Showing papers on "Imaging technology published in 2004"

In vivo molecular and genomic imaging: new challenges for imaging physics.

Abstract: The emerging and rapidly growing field of molecular and genomic imaging is providing new opportunities to directly visualize the biology of living organisms. By combining our growing knowledge regarding the role of specific genes and proteins in human health and disease, with novel ways to target these entities in a manner that produces an externally detectable signal, it is becoming increasingly possible to visualize and quantify specific biological processes in a non-invasive manner. All the major imaging modalities are contributing to this new field, each with its unique mechanisms for generating contrast and trade-offs in spatial resolution, temporal resolution and sensitivity with respect to the biological process of interest. Much of the development in molecular imaging is currently being carried out in animal models of disease, but as the field matures and with the development of more individualized medicine and the molecular targeting of new therapeutics, clinical translation is inevitable and will likely forever change our approach to diagnostic imaging. This review provides an introduction to the field of molecular imaging for readers who are not experts in the biological sciences and discusses the opportunities to apply a broad range of imaging technologies to better understand the biology of human health and disease. It also provides a brief review of the imaging technology (particularly for x-ray, nuclear and optical imaging) that is being developed to support this new field.

Methods for the Compensation of Imaging Technique In The Processing of Radiographic Images

Abstract: The present invention relates to methods and devices for analyzing x-ray images. In particular, devices, methods and algorithms are provided that allow for the accurate and reliable evaluation of bone structure and macro-anatomical parameters from x-ray images.

Physical principles and technology of clinical PET imaging.

Abstract: Molecular imaging with positron-emitting radionuclides is playing an increasingly important role in the diagnosis and staging of malignant disease and in monitoring response to therapy. To meet this challenge, significant improvements in the performance of the imaging technology have been achieved in recent years. Such developments are subject to the constraints imposed by the physics of positron emission tomography (PET) and the main objectives in designing or improving PET scanners are to achieve high spatial resolution and sensitivity while maximising the true coincidence count rate relative to contributions from noise processes. Noise contributions in PET include not only statistical effects associated with photon counting but also background processes such as scatter and random coincidences. The recent developments of new, faster scintillators and electronics for PET detectors, as well as statistically-based algorithms that reconstruct fully three-dimensional (3D) PET images in minutes, have dramatically reduced clinical imaging times while improving image quality. A recent advance, the combination of functional imaging and computed tomography (CT) in the PET/CT scanner has further reduced the study duration by eliminating the lengthy PET transmission scan and providing accurate anatomical localisation of functional abnormalities. PET imaging technology has now improved to where a combined anatomical and functional clinical study can be completed in less than 10 minutes--although taking advantage of such high throughput potential will challenge patient management in diagnostic imaging departments. This paper reviews the physical principles underlying PET and summarises the recent developments in PET scanner technology, from the introduction of new PET detectors to the development of the combined PET/CT scanner.

Techniques for brain imaging in vivo.

Abstract: Brain imaging technologies provide an unparalleled tool to assess the physiological and pathological changes in the central nervous system. The aim of this work is to review the technical characteristics of widely used imaging technologies, such as magnetic resonance imaging (MRI), positron emission tomography (PET), or single photon emission computed tomography (SPECT), as well as their utility in clinical diagnosis and follow-up of different neurological disorders. High-resolution developments of MRI and PET, as well as the more recent imaging technology, multiphoton microscopy, for small animal imaging are also analyzed, as rodent models offer an enormous opportunity to study not only the underlying mechanisms of Alzheimer's disease, Parkinson's disease, depression, and schizophrenia among others, but also potential new treatments for all these diseases.

