PhD Candidate
E-mail: m [dot] zreik [at] umcutrecht [dot] nl
Phone: +31 88 75 50565
LinkedIn; Google Scholar
In 2008 Majd obtained his Bachelor of Science degree in Biomedical Engineering at the Technion – Israel Institute of Technology, Haifa, Israel. In 2010 he received his Master’s Degree also in Biomedical Engineering at Tel Aviv University. His master’s thesis focused on signal processing techniques on in-vivo brain signals. From 2010 until 2015 he worked as algorithms engineer/team leader in the biomedical industry. In 2015 he started as a PhD-candidate at the Image Sciences Institute at UMC Utrecht where his main area of research is assessment of cardiovascular risk from Coronary CT Angiography (CCTA). Majd is interested in image processing, quantitative imaging and machine learning.
Journal Articles
1. M. Zreik, R.W. van Hamersvelt, N. Khalili, J.M. Wolterink, M. Voskuil, M.A. Viergever, T. Leiner, I. Išgum
Deep learning analysis of coronary arteries in cardiac CT angiography for detection of patients requiring invasive coronary angiography Journal Article
Transactions on Medical Imaging, 39 (5), pp. 1545-1557, 2020.
@article{Zreik2020b,
title = {Deep learning analysis of coronary arteries in cardiac CT angiography for detection of patients requiring invasive coronary angiography},
author = {M. Zreik, R.W. van Hamersvelt, N. Khalili, J.M. Wolterink, M. Voskuil, M.A. Viergever, T. Leiner, I. Išgum},
url = {https://www.ncbi.nlm.nih.gov/pubmed/31725371},
doi = {10.1109/TMI.2019.2953054},
year = {2020},
date = {2020-05-01},
journal = {Transactions on Medical Imaging},
volume = {39},
number = {5},
pages = {1545-1557},
abstract = {In patients with obstructive coronary artery disease, the functional significance of a coronary artery stenosis needs to be determined to guide treatment. This is typically established through fractional flow reserve (FFR) measurement, performed during invasive coronary angiography (ICA). We present a method for automatic and non-invasive detection of patients requiring ICA, employing deep unsupervised analysis of complete coronary arteries in cardiac CT angiography (CCTA) images. We retrospectively collected CCTA scans of 187 patients, 137 of them underwent invasive FFR measurement in 192 different coronary arteries. These FFR measurements served as a reference standard for the functional significance of the coronary stenosis. The centerlines of the coronary arteries were extracted and used to reconstruct straightened multi-planar reformatted (MPR) volumes. To automatically identify arteries with functionally significant stenosis that require ICA, each MPR volume was encoded into a fixed number of encodings using two disjoint 3D and 1D convolutional autoencoders performing spatial and sequential encodings, respectively. Thereafter, these encodings were employed to classify arteries using a support vector machine classifier. The detection of coronary arteries requiring invasive evaluation, evaluated using repeated cross-validation experiments, resulted in an area under the receiver operating characteristic curve of 0.81±0.02 on the artery-level, and 0.87±0.02 on the patient-level. The results demonstrate the feasibility of automatic non-invasive detection of patients that require ICA and possibly subsequent coronary artery intervention. This could potentially reduce the number of patients that unnecessarily undergo ICA.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In patients with obstructive coronary artery disease, the functional significance of a coronary artery stenosis needs to be determined to guide treatment. This is typically established through fractional flow reserve (FFR) measurement, performed during invasive coronary angiography (ICA). We present a method for automatic and non-invasive detection of patients requiring ICA, employing deep unsupervised analysis of complete coronary arteries in cardiac CT angiography (CCTA) images. We retrospectively collected CCTA scans of 187 patients, 137 of them underwent invasive FFR measurement in 192 different coronary arteries. These FFR measurements served as a reference standard for the functional significance of the coronary stenosis. The centerlines of the coronary arteries were extracted and used to reconstruct straightened multi-planar reformatted (MPR) volumes. To automatically identify arteries with functionally significant stenosis that require ICA, each MPR volume was encoded into a fixed number of encodings using two disjoint 3D and 1D convolutional autoencoders performing spatial and sequential encodings, respectively. Thereafter, these encodings were employed to classify arteries using a support vector machine classifier. The detection of coronary arteries requiring invasive evaluation, evaluated using repeated cross-validation experiments, resulted in an area under the receiver operating characteristic curve of 0.81±0.02 on the artery-level, and 0.87±0.02 on the patient-level. The results demonstrate the feasibility of automatic non-invasive detection of patients that require ICA and possibly subsequent coronary artery intervention. This could potentially reduce the number of patients that unnecessarily undergo ICA.2. M. Zreik, R.W. van Hamersvelt, J.M. Wolterink, T. Leiner, M.A. Viergever, I. Išgum
A recurrent CNN for automatic detection and classification of coronary artery plaque and stenosis in coronary CT angiography Journal Article
IEEE Transactions on Medical Imaging, 38 (7), 2018.
@article{Zreik2018,
title = {A recurrent CNN for automatic detection and classification of coronary artery plaque and stenosis in coronary CT angiography},
author = {M. Zreik, R.W. van Hamersvelt, J.M. Wolterink, T. Leiner, M.A. Viergever, I. Išgum},
url = {https://ieeexplore.ieee.org/abstract/document/8550784
https://arxiv.org/abs/1804.04360},
year = {2018},
date = {2018-11-28},
journal = {IEEE Transactions on Medical Imaging},
volume = {38},
number = {7},
abstract = {Various types of atherosclerotic plaque and varying grades of stenosis could lead to different management of patients with coronary artery disease. Therefore, it is crucial to detect and classify the type of coronary artery plaque, as well as to detect and determine the degree of coronary artery stenosis. This study includes retrospectively collected clinically obtained coronary CT angiography (CCTA) scans of 163 patients. In these, the centerlines of the coronary arteries were extracted and used to reconstruct multi-planar reformatted (MPR) images for the coronary arteries. To define the reference standard, the presence and the type of plaque in the coronary arteries (no plaque, non-calcified, mixed, calcified), as well as the presence and the anatomical significance of coronary stenosis (no stenosis, nonsignificant i.e. < 50% luminal narrowing, significant i.e. ≥ 50% luminal narrowing) were manually annotated in the MPR images by identifying the start- and end-points of the segment of the artery affected by the plaque. To perform automatic analysis, a multi-task recurrent convolutional neural network is applied on coronary artery MPR images. First, a 3D convolutional neural network is utilized to extract features along the coronary artery. Subsequently, the extracted features are aggregated by a recurrent neural network that performs two simultaneous multiclass classification tasks. In the first task, the network detects and characterizes the type of the coronary artery plaque. In the second task, the network detects and determines the anatomical significance of the coronary artery stenosis. The network was trained and tested using CCTA images of 98 and 65 patients, respectively. For detection and characterization of coronary plaque, the method achieved an accuracy of 0.77. For detection of stenosis and determination of its anatomical significance, the method achieved an accuracy of 0.80. The results demonstrate that automatic detection and classification of coronary artery plaque and stenosis are feasible. This may enable automated triage of patients to those without coronary plaque and those with coronary plaque and stenosis in need for further cardiovascular workup.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Various types of atherosclerotic plaque and varying grades of stenosis could lead to different management of patients with coronary artery disease. Therefore, it is crucial to detect and classify the type of coronary artery plaque, as well as to detect and determine the degree of coronary artery stenosis. This study includes retrospectively collected clinically obtained coronary CT angiography (CCTA) scans of 163 patients. In these, the centerlines of the coronary arteries were extracted and used to reconstruct multi-planar reformatted (MPR) images for the coronary arteries. To define the reference standard, the presence and the type of plaque in the coronary arteries (no plaque, non-calcified, mixed, calcified), as well as the presence and the anatomical significance of coronary stenosis (no stenosis, nonsignificant i.e. < 50% luminal narrowing, significant i.e. ≥ 50% luminal narrowing) were manually annotated in the MPR images by identifying the start- and end-points of the segment of the artery affected by the plaque. To perform automatic analysis, a multi-task recurrent convolutional neural network is applied on coronary artery MPR images. First, a 3D convolutional neural network is utilized to extract features along the coronary artery. Subsequently, the extracted features are aggregated by a recurrent neural network that performs two simultaneous multiclass classification tasks. In the first task, the network detects and characterizes the type of the coronary artery plaque. In the second task, the network detects and determines the anatomical significance of the coronary artery stenosis. The network was trained and tested using CCTA images of 98 and 65 patients, respectively. For detection and characterization of coronary plaque, the method achieved an accuracy of 0.77. For detection of stenosis and determination of its anatomical significance, the method achieved an accuracy of 0.80. The results demonstrate that automatic detection and classification of coronary artery plaque and stenosis are feasible. This may enable automated triage of patients to those without coronary plaque and those with coronary plaque and stenosis in need for further cardiovascular workup.3. R.W. van Hamersvelt*, M. Zreik*, M. Voskuil, M.A. Viergever, I. Išgum, T. Leiner
European Radiology, 29 (5), pp. 2350–2359, 2018, (*equal contribution).
