Myelography with metrizamide: effect of contrast removal on side effects

Moderately severe side effects, such as prolonged headache, nausea, vomiting, or psychoneurologic symptoms, were noted in 27 (32%) of 84 patients in whom the contrast medium was not removed. Conversely, among 73 patients from whom 20-25 ml of cerebrospinal fluid with the contrast medium was removed, only 10 (14%) experienced adverse effects, a statistically significant reduction. Although new contrast agents, such as iohexol and iopamidol, are reportedly less toxic than metrizamide, the contrast-removal technique described here may be indicated when large amounts of any contrast medium are used.