 06/20/2017] [Indexed: 11/21/2022]
Abstract
A rupture-prone carotid plaque can potentially be identified by calculating the peak cap stress (PCS). For these calculations, plaque geometry from MRI is often used. Unfortunately, MRI is hampered by a low resolution, leading to an overestimation of cap thickness and an underestimation of PCS. We developed a model to reconstruct the cap based on plaque geometry to better predict cap thickness and PCS. We used histological stained plaques from 34 patients. These plaques were segmented and served as the ground truth. Sections of these plaques contained 93 necrotic cores with a cap thickness <0.62mm which were used to generate a geometry-based model. The histological data was used to simulate in vivo MRI images, which were manually delineated by three experienced MRI readers. Caps below the MRI resolution (n=31) were (digitally removed and) reconstructed according to the geometry-based model. Cap thickness and PCS were determined for the ground truth, readers, and reconstructed geometries. Cap thickness was 0.07mm for the ground truth, 0.23mm for the readers, and 0.12mm for the reconstructed geometries. The model predicts cap thickness significantly better than the readers. PCS was 464kPa for the ground truth, 262kPa for the readers and 384kPa for the reconstructed geometries. The model did not predict the PCS significantly better than the readers. The geometry-based model provided a significant improvement for cap thickness estimation and can potentially help in rupture-risk prediction, solely based on cap thickness. Estimation of PCS estimation did not improve, probably due to the complex shape of the plaques.
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Affiliation(s)
- Annette M Kok
- Department of Biomedical Engineering, Thorax Center, Erasmus Medical Center, Rotterdam, The Netherlands.
| | - Aad van der Lugt
- Department of Radiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | | | | | - Jolanda J Wentzel
- Department of Biomedical Engineering, Thorax Center, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Frank J H Gijsen
- Department of Biomedical Engineering, Thorax Center, Erasmus Medical Center, Rotterdam, The Netherlands
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Nieuwstadt HA, Fekkes S, Hansen HHG, de Korte CL, van der Lugt A, Wentzel JJ, van der Steen AFW, Gijsen FJH. Carotid plaque elasticity estimation using ultrasound elastography, MRI, and inverse FEA - A numerical feasibility study. Med Eng Phys 2015; 37:801-7. [PMID: 26130603 DOI: 10.1016/j.medengphy.2015.06.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 06/02/2015] [Accepted: 06/07/2015] [Indexed: 12/13/2022]
Abstract
The material properties of atherosclerotic plaques govern the biomechanical environment, which is associated with rupture-risk. We investigated the feasibility of noninvasively estimating carotid plaque component material properties through simulating ultrasound (US) elastography and in vivo magnetic resonance imaging (MRI), and solving the inverse problem with finite element analysis. 2D plaque models were derived from endarterectomy specimens of nine patients. Nonlinear neo-Hookean models (tissue elasticity C1) were assigned to fibrous intima, wall (i.e., media/adventitia), and lipid-rich necrotic core. Finite element analysis was used to simulate clinical cross-sectional US strain imaging. Computer-simulated, single-slice in vivo MR images were segmented by two MR readers. We investigated multiple scenarios for plaque model elasticity, and consistently found clear separations between estimated tissue elasticity values. The intima C1 (160 kPa scenario) was estimated as 125.8 ± 19.4 kPa (reader 1) and 128.9 ± 24.8 kPa (reader 2). The lipid-rich necrotic core C1 (5 kPa) was estimated as 5.6 ± 2.0 kPa (reader 1) and 8.5 ± 4.5 kPa (reader 2). A scenario with a stiffer wall yielded similar results, while realistic US strain noise and rotating the models had little influence, thus demonstrating robustness of the procedure. The promising findings of this computer-simulation study stimulate applying the proposed methodology in a clinical setting.