@article{vanHamersvelt*2018er,
title = {Deep learning analysis of left ventricular myocardium in CT angiographic intermediate degree coronary stenosis improves the diagnostic accuracy for identification of functionally significant stenosis },
author = {R.W. van Hamersvelt*, M. Zreik*, M. Voskuil, M.A. Viergever, I. Išgum, T. Leiner},
url = {https://link.springer.com/article/10.1007%2Fs00330-018-5822-3},
year = {2018},
date = {2018-10-01},
journal = {European Radiology},
volume = {29},
number = {5},
pages = {2350–2359},
abstract = {Objectives: To evaluate the added value of deep learning (DL) analysis of the left ventricular myocardium (LVM) in resting coronary CT angiography (CCTA) over determination of coronary degree of stenosis (DS), for identification of patients with functionally significant coronary artery stenosis.
Methods: Patients who underwent CCTA prior to an invasive fractional flow reserve (FFR) measurement were retrospectively selected. Highest DS from CCTA was used to classify patients as having non-significant (≤ 24% DS), intermediate (25–69% DS), or significant stenosis (≥ 70% DS). Patients with intermediate stenosis were referred for fully automatic DL analysis of the LVM. The DL algorithm characterized the LVM, and likely encoded information regarding shape, texture, contrast enhancement, and more. Based on these encodings, features were extracted and patients classified as having a non-significant or significant stenosis. Diagnostic performance of the combined method was evaluated and compared to DS evaluation only. Functionally significant stenosis was defined as FFR ≤ 0.8 or presence of angiographic high-grade stenosis (≥ 90% DS).
Results: The final study population consisted of 126 patients (77% male, 59 ± 9 years). Eighty-one patients (64%) had a functionally significant stenosis. The proposed method resulted in improved discrimination (AUC = 0.76) compared to classification based on DS only (AUC = 0.68). Sensitivity and specificity were 92.6% and 31.1% for DS only (≥ 50% indicating functionally significant stenosis), and 84.6% and 48.4% for the proposed method.
Conclusion: The combination of DS with DL analysis of the LVM in intermediate-degree coronary stenosis may result in improved diagnostic performance for identification of patients with functionally significant coronary artery stenosis.},
note = {*equal contribution},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Objectives: To evaluate the added value of deep learning (DL) analysis of the left ventricular myocardium (LVM) in resting coronary CT angiography (CCTA) over determination of coronary degree of stenosis (DS), for identification of patients with functionally significant coronary artery stenosis.
Methods: Patients who underwent CCTA prior to an invasive fractional flow reserve (FFR) measurement were retrospectively selected. Highest DS from CCTA was used to classify patients as having non-significant (≤ 24% DS), intermediate (25–69% DS), or significant stenosis (≥ 70% DS). Patients with intermediate stenosis were referred for fully automatic DL analysis of the LVM. The DL algorithm characterized the LVM, and likely encoded information regarding shape, texture, contrast enhancement, and more. Based on these encodings, features were extracted and patients classified as having a non-significant or significant stenosis. Diagnostic performance of the combined method was evaluated and compared to DS evaluation only. Functionally significant stenosis was defined as FFR ≤ 0.8 or presence of angiographic high-grade stenosis (≥ 90% DS).
Results: The final study population consisted of 126 patients (77% male, 59 ± 9 years). Eighty-one patients (64%) had a functionally significant stenosis. The proposed method resulted in improved discrimination (AUC = 0.76) compared to classification based on DS only (AUC = 0.68). Sensitivity and specificity were 92.6% and 31.1% for DS only (≥ 50% indicating functionally significant stenosis), and 84.6% and 48.4% for the proposed method.
Conclusion: The combination of DS with DL analysis of the LVM in intermediate-degree coronary stenosis may result in improved diagnostic performance for identification of patients with functionally significant coronary artery stenosis.4. M. Zreik, N. Lessmann, R.W. van Hamersvelt, J.M. Wolterink, M. Voskuil, M.A. Viergever, T. Leiner, I. Išgum
Medical Image Analysis, 44 , pp. 72-85, 2018.
@article{Zreik2017b,
title = {Deep learning analysis of the myocardium in coronary CT angiography for identification of patients with functionally significant coronary artery stenosis},
author = {M. Zreik, N. Lessmann, R.W. van Hamersvelt, J.M. Wolterink, M. Voskuil, M.A. Viergever, T. Leiner, I. Išgum},
url = {https://arxiv.org/abs/1711.08917},
year = {2018},
date = {2018-02-01},
journal = {Medical Image Analysis},
volume = {44},
pages = {72-85},
abstract = {In patients with coronary artery stenoses of intermediate severity, the functional signicance needs to be determined. Fractional flow reserve (FFR) measurement, performed during invasive coronary angiography (ICA), is most often used in clinical practice. To reduce the number of ICA procedures, we present a method for automatic identication of patients with functionally signicant coronary artery stenoses, employing deep learning analysis of the left ventricle (LV) myocardium in rest coronary CT angiography (CCTA). The study includes consecutively acquired CCTA scans of 166 patients who underwent invasive FFR measurements. To identify patients with a functionally signicant coronary artery stenosis, analysis is performed in several stages. First, the LV myocardium is segmented using a multiscale convolutional neural network (CNN). To characterize the segmented LV myocardium, it is subsequently encoded using unsupervised convolutional autoencoder (CAE). As ischemic changes are expected to appear locally, the LV myocardium is divided into a number of spatially connected clusters, and statistics of the encodings are computed as features. Thereafter, patients are classied according to the presence of functionally signicant stenosis using an SVM classier based on the extracted features. Quantitative evaluation of LV myocardium segmentation in 20 images resulted in an average Dice coecient of 0:91 and an average mean absolute distance between the segmented and reference LV boundaries of 0:7 mm. Twenty CCTA images were used to train the LV myocardium encoder. Classication of patients was evaluated in the remaining 126 CCTA scans in 50 10-fold cross-validation experiments and resulted in an area under the receiver operating characteristic curve of 0.74 0.02. At sensitivity levels 0.60, 0.70 and 0.80, the corresponding specicity was 0.77, 0.71 and 0.59, respectively. The results demonstrate that automatic analysis of the LV myocardium in a single CCTA scan acquired at rest, without assessment of the anatomy of the coronary arteries, can be used to identify patients with functionally signicant coronary artery stenosis. This might reduce the number of patients undergoing unnecessary invasive FFR measurements.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In patients with coronary artery stenoses of intermediate severity, the functional signicance needs to be determined. Fractional flow reserve (FFR) measurement, performed during invasive coronary angiography (ICA), is most often used in clinical practice. To reduce the number of ICA procedures, we present a method for automatic identication of patients with functionally signicant coronary artery stenoses, employing deep learning analysis of the left ventricle (LV) myocardium in rest coronary CT angiography (CCTA). The study includes consecutively acquired CCTA scans of 166 patients who underwent invasive FFR measurements. To identify patients with a functionally signicant coronary artery stenosis, analysis is performed in several stages. First, the LV myocardium is segmented using a multiscale convolutional neural network (CNN). To characterize the segmented LV myocardium, it is subsequently encoded using unsupervised convolutional autoencoder (CAE). As ischemic changes are expected to appear locally, the LV myocardium is divided into a number of spatially connected clusters, and statistics of the encodings are computed as features. Thereafter, patients are classied according to the presence of functionally signicant stenosis using an SVM classier based on the extracted features. Quantitative evaluation of LV myocardium segmentation in 20 images resulted in an average Dice coecient of 0:91 and an average mean absolute distance between the segmented and reference LV boundaries of 0:7 mm. Twenty CCTA images were used to train the LV myocardium encoder. Classication of patients was evaluated in the remaining 126 CCTA scans in 50 10-fold cross-validation experiments and resulted in an area under the receiver operating characteristic curve of 0.74 0.02. At sensitivity levels 0.60, 0.70 and 0.80, the corresponding specicity was 0.77, 0.71 and 0.59, respectively. The results demonstrate that automatic analysis of the LV myocardium in a single CCTA scan acquired at rest, without assessment of the anatomy of the coronary arteries, can be used to identify patients with functionally signicant coronary artery stenosis. This might reduce the number of patients undergoing unnecessary invasive FFR measurements.5. N. Lessmann, B. van Ginneken, M. Zreik, P.A. de Jong, B.D. de Vos, M.A. Viergever, I. Išgum
Automatic calcium scoring in low-dose chest CT using deep neural networks with dilated convolutions Journal Article
IEEE Transactions on Medical Imaging, 37 (2), pp. 615-625, 2018.
