Dielectric effect artifact
Diagnosis not applicable
Updates to Case Attributes
Title
was changed:
Dielectric effect artefactartifact
Status
changed from draft to published (public).
Published At
was set to
.
Body
was changed:
This is not a problem with windowing and leveling, but the dielectric effect artefactartifact, an inherent limitation of higher field MRI systems.
As the field strength of an MRI unit increases, its radiofrequency (RF) wavelength in tissue decreases:
- 1.5 T: 52 cm
- 3.0 T: 26 cm
- 7.0 T: 11 cm
As the wavelength decreases to the point where it approximates the abdominal diameter (at 3.0 T, ~26 cm), the constructive constructive and destructive interference patterns may result, and in body MRI imaging, this most often results in a darkening/shading of the central portion of the image.
To improve the artefactartifact, the easiest solution is often to just switch the patient to a lower field system (e.g. 1.5 T) .
-<p>This is not a problem with windowing and leveling, but the dielectric effect artefact, an inherent limitation of higher field MRI systems. </p><p>As the field strength of an MRI unit increases, its radiofrequency (RF) wavelength in tissue decreases:</p><ul>- +<p>This is not a problem with windowing and leveling, but the <strong>dielectric effect artifact</strong>, an inherent limitation of higher field MRI systems. </p><p>As the field strength of an MRI unit increases, its radiofrequency (RF) wavelength in tissue decreases:</p><ul>
-</ul><p>As the wavelength decreases to the point where it approximates the abdominal diameter (at 3.0 T, ~26 cm), the constructive and destructive interference patterns may result, and in body MRI imaging, this most often results in a darkening/shading of the central portion of the image.</p><p>To improve the artefact, the easiest solution is often to just switch the patient to a lower field system (e.g. 1.5 T) .</p>- +</ul><p>As the wavelength decreases to the point where it approximates the abdominal diameter (at 3.0 T, ~26 cm), constructive and destructive interference patterns may result, and in body MRI imaging, this most often results in a darkening/shading of the central portion of the image.</p><p>To improve the artifact, the easiest solution is often to just switch the patient to a lower field system (e.g. 1.5 T) .</p>
Diagnostic Certainty
was set to
.
Updates to Study Attributes
Images Changes:
Image MRI (T2 fat sat) ( update )
Description
was added:
Dielectric effect artifact centrally (also motion artifact with ghost images in the phase encoding direction)
Image MRI (T2) ( update )
Description
was added:
Dielectric effect artifact
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