Fig 3.

Fast CSF leak with spinal extra-arachnoid fluid collection requiring dynamic CTM for leak localization. Fluid collection ventral to the thecal sac is best seen on axial T2-weighted images (A). This collection is smaller than the collection seen in Fig 2 and involves only the lower cervical and upper thoracic spine. Conventional CTM (B) shows a ventral contrast collection from C3 through T9, but the site of leak cannot be specified. Dynamic CTM (C) shows extra-arachnoid contrast accumulating ventral to thecal sac at C6-C7, consistent with a ventral leak at this level.