@article{Lessmann2017,
title = {Automatic calcium scoring in low-dose chest CT using deep neural networks with dilated convolutions},
author = {N. Lessmann, B. van Ginneken, M. Zreik, P.A. de Jong, B.D. de Vos, M.A. Viergever, I. Išgum},
url = {https://arxiv.org/pdf/1711.00349.pdf},
year = {2018},
date = {2018-02-01},
journal = {IEEE Transactions on Medical Imaging},
volume = {37},
number = {2},
pages = {615-625},
abstract = {Heavy smokers undergoing screening with low-dose chest CT are affected by cardiovascular disease as much as by lung cancer. Low-dose chest CT scans acquired in screening enable quantification of atherosclerotic calcifications and thus enable identification of subjects at increased cardiovascular risk. This paper presents a method for automatic detection of coronary artery, thoracic aorta and cardiac valve calcifications in low-dose chest CT using two consecutive convolutional neural networks. The first network identifies and labels potential calcifications according to their anatomical location and the second network identifies true calcifications among the detected candidates. This method was trained and evaluated on a set of 1744 CT scans from the National Lung Screening Trial. To determine whether any reconstruction or only images reconstructed with soft tissue filters can be used for calcification detection, we evaluated the method on soft and medium/sharp filter reconstructions separately. On soft filter reconstructions, the method achieved F1 scores of 0.89, 0.89, 0.67, and 0.55 for coronary artery, thoracic aorta, aortic valve and mitral valve calcifications, respectively. On sharp filter reconstructions, the F1 scores were 0.84, 0.81, 0.64, and 0.66, respectively. Linearly weighted kappa coefficients for risk category assignment based on per subject coronary artery calcium were 0.91 and 0.90 for soft and sharp filter reconstructions, respectively. These results demonstrate that the presented method enables reliable automatic cardiovascular risk assessment in all low-dose chest CT scans acquired for lung cancer screening.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Heavy smokers undergoing screening with low-dose chest CT are affected by cardiovascular disease as much as by lung cancer. Low-dose chest CT scans acquired in screening enable quantification of atherosclerotic calcifications and thus enable identification of subjects at increased cardiovascular risk. This paper presents a method for automatic detection of coronary artery, thoracic aorta and cardiac valve calcifications in low-dose chest CT using two consecutive convolutional neural networks. The first network identifies and labels potential calcifications according to their anatomical location and the second network identifies true calcifications among the detected candidates. This method was trained and evaluated on a set of 1744 CT scans from the National Lung Screening Trial. To determine whether any reconstruction or only images reconstructed with soft tissue filters can be used for calcification detection, we evaluated the method on soft and medium/sharp filter reconstructions separately. On soft filter reconstructions, the method achieved F1 scores of 0.89, 0.89, 0.67, and 0.55 for coronary artery, thoracic aorta, aortic valve and mitral valve calcifications, respectively. On sharp filter reconstructions, the F1 scores were 0.84, 0.81, 0.64, and 0.66, respectively. Linearly weighted kappa coefficients for risk category assignment based on per subject coronary artery calcium were 0.91 and 0.90 for soft and sharp filter reconstructions, respectively. These results demonstrate that the presented method enables reliable automatic cardiovascular risk assessment in all low-dose chest CT scans acquired for lung cancer screening.
Journal Articles |
|
1. | M. Zreik, R.W. van Hamersvelt, N. Khalili, J.M. Wolterink, M. Voskuil, M.A. Viergever, T. Leiner, I. Išgum Deep learning analysis of coronary arteries in cardiac CT angiography for detection of patients requiring invasive coronary angiography Journal Article Transactions on Medical Imaging, 39 (5), pp. 1545-1557, 2020. @article{Zreik2020b, title = {Deep learning analysis of coronary arteries in cardiac CT angiography for detection of patients requiring invasive coronary angiography}, author = {M. Zreik, R.W. van Hamersvelt, N. Khalili, J.M. Wolterink, M. Voskuil, M.A. Viergever, T. Leiner, I. Išgum}, url = {https://www.ncbi.nlm.nih.gov/pubmed/31725371}, doi = {10.1109/TMI.2019.2953054}, year = {2020}, date = {2020-05-01}, journal = {Transactions on Medical Imaging}, volume = {39}, number = {5}, pages = {1545-1557}, abstract = {In patients with obstructive coronary artery disease, the functional significance of a coronary artery stenosis needs to be determined to guide treatment. This is typically established through fractional flow reserve (FFR) measurement, performed during invasive coronary angiography (ICA). We present a method for automatic and non-invasive detection of patients requiring ICA, employing deep unsupervised analysis of complete coronary arteries in cardiac CT angiography (CCTA) images. We retrospectively collected CCTA scans of 187 patients, 137 of them underwent invasive FFR measurement in 192 different coronary arteries. These FFR measurements served as a reference standard for the functional significance of the coronary stenosis. The centerlines of the coronary arteries were extracted and used to reconstruct straightened multi-planar reformatted (MPR) volumes. To automatically identify arteries with functionally significant stenosis that require ICA, each MPR volume was encoded into a fixed number of encodings using two disjoint 3D and 1D convolutional autoencoders performing spatial and sequential encodings, respectively. Thereafter, these encodings were employed to classify arteries using a support vector machine classifier. The detection of coronary arteries requiring invasive evaluation, evaluated using repeated cross-validation experiments, resulted in an area under the receiver operating characteristic curve of 0.81±0.02 on the artery-level, and 0.87±0.02 on the patient-level. The results demonstrate the feasibility of automatic non-invasive detection of patients that require ICA and possibly subsequent coronary artery intervention. This could potentially reduce the number of patients that unnecessarily undergo ICA.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In patients with obstructive coronary artery disease, the functional significance of a coronary artery stenosis needs to be determined to guide treatment. This is typically established through fractional flow reserve (FFR) measurement, performed during invasive coronary angiography (ICA). We present a method for automatic and non-invasive detection of patients requiring ICA, employing deep unsupervised analysis of complete coronary arteries in cardiac CT angiography (CCTA) images. We retrospectively collected CCTA scans of 187 patients, 137 of them underwent invasive FFR measurement in 192 different coronary arteries. These FFR measurements served as a reference standard for the functional significance of the coronary stenosis. The centerlines of the coronary arteries were extracted and used to reconstruct straightened multi-planar reformatted (MPR) volumes. To automatically identify arteries with functionally significant stenosis that require ICA, each MPR volume was encoded into a fixed number of encodings using two disjoint 3D and 1D convolutional autoencoders performing spatial and sequential encodings, respectively. Thereafter, these encodings were employed to classify arteries using a support vector machine classifier. The detection of coronary arteries requiring invasive evaluation, evaluated using repeated cross-validation experiments, resulted in an area under the receiver operating characteristic curve of 0.81±0.02 on the artery-level, and 0.87±0.02 on the patient-level. The results demonstrate the feasibility of automatic non-invasive detection of patients that require ICA and possibly subsequent coronary artery intervention. This could potentially reduce the number of patients that unnecessarily undergo ICA. |
2. | M. Zreik, R.W. van Hamersvelt, J.M. Wolterink, T. Leiner, M.A. Viergever, I. Išgum A recurrent CNN for automatic detection and classification of coronary artery plaque and stenosis in coronary CT angiography Journal Article IEEE Transactions on Medical Imaging, 38 (7), 2018. @article{Zreik2018, title = {A recurrent CNN for automatic detection and classification of coronary artery plaque and stenosis in coronary CT angiography}, author = {M. Zreik, R.W. van Hamersvelt, J.M. Wolterink, T. Leiner, M.A. Viergever, I. Išgum}, url = {https://ieeexplore.ieee.org/abstract/document/8550784 https://arxiv.org/abs/1804.04360}, year = {2018}, date = {2018-11-28}, journal = {IEEE Transactions on Medical Imaging}, volume = {38}, number = {7}, abstract = {Various types of atherosclerotic plaque and varying grades of stenosis could lead to different management of patients with coronary artery disease. Therefore, it is crucial to detect and classify the type of coronary artery plaque, as well as to detect and determine the degree of coronary artery stenosis. This study includes retrospectively collected clinically obtained coronary CT angiography (CCTA) scans of 163 patients. In these, the centerlines of the coronary arteries were extracted and used to reconstruct multi-planar reformatted (MPR) images for the coronary arteries. To define the reference standard, the presence and the type of plaque in the coronary arteries (no plaque, non-calcified, mixed, calcified), as well as