Stereoscopic imaging: a real-time, in depth look

Abstract: There is a general push for biometric-based solutions to replace keys, ID cards, passwords and PINs. Facial recognition, as one of the computational biometrics technologies, has received renewed attention and publicity lately, but for its inaccurate results. One major reason for the inaccuracy is the fact that, generally, facial recognition tools are rooted in 2D imaging methods which are limited to front-profile 2D photographs with a maximum divergence of 20 degrees. 3D facial imaging technology eliminates much of the nagging problems, but the benefits come with the added cost of processing time, especially in the case of stereoscopic imaging. The requirement of timely processing is particularly important in access control applications. The distributed algorithm we propose represents a novel step in solving the 3D imaging problem using power processing. The algorithm enables cameras, fitted with special boards, to generate 3D images in less time than with existing methods. The algorithm exploits the well-known properties/constraints from the stereovision field. Thus, it is very reliable. The obvious impact areas for this work are the capture, display and transmission of stereoscopic images. However, other areas, such as stereoscopic HDTV, can benefit from a faster technique.

Catheter‐based intracardiac echocardiography in the interventional cardiac laboratory

Abstract: Recent advances in technology have engendered a renewed enthusiasm in the use of intracardiac echocardiography (ICE) to guide and assess cardiac interventions AcuNav is a phased-array sector imaging probe equipped with color and spectral Doppler capabilities Previous-generation imaging catheters yielded unfamiliar limited-depth radial images with no flow information Current imaging technology such as the AcuNav has not only consolidated the role of ICE but opened newer applications in the interventional laboratory ICE has clear advantages over transesophageal echocardiography as the imaging modality of choice in the cardiac catheterization and electrophysiological laboratories We review the technical evolution of ICE and describe the expanded utility of the AcuNav imaging catheter during cardiac interventions

Image-guided techniques for peripheral nerve blocks

Abstract: Purpose of review Success of plexus nerve block is most dependent upon the correct positioning of the local anaesthetic solution within proximity to the corresponding nerve trunk. With the aim of verifying the close approximation of needle and nerve, and increasing the corresponding success rate, in the course of the history of regional anaesthesia, and in addition to the classical methods like seeking of paraesthesia, different mechanical aids have been used for nerve detection. In the last two decades, important medical diagnostic and therapeutic advances in imaging technology have been presented. In this review we will analyse the role such imaging diagnostic procedures will play in regional anaesthesia practice. Recent findings Last developments in the field have produced increased interest in the application of imaging techniques in regional anaesthesia. Of special interest are ultrasound and low radiation x-ray techniques for location of the needle in relation with neural structures. Summary In this paper we will analyse which imaging techniques are of relevance to anaesthesia in terms of clinical outcome, research and teaching of regional anaesthetic techniques, and the clinical impact of such imaging techniques upon anaesthesia practice.

Improvements in radiotherapy practice: the impact of new imaging technologies

Abstract: Improvements in imaging technology are impacting on every stage of the radiotherapy treatment process. Fundamental to this is the move towards computed tomography (CT) simulation as the basis of all radiotherapy planning. Whilst for many treatments, the definition of three-dimensional (3D) tumour volumes is necessary, for geometrically simple treatments virtual simulation may be more speedily performed by utilising the reconstruction of data in multiple imaging planes. These multi-planar reconstructions may be used to define both the treatment volumes (e.g. for palliative lung treatments) and the organs at risk to be avoided (e.g. for para-aortic strip irradiation). For complex treatments such as conformal radiotherapy (CFRT) and intensity-modulated radiotherapy (IMRT) where 3D volumes are defined, improvements in imaging technologies have specific roles to play in defining the gross tumour volume (GTV) and the planning target volume (PTV). Image registration technologies allow the incorporation of functional imaging, such as positron emission tomography and functional magnetic resonance imaging, into the definition of the GTV to result in a biological target volume. Crucial to the successful irradiation of these volumes is the definition of appropriate PTV margins. Again improvements in imaging are revolutionising this process by reducing the necessary margin (active breathing control, treatment gating) and by incorporating patient motion into the planning process (slow CT scans, CT/fluoroscopy units). CFRT and IMRT are leading to far closer conformance of the treated volume to the defined tumour volume. To ensure that this is reliably achieved on a daily basis, new imaging technologies are being incorporated into the verification process. Portal imaging has been transformed by the introduction of electronic portal imaging devices and a move is underway from two-dimensional (2D) to 3D treatment verification (cone beam CT, optical video systems). A parallel development is underway from off-line analysis of portal images to the incorporation of imaging at the time of treatment using image-guided radiotherapy. By impacting on the whole process of radiotherapy (tumour definition, simulation, treatment verification), these new imaging technologies offer improvements in radiotherapy delivery with the potential for greater cure rates and a minimum level of treatment side effects.

