Comparison of nonionic contrast agents iohexol and iotrolan for cisternal myelography in dogs

Area of Science:

• Veterinary Radiology
• Diagnostic Imaging
• Neurology

Background:

• Cisternal myelography is a diagnostic procedure used in veterinary medicine to visualize the spinal cord.
• Contrast agents are essential for effective myelography, but their safety and efficacy can vary.
• Iohexol and iotrolan are non-ionic, low-osmolar contrast media used in various imaging applications.

Purpose of the Study:

• To compare the safety and efficacy of iohexol versus iotrolan for canine cisternal myelography.
• To evaluate the impact of these contrast agents on cerebrospinal fluid (CSF) parameters.
• To assess the radiographic quality and duration of visualization provided by each agent.

Main Methods:

• Six dogs underwent cisternal myelography with both iohexol and iotrolan, with a 6-week interval between procedures (each dog served as its own control).
• Cerebrospinal fluid (CSF) was collected pre-injection and at 1, 3, 7, and 14 days post-injection for cytologic and chemical analysis.
• Radiographic quality was assessed over time, and dogs were monitored for adverse events like seizures.

Main Results:

• No significant changes in CSF leucocyte count or glucose concentration were observed for either contrast agent.
• Iohexol showed a transient increase in CSF protein and lactate dehydrogenase activity, while iotrolan did not.
• Radiographic quality degraded over time for both agents, but iotrolan maintained superior visualization for longer periods compared to iohexol.

Conclusions:

• Both iohexol and iotrolan are safe for canine cisternal myelography, with no significant adverse neurological effects or pathological changes observed.
• Iotrolan demonstrates superior and more sustained radiographic quality compared to iohexol in canine cisternal myelography.
• Iotrolan may be a preferred contrast agent for canine cisternal myelography when prolonged visualization is required.