Air in the Brain

Ashley Davidoff MD

The Common vein Copyright 2010

Introduction

Calcification Mass and Air

An Evolving Abscess in the Left Basal Ganglion

The basal ganglia in the region of the caudate nucleus and globus pallidus are shown in axial projection in this 60 year old female who presents with neurological deficit and a fever. The CT scan shows asymmetric calcification in the region of the caudate nucleus and globus pallidus. The calcifications on the left are expanded by a low density presumably fluid collection (yellow). There is associated surrounding edema and mass effect on the ipsilateral ventricle. A small air bubble is noted in the anterior most portion of the left frontal horn. There is mild midline shift An MRI confirmed the presence of a complex fluid in the left basal ganglion and significant surrounding edema. The patient had a fever and the constellation of findings were consistent with an abscess of the basal ganglia on the left. In this diagram the intimate relationship of the basal ganglia to the ventricles is exemplified by the ipsilateral mass effect and the presence of air presumably from gas forming organisms.

Courtesy Ashley Davidoff MD Copyright 2010 All rights reserved 89065c01.8

Brain Abscess from Sinusitis

The MRI is from a 40 year old female who presents with a headache and has sinusitis which was complicated by a brain abscess.

Image (a) is a T1 weighted axial image taken at the level of the lateral ventricles and shosws a mass with an air bubble and a small air fliouid level in the right frontal lobe.

Image (b) is a T2 weighted image showing complex fluid in the abscess cavity that is not as intensely bright as the CSF.  There is surrounding edema in the brain substance and the black  air bubble is again seen.

Image c is FLAIR sequence in axial projection that has features similar to th T2 weighted image and image (d) is a coronal FLAIR sequence showing the paracentral location of the abscess.  In this image the left maxillary sinusitis is totally opacified consistent with the diagnosis of maxillary sinusitis

Courtesy Ashley Davidoff MD Copyright 2010 71604.c02