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Affiliation(s)
- H A Nieuwstadt
- Department of Biomedical Engineering, Erasmus MC, Rotterdam, The Netherlands.
| | - S Fekkes
- Department of Radiology and Nuclear Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - H H G Hansen
- Department of Radiology and Nuclear Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - C L de Korte
- Department of Radiology and Nuclear Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - A van der Lugt
- Department of Radiology, Erasmus MC, Rotterdam, The Netherlands
| | - J J Wentzel
- Department of Biomedical Engineering, Erasmus MC, Rotterdam, The Netherlands
| | - A F W van der Steen
- Department of Biomedical Engineering, Erasmus MC, Rotterdam, The Netherlands; Department of Imaging Science and Technology, Delft University of Technology, Delft, The Netherlands
| | - F J H Gijsen
- Department of Biomedical Engineering, Erasmus MC, Rotterdam, The Netherlands.
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Gijsen FJH, Nieuwstadt HA, Wentzel JJ, Verhagen HJM, van der Lugt A, van der Steen AFW. Carotid Plaque Morphological Classification Compared With Biomechanical Cap Stress: Implications for a Magnetic Resonance Imaging-Based Assessment. Stroke 2015; 46:2124-8. [PMID: 26081843 DOI: 10.1161/strokeaha.115.009707] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 04/21/2015] [Indexed: 02/04/2023]
Abstract
BACKGROUND AND PURPOSE Two approaches to target plaque vulnerability-a histopathologic classification scheme and a biomechanical analysis-were compared and the implications for noninvasive risk stratification of carotid plaques using magnetic resonance imaging were assessed. METHODS Seventy-five histological plaque cross sections were obtained from carotid endarterectomy specimens from 34 patients (>70% stenosis) and subjected to both a Virmani histopathologic classification (thin fibrous cap atheroma with <0.2-mm cap thickness, presumed vulnerable) and a peak cap stress computation (<140 kPa: presumed stable; >300 kPa: presumed vulnerable). To demonstrate the implications for noninvasive plaque assessment, numeric simulations of a typical carotid magnetic resonance imaging protocol were performed (0.62×0.62 mm(2) in-plane acquired voxel size) and used to obtain the magnetic resonance imaging-based peak cap stress. RESULTS Peak cap stress was generally associated with histological classification. However, only 16 of 25 plaque cross sections could be labeled as high-risk (peak cap stress>300 kPa and classified as a thin fibrous cap atheroma). Twenty-eight of 50 plaque cross sections could be labeled as low-risk (a peak cap stress<140 kPa and not a thin fibrous cap atheroma), leading to a κ=0.39. 31 plaques (41%) had a disagreement between both classifications. Because of the limited magnetic resonance imaging voxel size with regard to cap thickness, a noninvasive identification of only a group of low-risk, thick-cap plaques was reliable. CONCLUSIONS Instead of trying to target only vulnerable plaques, a more reliable noninvasive identification of a select group of stable plaques with a thick cap and low stress might be a more fruitful approach to start reducing surgical interventions on carotid plaques.
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Affiliation(s)
- Frank J H Gijsen
- From the Departments of Biomedical Engineering-Thoraxcenter (F.J.H.G., H.A.N., J.J.W., A.F.W.v.d.S.), Vascular Surgery (H.J.M.V.), and Radiology (A.v.d.L.), Erasmus MC, Rotterdam, The Netherlands; and Department of Applied Sciences, Delft University of Technology, Delft, The Netherlands (A.F.W.v.d.S.).
| | - Harm A Nieuwstadt
- From the Departments of Biomedical Engineering-Thoraxcenter (F.J.H.G., H.A.N., J.J.W., A.F.W.v.d.S.), Vascular Surgery (H.J.M.V.), and Radiology (A.v.d.L.), Erasmus MC, Rotterdam, The Netherlands; and Department of Applied Sciences, Delft University of Technology, Delft, The Netherlands (A.F.W.v.d.S.)
| | - Jolanda J Wentzel
- From the Departments of Biomedical Engineering-Thoraxcenter (F.J.H.G., H.A.N., J.J.W., A.F.W.v.d.S.), Vascular Surgery (H.J.M.V.), and Radiology (A.v.d.L.), Erasmus MC, Rotterdam, The Netherlands; and Department of Applied Sciences, Delft University of Technology, Delft, The Netherlands (A.F.W.v.d.S.)
