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brachial_plexus [2026/04/27 16:51] – [Tips and Tricks] scottbrachial_plexus [2026/06/29 16:18] (current) – scott
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 ==== A note on Localizers==== ==== A note on Localizers====
  
-When planning out your localizer images, be sure to use a LARGE FOV so that the forelimbs are well demonstrated, positioning can be checked, and coil extents can be seen. Use a LOT of slices to cover all the anatomy; you want to be able to find the shoulder joints, elbows,  and sternum on all three planes.+When planning out your localizer images, be sure to use a LARGE FOV so that the forelimbs and shoulders are well demonstrated, positioning can be checked, and coil extents can be seen. Use a LOT of slices to cover all the anatomy; you want to be able to find the shoulder joints, elbows,  and sternum on all three planes. 
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 ====Sagittal Plane==== ====Sagittal Plane====
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 For brachial plexus scout images, add more slices on all planes to cover sternum to spine dorsally, shoulder to shoulder sagittal, and C3 to T3 axially. On the axial and dorsal scout imaging, plan the slices parallel to the center of the spinal cord. On the sagittal scout image, center the FOV on C6/7. For brachial plexus scout images, add more slices on all planes to cover sternum to spine dorsally, shoulder to shoulder sagittal, and C3 to T3 axially. On the axial and dorsal scout imaging, plan the slices parallel to the center of the spinal cord. On the sagittal scout image, center the FOV on C6/7.
 For each patient, the FOV should be re-sized to include at least C4/5 to include the T3/4. On the dorsal scout image, add enough slices to cover out to the humeral head on both sides unless specifically doing a unilateral study. **Be sure to use an ODD number of slices. This will ensure that the center slice is in true midline through the spinal cord.** For each patient, the FOV should be re-sized to include at least C4/5 to include the T3/4. On the dorsal scout image, add enough slices to cover out to the humeral head on both sides unless specifically doing a unilateral study. **Be sure to use an ODD number of slices. This will ensure that the center slice is in true midline through the spinal cord.**
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 ====Dorsal Plane==== ====Dorsal Plane====
-The dorsal plane is particularly useful when scanning for brachial plexus pathology, as it provides a good overview of both forelimbs symmetrically. As a first screening sequence, the dorsal should cover from the sternum to just past the vertebral bodies, with the FOV large enough to demonstrate both forelimbs. The __Brachial Plexus__ nerves exit ventrocaudally  from C4/5 to T1/2 and extend into the forelimbs and dorsal to the humeral head. Incidental findings are also frequently located on the dorsal plane (Right image, red arrow)+ 
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 +The dorsal plane is particularly useful when scanning for brachial plexus pathology, as it provides a good overview of both forelimbs symmetrically. As a first screening sequence, the dorsal should cover from the sternum to just past the vertebral bodies, with the FOV large enough to demonstrate both forelimbs and shoulders. The __Brachial Plexus__ nerves exit ventrocaudally  from C4/5 to T1/2 and extend into the forelimbs and dorsal to the humeral head. Some plexus pathology may lead to changes in the signal intensity of muscles (Right image, red arrow)
  
 {{::bplexusdorplan.png?500|}}{{:dorincidental.png?500|}} {{::bplexusdorplan.png?500|}}{{:dorincidental.png?500|}}
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   * Run a dorsal early in the exam, preferably a STIR   * Run a dorsal early in the exam, preferably a STIR
-  * Check for symmetry; denervation changes are more easily spotted as fluid like intensity in muscles+  * Check for symmetry; denervation changes can lead to T2 hyperintensity or muscle atrophy
   * Good fat saturation; use Dixon techniques whenever possible. If no Dixon is available, be sure to manually shim the area of interest   * Good fat saturation; use Dixon techniques whenever possible. If no Dixon is available, be sure to manually shim the area of interest
 +  * Run high resolution NON-fat saturated sequences; the nerves are fairly dark and will be more apparent when surrounded by bright fat
  
 ===Fat Saturation=== ===Fat Saturation===
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   * Use Dixon techniques for fat saturation (Dixon, FLEX, IDEAL)   * Use Dixon techniques for fat saturation (Dixon, FLEX, IDEAL)
   * SPAIR/SPECIAL techniques may be a bit more homogenous if available   * SPAIR/SPECIAL techniques may be a bit more homogenous if available
-  * Manually shim to the area around the thoracic inlet+  * Manually shim to the area of interest
   * Position and scan close the isocenter   * Position and scan close the isocenter
   * Use the smallest appropriate FOV   * Use the smallest appropriate FOV