A) In the normal plexus, the cervical spinal nerves and trunks of the brachial plexus follow a straight trajectory with even spacing.

B) Scalene syndrome is demonstrated by a gentle deformation of the course of the nerve elements and loss of space between them. In patients with pain only there is usually no nerve hyperintensity. 

C1) Distortion of the shape of the C7 element (*) associated with a severe TOS case.

C2) A more anterior image plane in the same patient showing both a sharp kink (K) in the course of the lower trunk associated with a fibrous band and nerve hyperintensity (H) consistent with lower trunk motor symptoms.