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The application of process computed tomography to microchannels is considered in this paper. Using the process computed tomography system in microchannel, a particle distribution image can be obtained in a multiphase flow. Based on the reconstructed image, it is easy to estimate the particle diffusion behaviors in a fluid flow. A microchannel system is designed for process computed tomography. The...
Current available implant for total knee arthroplasty normally based on the western population knee. Asian knee were different from the European knee. A prospective morphometric study of the knee joint was carried out. One hundred (100) participants consisting of 50 males and 50 females were scanned using computed tomography equipment. The age of the participants vary from 19 to 38 years old, with...
The purpose of this study was to develop a quantitative method for myocardial blood flow (MBF) measurement that can be used to derive accurate myocardial perfusion measurements from contrast-enhanced multidetector computed tomography (MDCT) images with bolus tracking and helical scanning. Nine canine models of left anterior descending artery (LAD) stenosis were prepared and underwent MDCT perfusion...
The distensibility of a blood vessel is a marker of atherosclerotic disease. Manual measurement of the distensibility on CTA images is a difficult task. In this paper we describe a method to automatically determine the distensibility of the carotid artery by locally analyzing the deformation field of a nonrigid registration of a series of ECG-gated CTA images. We evaluate two variants of the method,...
Catheter ablation is an increasingly important curative procedure for atrial fibrillation. Knowledge of the local wall thickness is essential to determine the proper ablation energy. This paper presents the first semi-automatic atrial wall thickness measurement method for ablation guidance. It includes both endocardial and epicardial atrial wall segmentation on CT image data. Segmentation is based...
Fluid structure interaction (FSI) simulations of patient-specific fusiform non-ruptured and contained ruptured Abdominal Aortic Aneurysm (AAA) geometries were conducted. The goals were: (1) to test the ability of our FSI methodology to predict the location of rupture, by correlating the high wall stress regions with the rupture location, (2) estimate the state of the pathological condition by calculating...
In order to check validity of the porcine ligamentum flavum as a substitute of human tissue for evaluating the epidural needles, the thickness and the Young's modulus were measured, and a finite element analysis was carried out. Twenty-four specimens were stained by the Elastica-van Gieson method. The average value of the thickness was 1.2 mm. The tensile tester was employed for measuring the Young's...
3D computed tomography (CT) to single-plane 2D fluoroscopy registration is an emerging technology for many clinical applications such as kinematic analysis of human joints and image-guided surgery. However, previous registration approaches have suffered from the inaccuracy of determining precise motion parameters for out-of-plane movements. In this paper we compare kinematic measurements obtained...
The estimation of human femur morphology and angulation provide useful information for assisted surgery, follow-up evaluation and prosthesis design, cerebral palsy management, congenital dislocation of the hip and fractures of the femur. Conventional methods that estimate femoral neck anteversion employ planar projections because accurate 3D estimations require complex reconstruction routines. In...
The aim of this work was to create a method of an image data extracting to measure the intracranial fluids. This method can be used in medical practice for an exact diagnosis and a monitoring before and after patients' surgeries with hydrocephalus. Analyzed data were used from CT and MRI medical instruments. To solve this problem a software was designed and implemented. Semi-automatic selection of...
Measurement of cross-sectional area of spinal canal is always the research focus in medicine, so it has become more and more important to find an efficient and rational method. This paper proposes a new method, which uses coordinate axis rotation and projection transformation to measure the area. The advantages of this method are: transform the 3D measurement into 2D, reduces the computation complexity,...
Daily volume loss of the residual limp is reported as one of the greatest challenges in socket fitting. Assisted vacuum socket systems were developed to prevent stump's volume loss and maintain sufficient socket fit. There is however very little quantitative biomechanical research for the evaluation of below knee sockets with assisted vacuum systems. Highly accurate in-vivo measurements became recently...
In the framework of the realization of dedicated Cone-Beam Breast Computed Tomography (CBBCT) apparatus we report the MTF characterization of our prototype having the best performance in terms of detector pixel size and X ray focal spot than any other systems built or under construction. From our measurement we estimated a value of the longitudinal and transverse resolution of 4-5 lp/mm (at 10% MTF)...
In laser osteotomy bone is cut precisely with a laser. A robot is used to position an end-effector with a scanhead, which deflects the cutting laser. An optical tracking system (OTS) tracks the position of the bone, in our case a skull, and the end effector. The skull is registered to its model, based on a segmented CT data, as well as the robot to the OTS. With this a complete transformation chain...
In conventional CT-assisted perfusion imaging the quantitative assessment of diagnostically important parameters (e.g. cerebral blood flow and cerebral blood volume for brain perfusion) is based on the CT numbers in the acquired images. These CT numbers are distorted by a number of artifacts, especially by beam hardening. The distortion due to beam hardening can be avoided by acquiring the first images...
A pleural effusion is excess fluid that collects in the pleural cavity, the fluid-filled space that surrounds the lungs. Surplus amounts of such fluid can impair breathing by limiting the expansion of the lungs during inhalation. Measuring the fluid volume is indicative of the effectiveness of any treatment but, due to the similarity to surround regions, fragments of collapsed lung present and topological...
Bone is one of the most important anatomical structures in humans and osteoporosis is one of the major public health concerns in the world. Osteoporosis is a main target disease of bone, which can be detected by medical image techniques. The purpose of this study is to develop a fully automated computer scheme to measure bone-mineral-density (BMD) values for vertebral trabecular bones. This scheme...
CT colonography has emerged as a minimally invasive alternative to optical colonoscopy for the screening of polyps which are the precursors to colon cancer. Accurate polyp measurement is crucial as the size of a polyp is considered an indication of its potential for malignancy. We present a novel method for the automatic measurement of polyps. It is based on a level set algorithm capable of evolving...
Cystic Fibrosis (CF) is the most common lethal genetic disorder in the Caucasian population, affecting about 30,000 people in the United States. It results in inflammation, hence thickening of airway (AW) walls. It has been demonstrated that AW inflammation begins early in life producing structural AW damage. Because this damage can be present in patients who are relatively asymptomatic, lung disease...
Multimodality imaging systems combining optical techniques with MRI/CT provide high-resolution functional characterization of tissue by imaging molecular and vascular biomarkers. To optimize these hybrid systems for clinical use, faster and automatable algorithms are required for 3-D imaging. Towards this end, a boundary element model was used to incorporate tissue boundaries from MRI/CT into image...
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