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We showed that multidimensional parametric modeling is an interesting method to improve the spatial resolution of ultrasound images. The major issue is to estimate simultaneously the model parameters and orders. We recently proposed a least-square-based technique which is able to estimate both orders and parameters of a general N-dimensional auto-regressive (AR) model. This method has been extended...
The introduction of distributed or parallel medical video processing is a constant growing need, because despite the large increase of modern workstations computational power, the amount of data in medical videos is growing rapidly increasing the computational needs for processing and mining. In this paper the distributed processing approach of a video summarization technique for endoscopy videos...
Background: The spatial resolution of conventional imaging examinations is mostly millimeter level, which is difficult to implement the imaging of small hepatic tumors, thus the best time for treatment is bungled. The synchrotron radiation X-ray in-line phase-contrast imaging (IL-PCI) uses the phase information carried by X-rays after passing through the objects to image, and the spatial resolution...
Four-dimensional (4D) computed tomography (CT) can be used in radiation treatment planning to account for respiratory and organ motion. Current 4D CT techniques have limitations in either spatial or temporal resolution. In addition, 4D CT increases the radiation dose to the patients. The purpose of this study is to accurately predict images using 4D CT scan with the contour and projection imaging...
A prototype of photoacoustic standard CT(PSCT) has been designed for high resolution quasi-3D photoacoustic tomography with a focused digital phased array transducer. To realize photoacoustic computed tomography, each element of the transducer array possess a thin cylinder ultrasonic lens to select 2D image plane and suppress the out-of-plane signals. The modified LFBP algorithm is utilized to reconstruct...
Diffraction-enhanced imaging (DEI) is a synchrotron based imaging technique, which generates high spatial resolution and contrast of both calcified and soft tissues. This technique not only provides the visualization of absorption information like conventional X-ray imaging, but also refraction and scattering properties. Multiple image radiography (MIR) is an effective way to extract theses information...
In clinical applications, images with high resolution are often desired and required which may provide more details for doctors to make precise diagnosis. In this paper, an approach is proposed to increase image resolution of parallel magnetic resonance imaging. Since different receiver coils have different sensitivity profiles, different receiver channel models are constructed to map the original...
Detection of pectoral muscle in mammograms is an important pre-processing segmentation step. The pectoral muscle is one of the few anatomical features that appears clearly and reliably in medio-lateral oblique view mammograms. This new method overcomes the limitation of the straight-line representation considered in our initial investigation using the Hough transform.
Blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) is commonly performed using 2D single-shot echo-planar imaging (EPI). However, recent studies have suggested that 3D multi-shot sequences such as PRESTO may offer comparable BOLD contrast-to-noise ratio with increased volume coverage and decreased geometric distortions. A four-way comparison was performed between...
High-quality mammography is the most effective technology presently available for breast cancer screening. High resolution mammograms usually lead to more accurate diagnoses; however, they require large doses of radiation, which may have harmful effects. In this paper, we present a method to synthesize high-resolution mammograms from low-resolution inputs, which offers the potential of allowing accurate...
A novel super resolution method for enhancing the resolution of mammogram images based on statistical moment analysis (SMA) has been designed and implemented. The proposed SMA method enables high resolution mammogram images to be produced at lower levels of radiation exposure to the patient. The SMA method takes advantage of the statistical characteristics of the underlying breast tissues being imaged...
A field source reconstruction of the dipoles modeling the activated area of the brain while a subject performs the task of the voluntary motion of the hand is solved. Experimental data resulting from the integration of both EEG and fMRI are used.
Imaging protocols must obtain maximum information under tight time constraints, to minimize patient discomfort or attrition, and motion artifacts. As part of a pilot study optimizing DTI sequences for the Alzheimer's Disease Neuroimaging Initiative, we scanned 8 subjects with 3 DTI protocols of equal duration at two time-points (48 scans). If scan duration is fixed, collecting more diffusion-sensitized...
In this note, a novel approach to the problem of estimation of orientation distribution functions (ODFs) in q-ball imaging is presented. Rather than recovering the ODFs in a sequential manner, the proposed method performs a concurrent estimation of a set of ODFs pertaining to a specified volume. In this way, the method takes into account the spatial dependencies between different ODFs which are related...
We discuss here the use of spectral estimation algorithms for biomedical ultrasound imaging. B-mode ultrasound imagery is based on computing the envelope of acoustic individual radio-frequency (RF) lines. An envelope estimator is thus needed to improve spatial resolution and reduce speckle. There is an analogy between spectral analysis and envelope estimation. Indeed, the signal envelope can be seen...
Image super-resolution techniques provide a route to studying fine scale anatomical detail using one or more lower resolution acquisitions. A crucial issue in such algorithms is the form of image regularization used to constrain the image structure at points where there are insufficient data values. In this paper we examine the specific problem of reconstructing a high resolution isotropic image when...
There are many applications in MRI where it is desirable to have high spatial and high temporal resolution. This can be achieved by undersampling of k-space and requires special techniques for reconstruction. Even if undersampling artifacts are removed, sharpness of the edges can be a problem. We propose a new technique that uses the gradient from a reference image to improve the quality of the edges...
The objective of this work is to investigate the effect of both multilayer perceptron based and Gaussian maximum likelihood event positioning algorithms on the spatial resolution of a positron emission mammography (PEM) dectector, which use a continuous LSO crystal and a multianode photomultiplier tube, using Monte Carlo simulations. Moreover, the effect of crystal thickness on spatial resolution...
Shear Wave Imaging (SWI) is an ultrasound based technique for elasticity imaging that has been successfully tested on several organs in the framework of cancer diagnosis. In this work, the potential of this technique to map brain elasticity in vivo on trepanned small animals is investigated. From a SWI scan of the rat brain, 3D elasticity maps are reconstructed reaching a spatial resolution of 800...
In micro-CT imaging, the effective spatial resolution of the reconstructed images is generally limited by X-ray dose restrictions, the detector configuration or the scanning geometry. In this paper, we show that, using prior information on the grey values of the scanned objects, the spatial resolution of the reconstructed images can dramatically be improved. The proposed method is based on an upsampling...
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