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The use of three-dimensional (3D) printing allows for creation of custom models for clinical care, education, and simulation. Medical imaging, given the significant role it plays in both clinical diagnostics and procedures, remains an important area for such education and simulation. Unfortunately, the materials appropriate for use in simulation involving radiographic or ultrasound imaging remains poorly understood. Therefore, our study was intended to explore the characteristics of readily available 3D printing materials when visualized by computed tomography (CT) and ultrasound.Seven 3D printing materials were examined in standard shapes (cube, cylinder, triangular prism) with a selection of printing methods ("open," "whole," and "solid" forms). For CT imaging, these objects were suspended in a gelatin matrix molded to match a standard human CT phantom. For ultrasound imaging, the objects were placed in acrylic forms filled with a gelatin matrix. All images were examined using OsiriX software.Computed tomography imaging revealed marked variation in materials' Hounsfield units as well as patterning and artifact. The Hounsfield unit variations revealed a number of materials suitable for simulation various human tissues. Ultrasound imaging showed echogenicity in all materials, with some variability in shadowing and posterior wall visualization.We were able to demonstrate the potential utility for 3D printing in the creation of CT and ultrasound simulation models. The similar appearance of materials via ultrasound supports their broad utility for select tissue types, whereas the more variable appearance via CT suggests greater potential for simulating differing tissues but requiring multiple printer technologies to do so.

The needs and the feasibility of simultaneous computed tomography (CT) and magnetic resonance imaging (MRI) were recently reported. In this paper, a spiral magnetic resonance X-ray CT (MRX) imaging system is proposed for head and extremities imaging, which serves as a simple, cost-effective solution on the path to a full-scale CT-MRI fusion. While MRI and X-ray radiography were integrated before, we propose novel designs to acquire simultaneous CT and MR views for synchronized radiographic imaging or joint tomographic reconstruction. Our preliminary permanent magnet configurations achieve a magnetic field strength between 0.1 and 0.2 T while keeping weight low enough for portability. We have also shown that a field strength up to 0.35 T is achievable with permanent magnets that maintain a compact profile, though increased weight would hinder ease of transportation. Simulation results of a joint tomographic reconstruction scheme show the advantage of simultaneously acquired images. The proposed MRX system performs double helical scans in CT and MRI mechanisms, and has multiple niche applications, such as medical imaging on disaster sites, in battle fields, and for under-developed regions.

This study describes the development of a multisource computed tomography (CT) system that proved to be a useful tool to study multiphase systems. In this CT system, two different radioisotope sources, 192 Ir (317 keV and 448 keV) and 137 Cs (662 keV), were placed in a single lead collimator and several tomography measurements carried out. The multisource CT system was capable of determining as well as differentiating the attenuation coefficients of materials with two phases (gas and liquid). It was also able to provide important information concerning the hydrodynamics occurring inside a multiphase column.

The main advantages of the use of computed x-ray tomography for nondestructive testing of the state of the internal structure of laminated polymer composite materials with the aim of improving the quality of manufacture of products from composites have been demonstrated.

Because of low resolution, Electrical Impedance Tomography (EIT) had been criticized by the experts and scholars. Although the resolution of the Magnetic Resonance Electrical Impedance Tomography (MREIT) which is combined EIT with Magnetic Resonance Imaging (MRI) technology and the resolution of the Magneto-Acoustic-Electrical Tomography (MAET) which is combined EIT with ultrasonic technology are improved, there are still existing problems, which are the electrode RF shielding in MREIT, the difficulty of further improving resolution in MAET. Combining the technologies of MRI and MAET for mutual advantage, this paper proposed a new method of Magnetic Resonance Motional-Electrical Tomography (MRMET) based on the principle of MAET. The software Comsol and Matlab were used to establish a two-dimensional simulation model, and the forward problem and inverse problem of MRMET were researched on the simulation works. The simulation results could reflect the conductivity distribution inside the simulation model, and MRMET could solve the problems of the EIT combination technologies.