Synergy of ultrasound, elasticity, and optoacoustic imaging for improved detection and differentiation of cancerous tissue

Abstract: The effective management of cancer requires early yet reliable detection, localization, and diagnosis Therefore, there is a definite and urgent clinical need for an imaging technique that is widely available, is simple to perform, is safe, and that can detect and adequately diagnose cancer In this paper we present a hybrid imaging technology based on fusion of complementary imaging modalities ultrasound, optoacoustics, and elastography to take full advantage of the many synergistic features of these modalities and thus to significantly improve sensitivity and specificity of cancer imaging To evaluate our approach, numerical and experimental studies were performed using heterogeneous phantoms where ultrasonic, optical, and viscoelastic properties of the materials were chosen to closely mimic soft tissue The results of this study suggest that combined ultrasound‐based imaging is possible and can provide more accurate, reliable and earlier detection and diagnosis of tissue pathology In addition, monitoring of cancer treatment and guidance of tissue biopsy are possible with combined imaging system Practical and experimental aspects of combined imaging will be discussed with emphasis on data capture and signal/image processing algorithms The paper will conclude with a discussion of the advantages, limitations, and potential clinical applications of the combined imaging technique

CHAPTER 3 – Evolution of Clinical Emission Tomography

Abstract: This chapter discusses the historical development of Emission Tomography (ET) and its clinical applications. It first discusses the beginnings of nuclear medicine imaging and recalls some of the history, experience, and theoretical developments that guided the development of the technology. Emission tomography has made it possible to increase the visibility of low-contrast structures and provides quantitative information on the structure, uptake, turnover, and metabolic properties of biological systems, along with the pharmacokinetic behavior of radiolabeled drugs. Emission tomography has made it possible to move seamlessly from destructive 3D studies in animals to noninvasive nuclear imaging procedures in humans that are enhancing knowledge in many areas of medicine. The development of new imaging technology has revolutionized the diagnostic and therapeutic processes. The understanding of biochemical pathways and physiological processes was the first focus of nuclear medicine research. Furthermore, this chapter discusses the role of ET in several areas such as, brain imaging, thyroid imaging, cardiac imaging, kidney imaging, lung imaging, bone imaging, reticuloendothelial system, imaging tumor, and imaging molecular biology.

Principle and applications of digital holography

Abstract: Digital holography, a new imaging technology, has been introduced through the development of computers and CCD technology. We briefly review the basic principle of digital holography, methods of holographic reconstruction, and the advantages and potential applications of this technology in various different fields.

Infrared imaging face recognition using nonlinear kernel-based classifiers

Abstract: : In recent years there has been an increased interest in effective individual control and enhanced security measures, and face recognition schemes play an important role in this increasing market. In the past, most face recognition research studies have been conducted with visible imaging data. Only recently have IR imaging face recognition studies been reported for wide use applications, as uncooled IR imaging technology has improved to the point where the resolution of these much cheaper cameras closely approaches that of their cooled counterparts. This study is part of ongoing research conducted at the Naval Postgraduate School that investigates the feasibility of applying a low-cost, uncooled IR camera for face recognition applications. This specific study investigates whether nonlinear kernel-based classifiers may improve overall classification rates over those obtained with linear classification schemes. The study is applied to a 50-subject IR database developed inhouse with a low-resolution, uncooled IR camera. Results show best overall mean classification performances around 98.55%, which represents a 5% performance improvement over the best linear classifier results obtained previously on the same database. The study also considers several metrics to evaluate the impacts variations in various user-specified parameters have on the resulting classification performances. These results show that a low-cost, low-resolution IR camera combined with an efficient classifier can play an effective role in security-related applications.

