Male, 40 years old, with left facial palsy and cranial nerve VI palsy, status post AVM resection in 9/25. Postoperative findings are redemonstrated compatible with prior left suboccipital craniectomy and lesion resection from the left pontomedullary junction. A pseudomeningocele is partially visualized within the left posterior neck soft tissues, having become somewhat larger and better organized than on the prior examination. This collection does not appear to exert mass effect upon the brainstem in any way.At the level of the pontomedullary junction on the left, a hemosiderin stained region of tissue is again seen measuring approximately 14 x 12 mm on T2-weighted images (image 10 series 1001). This lesion is similar in size to that noted on the prior examination, but demonstrates less internal bubbly T2 hyperintensity. A curvilinear enhancing structure is seen coursing along the right margin of the lesion, similar to that noted on a prior exam, likely representing a small venous structure or DVA. No significant edema is evident surrounding the lesion.A 2 mm focus of susceptibility is evident along the right lateral ventricular margin which appears to be new when compared to prior examinations. No other new findings are seen. No additional areas of significant parenchymal signal abnormality are detected. Diffusion-weighted images are within normal limits. The pattern of contrast enhancement is otherwise unremarkable. Ventricular size and morphology are stable and normal.
1.Expected findings status post left suboccipital approach for resection of a lesion from the left pontomedullary junction. A pseudomeningocele within the posterior soft tissue operative bed has become somewhat larger and better organized than on the prior examination, but no significant mass effect is exerted upon the brainstem.2.Hemosiderin staining of the left pontomedullary junction appears similar in overall size to the prior examination which may reflect a combination of postoperative change and/or residual lesion. Bubbly internal T2 hyperintensity has decreased in prominence. No significant parenchymal edema is identified. A small likely venous structure or DVA is again seen traversing the right margin of the lesion similar to prior.3.A punctate focus of susceptibility appears to be new along the lateral margin of the right lateral ventricle. This is nonspecific. No other new or concerning intracranial lesions are seen.