Both computed tomography (CT) and positron emission tomography (PET) may be useful in addition to echocardiography and magnetic resonance (MR) imaging to study cardiac tumors. CT scan may be used as an alternative imaging modality in patients who cannot undergo MR because it is contraindicated or in patients already examined with other noninvasive methods without obtaining adequate images. High-speed equipments with electrocardiographic (ECG) gating can provide images with resolution

Process tomography (PT) techniques have been developed rapidly for visualizing the internal behavior of industrial processes, e.g. multi-phase flow measurement. Most of tomography systems employ a single measurement technique, such as computerized tomography (CT), optical tomography (OT), electrical resistance tomography (ERT) or electrical capacitance tomography (ECT). It is now possible to fit two or more tomographic systems to an industrial process. Detailed information from different modalities can be gained by inspection of separate tomographs, and the advantage of the strongest features provided by each unit can be taken. A combined tomogram can be produced of superior quality to any of the separate tomograms. To maximize the information available from the combined tomographic system, data fusion is the better option. In this paper, a dual-mode tomography system based on capacitance sensor and gamma sensor was developed to capture oil–gas two-phase flow. The two modalities can work at the same time. Two fusion methods, namely image fusion method and data fusion method, are proposed. Both simulation and static experiments for oil–gas two-phase flow were conducted. The reconstruction results of different fusion methods and modalities were compared and discussed.

Ring artifacts have been studied for X–ray based Computed Tomography (CT) systems but not on γ-ray based in-situ applications. This paper discusses application of recently proposed automatic ring artifact reduction method (Yoon et al., 2016) on previously obtained experimental projection data from a γ-ray based Industrial Process Tomography (IPT) system for a prototype catalytic column. Studies include qualitative and quantitative evaluation of the method. It is observed that ring artifacts are suppressed without loss of significant information in γ-ray PT images.

As a rather new technology, X-Ray Computed Tomography offers new and promising possibilities in manufacturing metrology in comparison to well-established tactile or optical measurements. The main benefit is the volumetric model which results of each measurement and represents the measurement object holistically with high point density.

This paper presents a novel method of combining dual modality electrical capacitance and optical tomography for applications in monitoring and investigating solid/gas flow. The objective of this method is to obtain a good quality image of the full-scale concentration distribution of solid/gas flow. A new image reconstruction algorithm fused the dual modality images is developed and evaluated.

Medically, electrical impedance tomography (EIT) is a relatively inexpensive, safe, non-invasive and portable technique compared with computerized tomography (CT) and magnetic resonance imaging (MRI). In this paper, EIT_TJU_II system is developed including both the data collection system and image reconstruction algorithm. The testing approach of the system performance, including spatial resolution and sensitivity, is described through brine tank experiments. The images of the thorax physical model verify that the system can reconstruct the interior resistivity distribution. Finally, the lung ventilation functional monitoring in vivo is realized by EIT, and the visualized images indicate that the configuration and performance of EIT_TJU_II system are feasible and EIT is a promising technique in clinical monitoring application.

The amelioration of present X-ray imaging systems especially in computed tomography to resolutions below 1 μm necessitates very precise equipment details such as the manipulators, focus size and stability of the tube and the detector adjustment. In this paper, we present an experimental setup of a computed tomography system with sub-micrometer resolution. The requirements on and characteristics of the components and their influence on the measurements are discussed and exemplary results of different test objects in the field of non-destructive testing with sub-micrometer resolution are presented.

Optical Tomography (OT) is a form of computed tomography using a digital model of the volume of an object by reconstructing an image of the light transmitted and scattered by the object. OT is used mostly as a form of research in medical imaging. OT depends on the reference object being at least partially light transmitting or translucent, so it works best on soft tissue, such as breast and brain tissue. Optical Coherence Tomography (OCT) is a new technology for performing high-resolution cross-sectional imaging. OCT is similar to ultrasound imaging, but uses different types of light instead of sound. OCT can provide cross-sectional images of tissue structure on the micrometer scale and in real time. OCT serves as a kind of optical biopsy and is used as a medical diagnostic imaging technology because, unlike conventional histopathology, it does not require the removal and processing of tissue specimens for microscopic examination. The study was carried out to see how the two types of optical imaging and the use of concepts and components used in the system. The light source is used to show different levels of penetration and resolution for both methods is used. The use of an interferometer in optical imaging applications is discussed along with examples of commonly used methods. The optical imaging method contributes significantly to the diversity of tomography systems.