| | - Hence J M Verhagen
- From the Departments of Biomedical Engineering-Thoraxcenter (F.J.H.G., H.A.N., J.J.W., A.F.W.v.d.S.), Vascular Surgery (H.J.M.V.), and Radiology (A.v.d.L.), Erasmus MC, Rotterdam, The Netherlands; and Department of Applied Sciences, Delft University of Technology, Delft, The Netherlands (A.F.W.v.d.S.)
| | - Aad van der Lugt
- From the Departments of Biomedical Engineering-Thoraxcenter (F.J.H.G., H.A.N., J.J.W., A.F.W.v.d.S.), Vascular Surgery (H.J.M.V.), and Radiology (A.v.d.L.), Erasmus MC, Rotterdam, The Netherlands; and Department of Applied Sciences, Delft University of Technology, Delft, The Netherlands (A.F.W.v.d.S.)
| | - Antonius F W van der Steen
- From the Departments of Biomedical Engineering-Thoraxcenter (F.J.H.G., H.A.N., J.J.W., A.F.W.v.d.S.), Vascular Surgery (H.J.M.V.), and Radiology (A.v.d.L.), Erasmus MC, Rotterdam, The Netherlands; and Department of Applied Sciences, Delft University of Technology, Delft, The Netherlands (A.F.W.v.d.S.)
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Nieuwstadt HA, Kassar ZAM, van der Lugt A, Breeuwer M, van der Steen AFW, Wentzel JJ, Gijsen FJH. A computer-simulation study on the effects of MRI voxel dimensions on carotid plaque lipid-core and fibrous cap segmentation and stress modeling. PLoS One 2015; 10:e0123031. [PMID: 25856094 PMCID: PMC4391711 DOI: 10.1371/journal.pone.0123031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 02/16/2015] [Indexed: 11/25/2022] Open
Abstract
Background The benefits of a decreased slice thickness and/or in-plane voxel size in carotid MRI for atherosclerotic plaque component quantification accuracy and biomechanical peak cap stress analysis have not yet been investigated in detail because of practical limitations. Methods In order to provide a methodology that allows such an investigation in detail, numerical simulations of a T1-weighted, contrast-enhanced, 2D MRI sequence were employed. Both the slice thickness (2 mm, 1 mm, and 0.5 mm) and the in plane acquired voxel size (0.62x0.62 mm2 and 0.31x0.31 mm2) were varied. This virtual MRI approach was applied to 8 histology-based 3D patient carotid atherosclerotic plaque models. Results A decreased slice thickness did not result in major improvements in lumen, vessel wall, and lipid-rich necrotic core size measurements. At 0.62x0.62 mm2 in-plane, only a 0.5 mm slice thickness resulted in improved minimum fibrous cap thickness measurements (a 2–3 fold reduction in measurement error) and only marginally improved peak cap stress computations. Acquiring voxels of 0.31x0.31 mm2 in-plane, however, led to either similar or significantly larger improvements in plaque component quantification and computed peak cap stress. Conclusions This study provides evidence that for currently-used 2D carotid MRI protocols, a decreased slice thickness might not be more beneficial for plaque measurement accuracy than a decreased in-plane voxel size. The MRI simulations performed indicate that not a reduced slice thickness (i.e. more isotropic imaging), but the acquisition of anisotropic voxels with a relatively smaller in-plane voxel size could improve carotid plaque quantification and computed peak cap stress accuracy.
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Affiliation(s)
- Harm A. Nieuwstadt
- Department of Biomedical Engineering, Erasmus MC, Rotterdam, the Netherlands
| | - Zaid A. M. Kassar
- Department of Biomedical Engineering, Erasmus MC, Rotterdam, the Netherlands
- Department of Radiology, Erasmus MC, Rotterdam, the Netherlands
| | | | - Marcel Breeuwer
- Philips Healthcare, Best, the Netherlands
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - Anton F. W. van der Steen
- Department of Biomedical Engineering, Erasmus MC, Rotterdam, the Netherlands
- Department of Imaging Science and Technology, Delft University of Technology, Delft, the Netherlands
| | - Jolanda J. Wentzel
- Department of Biomedical Engineering, Erasmus MC, Rotterdam, the Netherlands
| | - Frank J. H. Gijsen
- Department of Biomedical Engineering, Erasmus MC, Rotterdam, the Netherlands
- * E-mail:
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