Tomography computer

The classical computer tomography (CT), including the medical one, has already been demonstrated its efficiency in many practical applications. At the same time, the request of the all-round survey of the object, which is usually unattainable, makes it important to find alternative approaches with less rigid restrictions to the number of projections and accessible views for observation. In the last time, it was understood that one effective way to withstand the extreme lack of data is to introduce a priori knowledge based upon classical inverse theory (including Maximum Entropy Method (MEM)) of the solution of ill-posed problems [1-6]. As shown in [6] for objects with binary structure, the necessary number of projections to get the quality of image restoration compared to that of CT using multistep reconstruction (MSR) method did not exceed seven and eould be reduced even further. 

To search for the forms of potentials we are considering here simple mechanical models. Two of them, namely cluster support algorithm (CSA) and plane support algorithm (PSA), were described in details in [6]. Providing the experiments with simulated and experimental data, it was shown that the iteration procedure yields the sweeping of the structures which are not volumetric-like or surface-like, correspondingly. While the number of required projections for the reconstruction is reduced by 10 -100 times, the quality of reconstruction estimated quantitatively remained quite comparative (sometimes even with less artefacts) with that result obtained by classic Computer Tomography (CT). 

Although the discontinuities may be seen clearly in the circular C-scan image, the image represents only a projection of discontinuities in a specific direction (i.e., a shadow of overlapping discontinuities). More information of the discontinuities according to location, dimension and type may be achieved by ultrasonic computed tomography (UCT) imaging. 

ASTM, Standard guide for Computed Tomography (CT) Imaging, 1995... 

Robb R.A., et. al. The Dynamic Spartial Reconstructor a computed tomography system for high-speed simultaneous scanning of multiple cross section of the heart., J. Med. Syst., V. 4, 1980, p. 253-288. 

Article is denoted to the investigation and the creation of the new ultrasonic and information technologies (IT) and the technical methods of non-destructive evaluation (NDE) of material state in the product, which are based on principles of ultrasonic computing tomography (USCT). These results concern two important questions ... 

High Resolution Computed Tomography on Large-Sized Objects. 

High-resolution computed tomography on larged-size objects... 

Computed Tomography of high performance for the inspection of large objects 7 European Conference for Non-Destructive Testing (ECNDT), these proceedings... 

The key company of the new NDT- centre is HAPEG (Hattinger Priif- und Entwicklungs-gesellschaft), which operates a Computed Tomography system and offers service measurements on test samples of their customers [1]. The basic set up and technical details of this CT-system are presented in this paper. Details of the extension towards 3D visualisation, 3D-Tomography and the software involved are presented in a different paper [2]. 

The GAMMASCAN 1500 HR is a combined system for two-dimensional (2D-CT) and three-dimensional (3D-CT) computed tomography, as well as digital radiography (DR). The system is equipped with two separate detector systems for the fan-beam and cone-beam CT. The sire of the objects is limited to a height of four meters, maximum diameters of 1.5 meters and a weight of up to 15 tons. The turntable which carries the test samples can be moved along and across the beam direction ( X- and Y- direction). The radiation source and the detector systems can be moved in Z- direction, both, simultaneously and independently. 

Computed Tomography for very large and heavy objects is a demanding challenge for the manufacturer and his subsuppliers in many respects, especially with regard to the strongest advantages of CT ... 

X- and Gamma-Ray Computed Tomography Scanners for Industrial Applications. 

Various computed tomography CT- scanners for industrial applications have been designed and constructed) They use as radiation sources X-ray tubes or gamma emitting radioisotopes and as detectors NaI(Tl)-scintillators for gamma rays and image intensifiers for X-rays. 

The techniques of quantitative computer tomography are realized in tomographic units constructed of RF Technical Physics and Automation Research Institute, Moscow, for the control of objects of atomic engineering and airspace technics constructed of RF Technical Physics and Automation Research Institute, Moscow. 

The visualization of volumetric properties is more important in other scientific disciplines (e.g., computer tomography in medicine, or convection streams in geology). However, there are also some applications in chemistry (Figure 2-125d), among which only the distribution of water density in molecular dynamics simulations will be mentioned here. Computer visualization of this property is usually realized with two or three dimensional textures [203]. 

Single photon emission computed tomography (SPECT)... 

Single-photon emission computed tomography (SPECT) studies are acquired by rotating the y-camera around the patient s long axis. These data are then used to reconstmct the radioactivity distribution in three dimensions. This may be displayed as sHces of radioactivity concentration or rendered so as to present the appearance of a soHd volume. 

A Similar aphical presentation of the spatial distribution of a tracer g is or a real contaminant and thereby to some extent the airflow in the studied area is based on the use of computed tomography and optical remote sens-jt]g I2.M beams are sent out horizontally and reflected back to an IR analytical instrument, analyzing the average concentration of the contaminant along the IR beam. By combining data from several measured tines it is possible ro present data in a similar way to Fig. 12.8. Those methods presuppose access ro an expensive and complicated sampling/data processing system. 

Pancreas Oral cholecysto-graphic agent iopanoate ( ) experimental Unknown excretion into pancreatic duct Schmiedl U etal (1994) Imaging of exocrine pancreatic function investigation of the bioavailability of weak organic acids as potential pancreatic contrast agents for computed tomography. Invest Radiol 29 689-694... 

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