This article presents and compares analytical and numerical methods for electrical property retrievals that are developed recently in our research group. The methods create electrical property maps of human body only on the basis of typical data from magnetic resonance imaging (MRI) (without using any additional devises or data). Derivations and results are included. Analysis and comparison of the methods are presented.

Computerized tomography (CT) is the process of recovering a distribution of some parameter from physically obtained approximations of its line integrals along lines of known locations. CT devices used in brain imaging include x-ray CT that aims at recovering the distribution of x-ray attenuation coefficients and positron emission tomography and single-photon emission computerized tomography, which aim at recovering the distribution of radioactivity that results in the emission of positrons and single photons, respectively. The production of the desired distribution from data collected by such a device is done on a computer by a reconstruction method. Such methods are the subject matter of this article.

This paper deals with tomographic techniques for two-dimensional spatially resolved concentration measurements indoors. This represents a significant advance over the traditional point measuring me ...

Summary Computed tomography utilises a rotating X-ray source combined with multiple detectors in the latest scanners. This data can then be processed in numerous ways to provide axial, multi-planar and 3D images for diagnostic purposes. This modality has rapidly developed since its inception in direct relationship to the exponential increase in computer technology with a corresponding increase in its range of applications.

Dual-modality imaging is a technique in which computed tomography (CT) or magnetic resonance imaging is combined with positron emission tomography or single-photon emission CT to acquire structural and functional images with an integated system. The data are acquired in a single procedure; the patient remains on the scanner table while undergoing both x-ray and radionuclide studies to facilitate correlation between the structural and functional images. The resulting data can aid in localization, enabling more specific diagnosis than can be obtained with a conventional imaging study. In addition, the anatomic information can be used to compensate the correlated radionuclide data for physical perturbations such as photon attenuation, scatter radiation, and partial volume errors. Thus, dual-modality imaging provides a priori information that can improve both the visual quality and the quantitative accuracy of the radionuclide images. Dual-modality imaging systems are also being developed for biologic research involving small animals. Small-animal dual-modality systems offer advantages for measurements that currently are performed invasively with autoradiography and tissue sampling. By acquiring data noninvasively, dual-modality imaging permits serial studies in a single animal, enables measurements to be performed with fewer animals, and improves the statistical quality of the data.

Methods of optical tomography of biological tissues are considered, which include pulse-modulation and frequency-modulation tomography, diffusion tomography with the use of cw radiation sources, optical coherent tomography, speckle-correlation tomography of nonstationary media, and optoacoustic tomography. The method for controlling the optical properties of tissues is studied from the point of view of increasing a probing depth in optical coherent tomography. The modern state and prospects of the development of optical tomography are discussed.

The inspection system is crucial to ensure the system is always in a good condition. A technique that can be used for inspection system is process tomography. By promising non-destructive approach; various types of process tomography applied in civil, manufacturing and electrical applications. The purpose of this paper is to review the types of process tomography such as ultrasonic tomography, x-ray tomography, optical tomography, electrical resistance tomography, and electrical impedance tomography that had been applied to the inspection system. Variety techniques of inspection based on those sensors briefly discussed in this paper. The result showed that the process tomography expanded tremendously in the inspection system. Finally, a potential future research on the inspection system in the civil application proposed in this paper.

In a first pilot study with 3D Ultrasound Computer Tomography especially the speed of sound images of the breast showed promising results for breast cancer detection. Yet, the resolution of transmission tomography in our system is limited in comparison to the reflectivity volumes. In this paper we describe a setup for an improved device overcoming this limitation. An optimized geometry of the transducers in a sparse distribution improves both the contrast in reflection and contrast and resolution in transmission tomography by nearly an order of magnitude. Furthermore data acquisition is accelerated from 10 to less than 2 minutes. The derived methods, simulation, and measuring results are described.

Tomography is a method that has been used for image reconstruction in the medical and engineering fields. Optical tomography is one of the various methods applied in tomography systems. This tomography method is widely used in the medical and processing industries fields because of its special characteristics, such as immunity to electrical noise and interference, high resolution and its hard field sensors. The basic principle of the optical tomography system in measuring an object is based on its wave and radiation source. This article is a review of the characteristics of light and its interaction with matter, the types of optical tomography system, the basic construction of an optical tomography system, types of optoelectronic sensors and image reconstruction.