the presence and the anatomical significance of coronary stenosis (no stenosis, nonsignificant i.e. < 50% luminal narrowing, significant i.e. ≥ 50% luminal narrowing) were manually annotated in the MPR images by identifying the start- and end-points of the segment of the artery affected by the plaque. To perform automatic analysis, a multi-task recurrent convolutional neural network is applied on coronary artery MPR images. First, a 3D convolutional neural network is utilized to extract features along the coronary artery. Subsequently, the extracted features are aggregated by a recurrent neural network that performs two simultaneous multiclass classification tasks. In the first task, the network detects and characterizes the type of the coronary artery plaque. In the second task, the network detects and determines the anatomical significance of the coronary artery stenosis. The network was trained and tested using CCTA images of 98 and 65 patients, respectively. For detection and characterization of coronary plaque, the method achieved an accuracy of 0.77. For detection of stenosis and determination of its anatomical significance, the method achieved an accuracy of 0.80. The results demonstrate that automatic detection and classification of coronary artery plaque and stenosis are feasible. This may enable automated triage of patients to those without coronary plaque and those with coronary plaque and stenosis in need for further cardiovascular workup.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Various types of atherosclerotic plaque and varying grades of stenosis could lead to different management of patients with coronary artery disease. Therefore, it is crucial to detect and classify the type of coronary artery plaque, as well as to detect and determine the degree of coronary artery stenosis. This study includes retrospectively collected clinically obtained coronary CT angiography (CCTA) scans of 163 patients. In these, the centerlines of the coronary arteries were extracted and used to reconstruct multi-planar reformatted (MPR) images for the coronary arteries. To define the reference standard, the presence and the type of plaque in the coronary arteries (no plaque, non-calcified, mixed, calcified), as well as the presence and the anatomical significance of coronary stenosis (no stenosis, nonsignificant i.e. < 50% luminal narrowing, significant i.e. ≥ 50% luminal narrowing) were manually annotated in the MPR images by identifying the start- and end-points of the segment of the artery affected by the plaque. To perform automatic analysis, a multi-task recurrent convolutional neural network is applied on coronary artery MPR images. First, a 3D convolutional neural network is utilized to extract features along the coronary artery. Subsequently, the extracted features are aggregated by a recurrent neural network that performs two simultaneous multiclass classification tasks. In the first task, the network detects and characterizes the type of the coronary artery plaque. In the second task, the network detects and determines the anatomical significance of the coronary artery stenosis. The network was trained and tested using CCTA images of 98 and 65 patients, respectively. For detection and characterization of coronary plaque, the method achieved an accuracy of 0.77. For detection of stenosis and determination of its anatomical significance, the method achieved an accuracy of 0.80. The results demonstrate that automatic detection and classification of coronary artery plaque and stenosis are feasible. This may enable automated triage of patients to those without coronary plaque and those with coronary plaque and stenosis in need for further cardiovascular workup. |
3. | R.W. van Hamersvelt*, M. Zreik*, M. Voskuil, M.A. Viergever, I. Išgum, T. Leiner European Radiology, 29 (5), pp. 2350–2359, 2018, (*equal contribution). @article{vanHamersvelt*2018er, title = {Deep learning analysis of left ventricular myocardium in CT angiographic intermediate degree coronary stenosis improves the diagnostic accuracy for identification of functionally significant stenosis }, author = {R.W. van Hamersvelt*, M. Zreik*, M. Voskuil, M.A. Viergever, I. Išgum, T. Leiner}, url = {https://link.springer.com/article/10.1007%2Fs00330-018-5822-3}, year = {2018}, date = {2018-10-01}, journal = {European Radiology}, volume = {29}, number = {5}, pages = {2350–2359}, abstract = {Objectives: To evaluate the added value of deep learning (DL) analysis of the left ventricular myocardium (LVM) in resting coronary CT angiography (CCTA) over determination of coronary degree of stenosis (DS), for identification of patients with functionally significant coronary artery stenosis. Methods: Patients who underwent CCTA prior to an invasive fractional flow reserve (FFR) measurement were retrospectively selected. Highest DS from CCTA was used to classify patients as having non-significant (≤ 24% DS), intermediate (25–69% DS), or significant stenosis (≥ 70% DS). Patients with intermediate stenosis were referred for fully automatic DL analysis of the LVM. The DL algorithm characterized the LVM, and likely encoded information regarding shape, texture, contrast enhancement, and more. Based on these encodings, features were extracted and patients classified as having a non-significant or significant stenosis. Diagnostic performance of the combined method was evaluated and compared to DS evaluation only. Functionally significant stenosis was defined as FFR ≤ 0.8 or presence of angiographic high-grade stenosis (≥ 90% DS). Results: The final study population consisted of 126 patients (77% male, 59 ± 9 years). Eighty-one patients (64%) had a functionally significant stenosis. The proposed method resulted in improved discrimination (AUC = 0.76) compared to classification based on DS only (AUC = 0.68). Sensitivity and specificity were 92.6% and 31.1% for DS only (≥ 50% indicating functionally significant stenosis), and 84.6% and 48.4% for the proposed method. Conclusion: The combination of DS with DL analysis of the LVM in intermediate-degree coronary stenosis may result in improved diagnostic performance for identification of patients with functionally significant coronary artery stenosis.}, note = {*equal contribution}, keywords = {}, pubstate = {published}, tppubtype = {article} } Objectives: To evaluate the added value of deep learning (DL) analysis of the left ventricular myocardium (LVM) in resting coronary CT angiography (CCTA) over determination of coronary degree of stenosis (DS), for identification of patients with functionally significant coronary artery stenosis. Methods: Patients who underwent CCTA prior to an invasive fractional flow reserve (FFR) measurement were retrospectively selected. Highest DS from CCTA was used to classify patients as having non-significant (≤ 24% DS), intermediate (25–69% DS), or significant stenosis (≥ 70% DS). Patients with intermediate stenosis were referred for fully automatic DL analysis of the LVM. The DL algorithm characterized the LVM, and likely encoded information regarding shape, texture, contrast enhancement, and more. Based on these encodings, features were extracted and patients classified as having a non-significant or significant stenosis. Diagnostic performance of the combined method was evaluated and compared to DS evaluation only. Functionally significant stenosis was defined as FFR ≤ 0.8 or presence of angiographic high-grade stenosis (≥ 90% DS). Results: The final study population consisted of 126 patients (77% male, 59 ± 9 years). Eighty-one patients (64%) had a functionally significant stenosis. The proposed method resulted in improved discrimination (AUC = 0.76) compared to classification based on DS only (AUC = 0.68). Sensitivity and specificity were 92.6% and 31.1% for DS only (≥ 50% indicating functionally significant stenosis), and 84.6% and 48.4% for the proposed method. Conclusion: The combination of DS with DL analysis of the LVM in intermediate-degree coronary stenosis may result in improved diagnostic performance for identification of patients with functionally significant coronary artery stenosis. |
4. | M. Zreik, N. Lessmann, R.W. van Hamersvelt, J.M. Wolterink, M. Voskuil, M.A. Viergever, T. Leiner, I. Išgum Medical Image Analysis, 44 , pp. 72-85, 2018. @article{Zreik2017b, title = {Deep learning analysis of the myocardium in coronary CT angiography for identification of patients with functionally significant coronary artery stenosis}, author = {M. Zreik, N. Lessmann, R.W. van Hamersvelt, J.M. Wolterink, M. Voskuil, M.A. Viergever, T. Leiner, I. Išgum}, url = {https://arxiv.org/abs/1711.08917}, year = {2018}, date = {2018-02-01}, journal = {Medical Image Analysis}, volume = {44}, pages = {72-85}, abstract = {In patients with coronary artery stenoses of intermediate severity, the functional signicance needs to be determined. Fractional flow reserve (FFR) measurement, performed during invasive coronary angiography (ICA), is most often used in clinical practice. To reduce the number of ICA procedures, we present a method for automatic identication of patients with functionally signicant coronary artery stenoses, employing deep learning analysis of the left ventricle (LV) myocardium in rest coronary CT angiography (CCTA). The study includes consecutively acquired CCTA scans of 166 patients who underwent invasive FFR measurements. To identify patients with a functionally signicant coronary artery stenosis, analysis is performed in several stages. First, the LV myocardium is segmented using a multiscale convolutional neural network (CNN). To characterize the segmented LV myocardium, it is subsequently encoded using unsupervised convolutional autoencoder (CAE). As ischemic changes are expected to appear locally, the LV myocardium is divided into a number of spatially connected clusters, and statistics of the encodings are computed as features. Thereafter, patients are classied according to the presence of functionally signicant stenosis using an SVM classier based on the extracted features. Quantitative evaluation of LV myocardium segmentation in 20 images resulted in an average Dice coecient of 0:91 and an average mean absolute distance between the segmented and reference LV boundaries of 0:7 mm. Twenty CCTA images were used to train the LV myocardium encoder. Classication of patients was evaluated in the remaining 126 CCTA scans in 50 10-fold cross-validation experiments and resulted in an area under the receiver operating characteristic curve of 0.74 0.02. At sensitivity levels 0.60, 0.70 and 0.80, the corresponding specicity was 0.77, 0.71 and 0.59, respectively. The results demonstrate that automatic analysis of the LV myocardium in a single CCTA scan acquired at rest, without assessment of the anatomy of the coronary arteries, can be used to identify patients with functionally signicant coronary artery stenosis. This might reduce the number of patients undergoing unnecessary invasive FFR measurements.