Effect of intravenous contrast material on the integrity of the blood-brain barrier: experimental study

Increasingly large doses of contrast medium have been advocated for enhanced computed tomography. It is assumed that such large intravenous doses, which increase the osmolality of the blood, do not affect the blood-brain barrier in the same way as intracarotid injections of the same solutions. Using a qualitative marker, Evans blue dye, and a quantitative marker, 99mTc-pertechnetate, a study was performed in rabbits to assess the effect of intravenous sodium iothalamate (Conray-420) at a dose of 8 ml/kg on the integrity of the blood-brain barrier. No qualitative or quantitative evidence of disruption of the blood-brain barrier was demonstrated. Since histologic examination was not done, morphologic changes cannot be excluded.