In this paper, we propose a method dedicated to classification between benign and malignant lesions in Dermatology in the aim to help the clinicians for melanoma diagnosis'. The proposed methodology reduces the ve...
详细信息
ISBN:
(纸本)3540651365
In this paper, we propose a method dedicated to classification between benign and malignant lesions in Dermatology in the aim to help the clinicians for melanoma diagnosis'. The proposed methodology reduces the very numerous informations contained in the digitized images to a finite set of parameters giving a description of the colour and the shape of the lesions. The whole process is shared in three steps: preprocessing, segmentation and classification of the lesions. The proposed method was applied on a data base of 38 lesions (20 benign lesions and 18 malignant lesions) in the aim to assess the feasability of the proposed method. The good classification rate obtained with the method is discussed and Inter tests to engage are underlined.
We have implemented automatic 3D thin-plate spline warping as a geometric interpolant to map one dataset volume onto another. Homologous control points in one space are iteratively moved by an optimizer to maximize th...
详细信息
ISBN:
(纸本)3540651365
We have implemented automatic 3D thin-plate spline warping as a geometric interpolant to map one dataset volume onto another. Homologous control points in one space are iteratively moved by an optimizer to maximize the global mutual information between the two data volumes. Given two different poses between highly deformed objects we desire to compute the relative geometric deformation using a minimal set of control points as determined by number and placement. The general solution to this problem is not known. In this paper we assess retrospective control point selection for the case of significant patient motion during MRI breast imaging.
This paper describes the FRACAS computer-integrated orthopaedic system for assisting surgeons in closed long bone fracture reduction. FRACAS' goals are to reduce the surgeon's cumulative exposure to radiation ...
详细信息
ISBN:
(纸本)3540651365
This paper describes the FRACAS computer-integrated orthopaedic system for assisting surgeons in closed long bone fracture reduction. FRACAS' goals are to reduce the surgeon's cumulative exposure to radiation and improve the positioning accuracy by replacing uncorrelated static fluoroscopic images with a virtual reality display of 3D bone models created from preoperative CT and tracked intraoperatively in real-time. Fluoroscopic images are used to register the bone models to the intraoperative situation and to verify that the registration is maintained. This paper describes the system concept, and the software prototypes of the modeling, preoperative planning, and visualization modules.
In recent years, the quantitative analysis of MRI data has become a standard surrogate marker in clinical trials in multiple sclerosis (MS). We have developed INSECT (Intensity Normalized Stereotaxic Environment for C...
详细信息
ISBN:
(纸本)3540651365
In recent years, the quantitative analysis of MRI data has become a standard surrogate marker in clinical trials in multiple sclerosis (MS). We have developed INSECT (Intensity Normalized Stereotaxic Environment for Classification of Tissues), a fully automatic system aimed at the quantitative morphometric analysis of 3D MRI brain data sets. This paper describes the design and validation of INSECT in the context of a multi-center clinical trial in MS. It is shown that no statistically significant differences exist between MS lesion load measurements obtained with INSECT and those obtained manually by trained human observers from seven different clinical centers.
A three-dimensional pre-surgical planner and image-guided surgery system for high tibial osteotomy has been developed. The planning software permits a surgeon to establish the tibial axes, plan the corrective osteotom...
详细信息
ISBN:
(纸本)3540651365
A three-dimensional pre-surgical planner and image-guided surgery system for high tibial osteotomy has been developed. The planning software permits a surgeon to establish the tibial axes, plan the corrective osteotomy, and visualize both the preoperative state and the predicted postoperative state in three dimensions. The parameters that describe the placement and orientation of the osteotomy resection planes can be transmitted to an accompanying guidance system that allows the surgeon to accurately perform the planned procedure. Tests were performed in vitro to compare the accuracy of the computer-enhanced technique to the traditional technique, and an in vivo pilot study has been initiated. The computer-enhanced technique produced a significant reduction in the error of correction and is simple to use while performing the surgical procedure. The work indicates that three-dimensional planning and surgical performance of high tibial osteotomy is essential to the accuracy of the procedure.
作者：
Mangin, JFCoulon, OFrouin, VCEA
Serv Hosp Frederic Joliot Dept Rech Med Direct Sci Vivant F-91406 Orsay France ENST
Dept Signal & Image Paris France
In this paper, we propose a robust fully non-supervised method dedicated to the segmentation of the brain in T1-weighted MR images. The first step consists in the analysis of the scale-space of the histogram first and...
详细信息
ISBN:
(纸本)3540651365
In this paper, we propose a robust fully non-supervised method dedicated to the segmentation of the brain in T1-weighted MR images. The first step consists in the analysis of the scale-space of the histogram first and second derivative. We show first that the crossings in scale-space of trajectories of extrema of different derivative orders follow regular topological properties. These properties allow us to design a new structural representation of a 1D signal. Then we propose an heuristics using this representation to infer statistics on grey and white matter grey level values from the histogram. These statistics are used by an improved morphological process combining two opening sizes to segment the brain. The method has been validated with 70 images coming from 3 different scanners and acquired with various MR sequences.
We present a hierarchical object-based deformable atlas, a promising new approach for the automatic localization and quantitative analysis of neuroanatomy in MR images. The 3D finite element-based elastic atlas combin...
