Use of enhanced computerized tomography to evaluate osmotic blood-brain barrier disruption.

Enhanced computerized tomography (CT) is a noninvasive means of monitoring blood-brain barrier (BBB) disruption. In the present study this technique was used to monitor the degree, distribution, extent, and reversibility of osmotic BBB disruption. With a canine model, the timing of administration of iodinated contrast agent was shown to be crucial to optimize enhancement by CT of the disrupted BBB. Meglumine iothalamate given intravenously resulted in excellent enhancement on CT scan. Intracarotid infusion of this contrast agent was less satisfactory. Under similar conditions, enhancement due to metrizamide was less marked and more transient than that observed with meglumine iothalamate. Systemically administered methotrexate after osmotic BBB disruption resulted in increased brain levels in areas that closely correlated with CT scan enhancement. These results suggest that the CT scan provides an excellent noninvasive monitor of both BBB disruption and the delivery of chemotherapeutic agents to the brain. (Neurosurgery 6: 49--56, 1980)