Contrast media for myelography and possible complications following their application

Abstract

Myelography is the radiological method of examination of the spinal column, and involves the application of contrast media into the subarachnoidal space in order to diagnose different pathological conditions. The formerly used application of oil-based contrast media did not yield consistent, satisfactory results and also carried certain risks. Due to the poor mixing of oil-based contrast agents with cerebrospinal fluid, distribution along the spinal canal was uneven, excretion from the body very slow, and their application often caused chronic inflammation. For these reasons, oilbased contrast media have since been replaced with low osmolality, water soluble, non-ionic contrasts. In contemporary radiology, the commonly used contrast media for myelography are metrizamide, iopamidol and iohexol. Metrizamide is often used as an isotonic solution containing 170 mg I/mL, while iopamidol and iohexol are slightly hypertonic, containing approximately 300 mg I/mL. The application of these contrast agents can also produce a wide range of complications in clinical practice, such as neurological exacerbation, hyperaesthesia, vomiting and apnea. These symptoms are usually a consequence of metrizamide, but may also occur following the administration of iopamidol and iohexsol. In that case, complications are mostly transient. Regarding the facts presented, a large number of literature data are outlined in this paper. Moreover, different author reports are described regarding the selection of contrast agents, their method of application, and the possible complications that can occur as a result of their usage.