The aim was to evaluate the effects of Functional Endoscopic Sinus Surgery (FESS) on nasal aerody... more The aim was to evaluate the effects of Functional Endoscopic Sinus Surgery (FESS) on nasal aerodynamic flow patterns using Computational Fluid Dynamics (CFD) simulations. A 3-dimensional model of nasal cavity was first constructed from CT scans of a human subject with FESS interventions on left nasal cavity. Computational fluid dynamics (CFD) simulations were then carried out for unsteady airflow inside the nasal cavity as well as the sinuses. Comparisons of the local velocity magnitude and streamline distributions inside the left and right nasal cavity and maxillary sinus regions were presented. Existence and distributions of local circulations (vortexes) were found to be different at different phases, which showed the importance of local inertial effects especially in the sinus around FESS operated region. Possible outcomes on functional performances of the nose were also examined and discussed. Such physical assessments of nasal airflow based on a model from the patient's CT scans may help clinicians to determine the best treatment in advance.
In this paper, we consider the extraction of nasopharyngeal carcinoma lesion from MR images as a ... more In this paper, we consider the extraction of nasopharyngeal carcinoma lesion from MR images as a region segmentation problem. We propose a semi-supervised segmentation approach to segment the lesion in two steps. First, a metric is learned in a supervised fashion, which maximizes the separation between two groups of pixels (tumor or non-tumor) with minimal user interaction. Second, the learned metric is used to complete extraction of tumor region in an unsupervised fashion. Several experiments were conducted to evaluate the performance of similar methods with learned metrics for grouping or classifying pixels to form the tumor region. It is observed that the spectral clustering-based method performs well and the performance is comparable or marginally better than the discriminative SVM-based method.
Three-dimensional segmentation is reliable approach to achieve a proper estimation of tumor volum... more Three-dimensional segmentation is reliable approach to achieve a proper estimation of tumor volume. Among all possible methods for this purpose, level set can be used as a powerful tool which implicitly extracts the tumor surface. In this paper, we introduce a threshold-based algorithm for 3D tumor segmentation using level set (TSL). This algorithm uses a global threshold to form the level set speed function which is updated iteratively throughout the level set grow-ing process. An important feature of TSL is that no explicit knowledge about the tumor and non-tumor density functions is required. The proposed method can be implemented in the automatic and semi-automatic forms depending on the complexity of the tumor shape. TSL is examined on several clinical MRIs for both visual and quantitative evaluation. Experimental results demonstrate the effectiveness of our approach. 1.
In image segmentation, one challenge is how to deal with the nonlinearity of real data distributi... more In image segmentation, one challenge is how to deal with the nonlinearity of real data distribution, which often makes segmentation methods need more human interactions and make unsatisfied segmentation results. In this paper, we formulate this research issue as a one-class learning problem from both theoretical and practical viewpoints with application on medical image segmentation. For that, a novel and user-friendly tumor segmentation method is proposed by exploring one-class support vector machine (SVM), which has the ability of learning the nonlinear distribution of the tumor data without using any prior knowledge. Extensive experimental results obtained from real patients ’ medical images clearly show that the proposed unsupervised one-class SVM segmentation method outperforms supervised two-class SVM segmentation method in terms of segmentation accuracy, speed and with less human intervention. 1.
It was a hectic but immensely enjoyable week for me. Following the ICIS meeting in Paris, I flew ... more It was a hectic but immensely enjoyable week for me. Following the ICIS meeting in Paris, I flew home to Singapore for an overnight stop before heading off to the Philippines, a nation comprising of more than 7000 islands. (The exact number of islands, I was told, depends on whether it is high tide or low tide!) Anyway, it was a great honour to be invited by the Philippines CT and MRI Society to speak on Head & Neck Oncological Imaging. When Magellan came upon the island of Homonhon in 1521, he claimed these islands in the name of King Philip II of Spain and named them Felipinas (and hence, the Philippines). Recognising the potential of these strategically located islands, the Spaniards established a colonial government in Manila in 1571 and from there, ruled the country and the galleon trade for nearly 333 years. The first nationalistic revolution took place in 1896 and after several attempts, the Philippines declared her first independence on June 12, 1898. This republic was short...
Colorectal cancer is the third most common cancer in both men and women. Mixed adenoneuroendocrin... more Colorectal cancer is the third most common cancer in both men and women. Mixed adenoneuroendocrine carcinoma is a rare subtype of colorectal cancer defined as malignant neoplasms in which each component represents at least 30% of the lesion. It was named as Mixed adenoneuroendocrine carcinoma and described by the World Health Organization in 2010. Due to its morphological heterogeneity and the rarity of the condition, it becomes quite challenging to formulate an appropriate treatment plan. In this report, we present a case of 67-year-old man found to have a rectal mixed adenoneuroendocrine carcinoma. We discussed the current management strategies and provide a review of the literature.
