![]() metal artifact reduction sequence (MARS).turbo inversion recovery magnitude (TIRM).fluid attenuation inversion recovery (FLAIR).diffusion tensor imaging and fiber tractography.MRI pulse sequences ( basics | abbreviations | parameters).iodinated contrast-induced thyrotoxicosis.iodinated contrast media adverse reactions.clinical applications of dual-energy CT. ![]() as low as reasonably achievable (ALARA).3 Ways to reduce scatter include close collimation, grids, or air gap technique. Factors that contribute to scatter radiation are increasing volume of tissue, tube kilovoltage, the density of matter, and field size. Scatter radiation will decrease the contrast of the radiograph. Hence the high kV technique of the chest x-ray is employed to present a more uniformly dense image to better appreciate the lung markings.Ī 15% increase in kV will essentially correlate to an increase in density similar to double the mAs 2. A primary beam with greater kV results in an overall rise in penetration through all tissues (decrease in attenuation differences), therefore resulting in a lower contrast radiograph. The kilovoltage (kV) during the radiographic examination will determine the primary beams' energy higher energy effects increased penetrating power. Radiographic contrast is dependent on the technical factors of the radiographs taken. Long-scale radiographs are preferred while examining the lung fields, where subtle changes in density are pertinent to a diagnostic image. Long-scale radiographs are considered 'lower-contrast' whereby density differences are less noticeable however possess many more shades of grey. Short-scale radiographs are considered 'high-contrast' whereby density differences albeit greater, overall possess fewer in density steps (lesser shades of grey). It is due to this that the radiographic contrast of an entire image is referred to as 'long-scale' or 'short-scale.' Short-scale contrast Contrast scaleĪs radiographs have varying regions of density, one cannot simply make assumptions based on a small region of interest. Low radiographic contrast is seen on radiographic images where adjacent regions have a low-density difference (black to grey). High radiographic contrast is observed in radiographs where density differences are notably distinguished (black to white). Radiographic contrast is the density difference between neighboring regions on a plain radiograph.
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