CT imaging

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

Sekihara, K., H. Kohno, and S. Yamamoto, Theoretical prediction of x-ray CT image quality using contrast-detail diagrams. IEEE Transactions on Nuclear Science, 1982. NS-29(6) p. 2115-2121. 

Cohen B., Improving Analog CT Image Quality , 1991, Research Thesis, Doctor of Science, The Department of Quality Assurance and Reliability,. Technion. 

The amount of contrast material required for CTA is comparable to that used for conventional contrast-enhanced CT imaging. The amount of scanning time required for a CTA examination of the head and neck, such as is usually performed for acute... 

Lev MH, Segal AZ, Farkas J, Hossain ST, Putman C, Hunter GJ, Budzik R, Harris GJ, Buonanno FS, Ezzeddine MA, Chang Y, Koroshetz WJ, Gonzalez RG, Schwamm LH. Utility of perfusion-weighted CT imaging in acute middle cerebral artery stroke treated with intra-arterial thrombolysis prediction of final infarct volume and clinical outcome. Stroke 2001 32 2021-2028. 

The telemedicine-based evaluation of acute stroke is especially challenging. It requires a rapid neurological assessment, CT image acquisition and review, and a detailed history for rt-PA exclusion criteria. Low-cost teleradiology systems are now available for the transmission of compressed CT images viewable on a conventional personal computer (PC) monitor, in accordance with published standards. 

To make the process practical for community hospitals, this technology must be inexpensive and easily operated in the ED. Transmission of CT images to experienced radiologists for formal and final interpretation is essential for quality control and feedback. As a result, systems that permit remote decision-making by expert physicians reduce the manpower needed to provide acute stroke team coverage in ED without around-the-clock access to in-house stroke neurology. 

Apple SL, Schmidt JH. Technique for neurosurgically relevant CT image transfers using inexpensive video digital technology. Surg Neurol 2000 53 411 16. 

Figure 3 3D computerized tomography (CT) image of a foamed polysiloxane incorporating a small admixture of carborane cages. 

CT images provide a large amount of detailed information about each individual object packed in articles of luggage. This information is not available in images produced by conventional X-ray scanners. 

This chapter discusses the features of CT imaging and outlines how the images are formed. Several different technical approaches are described along with examples. Finally, issues to be considered in designing luggage scanners are presented. 

Since is proportional to material density (g/cm ), it is common to refer to the CT image as a density image. 

Figure l Schematic drawing of the slice-by-slice generation of a 3D CT image of a bag containing seven sticks of dynamite and one book. 

Numerous texts and a wealth of literature exist that describe many approaches to X-ray CT imaging. Examples include Refs [2—4]. All approaches involve a large number of X-ray transmission measurements of the item being imaged. In addition to measuring transmission at different positions of the item, all these measurements are then repeated at a large number of different trajectory directions of the incident X-ray beams. 

Dual-energy is a CT imaging approach aimed at generating and extracting additional information beyond material density from image slices. The additional information, a second material property, is known as the effective atomic number, Zeff. Although the X-ray attenuation coefficient is proportional to a material s density p, it is also a function (i) of the atomic number Z of each of the material s... 

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