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In patients with coronary artery stenoses of intermediate severity, the functional signicance needs to be determined. Fractional flow reserve (FFR) measurement, performed during invasive coronary angiography (ICA), is most often used in clinical practice. To reduce the number of ICA procedures, we present a method for automatic identication of patients with functionally signicant coronary artery stenoses, employing deep learning analysis of the left ventricle (LV) myocardium in rest coronary CT angiography (CCTA). The study includes consecutively acquired CCTA scans of 166 patients who underwent invasive FFR measurements. To identify patients with a functionally signicant coronary artery stenosis, analysis is performed in several stages. First, the LV myocardium is segmented using a multiscale convolutional neural network (CNN). To characterize the segmented LV myocardium, it is subsequently encoded using unsupervised convolutional autoencoder (CAE). As ischemic changes are expected to appear locally, the LV myocardium is divided into a number of spatially connected clusters, and statistics of the encodings are computed as features. Thereafter, patients are classied according to the presence of functionally signicant stenosis using an SVM classier based on the extracted features. Quantitative evaluation of LV myocardium segmentation in 20 images resulted in an average Dice coecient of 0:91 and an average mean absolute distance between the segmented and reference LV boundaries of 0:7 mm. Twenty CCTA images were used to train the LV myocardium encoder. Classication of patients was evaluated in the remaining 126 CCTA scans in 50 10-fold cross-validation experiments and resulted in an area under the receiver operating characteristic curve of 0.74 0.02. At sensitivity levels 0.60, 0.70 and 0.80, the corresponding specicity was 0.77, 0.71 and 0.59, respectively. The results demonstrate that automatic analysis of the LV myocardium in a single CCTA scan acquired at rest, without assessment of the anatomy of the coronary arteries, can be used to identify patients with functionally signicant coronary artery stenosis. This might reduce the number of patients undergoing unnecessary invasive FFR measurements. |
5. | N. Lessmann, B. van Ginneken, M. Zreik, P.A. de Jong, B.D. de Vos, M.A. Viergever, I. Išgum Automatic calcium scoring in low-dose chest CT using deep neural networks with dilated convolutions Journal Article IEEE Transactions on Medical Imaging, 37 (2), pp. 615-625, 2018. @article{Lessmann2017, title = {Automatic calcium scoring in low-dose chest CT using deep neural networks with dilated convolutions}, author = {N. Lessmann, B. van Ginneken, M. Zreik, P.A. de Jong, B.D. de Vos, M.A. Viergever, I. Išgum}, url = {https://arxiv.org/pdf/1711.00349.pdf}, year = {2018}, date = {2018-02-01}, journal = {IEEE Transactions on Medical Imaging}, volume = {37}, number = {2}, pages = {615-625}, abstract = {Heavy smokers undergoing screening with low-dose chest CT are affected by cardiovascular disease as much as by lung cancer. Low-dose chest CT scans acquired in screening enable quantification of atherosclerotic calcifications and thus enable identification of subjects at increased cardiovascular risk. This paper presents a method for automatic detection of coronary artery, thoracic aorta and cardiac valve calcifications in low-dose chest CT using two consecutive convolutional neural networks. The first network identifies and labels potential calcifications according to their anatomical location and the second network identifies true calcifications among the detected candidates. This method was trained and evaluated on a set of 1744 CT scans from the National Lung Screening Trial. To determine whether any reconstruction or only images reconstructed with soft tissue filters can be used for calcification detection, we evaluated the method on soft and medium/sharp filter reconstructions separately. On soft filter reconstructions, the method achieved F1 scores of 0.89, 0.89, 0.67, and 0.55 for coronary artery, thoracic aorta, aortic valve and mitral valve calcifications, respectively. On sharp filter reconstructions, the F1 scores were 0.84, 0.81, 0.64, and 0.66, respectively. Linearly weighted kappa coefficients for risk category assignment based on per subject coronary artery calcium were 0.91 and 0.90 for soft and sharp filter reconstructions, respectively. These results demonstrate that the presented method enables reliable automatic cardiovascular risk assessment in all low-dose chest CT scans acquired for lung cancer screening.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Heavy smokers undergoing screening with low-dose chest CT are affected by cardiovascular disease as much as by lung cancer. Low-dose chest CT scans acquired in screening enable quantification of atherosclerotic calcifications and thus enable identification of subjects at increased cardiovascular risk. This paper presents a method for automatic detection of coronary artery, thoracic aorta and cardiac valve calcifications in low-dose chest CT using two consecutive convolutional neural networks. The first network identifies and labels potential calcifications according to their anatomical location and the second network identifies true calcifications among the detected candidates. This method was trained and evaluated on a set of 1744 CT scans from the National Lung Screening Trial. To determine whether any reconstruction or only images reconstructed with soft tissue filters can be used for calcification detection, we evaluated the method on soft and medium/sharp filter reconstructions separately. On soft filter reconstructions, the method achieved F1 scores of 0.89, 0.89, 0.67, and 0.55 for coronary artery, thoracic aorta, aortic valve and mitral valve calcifications, respectively. On sharp filter reconstructions, the F1 scores were 0.84, 0.81, 0.64, and 0.66, respectively. Linearly weighted kappa coefficients for risk category assignment based on per subject coronary artery calcium were 0.91 and 0.90 for soft and sharp filter reconstructions, respectively. These results demonstrate that the presented method enables reliable automatic cardiovascular risk assessment in all low-dose chest CT scans acquired for lung cancer screening. |
Inproceedings |
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1. | M. Zreik, N. Hampe, T. Leiner, N. Khalili, J.M. Wolterink, M. Voskuil, M.A. Viergever, I. Išgum In: SPIE Medical Imaging, pp. 115961F, 2021. @inproceedings{Zreik2021, title = {Combined analysis of coronary arteries and the left ventricular myocardium in cardiac CT angiography for detection of patients with functionally significant stenosis}, author = {M. Zreik, N. Hampe, T. Leiner, N. Khalili, J.M. Wolterink, M. Voskuil, M.A. Viergever, I. Išgum}, doi = {10.1117/12.2580847}, year = {2021}, date = {2021-02-16}, booktitle = {SPIE Medical Imaging}, volume = {11596}, pages = {115961F}, abstract = {Treatment of patients with obstructive coronary artery disease is guided by the functional significance of a coronary artery stenosis. Fractionalflow reserve (FFR), measured during invasive coronary angiography (ICA), is considered the references standard to define the functional significance of a coronary stenosis. Here, we present an automatic method for non-invasive detection of patients with functionally significant coronary artery stenosis based on 126 retrospectively collected cardiac CT angiography (CCTA) scans with corresponding FFR measurement. We combine our previous works for the analysis of the complete coronary artery tree and the LV myocardium by applying convolutional autoencoders (CAEs) to characterize both, coronary arteries and the LV myocardium. To handle the varying number of coronary arteries in a patient, an attention-based neural network is trained to obtain a combined representation per patient, and to classify each patient according to the presence of functionally significant stenosis. Cross-validation experiments resulted in an average area under the receiver operating characteristic curve of 0.74, and showed that the proposed combined analysis outperformed the analysis of the coronary arteries or the LV myocardium alone. This may lead to a reduction in the number of unnecessary ICA