Recent progress of ultrasound elasticity imaging technology

Abstract: Previously, we proposed a method for elasticity images, which is suited to clinical use, since it can yield strain distribution with high-speed processing, high accuracy, a wide dynamic range and robustness for lateral motion induced by freehand compression. In order to verify the feasibility of our method, we recently architected a system for clinical use in which our algorithm is installed, using a commercial ultrasound scanner operating at 7.5 MHz linear type for breast and transrectal type for prostate. In this system, the echo signals are captured in real time, more than 25 fps, while the probe compresses or relaxes the body through freehand operation, and the strain images are superimposed on B-mode images with a translucent color scale. The clinical evaluation of this system was performed on breast tissue from over 20 patients. Results of these clinical assessments using a developed system demonstrated the high potential of the tissue elasticity image for breast examination, especially for the detection of carcinoma.

First results with real-time selenium-based full-field digital mammography three-dimensional imaging system

Abstract: Our goal in this paper is to evaluate the capability of real-time selenium-technology-based full-field digital mammography (FFDM) system in breast tomosynthesis. The objective of this study is to find out the present status of amorphous selenium technology in the sense of advanced applications in clinical use. We were using tuned aperture computed tomography (TACT+) 3-dimensional (3D) technology for reconstruction. Under evaluation were amorphous selenium signal-to-noise-ratio, flat panel image artefacts and acquisition time to perform full-field digital mammography 3D examination. To be able to validate the system we used a special breast phantom. We found out that 3D imaging technology provides diagnostic value and benefits over 2-dimensional (2D) imaging. 3D TACT advantages are to define if mammography finding is caused by a real abnormal lesion or by superposition of normal parenchymal structures, to be able to diagnose and analyze the findings properly, to detect changes in breast tissue which would otherwise be missed, to verify the possible multifocality of the breast cancers, to verify the correct target for biopsies and to reduce number of biopsies performed. Slice visualization and 3D volume model provide greater diagnostic information compared to 2D projection screening and diagnostic imaging.

Distortion corrections for better character recognition of camera-based document images

Abstract: The usage of cellular camera phones and digital cameras is rapidly increasing. but camera imaging application is not so expanded due to the lack of practical camera imaging technology. Especially the acquisition environments of camera images are very different from those of scanner images. The status of light condition, viewing distance and viewing angles constantly varies in case of cameras. The variations of light condition and viewing distance make it difficult to extract character areas from images through binarization and the variation of camera viewing angles makes the images distorted geometrically. Therefore, the extraction of character areas for camera document images is far more complex and difficult than for scanner images. In this paper, these problems are totally discussed and the resolving methods are suggested for better image recognition. The solutions such as adaptive binarization, color conversion, correction of lens distortion and geometrical distortion correction are discussed and the correction methods are suggested for accurate document image recognition. In experiment, we use the various types of document images captured by mobile phone cameras and digital cameras. The results of distortion correction show that our image processing methods are efficient to increase the accuracy of character recognition for camera based document image.

