Figure 1: A case of left brachial plexus birth palsy. Images (a-f) show MRI of brachial plexus in a three-month-old infant. (a, b) Axial T2W CISS sequence and Coronal T2W image shows thecal sac without pseudomeningocele. (c) Axial STIR image shows thickening and increased signals from C5 cervical nerve (arrow) on the left side. (d) Coronal STIR image shows increased signals from the C5, C6 and C7 cervical nerves (arrow) on the left side. (e) Axial T2W image shows swelling of left scalene muscles with an abnormal T2 bright (arrow) periscalene signal. (f) Axial T1W images show isointense signal giving a mass like appearance (arrow).