Non-contrast imaging through the brain has been obtained and compared to preoperative imaging of the brain. Small amount of gas is seen within subarachnoid space anteriorly within the ventricles, and a small locule of gas seen within the right side of the splenium corpus callosum the site of biopsy, which should be within the area of abnormality.
Please note there has been dramatic reduction in the amount of enhancement in the region, presumably due to steroid use; this is further support that this represents CNS lymphoma, however it may make histological assessment more difficult.