Blood-brain barrier injury following intracarotid injection of radiographic contrast media. In vivo quantification using magnetic resonance imaging and Gd-DTPA

Changes in signal intensity of the brain at magnetic resonance (MR) imaging before and after Gd-DTPA were used for in vivo quantification of injury to the blood-brain barrier (BBB). Immediately following intracarotid injection of 2 ml/kg of radiographic contrast medium (CM) 0.4 mmol/kg of Gd-DTPA was injected intravenously. MR imaging was performed with a 400/25 partial saturation pulse sequence. The maximum percentage changes (mean +/- SD) in signal intensity of the brain after CM and Gd-DTPA were 1.6 +/- 1.6% with saline, 3.2 +/- 2.0% with iotrolan, 4.3 +/- 1.7% with iohexol, 6.6 +/- 3.6% with ioxaglate and 8.2 +/- 3.6% with diatrizoate. Not only the osmolality but also the ionicity and chemotoxicity seemed to influence Gd-DTPA leakage. A subtle BBB injury had a stronger tendency to occur in the basal ganglia than in the cerebral cortex. MR enhancement is proposed as a sensitive method for in vivo quantification of the BBB injury caused by intracarotid CM injection.