Blood-Brain Barrier Injury following Intracarotid Injection of Radiographic Contrast Media

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.