Intracranial gas is commonly detected on neuroimaging. The recognition of this finding can at first blush be unsettling. Being able to localize this gas to a specific compartment: intraarterial, intravenous, intraparenchymal, subdural, epidural, subarachnoid and intraventricular, is the first step in determining the importance of the gas. Determination of the route of entry: through the skull, extension from a paranasal sinus or the mastoid air cells, via the spine, or trans-vascular, is the other important factor in determining potential consequences. Understanding these parameters allows for a confident determination of etiology. More importantly, it generally provides guidance as to what must be done: either to disregard (e.g., subarachnoid gas following lumbar puncture and intravenous gas following IV placement), obtain follow-up (e.g., postoperative gas), or administer emergent treatment (e.g., intraarterial gas and epidural abscess). In this review, we use gas location and route of entry to classify the various causes of pneumocephalus and provide examples of each of these etiologies.
The accuracy of ADC ratios in discriminating brain abscesses from cystic or necrotic neoplasms is very high and can be further improved using T2 rim characteristics.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.