Although computed tomography is a relatively accurate imaging technique, it is prone to producing various artifacts. For example, aliasing artifacts or streaks appear as dark lines that radiate away from sharp corners. These artifacts occur because it is impossible for the scanner to "sample" or take enough projections of the object, which is usually metallic. They also can occur when an insufficient mA is selected, resulting in insufficient penetration of the x-ray beam. This is especially the case with metallic artifacts on or in a patient. Partial volume effect appears as "blurring" over sharp edges. It is due to the scanner being unable to differentiate between overlying structures. The processor tries to average out the 2 densities or structures. This can be partially overcome by scanning using thinner slices.
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