详细信息
ISBN:
(纸本)3540651365
We present a hierarchical object-based deformable atlas, a promising new approach for the automatic localization and quantitative analysis of neuroanatomy in MR images. The 3D finite element-based elastic atlas combines the advantages of both volumetric- and surface-based deformable atlases in one single unifying framework. This multiresolution framework is not only capable of deforming entire volumes or subvolumes but can deform individual atlas objects, allowing greater and more effective use of object shape and local image feature information. Object surface representations are embedded in the volumetric deformable atlas and image-feature-derived forces acting on these surfaces are automatically transferred to the containing 3D finite element lattice. Consequently, spatial relationship constraints of the atlas objects are maintained via the elastic lattice while an object is deformed to match a target boundary. Atlas objects are deformed in a hierarchical fashion, begining with objects exhibiting well-defined image features in the target scan and proceeding to objects with slightly less well-defined features. Experiments involving several subcortical atlas objects are presented.
Registration error resulting from intraoperative brain shift due to applied surgical loads has long been recognized as one of the most challenging problems in the field of frameless stereotactic neurosurgery. To addre...
详细信息
ISBN:
(纸本)3540651365
Registration error resulting from intraoperative brain shift due to applied surgical loads has long been recognized as one of the most challenging problems in the field of frameless stereotactic neurosurgery. To address this problem, we have developed a 3-dimensional finite element model of the brain and have begun to quantify its predictive capability in an in vivo porcine model. Previous studies have shown that we can predict the average total displacement within 15% and 6.6% error using intraparenchymal and temporal deformation sources, respectively, under relatively simple model assumptions. In this paper, we present preliminary results using a heterogeneous model with an expanding temporally located mass and show that we are capable of predicting an average total displacement to 5.7% under similar model initial and boundary conditions. We also demonstrate that our approach can be viewed as having the capability of recapturing approximately 75% of the registration inaccuracy that may be generated by preoperative-based image-guided neurosurgery.
3D reconstruction of arterial vessels from planar radiographs obtained at several angles around the object has gained increasing interest. The motivating application has been interventional angiography. In order to ob...
详细信息
ISBN:
(纸本)3540651365
3D reconstruction of arterial vessels from planar radiographs obtained at several angles around the object has gained increasing interest. The motivating application has been interventional angiography. In order to obtain a three-dimensional reconstruction from a C-arm mounted X-Ray image Intensifier (XRII) traditionally the trajectory of the source and the detector system is characterized and the pixel size is estimated. The main use of the imaging geometry characterization is to provide a correct 3D-2D mapping between the 3D voxels to be reconstructed and the 2D pixels on the radiographic images. We propose using projection matrices directly in a voxel driven backprojection for the reconstruction as opposed to that of computing all the geometrical parameters, including the imaging parameters. We discuss the simplicity of the entire calibration-reconstruction process, and the fact that it makes the computation of the pixel size, source to detector distance, and other explicit imaging parameters unnecessary. A usual step in the reconstruction is sinogram weighting, in which the projections containing corresponding data from opposing directions have to be weighted before they are filtered and backprojected into the object space. The rotation angle of the C-arm is used in the sinogram weighting. This means that the C-arm motion parameters must be computed from projection matrices. The numerical instability associated with the decomposition of the projection matrices into intrinsic and extrinsic parameters is discussed in the context. The paper then describes our method of computing motion parameters without matrix decomposition. Examples of the calibration results and the associated volume reconstruction are also shown.
The proceedings contain 134 papers. The special focus in this conference is on Surgical Planning, Surgical Navigation and Measurements. The topics include: Planning and evaluation of reorienting osteotomies of the pro...
ISBN:
(纸本)3540651365
The proceedings contain 134 papers. The special focus in this conference is on Surgical Planning, Surgical Navigation and Measurements. The topics include: Planning and evaluation of reorienting osteotomies of the proximal femur in cases of SCFE using virtual three-dimensional models;computer-aided planning of patellofemoral joint OA surgery;computerassisted orthognathic surgery;computer-aided image-guided bone fracture surgery;a surgical planning and guidance system for high tibial osteotomies;measurement of intraoperative brain surface deformation under a craniotomy;clinical experience with a high precision image-guided neurosurgery system;three-dimensional reconstruction and surgical navigation in pediatric epilepsy surgery;treatment of pelvic ring fractures;model tags;quantitative three dimensional echocardiograpy;measurement of 3d motion of myocardial material points from explicit b-surface reconstruction of tagged MRI data;multiscale vessel enhancement filtering;fast quantification of abdominal aortic aneurysms from CTA volumes;3-D fusion of biplane angiography and intrawascular ultrasound for accurate visualization and volumetry;patient-specific analysis of left ventricular blood flow;dense 2d displacement reconstruction from SPAMM-MRI with constrained elastic splines: implementation and validation;motion analysis of the right ventricle from mri images;magnetic resonance guided radiofrequency ablation;human versus robotic organ retraction during laparoscopic nissen fundoplication;a new laparoscope manipulator with an optical zoom;a newly developed stereotactic robot with detachable drive for neurosurgery;calibration of video cameras to the coordinate system of a radiation therapy treatment machine and an image overlay system for medical data visualization and volumetric image guidance via a stereotactic endoscope.
暂无评论