From the Department of Radiology, Division of Neuroradiology,a and Division of Musculoskeletal Imaging,b Indiana University School of Medicine. Reprint requests: Karen S. Caldemeyer, MD, Indiana University School of Medicine, University Hospital, Room 0279, 550 N University Blvd, Indianapolis, IN 46202-5253. J Am Acad Dermatol 1999;41:768-71. Copyright © 1999 by the American Academy of Dermatology, Inc. 0190-9622/99/$8.00 + 0 16/1/98499 C omputed tomography (CT) and magnetic resonance imaging (MRI) are the most widely used cross-sectional imaging methods used in medicine. CT was a revolutionary development of the 1970s. The term computed tomography derives from computed (with computer), tomo (to cut), and graph(y) (pictures). CT uses ionizing radiation, or x-rays, coupled with an electronic detector array to record a pattern of densities and create an image of a “slice” or “cut” of tissue. The x-ray beam rotates around the object within the scanner such that multiple x-ray projections pass through the object (Fig 1). The internal structure of the object can then be reconstructed from the multiple projections of that object.1 As x-rays pass through the patient, they are attenuated. The amount of attenuation depends on the type of tissue through which the x-ray beam passes. X-ray imaging contrast is generated as a consequence of differences in attenuation between adjacent tissues. The higher the attenuation of the x-ray beam, the brighter the tissue on CT images, and the lower the attenuation, the darker the tissue on CT images. Therefore bone and calcification that significantly attenuate the x-ray beam are white. Fat, being rich in carbon, is more transparent than water containing oxygen, which attenuates x-rays to a greater degree.1 Therefore fat is blacker than water on CT. Air causes little attenuation of x-rays and is very black (Figs 2 and 3). Regional or focal deviations from the normal CT appearance will be

This paper describes an investigation into the use of optical-fibre sensors in a tomographic measurement system, designed to measure the flow of dry solids in gravity-drop and pneumatic conveyors. A simple model of the system is provided and used to predict the response of both individual sensors and the full system. Results are provided which show that the model is acceptable. The system is used to provide tomographic images of solid concentration within a gravity conveyor.

SummaryMinimally invasive procedures are increasingly combined with radiologic imaging to optimise access and treatment techniques. While endoscopy has become a standard technique in the surgical field for diagnosis and therapy, tomographic guidance is new. Combining both modalities, the transparency of computed tomography and of ultrafast electron beam tomography, together with magnetic resonance imaging (MRI), will optimise both guidance and therapy. By using tomographic scanners for precise instrument positioning, the diameter of instruments [mechanical, laser, radiofrequency (RF), endoscopes etc.] can be minimised. Also electronic equipment, for visualisation and therapy should be integrated into a tomographic work-station. Instruments and electronic equipment are sensitive to MRI and ferromagnetic alloys, and electric impulses cause artifacts in imaging. These problems have to be solved for future therapeutic workstations.

A condensed review of recent advances accomplished in the development and the applications of noninvasive tomographic and velocimetric measurement techniques to multiphase flows and systems is presented. In recent years utilization of such noninvasive techniques has become widespread in many engineering disciplines that deal with systems involving two immiscible phases or more. Tomography provides concentration, holdup, or 2D or 3D density distribution of at least one component of the multiphase system, whereas velocimetry provides the dynamic features of the phase of interest such as the flow pattern, the velocity field, the 2D or 3D instantaneous movements, etc. The following review is divided into two parts. The first part summarizes progress and developments in flow imaging techniques using γ-ray and X-ray transmission tomography; X-ray radiography; neutron transmission tomography and radiography; positron emission tomography; X-ray diffraction tomography; nuclear magnetic resonance imaging; electrica...

X-ray computed tomography is a 3D imaging technique for the non-invasive, non-destructive visualisation and measurement of the internal microstructure of materials. Using X-rays, a series of radiographs of a sample are recorded from different angles, and then used to reconstruct the internal 3D microstructure by means of a suitable reconstruction algorithm. The method has a high penetrating power and probing efficiency, and is unlimited by morphological complexity. This chapter describes the technique, its advantages and limitations, the latest technological advances, and reviews of applications in food systems.