MACROscopic imaging of tumor xenografts using fluorescence, phase contrast, and transmitted light

Abstract: Recent advances in imaging technology have contributed greatly to biological science. Confocal fluorescence microscopy (CFM) facilitates high-contrast 2D and 3D images of biological samples such as living cells, and frozen or fixed tissue sections. However, to date, imaging with existing confocal microscopes has been limited by practicality, especially when samples are large and overfill the field of view (FOV) of typical microscope objectives (e.g., ~10 mm2 tissue section). In this case, image-tiling must be employed to cover the entire specimen. This can be time consuming and cause artifacts in the composite image. The MACROscope® system (Biomedical Photometrics Inc, Waterloo, Canada), is a confocal device with a 2x7 cm2 FOV, and is ideal for imaging large tissue sections in a single frame. The system used in this work is a prototype capable of simultaneous acquisition from two detection channels. Reflected light (RL), transmitted light (TL) and differential phase contrast (DPC) images of whole cut mouse tumor xenografts were collected with the same system. Preliminary results demonstrate that the MACROscope® can produce high quality images of large tissue samples; comparable in resolution and contrast to those obtained with conventional CFM using low-power (5-10x) objectives, but at increased imaging speeds (>10x), and FOV (>20x). This new device avoids the need for image-tiling and provides simultaneous imaging of multiple tissue-specific fluorescent labels in large biological samples with high resolution and contrast; thereby allowing time- and cost-efficient high-throughput screening of immunohistopathological samples. This device may also serve in the imaging of high-throughput DNA and tissue arrays.

Hybrid imaging: a quantum leap in scientific imaging

Abstract: ImagerLabs has advanced its patented next generation imaging technology called the Hybrid Imaging Technology (HIT) that offers scientific quality performance. The key to the HIT is the merging of the CCD and CMOS technologies through hybridization rather than process integration. HIT offers exceptional QE, fill factor, broad spectral response and very low noise properties of the CCD. In addition, it provides the very high-speed readout, low power, high linearity and high integration capability of CMOS sensors. In this work, we present the benefits, and update the latest advances in the performance of this exciting technology.

Application of Near Infrared CCD Imaging Technology in the Strip Correcting System

Abstract: The application of the near infrared CCD imaging technology in the strip correcting system was presented in detail. The principle and constitution of the system were described. The correcting procedure of the software was illustrated with examples.

Chronic daily headache: recent insights from functional imaging

Abstract: New imaging technology allows us to study neurologic disorders that have had no previous structural basis There have been recent reports on the involvement of nociceptive pathways in daily headache A systematic review was performed using key words “chronic daily headache” and “imaging” This paper reviews the literature on imaging studies performed on daily headache with emphasis on the new imaging technology

Imaging of the female pelvis in the evaluation of developmental anomalies

Abstract: Introduction The use of imaging for the evaluation of developmental anomalies of the female pelvis has rapidly expanded since the 1980s mainly because of the development and availability of imaging technology, particularly high-resolution ultrasound with Doppler, spiral computed tomography (CT) and magnetic resonance imaging (MRI). Imaging is now used in virtually every case to confirm diagnosis or to show the anatomy of the structural abnormalities of the genital tract and other related disorders. Imaging is used extensively for planning the surgical management of the primary condition and any associated complications. The most commonly used imaging modalities are fluoroscopy (usually with contrast agents), ultrasound and MRI. Each technique has particular advantages and disadvantages, and knowledge of these is important for the appropriate choice of imaging technique. A major consideration when imaging children is the use and dose of ionizing radiation, particularly as many patients are likely to need multiple investigations during the course of their lifetime. Imaging modalities Fluoroscopy Genitograms and micturating cystourethrography are the traditional fluoroscopic methods for evaluating children with disorders of sexual differentiation. All perineal orifices are examined with the catheter inserted only a short distance into the orifice. Contrast is injected gently under direct fluoroscopic screening to allow visualization of the morphology of the urogenital sinus. The important features that are noted include the presence or absence of a vagina, its relationship to the urethra and the level of the external sphincter (which has important surgical implications), and the recognition of a male or female type urethral configuration (Aaronson, 1992).

Networking Development Trends of Modern Medical Imaging Technology

Abstract: The thesis gives a summarization and analysis of networking development trends and global development characteristics of modern medical imaging technology.The paper prognosticates also its main progress directions and outlines important issues necessary to be solved for its further advancement.