Figure 3. (a) T₁ weighted sagittal image (460/15/2 [TR/TE/excitation]) at midline shows the herniation of thoracic spinal cord into the posterior mediastinal cyst through the defect in the vertebrae bodies (open arrow). Note the band extends between the anterior surface of cord and the walls of cyst (arrow head). (b) T₂ weighted sagittal (4000/90/2) image reveals the signal void due to cerebrospinal fluid flow in the subarachnoid space towards the lumen of mediastinal cyst (arrow) and in the cyst (open arrow). Note the hypointense band extending between the cord and superior wall of the cyst (arrow head).