procedures in patients with suspected obstructive CAD. }, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } Treatment of patients with obstructive coronary artery disease is guided by the functional significance of a coronary artery stenosis. Fractionalflow reserve (FFR), measured during invasive coronary angiography (ICA), is considered the references standard to define the functional significance of a coronary stenosis. Here, we present an automatic method for non-invasive detection of patients with functionally significant coronary artery stenosis based on 126 retrospectively collected cardiac CT angiography (CCTA) scans with corresponding FFR measurement. We combine our previous works for the analysis of the complete coronary artery tree and the LV myocardium by applying convolutional autoencoders (CAEs) to characterize both, coronary arteries and the LV myocardium. To handle the varying number of coronary arteries in a patient, an attention-based neural network is trained to obtain a combined representation per patient, and to classify each patient according to the presence of functionally significant stenosis. Cross-validation experiments resulted in an average area under the receiver operating characteristic curve of 0.74, and showed that the proposed combined analysis outperformed the analysis of the coronary arteries or the LV myocardium alone. This may lead to a reduction in the number of unnecessary ICA procedures in patients with suspected obstructive CAD. |
2. | N. Khalili, E. Turk, M. Zreik, M.A. Viergever, M.J.N.L. Benders, I. Išgum Generative adversarial network for segmentation of motion affected neonatal brain MRI Inproceedings In: Medical Image Computing and Computer Assisted Intervention (MICCAI 2019), Lecture Notes in Computer Science, 2019. @inproceedings{Khalili2019b, title = {Generative adversarial network for segmentation of motion affected neonatal brain MRI}, author = {N. Khalili, E. Turk, M. Zreik, M.A. Viergever, M.J.N.L. Benders, I. Išgum}, url = {https://arxiv.org/abs/1906.04704}, year = {2019}, date = {2019-06-05}, booktitle = {Medical Image Computing and Computer Assisted Intervention (MICCAI 2019), Lecture Notes in Computer Science}, volume = {11766}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
3. | S.G.M. van Velzen, M. Zreik, N. Lessmann, M.A. Viergever, P.A. de Jong, H.M. Verkooijen, I. Išgum Direct prediction of cardiovascular mortality from low-dose chest CT using deep learning Inproceedings In: SPIE Medical Imaging, pp. 109490X, 2019. @inproceedings{Velzen2019, title = {Direct prediction of cardiovascular mortality from low-dose chest CT using deep learning}, author = {S.G.M. van Velzen, M. Zreik, N. Lessmann, M.A. Viergever, P.A. de Jong, H.M. Verkooijen, I. Išgum}, url = {https://arxiv.org/abs/1810.02277}, doi = {10.1117/12.2512400}, year = {2019}, date = {2019-02-17}, booktitle = {SPIE Medical Imaging}, volume = {10949}, pages = {109490X}, abstract = {Cardiovascular disease (CVD) is a leading cause of death in the lung cancer screening population. Chest CT scans made in lung cancer screening are suitable for identification of participants at risk of CVD. Existing methods analyzing CT images from lung cancer screening for prediction of CVD events or mortality use engineered features extracted from the images combined with patient information. In this work we propose a method that automatically predicts 5-year cardiovascular mortality directly from chest CT scans without the need for hand-crafting image features. A set of 1,583 participants of the National Lung Screening Trial was included (1,188 survivors, 395 non-survivors). Low-dose chest CT images acquired at baseline were analyzed and the follow-up time was 5 years. To limit the analysis to the heart region, the heart was first localized by our previously developed algorithm for organ localization exploiting convolutional neural networks. Thereafter, a convolutional autoencoder was used to encode the identified heart region. Finally, based on the extracted encodings subjects were classified into survivors or non-survivors using a support vector machine classifier. The performance of the method was assessed in eight cross-validation experiments with 1,433 images used for training, 50 for validation and 100 for testing. The method achieved a performance with an area under the ROC curve of 0.72. The results demonstrate that prediction of cardiovascular mortality directly from low-dose screening chest CT scans, without hand-crafted features, is feasible, allowing identification of subjects at risk of fatal CVD events.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } Cardiovascular disease (CVD) is a leading cause of death in the lung cancer screening population. Chest CT scans made in lung cancer screening are suitable for identification of participants at risk of CVD. Existing methods analyzing CT images from lung cancer screening for prediction of CVD events or mortality use engineered features extracted from the images combined with patient information. In this work we propose a method that automatically predicts 5-year cardiovascular mortality directly from chest CT scans without the need for hand-crafting image features. A set of 1,583 participants of the National Lung Screening Trial was included (1,188 survivors, 395 non-survivors). Low-dose chest CT images acquired at baseline were analyzed and the follow-up time was 5 years. To limit the analysis to the heart region, the heart was first localized by our previously developed algorithm for organ localization exploiting convolutional neural networks. Thereafter, a convolutional autoencoder was used to encode the identified heart region. Finally, based on the extracted encodings subjects were classified into survivors or non-survivors using a support vector machine classifier. The performance of the method was assessed in eight cross-validation experiments with 1,433 images used for training, 50 for validation and 100 for testing. The method achieved a performance with an area under the ROC curve of 0.72. The results demonstrate that prediction of cardiovascular mortality directly from low-dose screening chest CT scans, without hand-crafted features, is feasible, allowing identification of subjects at risk of fatal CVD events. |
4. | S. Bruns, J.M. Wolterink, R.W. van Hamersvelt, M. Zreik, T. Leiner, I. Išgum Improving myocardium segmentation in cardiac CT angiography using spectral information Inproceedings In: SPIE Medical Imaging, pp. 109492M, 2019. @inproceedings{Bruns2019, title = {Improving myocardium segmentation in cardiac CT angiography using spectral information}, author = {S. Bruns, J.M. Wolterink, R.W. van Hamersvelt, M. Zreik, T. Leiner, I. Išgum}, url = {https://arxiv.org/abs/1810.03968}, doi = {10.1117/12.2512229}, year = {2019}, date = {2019-02-17}, booktitle = {SPIE Medical Imaging}, volume = {10949}, pages = {109492M}, abstract = {Left ventricle myocardium segmentation in cardiac CT angiography (CCTA) is essential for the assessment of myocardial perfusion. Since deep-learning methods for segmentation in CCTA suffer from differences in contrast-agent attenuation, we propose training a 3D CNN with augmentation using virtual mono-energetic reconstructions from a spectral CT scanner. We compare this with augmentation by linear intensity scaling, and combine both augmentations. We train a network with 10 conventional CCTA images and corresponding virtual mono-energetic images acquired on a spectral CT scanner and evaluate on 40 conventional CCTA images. We show that data augmentation with virtual mono-energetic images significantly improves the segmentation.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } Left ventricle myocardium segmentation in cardiac CT angiography (CCTA) is essential for the assessment of myocardial perfusion. Since deep-learning methods for segmentation in CCTA suffer from differences in contrast-agent attenuation, we propose training a 3D CNN with augmentation using virtual mono-energetic reconstructions from a spectral CT scanner. We compare this with augmentation by linear intensity scaling, and combine both augmentations. We train a network with 10 conventional CCTA images and corresponding virtual mono-energetic images acquired on a spectral CT scanner and evaluate on 40 conventional CCTA images. We show that data augmentation with virtual mono-energetic images significantly improves the segmentation. |
