Clinical question: Evaluate for infection. Signs and symptoms: Meningitis, post infection, stopped antibiotic one week ago now with headaches and low grade temperature. Pre-and post-enhanced brain MRI:Diffusion-weighted images are extensively obscured by metallic artifact ( large aneurysm clips) which partially also a few incisional left craniectomy. Within this limitation there is no evidence of restricted diffusion. The extra-axial fluid collection at the surgical site also is negative for any restricted diffusion.Flair and T2 weighted images demonstrate mild dilatation of lateral ventricles (right greater than left. There is a focus of encephalomalacia in the right posterior temporal and occipital lobe with ex vacuo dilatation of trigone and occipital horn of right lateral ventricle similar to multiple prior CT exams. There is a large left anterior frontal and temporal craniectomy. There is a CSF signal intensity epidural collection at the site measuring maximum of 21 mm in transverse axis and 43 mm in AP. The adjacent parenchyma demonstrates no evidence of any inflammatory/edematous changes. This finding applies subtle mass effect on the left anterior frontal lobe. Post-enhanced images demonstrate expected pain uniform enhancement of dura and a thin uniform enhancement of lateral soft tissue boundary of fluid collection. Overlapping soft tissues demonstrate no edematous changes and adjacent native calvarial bone demonstrate no evidence edematous changes. There is no evidence of interval change in the size of this collection since prior head CT exam from 24 hours earlier. Based on findings on this exam there is no convincing evidence of an infectious process present however the extra-axial collection is superficially located and accessible for aspiration biopsy if clinically deemed necessary.Additionally there is a small left anterior frontal subdural collection which extends from the anterior edge of craniectomy medially and reaching the falx. This finding demonstrates a tiny linear enhancement along its dorsal edge. It measures approximately 32 mm in transverse axis and axial view and 6.7-mm in thickness. The finding results in very subtle flattening of the adjacent brain parenchyma.
1.No diffusion-weighted abnormality although this sequence is severely compromised due to metallic artifact from aneurysm clips on the left.2.CSF signal intensity extra axial epidural collection in the left anterior frontal -- temporal lobe with very thin rim of enhancement is highly suggestive of post operative change and findings are not highly suggestive of an infectious process however this collection can be directly aspirated for analysis if clinically deemed necessary. Please see detailed report above.3.Tiny extra-axial left anterior frontal subdural collection as detailed.4.Stable size of ventricular system and large area of encephalomalacia in the right posterior temporal -- occipital region at the site of previously treated AVM. 5.No areas of abnormal enhancement of brain parenchymal for the pia meninges.