The aim was to evaluate the effects of Functional Endoscopic Sinus Surgery (FESS) on nasal aerody... more The aim was to evaluate the effects of Functional Endoscopic Sinus Surgery (FESS) on nasal aerodynamic flow patterns using Computational Fluid Dynamics (CFD) simulations. A 3-dimensional model of nasal cavity was first constructed from CT scans of a human subject with FESS interventions on left nasal cavity. Computational fluid dynamics (CFD) simulations were then carried out for unsteady airflow inside the nasal cavity as well as the sinuses. Comparisons of the local velocity magnitude and streamline distributions inside the left and right nasal cavity and maxillary sinus regions were presented. Existence and distributions of local circulations (vortexes) were found to be different at different phases, which showed the importance of local inertial effects especially in the sinus around FESS operated region. Possible outcomes on functional performances of the nose were also examined and discussed. Such physical assessments of nasal airflow based on a model from the patient's CT scans may help clinicians to determine the best treatment in advance.
In this paper, we consider the extraction of nasopharyngeal carcinoma lesion from MR images as a ... more In this paper, we consider the extraction of nasopharyngeal carcinoma lesion from MR images as a region segmentation problem. We propose a semi-supervised segmentation approach to segment the lesion in two steps. First, a metric is learned in a supervised fashion, which maximizes the separation between two groups of pixels (tumor or non-tumor) with minimal user interaction. Second, the learned metric is used to complete extraction of tumor region in an unsupervised fashion. Several experiments were conducted to evaluate the performance of similar methods with learned metrics for grouping or classifying pixels to form the tumor region. It is observed that the spectral clustering-based method performs well and the performance is comparable or marginally better than the discriminative SVM-based method.
Three-dimensional segmentation is reliable approach to achieve a proper estimation of tumor volum... more Three-dimensional segmentation is reliable approach to achieve a proper estimation of tumor volume. Among all possible methods for this purpose, level set can be used as a powerful tool which implicitly extracts the tumor surface. In this paper, we introduce a threshold-based algorithm for 3D tumor segmentation using level set (TSL). This algorithm uses a global threshold to form the level set speed function which is updated iteratively throughout the level set grow-ing process. An important feature of TSL is that no explicit knowledge about the tumor and non-tumor density functions is required. The proposed method can be implemented in the automatic and semi-automatic forms depending on the complexity of the tumor shape. TSL is examined on several clinical MRIs for both visual and quantitative evaluation. Experimental results demonstrate the effectiveness of our approach. 1.
In image segmentation, one challenge is how to deal with the nonlinearity of real data distributi... more In image segmentation, one challenge is how to deal with the nonlinearity of real data distribution, which often makes segmentation methods need more human interactions and make unsatisfied segmentation results. In this paper, we formulate this research issue as a one-class learning problem from both theoretical and practical viewpoints with application on medical image segmentation. For that, a novel and user-friendly tumor segmentation method is proposed by exploring one-class support vector machine (SVM), which has the ability of learning the nonlinear distribution of the tumor data without using any prior knowledge. Extensive experimental results obtained from real patients ’ medical images clearly show that the proposed unsupervised one-class SVM segmentation method outperforms supervised two-class SVM segmentation method in terms of segmentation accuracy, speed and with less human intervention. 1.
It was a hectic but immensely enjoyable week for me. Following the ICIS meeting in Paris, I flew ... more It was a hectic but immensely enjoyable week for me. Following the ICIS meeting in Paris, I flew home to Singapore for an overnight stop before heading off to the Philippines, a nation comprising of more than 7000 islands. (The exact number of islands, I was told, depends on whether it is high tide or low tide!) Anyway, it was a great honour to be invited by the Philippines CT and MRI Society to speak on Head & Neck Oncological Imaging. When Magellan came upon the island of Homonhon in 1521, he claimed these islands in the name of King Philip II of Spain and named them Felipinas (and hence, the Philippines). Recognising the potential of these strategically located islands, the Spaniards established a colonial government in Manila in 1571 and from there, ruled the country and the galleon trade for nearly 333 years. The first nationalistic revolution took place in 1896 and after several attempts, the Philippines declared her first independence on June 12, 1898. This republic was short...
Colorectal cancer is the third most common cancer in both men and women. Mixed adenoneuroendocrin... more Colorectal cancer is the third most common cancer in both men and women. Mixed adenoneuroendocrine carcinoma is a rare subtype of colorectal cancer defined as malignant neoplasms in which each component represents at least 30% of the lesion. It was named as Mixed adenoneuroendocrine carcinoma and described by the World Health Organization in 2010. Due to its morphological heterogeneity and the rarity of the condition, it becomes quite challenging to formulate an appropriate treatment plan. In this report, we present a case of 67-year-old man found to have a rectal mixed adenoneuroendocrine carcinoma. We discussed the current management strategies and provide a review of the literature.
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Papers by Vincent Chong