5. | M. Zreik, R.W. van Hamersvelt, J.M. Wolterink, T. Leiner, M.A. Viergever, I. Išgum In: Medical Imaging with Deep Learning (MIDL 2018), 2018. @inproceedings{Zreik2018midl, title = {Automatic Detection and Characterization of Coronary Artery Plaque and Stenosis using a Recurrent Convolutional Neural Network in Coronary CT Angiography}, author = {M. Zreik, R.W. van Hamersvelt, J.M. Wolterink, T. Leiner, M.A. Viergever, I. Išgum}, url = {https://openreview.net/pdf?id=BJenxxhof}, year = {2018}, date = {2018-07-04}, booktitle = {Medical Imaging with Deep Learning (MIDL 2018)}, journal = {Medical Imaging with Deep Learning (MIDL 2018)}, abstract = {Different types of atherosclerotic plaque and varying grades of stenosis lead to different management of patients with obstructive coronary artery disease. Therefore, it is crucial to determine the presence and classify the type of coronary artery plaque, as well as to determine the presence and the degree of a stenosis. The study includes consecutively acquired coronary CT angiography (CCTA) scans of 131 patients. In these, presence and plaque type in the coronary arteries (no plaque, non-calcified, mixed, calcified) as well as presence and anatomical significance of coronary stenosis (no stenosis, non-significant, significant) were manually annotated by identifying the start and end points of the fragment of the artery affected by the plaque. To perform automatic analysis, a multi-task recurrent convolutional neural network is utilized. The network uses CCTA and coronary artery centerline as its inputs, and extracts features from the region defined along the coronary artery centerline using a 3D convolutional neural network. Subsequently, the extracted features are used by a recurrent neural network that performs two simultaneous multi-label classification tasks. In the first task, the network detects and characterizes the type of the coronary artery plaque. In the second task, the network detects and determines the anatomical significance of the coronary artery stenosis. The results demonstrate that automatic characterization of coronary artery plaque and stenosis with high accuracy and reliability is feasible. This may enable automated triage of patients to those without coronary plaque, and those with coronary plaque and stenosis in need for further cardiovascular workup.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } Different types of atherosclerotic plaque and varying grades of stenosis lead to different management of patients with obstructive coronary artery disease. Therefore, it is crucial to determine the presence and classify the type of coronary artery plaque, as well as to determine the presence and the degree of a stenosis. The study includes consecutively acquired coronary CT angiography (CCTA) scans of 131 patients. In these, presence and plaque type in the coronary arteries (no plaque, non-calcified, mixed, calcified) as well as presence and anatomical significance of coronary stenosis (no stenosis, non-significant, significant) were manually annotated by identifying the start and end points of the fragment of the artery affected by the plaque. To perform automatic analysis, a multi-task recurrent convolutional neural network is utilized. The network uses CCTA and coronary artery centerline as its inputs, and extracts features from the region defined along the coronary artery centerline using a 3D convolutional neural network. Subsequently, the extracted features are used by a recurrent neural network that performs two simultaneous multi-label classification tasks. In the first task, the network detects and characterizes the type of the coronary artery plaque. In the second task, the network detects and determines the anatomical significance of the coronary artery stenosis. The results demonstrate that automatic characterization of coronary artery plaque and stenosis with high accuracy and reliability is feasible. This may enable automated triage of patients to those without coronary plaque, and those with coronary plaque and stenosis in need for further cardiovascular workup. |
6. | M. Zreik; T. Leiner; B.D. de Vos; R.W. van Hamersvelt; M.A. Viergever; I. Isgum Automatic segmentation of the left ventricle in cardiac CT angiography using convolutional neural networks Inproceedings In: IEEE International Symposium on Biomedical Imaging, pp. pp. 40-43, 2016. @inproceedings{zreik:2016-3002, title = {Automatic segmentation of the left ventricle in cardiac CT angiography using convolutional neural networks}, author = {M. Zreik and T. Leiner and B.D. de Vos and R.W. van Hamersvelt and M.A. Viergever and I. Isgum}, year = {2016}, date = {2016-01-01}, booktitle = {IEEE International Symposium on Biomedical Imaging}, pages = {pp. 40-43}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Abstracts |
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1. | R.W. van Hamersvelt, M. Zreik, M. Voskuil, I. Išgum, T. Leiner Deep learning-based analysis of the left ventricular myocardium in coronary CTA images improves specificity for detection of functionally significant coronary artery stenosis Abstract In: 2018. @booklet{vanHamersvelt2018, title = {Deep learning-based analysis of the left ventricular myocardium in coronary CTA images improves specificity for detection of functionally significant coronary artery stenosis}, author = {R.W. van Hamersvelt, M. Zreik, M. Voskuil, I. Išgum, T. Leiner}, year = {2018}, date = {2018-03-01}, booktitle = {European Congress of Radiology (ECR)}, abstract = {Purpose: To evaluate the added value of fully automatic deep learning-based analysis of left ventricular myocardium (LVM) in addition to routine stenosis degree assessment for the detection of functionally significant coronary artery stenosis in resting coronary computed tomography angiography (CCTA). Methods and Materials: We retrospectively studied 126 consecutive patients (76.9% male) who received a CCTA within one year prior to an invasive fractional flow reserve (FFR) measurement. An FFR≤0.80 and/or PCI performed was used as a reference to indicate a functionally significant stenosis. Resting CCTA scans were performed on a 256-slice CT. Stenosis degree was categorised as 0%, 1-30%, 31-49%, 50-69% and ≥70% by visual assessment. Patients with stenosis ≥70% were considered significant and ≤30% non-significant. Patients with intermediate stenosis (31-69%) were referred for deep learning analysis of the LVM evaluating presence of functionally significant stenosis. LVM was automatically segmented using a multiscale convolutional neural network and subsequently characterised using a convolutional auto-encoder. Using these encodings, patients with functionally significant stenosis were identified using a support vector machine classifier. Diagnostic performance of the combined method was compared with stenosis degree evaluation on CCTA alone (≥50% stenosis indicating functional significance). Results: In 84 patients (66.7%) a functionally significant stenosis was present. Sensitivity and specificity of stenosis degree evaluation alone (cut-off≥50%) were 91.7% and 31.0%. The combined method resulted in an increase in specificity to 50% with only minor decrease in sensitivity (82.1%). Conclusion: Adding deep learning-based analysis of the LVM to stenosis grading improves specificity with only minor decrease in sensitivity.}, month = {03}, keywords = {}, pubstate = {published}, tppubtype = {booklet} } Purpose: To evaluate the added value of fully automatic deep learning-based analysis of left ventricular myocardium (LVM) in addition to routine stenosis degree assessment for the detection of functionally significant coronary artery stenosis in resting coronary computed tomography angiography (CCTA). Methods and Materials: We retrospectively studied 126 consecutive patients (76.9% male) who received a CCTA within one year prior to an invasive fractional flow reserve (FFR) measurement. An FFR≤0.80 and/or PCI performed was used as a reference to indicate a functionally significant stenosis. Resting CCTA scans were performed on a 256-slice CT. Stenosis degree was categorised as 0%, 1-30%, 31-49%, 50-69% and ≥70% by visual assessment. Patients with stenosis ≥70% were considered significant and ≤30% non-significant. Patients with intermediate stenosis (31-69%) were referred for deep learning analysis of the LVM evaluating presence of functionally significant stenosis. LVM was automatically segmented using a multiscale convolutional neural network and subsequently characterised using a convolutional auto-encoder. Using these encodings, patients with functionally significant stenosis were identified using a support vector machine classifier. Diagnostic performance of the combined method was compared with stenosis degree evaluation on CCTA alone (≥50% stenosis indicating functional significance). Results: In 84 patients (66.7%) a functionally significant stenosis was present. Sensitivity and specificity of stenosis degree evaluation alone (cut-off≥50%) were 91.7% and 31.0%. The combined method resulted in an increase in specificity to 50% with only minor decrease in sensitivity (82.1%). Conclusion: Adding deep learning-based analysis of the LVM to stenosis grading improves specificity with only minor decrease in sensitivity. |
2. | R. van Hamersvelt, M. Zreik, N. Lessmann, J. Wolterink, M. Voskuil, M.A Viergever, T. Leiner, I. Isgum Improving Specificity of Coronary CT Angiography for the Detection of Functionally Significant Coronary Artery Disease: A Deep Learning Approach Abstract In: 2017. @booklet{vanHamersvelt2017, title = {Improving Specificity of Coronary CT Angiography for the Detection of Functionally Significant Coronary Artery Disease: A Deep Learning Approach}, author = {R. van Hamersvelt, M. Zreik, N. Lessmann, J. Wolterink, M. Voskuil, M.A Viergever, T. Leiner, I. Isgum}, year = {2017}, date = {2017-11-30}, booktitle = {Radiological Society of North America, 103rd Annual Meeting}, abstract = {PURPOSE Coronary computed tomography angiography (CCTA) is an increasingly important diagnostic tool for the detection of coronary artery disease (CAD). However, due to calcium blooming and beam hardening, specificity for diagnosing functionally significant CAD is limited. The purpose of this study was to evaluate to what extent the specificity of CCTA for detection of functionally significant CAD could be improved by combining simple stenosis grading with deep-learning based analysis of left ventricular myocardium (LVM). METHOD AND MATERIALS We retrospectively included 126 patients (77% male, 58.7±9.5 years) who underwent CCTA prior to invasive fractional flow reserve (FFR). Functionally significant CAD was defined as an invasively measured FFR value below 0.78. First, the presence and degree of coronary artery stenosis was analyzed using the CAD-RADS system. Patients without a significant