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In this note, we present an approach for developing patient-specific 3D models of portal veins to provide geometric boundary conditions for computational fluid dynamics (CFD) simulations of the blood flow inside portal veins. The study is based on MRI liver images of individual patients to which we apply image registration and segmentation techniques and inlet and outlet velocity profiles acquired...
This paper outlines a semi-automated intra-operative fluoroscopy guidance and monitoring approach for osteotomy and external-fixator application in orthopedic surgery. Intra-operative Guidance module is one component of the "LegPerfect Suite" developed for assisting the surgical correction of lower extremity angular deformity. The Intra-operative Guidance module utilizes information from...
In this note, we present an approach for developing patient-specific 3D models of portal veins to provide geometric boundary conditions for computational fluid dynamics (CFD) simulations of the blood flow inside portal veins. The study is based on MRI liver images of individual patients to which we apply image registration and segmentation techniques and inlet and outlet velocity profiles acquired...
A novel algorithm for performing registration of dynamic contrast-enhanced (DCE) MRI data of the breast is presented. It is based on an algorithm known as iterated dynamic programming originally devised to solve the stereo matching problem. Using artificially distorted DCE-MRI breast images it is shown that the proposed algorithm is able to correct for movement and distortions over a larger range...
Combined PET/CT scanners provide the ability to produce matching metabolic (from PET) and anatomic (from CT) information in a single examination. However, misalignments continue to exist in tumor localization in PET and CT images acquired using these scanners, due to their inability to compensate for nonrigid misalignment resulting from patient breathing and involuntary movement. We demonstrate that...
Image fusion, or combination of two images obtained by different techniques, has been widely used in medical imaging. Vibro-acoustography (VA) is a new imaging modality that has been applied to both medical and industrial imaging. Combining unique diagnostic information of VA with other medical imaging is one of our research interests. In this work, we studied the VA and X-ray image pairs and adopted...
The paper describes restitution of geometrical distortions and improvement of signal-to-noise ratio of auto-fluorescence retinal images, finally aimed at segmentation and area estimation of the lipofuscin spots as one of the features to be included in glaucoma diagnosis. The main problems - geometrical and illumination incompatibility of frames in the image sequence and a non-negligible "shear"...
Thermography captures the temperature distribution of the human skin and is employed in various medical applications. Often it is useful to cross-reference the resulting thermograms with visual images of the patient, either to see which part of the anatomy is affected by a certain disease or to judge the efficacy of the treatment. An attractive approach to provide this information is to overlay the...
Dynamic infrared imaging has been proposed in literature as an interesting adjunctive technique to mammography in breast cancer diagnosis. For a correct analysis of the infrared image sequences, however, a preprocessing registration step may be fundamental. In this paper, we provide a first quantitative evaluation of the performances of registration on dynamic infrared images for this specific application...
This paper presents a phantom study that was conducted for an ultrasound-guided shoulder arthroscopy navigation system. The navigation system uses a surface model generated from pre-operative computed tomography images, which has to be registered to the patient during the procedure. The goal of this study was to determine the optimal regions on the scapula bone of the shoulder to achieve an acceptable...
Detection of unruptured aneurysms is a major task in magnetic resonance angiography (MRA). However, it is difficult for radiologists to detect small aneurysms on the maximum intensity projection (MIP) images because adjacent vessels may overlap with the aneurysms. Therefore, we proposed a method for making a new MIP image, the SelMIP image, with the interested vessels only, as opposed to all vessels,...
An image registration technique based on feed forward neural network and Fourier Transform is developed and presented. In the proposed scheme, the spectrums of the acquired images are computed, the Fourier coefficients within a selected central window of each spectrum are extracted and fed as inputs to the neural network. The feed forward neural network is implemented to estimate the transformation,...
High-throughput gene expression is an important aspect of modern post-genomic research. Microarray technology is the driving force of this revolution, a technology that allows the simultaneous monitoring of expression for thousands of genes. The need for accurate and reproducible research has driven the development of robust analysis frameworks for maximizing the information content of biological...
Periventricular leukomalacia (PVL) is a neonatal brain pathology occuring on preterms with a very low birth weight (<1500 g). Next to ultrasound (US) imaging, which is the first and most common step, magnetic resonance image (MRI) volumes are used for the inspection of this pathology. Since on both modalities, up to now, we still lack a golden standard for the quantification of the pathology cross-validation...
Current density imaging (CDI) is a technique that uses magnetic resonance imaging (MRI) to measure the distribution of externally applied electric current inside tissues. However, GDI processing is rendered inaccurate by the distortion caused by the nonlinearity of MRI gradient fields. The distortion interferes with the proper registration and the curl operation required for correct computation of...
A method is presented to validate the segmentation of computed tomography (CT) image sequences, and im prove the accuracy and efficiency of the subsequent registration of the 3D surfaces that are reconstructed from the segmented slices. The method compares the shapes of contours extracted from neighborhoods of slices in CT stacks of tibias. The bone is first segmented by an automatic segmentation...
Rapid advances in 18FDG-PET/CT technology and novel co-registration algorithms have created a strong interest in 18 FDG-PET/CT's application in intensity modulated radiation therapy (IMRT) and image-guided radiation therapy (IGRT). Accurate target volume delineation, particularly identification of pathologically positive lymph nodes, could translate into favorable treatment outcome. However, gross...
We propose a new similarity measure for medical image registration and make comparisons with two kinds of mutual information (MI) methods in the literature. This new measure is computed from the normal vector information (NVI) of the images instead of pixel intensity that the MI methods based. The NVI of an image is extracted from the relationship between pixels and computed from the normal vector...
This paper outlines a semi-automated intra-operative fluoroscopy guidance and monitoring approach for osteotomy and external-fixator application in orthopedic surgery. Intra-operative Guidance module is one component of the "LegPerfect Suite" developed for assisting the surgical correction of lower extremity angular deformity. The Intra-operative Guidance module utilizes information from...
Image guided radiotherapy can be performed by fusing the daily treatment and reference planning computed tomography scans. Decreased errors in patient setup can lead to smaller target margins that significantly improve treatment efficacy and outcome. The purpose of this work is to present a clinical procedure to analytically compute the accuracy of the registration. Accepted techniques such as normalized...
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