(RSNA) The Radiological Society of North America, established in 1915, has the mission to promote and develop the highest standards of radiology and related sciences through education and research.

Raw data are the values of all measured detector signals during a scan. After calibration for fluctuations in tube output and beam hardening, the attenuation properties of each x-ray signal are accounted and correlated with the ray position. From these data the CT images are reconstructed including the use of mathematical procedures like convolution filtering and back projection.
Raw data can also be used for later reconstruction of additional planes and images by using a different convolution filter, zoom reconstruction, or an alternative CT number scale.

See also Magnification, Archiving, Number of Measurements and Convolution.

Thorotrast is an obsolete contrast medium containing a colloidal suspension of thorium dioxide. Contrast agents based on thorium have been abandoned since they turned out to be carcinogenic.

Whole body scintigraphy is the measurement of radioactivity in the entire body.
Whole body scintigraphy is useful for example in detection of tumors, infections, evaluation of metastases, and diseases with multiple organ involvement.
Different whole body scan techniques include:

Zonography is a variation of linear tomography, where a limited arc of movement is used. It is still used in some centers for visualizing the kidney during intravenous urography (IVU).