In integrated positron emission tomography (PET)/magnetic resonance imaging (MRI), the PET data acquisition is performed simultaneously to the magnetic resonance data acquisition, leaving latitude for the duration of PET acquisition time. This establishes emission time as an important parameter in forthcoming PET/MRI protocols because it is one of the key factors determining PET image quality. Thus, the purpose of the current study was to identify optimal duration of PET acquisition time in PET/MRI.A total of 22 consecutive patients (7 men, 15 women) underwent fluorine-18-labeled fluorodeoxyglucose (18[F]FDG) PET/MRI after clinical PET/computed tomography. Positron emission tomography/magnetic resonance scans were acquired for 8 minutes per bed position (mpb). Positron emission tomography was extracted to reconstruct images with 2, 4, 6, and 8 mpb for each patient. Visual and quantitative approaches were used to assess image quality and lesion detectability for each image. For image quality, (a) 3 readers independently scored subjective image quality on a 4-point scale and (b) a region-of-interest approach was used to obtain a quantitative estimate of image quality in terms of noise. For lesion detectability, (a) the readers independently counted the number of hypermetabolic lesions and (b) signal-to-noise ratio and contrast-to-noise ratio were computed in a region-of-interest approach. Moreover, the mean and maximal standardized uptake value (SUV mean and SUV max, respectively) of the hypermetabolic lesions was compared across all acquisition times.For image quality, subjective image quality significantly declined from 8 to 2 mpb (P; 0.05), with the exception of the difference between 6 and 8 mpb. Image noise increased with shorter imaging duration, ranging from 13% on average in the 8-mpb scans to 23% in the 2-mpb scans (differences were statistically significant for 2 vs 6 mpb, 2 vs 8 mpb, and 4 vs 8 mpb; P; 0.05). For lesion detectability, 39 hypermetabolic lesions were identified by consensus. There was no difference in detected lesions across all acquisition times. Signal-to-noise ratio and contrast-to-noise ratio were constantly high and did not differ significantly across the acquisition times. The SUV mean and SUV max did not differ significantly across all acquisition times.Positron emission tomography acquisition times on integrated PET/MRI do not need to exceed usual acquisition times on current PET/computed tomography scanners: Although the PET image quality suffers from short acquisition times, even a duration of 2 mpb permits sufficient lesion detection. Moreover, quantitative measures of tracer uptake are also reasonably precise at short acquisition times.

This chapter begins by reviewing several research projects which were considered to be useful for industrial application in the IRMMW – THz 2010 conference. Next, our recent studies of industrial applications are introduced: a computed tomography system using terahertz (THz) to millimeter waves, and a time-of-flight (TOF) THz tomography system. In the study of the tomography system, non-destructive investigation of the soot-removal filter installed in the internal combustion engine is demonstrated. Finally, a component analysis method for powder material using THz waves is introduced.

Radioisotope emission tomographic methods, as developed in nuclear medicine, are reviewed with reference for their suitability for process tomography. The most promising techniques appear to be positron emission tomography and its offshoot positron emission particle tracking.

Electrical impedance tomography (ET) is a technique for reconstructing conductivity of an inhomogeneous medium by injecting current at the boundary of an object and measuring the resulting voltage changes. ET techniques have been widely adopted for visualizing distributions of materials in industrial processes. In comparison to other tomography modalities, ET's advantages include low cost, rapid response, no radiation and being non-intrusive. In this paper, a group of most widely adopted electrical imaging algorithms are compared based on imaging time, correlation coefficient, the relative error, the objective function value, iterative times and convergence speed in a visualization tool OPTICS. Experiment results show the applicable ranges, limitations and complementary natures of different imaging algorithms.

This paper presents a tomographic system at 100 GHz for imaging based on MST technique. At 100 GHz, a good compromise is obtained between penetration and reso- lution for biomedical and non-destructive testing applications. Moreover, this system just requires low frequency wiring and reduces the RF equipment necessary for performing real-time imaging. The system has been built and successfully validated with a set of measurements for a canonical scenario.

X-ray computed tomography (CT) provides quantitative, readily interpretable data and enables the inspection of structures that are not amenable to any other nondestructive evaluation technique. As a result, CT has become well established as an inspection, evaluation, and analysis tool in industry. Many of the applications have been in the aerospace industry, where the high cost and performance requirements of components justifies the cost of CT inspection, but use in other industries is growing as equipment becomes increasingly available.

