Iohexol compared to metrizamide in cervical and thoracic myelography

Summary A randomized double blind study with iohexol (Omnipaque) and metrizamide (Amipaque) in cervical myelography was performed in 50 patients, 29 with iohexol and 21 with metrizamide. The myelographies were performed either with lumbar or with C₁–C₂ puncture in about equal groups, using 300 mg I/ml and 240 mg I/ml of the contrast media respectively. The image quality was equal with both contrast media, excellent in about 4/5 and good in 1/5 of the examinations. Subjective side effects were twice as frequent with metrizamide as with iohexol. The most frequent side effect was headache, occurring in 34% with iohexol and in 67% with metrizamide. Altogether 24% or the patients had EEG changes after iohexol as compared to 47% after metrizamide. All EEG changes were slight dysrythmia-except in three patients with spike activity after metrizamide. These were the only ones with mental reactions as well. It can be concluded that in this trial iohexol was better suited for cervical myelography than metrizamide.