stenosis reported on CCTA scans were scored as functionally non-significant. For the remaining patients, fully automatic deep learning analysis of the LVM was used to identify presence of functionally significant CAD. LVM was first segmented using a convolutional neural network and then characterized by a convolutional auto-encoder (CAE). Based on the encodings generated by the CAE a support vector machine classifier identified patients with functionally significant stenosis. Diagnostic performance of this combined analysis was evaluated and compared with patient identification based only on ≥50% stenosis degree as measured in CCTA. RESULTS FFR was significant in 64 (51%) of the patients. Sensitivity and specificity of stenosis degree reported on CCTA alone were 91% and 18%, respectively. Adding deep-learning based analysis of LVM to stenosis detection resulted in improved specificity with a slight decline in sensitivity. The combined evaluation resulted in a sensitivity of 83% and a specificity of 73%. CONCLUSION Our results show that, at the expense of only a mild sensitivity decrease, a combination of clinical stenosis evaluation and automatic LVM analysis in CCTA led to substantial increase of the specificity. CLINICAL RELEVANCE/APPLICATION Adding deep learning analysis of LVM to stenosis assessment holds the potential to substantially increase specificity of CCTA and to decrease number of patients unnecessarily referred to invasive FFR.}, month = {11}, keywords = {}, pubstate = {published}, tppubtype = {booklet} } PURPOSE Coronary computed tomography angiography (CCTA) is an increasingly important diagnostic tool for the detection of coronary artery disease (CAD). However, due to calcium blooming and beam hardening, specificity for diagnosing functionally significant CAD is limited. The purpose of this study was to evaluate to what extent the specificity of CCTA for detection of functionally significant CAD could be improved by combining simple stenosis grading with deep-learning based analysis of left ventricular myocardium (LVM). METHOD AND MATERIALS We retrospectively included 126 patients (77% male, 58.7±9.5 years) who underwent CCTA prior to invasive fractional flow reserve (FFR). Functionally significant CAD was defined as an invasively measured FFR value below 0.78. First, the presence and degree of coronary artery stenosis was analyzed using the CAD-RADS system. Patients without a significant stenosis reported on CCTA scans were scored as functionally non-significant. For the remaining patients, fully automatic deep learning analysis of the LVM was used to identify presence of functionally significant CAD. LVM was first segmented using a convolutional neural network and then characterized by a convolutional auto-encoder (CAE). Based on the encodings generated by the CAE a support vector machine classifier identified patients with functionally significant stenosis. Diagnostic performance of this combined analysis was evaluated and compared with patient identification based only on ≥50% stenosis degree as measured in CCTA. RESULTS FFR was significant in 64 (51%) of the patients. Sensitivity and specificity of stenosis degree reported on CCTA alone were 91% and 18%, respectively. Adding deep-learning based analysis of LVM to stenosis detection resulted in improved specificity with a slight decline in sensitivity. The combined evaluation resulted in a sensitivity of 83% and a specificity of 73%. CONCLUSION Our results show that, at the expense of only a mild sensitivity decrease, a combination of clinical stenosis evaluation and automatic LVM analysis in CCTA led to substantial increase of the specificity. CLINICAL RELEVANCE/APPLICATION Adding deep learning analysis of LVM to stenosis assessment holds the potential to substantially increase specificity of CCTA and to decrease number of patients unnecessarily referred to invasive FFR. |
3. | M. Zreik, N. Lessmann, R. van Hamersvelt, J. Wolterink, M. Voskuil, M.A Viergever, T. Leiner, I. Isgum Deep learning analysis of the left ventricular myocardium in cardiac CT images enables detection of functionally significant coronary artery stenosis regardless of coronary anatomy Abstract In: 2017. @booklet{Zreik2017, title = {Deep learning analysis of the left ventricular myocardium in cardiac CT images enables detection of functionally significant coronary artery stenosis regardless of coronary anatomy}, author = {M. Zreik, N. Lessmann, R. van Hamersvelt, J. Wolterink, M. Voskuil, M.A Viergever, T. Leiner, I. Isgum}, year = {2017}, date = {2017-08-23}, booktitle = {Radiological Society of North America, 103rd Annual Meeting}, abstract = {PURPOSE Fractional flow reserve (FFR), performed during invasive coronary angiography (ICA), is the current reference standard to determine the functional significance of a coronary stenosis. Coronary Computed Tomography Angiography (CCTA) derived virtual FFR is a promising but time and computationally expensive non-invasive alternative that can reduce the number of unnecessary ICA procedures by modeling coronary artery flow dynamics. We propose a method for fully automatic identification of patients with significant coronary artery stenosis based on deep learning analysis of only the left ventricle (LV) myocardium in CCTA. METHOD AND MATERIALS The study included resting CCTA scans (Philips Brilliance iCT, 120kVp, 210-300mAs) of 166 consecutive patients (59.2 ± 9.5 years, 128 males) who underwent invasive FFR (0.79 ± 0.10). FFR provided the reference for presence of a functionally significant stenosis (cut-off 0.78) . Automatic analysis first segmented the LV myocardium using a multiscale convolutional neural network (CNN). Next, the segmented myocardium was represented with a number of encodings generated by a convolutional auto-encoder (CAE). To detect local ischemic changes, the LV myocardium was divided into a number of spatially connected clusters. Per-cluster statistics of the encodings were subsequently used by a support vector machine classifier to identify patients with functionally significant stenosis. CCTA scans of 20 patients were used to train the CNN, and an additional 20 scans were used to train the CAE. Accuracy of patient classification was evaluated using the remaining 126 CCTA scans in 50 ten-fold cross-validation experiments. In each experiment, patients were randomly assigned to training and test sets. RESULTS Classification of patients resulted in an area under the receiver operating characteristic curve of 0.74 ± 0.02. At sensitivity levels 0.60, 0.70 and 0.80, the corresponding specificity was 0.77, 0.71 and 0.59, respectively. CONCLUSION The results demonstrate that fully automatic analysis of only the LV myocardium in resting CCTA scans, without assessment of the anatomy of the coronary arteries, can be used to identify patients with functionally significant coronary artery stenosis. CLINICAL RELEVANCE/APPLICATION Deep learning analysis of the LV myocardium could increase the specificity of the clinically used visual stenosis assessment in CCTA and reduce the number of patients undergoing unnecessary ICA.}, month = {08}, keywords = {}, pubstate = {published}, tppubtype = {booklet} } PURPOSE Fractional flow reserve (FFR), performed during invasive coronary angiography (ICA), is the current reference standard to determine the functional significance of a coronary stenosis. Coronary Computed Tomography Angiography (CCTA) derived virtual FFR is a promising but time and computationally expensive non-invasive alternative that can reduce the number of unnecessary ICA procedures by modeling coronary artery flow dynamics. We propose a method for fully automatic identification of patients with significant coronary artery stenosis based on deep learning analysis of only the left ventricle (LV) myocardium in CCTA. METHOD AND MATERIALS The study included resting CCTA scans (Philips Brilliance iCT, 120kVp, 210-300mAs) of 166 consecutive patients (59.2 ± 9.5 years, 128 males) who underwent invasive FFR (0.79 ± 0.10). FFR provided the reference for presence of a functionally significant stenosis (cut-off 0.78) . Automatic analysis first segmented the LV myocardium using a multiscale convolutional neural network (CNN). Next, the segmented myocardium was represented with a number of encodings generated by a convolutional auto-encoder (CAE). To detect local ischemic changes, the LV myocardium was divided into a number of spatially connected clusters. Per-cluster statistics of the encodings were subsequently used by a support vector machine classifier to identify patients with functionally significant stenosis. CCTA scans of 20 patients were used to train the CNN, and an additional 20 scans were used to train the CAE. Accuracy of patient classification was evaluated using the remaining 126 CCTA scans in 50 ten-fold cross-validation experiments. In each experiment, patients were randomly assigned to training and test sets. RESULTS Classification of patients resulted in an area under the receiver operating characteristic curve of 0.74 ± 0.02. At sensitivity levels 0.60, 0.70 and 0.80, the corresponding specificity was 0.77, 0.71 and 0.59, respectively. CONCLUSION The results demonstrate that fully automatic analysis of only the LV myocardium in resting CCTA scans, without assessment of the anatomy of the coronary arteries, can be used to identify patients with functionally significant coronary artery stenosis. CLINICAL RELEVANCE/APPLICATION Deep learning analysis of the LV myocardium could increase the specificity of the clinically used visual stenosis assessment in CCTA and reduce the number of patients undergoing unnecessary ICA. |