We introduce ultrafast electron beam X-ray tomography as an imaging modality for multiphase flow studies. A dedicated electron beam tomography scanner (ROFEX) has been developed which allows cross-sectional X-ray tomography with 1 mm spatial resolution and up to 7000 cross-sectional images per second recording speed. It is applicable to flow problems in vessels with up to 120 mm diameter and moderate X-ray attenuation. The tomography system has been applied in various flow studies, including gas-liquid two-phase flow in vertical pipes and channel structures.

Computed Tomography (CT) is a well established method for non-destructive reconstruction of an object's interior structures. It is especially well suited for use with e.g. light metal alloys, injection molded plastic components or composite materials. The CT volume data can either be evaluated manually or automatically through the use of image processing software. Recently helical CT has become available for use in industrial quality testing of light alloy cast parts. This paper discusses the use of helical CT as an additional tool for inline inspection in a production environment.

We report applications of full-field swept-source optical coherence tomography (SS-OCT) for non-destructive testing and evaluation. Results of topography and tomography of latent fingerprints, silicon microelectronic circuits and composite materials are presented. The system is completely non-mechanical scanning, compact and low-cost.

SPECT (Single Photon Emission Computed Tomography) provides for an invaluable non‐invasive technique for the characterization and activity distribution of the gamma‐emitting source. For many applications of radioisotopes for medical and industrial application, not only the positional information of the distribution of radioisotopes is needed but also its strength. The well‐established X‐ray radiography or transmission tomography techniques do not yield sufficient quantitative information about these objects. Emission tomography is one of the important methods for such characterization. Application of parallel beam, fan beam and 3D cone beam emission tomography methods have been discussed in this paper. Simulation studies to test these algorithms have been carried out to validate the technique.

A NIR diffuse tomography system with spectrally-encoded sources allows simultaneous detection of all data. It can provide images of high-contrast, fast changes in tissue optical properties to be overlayed on the magnetic resonance breast scan. Article not available.

x-Ray computed axial tomography (CT) provides cross-sectional views of materials, components, and assemblies for industrial non-destructive evaluation. We have applied CT imaging to quantitatively measure the 3-D distribution ogf x-ray attenuation at reasonably high resolutions. In our industrial x-ray CT-studies, we have centered on two technical approaches: a first-generation translate/rotate CT system that consist of well-collimated (∼ 0.55 mm) photon source detector, and a third-generation scanner that uses a fluoroscopy detector.

With the advent of more sophisticated and powerful imaging instruments using a variety of radiant energy forms, numerous improvements have been made to the basic tomographic techniques. These improvements enable greater specificity and sensitivity in clinical diagnostic and basic investigative imaging procedures. Modern medical imaging modalities, which include magnetic resonance imaging (MRI), positron emission tomography (PET), single photon emission computed tomography (SPECT), ultrasound, and x-ray CT, have revolutionized diagnostic capabilities. Medical professionals are now provided with significant capabilities for noninvasive and accurate examination of internal anatomy. These modern imaging modalities can capture not only anatomical information but also physiological, metabolic, and functional information. Keywords: magnetic resonance imaging (MRI); X ray ultrasound; computed tomography (CT); positron emission tomography; single photon emission computed tomography (SPECT)

A magnetic resonance-electrical impedance tomography (MREIT) technique for determining the local conductivity of an object. The MREIT technique combines magnetic resonance current density imaging (MRCDI) with electrical impedance tomography (EIT) in order to obtain the benefits of both procedures. The MREIT technique includes the step of current density imaging by performing the steps of placing a series of electrodes around the patient or object to be imaged for the application of current, placing the patient or object in a strong magnetic field, and applying an MR imaging sequence which is synchronized with the application of current through the electrodes. Next, the electric potentials of the surface of the object or patient are measured simultaneously with the MR imaging sequence, as in EIT. Then, the MR imaging signal containing information about the current and the measured potential are processed to calculate the internal conductivity (impedance) of the object or patient.

We use simulation and singular value analysis to optimize source-detector geometry for breast imaging in the parallel plane geometry.

Optical computer tomography requires high quality of image and up-to-now no method of optical imaging presented in the paper are sufficient for that. Nevertheless we know about optical imaging in high scattering media much more than few years ago and some results are promising.