Osmotic demyelination of the pons | Figure 1
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Osmotic demyelination of the pons
Axial T2 weighted MRI shows trident-shaped signal abnormality (arrow) within the pons characteristic of osmotic demyelination. Osmotic demyelination occurs with rapid correction of hyponatremia. The rapid correction of the organic osmolytes places oligodendrocytes at the risk of self-shrinkage and demyelination.
Key points:
- Atlas and direct imaging-based methods are 2 major categories of MR-based PET/MR attenuation correction.
- Atlas-based methods are accurate and robust in brain PET attenuation correction; however, atlas-based approach cannot account for intersubject variations and is time-consuming.
- Direct imaging-based MR attenuation correction methods are rapid and can account for variations across patients.
- Direct imaging with segmentation only approaches have large attenuation correction errors owing to discrete linear attenuation coefficient values.
- Direct imaging with segmentation and MR-computed tomography conversion has similar PET attenuation correction accuracy as the atlas-based MR attenuation correction.
From Magnetic Resonance Imaging Clinics of North America (Volume 25, Issue 2, May 2017, Pages 245-255) © 2016 Elsevier Inc.