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  2. Dense MCA sign - Wikipedia

    en.wikipedia.org/wiki/Dense_MCA_sign

    vascular calcification, high hematocrit, artifacts The dense MCA sign is a dense artery sign observed on non-contrast computed tomography (CT) of the brain and is an important early marker of acute ischemic stroke involving the middle cerebral artery territory. [ 1 ]

  3. MRI artifact - Wikipedia

    en.wikipedia.org/wiki/MRI_artifact

    An MRI artifact is a visual artifact (an anomaly seen during visual representation) in magnetic resonance imaging (MRI). It is a feature appearing in an image that is not present in the original object. [1] Many different artifacts can occur during MRI, some affecting the diagnostic quality, while others may be confused with pathology.

  4. Diffusion-weighted magnetic resonance imaging - Wikipedia

    en.wikipedia.org/wiki/Diffusion-weighted...

    In present-day clinical neurology, various brain pathologies may be best detected by looking at particular measures of anisotropy and diffusivity. The underlying physical process of diffusion causes a group of water molecules to move out from a central point, and gradually reach the surface of an ellipsoid if the medium is anisotropic (it would ...

  5. Attenuation - Wikipedia

    en.wikipedia.org/wiki/Attenuation

    The attenuation in the signal of ground motion intensity plays an important role in the assessment of possible strong groundshaking. A seismic wave loses energy as it propagates through the earth (seismic attenuation). This phenomenon is tied into the dispersion of the seismic energy with the distance. There are two types of dissipated energy:

  6. Ringing artifacts - Wikipedia

    en.wikipedia.org/wiki/Ringing_artifacts

    The main cause of ringing artifacts is overshoot and oscillations in the step response of a filter.. The main cause of ringing artifacts is due to a signal being bandlimited (specifically, not having high frequencies) or passed through a low-pass filter; this is the frequency domain description.

  7. Path loss - Wikipedia

    en.wikipedia.org/wiki/Path_loss

    Path loss, or path attenuation, is the reduction in power density (attenuation) of an electromagnetic wave as it propagates through space. [1] Path loss is a major component in the analysis and design of the link budget of a telecommunication system. This term is commonly used in wireless communications and signal propagation.

  8. Projectional radiography - Wikipedia

    en.wikipedia.org/wiki/Projectional_radiography

    What remains of the primary beam after attenuation is known as the remnant beam. The remnant beam is responsible for exposing the image receptor. Areas on the image receptor that receive the most radiation (portions of the remnant beam experiencing the least attenuation) will be more heavily exposed, and therefore will be processed as being darker.

  9. Mathematical descriptions of opacity - Wikipedia

    en.wikipedia.org/wiki/Mathematical_descriptions...

    mass attenuation coefficient, also called mass extinction coefficient, is the attenuation coefficient divided by density; see mass attenuation coefficient for details; absorption cross section and scattering cross section are both quantitatively related to the attenuation coefficient; see absorption cross section and scattering cross section ...