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Quantitative analysis of myocardial perfusion requires detection of myocardial boundaries in many short-axis MR images. Manual tracing of myocardial boundaries is a time-consuming and tedious task, which may limit the clinical use of quantitative analysis. In this paper, we propose an automatic detection algorithm based on active contours. For initialization, starting contours need to be defined....
Correctly counting the live cells plays a great role in the ectogenetic anti-virus experiment. According to the irregular shape and arbitrary size of the wall pasted Hela cells overlapping each other, we propose a scheme to segment and count the cells using Gabor filter with different parameters and morphological operation. Experiments reveal that filters with different parameters will lead to different...
This study is part of the research of improving early detection of breast cancer in screening mammograms by focusing on computerized analysis and detection of cancers missed by radiologists. It is directed to the analysis of breast density in missed cancer cases and the effect of tissue density on cancer detection. A total of 100 missed cancer cases were collected which were used to generate three...
Microscopic imaging is an important phenotyping tool to characterize the phenotype (e.g., morphology and behavior) change caused by genotype manipulation such as mutation and gene knockout. Recently we use high resolution microscopic imaging to study the morphological change on mouse placenta induced by retinoblast (Rb) gene knockout. In order to assess the morphological change we first segment each...
This paper focused on the brain magnetic resonance (MR) images, which is one of the key problems in image processing. A novel segmentation method based on watershed transform and wavelets transform is presented for white matter in thin sliced single-channel brain magnetic resonance scans. The original image is smoothed by using anisotropic filter and over-segmented by the watershed algorithm. Finally,...
Invasive intracranial electroencephalography (EEG) studies help identify the epileptogenic focus and assess if the identified zone overlies eloquent cortex by means of cortical stimulation. Proper interpretation and use of the intracranial recording/stimulation studies requires an effective display of multimodal information. We developed a software system which can combine the patient's segmented...
In the diagnosis and therapy of prostate cancer, it is critical to measure the volume of the prostate and locate its boundary. Three-dimensional transrectal ultrasound (3D TRUS) imaging has been demonstrated to be a useful technique to perform such a task. Due to image speckle as well as low contrast in ultrasound images, segmentation of the prostate in 3D US images is challenging. In this paper,...
The image segmentation based on active contour model is currently a hot-spot issue, among which Mumford-Shah model is an important method. To solve the problem of unbearable computing time, this paper intends to combine Mumford-Shah model and watershed algorithm in the image segmentation. Specifically, the image will be segmented firstly through Watershed algorithm and then the border produced will...
A very important artifact corrupting magnetic resonance images is the RF inhomogeneity. This kind of artifact generates variations of illumination which trouble both direct examination by the doctor and segmentation algorithms. Even if homomorphic filtering approaches have been presented in literature, none of them has developed a measure to determine the cut-off frequency. In this work we present...
A novel implementation of watershed transform using a multi-degree immersion simulation is presented in this paper. The method is based on the improvement of traditional watershed by simulating immersion, which is originally proposed by Vincent & Soille in 1991. By changing the simulation procedure to multi-degree, which means the flood step is different on each degree of intensity, the proposed...
This paper presents a method to locate wire center on performance phantom image to get MTF curve during CT spatial resolution measurement. We get the circular edge of the wire area by automatic threshold segmentation and edge tracking. After that, using Hough transform, we can locate the wire center automatically. Compared with old method, it's immune to noise and more convenient to operate. Experimental...
While focusing at accurate 3D joint kinematics, this paper explores the problem of how to perform a robust rigid registration for a sequence of object surfaces observed using standard 3D medical imaging techniques. Each object instance is assumed to give access to a polyhedral encoding of its boundary. We consider the case where object instances are noised with significant truncations and segmentation...
In this paper, a region level based image fusion technique, using wavelet transform, has been implemented and analyzed. The proposed methodology considers regions as the basic feature for representing images and uses region properties for extracting the information from them. A segmentation algorithm is proposed for extracting the regions in an effective way for fusing the images. The fusion strategy...
Automatic contouring for breast tumors using medical ultrasound (US) imaging may assist physicians, without relevant experience, in making correct diagnoses. This study utilizes the watershed transform and active contour model (ACM) to overcome the natural properties of US images, speckle, noise and tissue-related textures, to segment the breast tumors precisely. The watershed transform is performed...
The detection of unruptured intracranial aneurysms is a major subject in magnetic resonance angiography (MRA) images. However, it is difficult for radiologists to detect small aneurysms on the maximum intensity projection (MIP) images, because adjacent vessels overlap with the aneurysm. The purpose of this study was to develop an automated computerized detection of aneurysms in order to assist radiologists'...
Image signal-to-noise ratio (SNR) and signal intensity (SI) inhomogeneities are factors that strongly affect the accuracy and precision of brain tissue segmentations in magnetic resonance image (MRI). In this work, SNR and contrast of brain images are optimized by TR and inversion recovery time TI in multi-spectrum MRI data sets. SI inhomogeneities are measured in vivo using a recently developed method...
This paper describes a system for dynamic intraoperative prostate brachytherapy using 3D ultrasound guidance with robotic assistance. The system consists of 3D TRUS imaging, a robot and software for prostate segmentation, intraoperative planning, oblique needle segmentation and tracking, seed segmentation, and 3D dose planning. The robot and 3D TRUS coordinate systems are unified through robot and...
Recent advances in medical imaging have resulted in the introduction of dual-modality scanners which can simultaneously acquire two independent imaging modalities, such as positron emission tomography (PET) and computed tomography (CT) image data in a single session. These multi-dimensional PET-CT data contain both the functional and anatomical information of the human body, thus, providing the ability...
The accurate segmentation of the teeth from the triangle mesh is an important step in computer-aided orthodontic. Because teeth come in different shapes and their arrangements vary substantially from one individual to another, tooth segmentation is difficult. This paper proposes a new method to accurately segment the teeth interactively. Based on curvature values of the triangle mesh, feature points...
The FEM geometry modeling of realistic head is a key issue for the research on FEM-based EEG/MEG. In this paper, a methodology is developed to construct this kind of model. By using this method, a five -layer realistic head FEM model is obtained, and with its application in FEM-based EEG, a satisfying result shows the reliability of the model
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