Iohexol Myelography in the Dog

Abstract

Myelography with iohexol (180 mg iodine/ml, 0.25 ml/kg), a new nonionic radiologic contrast medium, was performed in 100 dogs of 33 different breeds. In 96 of the dogs the iohexol mixed evenly with the cerebrospinal fluid, providing an homogeneous, continuous column of contrast medium within the subarachnoid space, and a radiologic diagnosis of a normal myelogram or disease involving the spinal cord was made. Pooling of iohexol in the dorsal part of the subarachnoid space occurred in four dogs; whether this was related to poor mixing of contrast medium with cerebrospinal fluid or disease of the spinal cord and meninges requires further study. Postmyelographic signs of central nervous system irritation (fasciculations of the temporal muscles and three episodes of seizure activity) were observed in only one dog and were controlled with diazepam. The presenting neurologic signs were aggravated after myelography in four other dogs, two of which were eventually killed. This study provided further evidence of the increased safety of iohexol compared with metrizamide, the first of the nonionic media, as a contrast medium for myelography in the dog.

Application of Short-time Magnetic Resonance Examination for Intervertebral Disc Diseases in Dogs.

“…With the advent of non-ionic contrast agents [1,6], the safety of radiographic myelography has remarkably improved, but radiographic myelography is sometimes difficult to use in obese animals and it cannot be denied that this procedure entails substantial intervention with vertebral canal puncture [3,5]. The usefulness of magnetic resonance (MR) has already been established; it enables the clinician to delineate the lesion three-dimensionally with a non-invasive method.…”

Diagnostic aids

“…Hyperosmolar or hypertonic solutions must be avoided. A non-ionic, water-soluble contrast medium must be used-Iohexol (Omnipaque, Nycomed) is the contrast medium of choice (Wheeler and Davies, 1985;Allen and Wood, 1988). Concentrations in the range of 180-350 mg iodine/ml are used-most often 240 or 300 mg iodine/ ml.…”

“…Neurological deterioration can occur in some animals after myelography (Allen and Wood, 1988). Largebreed dogs with significant cervical cord lesions; dogs with chronic spinal cord compression, meningitis or extradural tumors; and those with degenerative myelopathy seem to be affected most often.…”

“…Seizures occur infrequently on recovery from anesthesia following myelography (Wheeler and Davies, 1985;Allen and Wood, 1988). The site of injection appears not to influence the frequency of seizures; dogs with CSM may be prone to this complication (Lewis and Hosgood, 1992).…”

Mielografia lombar no diagnóstico de extrusão do disco intervertebral toracolombar em cães: estudo prospectivo

“…O meio de contraste mais utilizado na medicina veterinária é o iohexol (DA COSTA; PARENT; DOBSON, 2011). A incidência de convulsões pós-mielografias com iohexol varia de 0 a 10% e tem sido associada com o peso do paciente (pacientes maiores), o volume de injeção de contraste (volumes maiores), a injeção na cisterna magna, localização da lesão (cervical mais provável), sexo (maior risco em machos) e raça (maior risco em dobermans pinchers) (WHEELER; DAVIES, 1985;LEWIS;HOSGOOD, 1992;HOULTON, 1994;ALLAN;WOOD, 1988;BARONE et al, 2002;DA COSTA;PARENT;DOBSON, 2011;NEWCOMB et al, 2012). A injeção do contraste em L5 e L6 para a mielografia em cães mais leves que 20 kg está associada com taxas mais baixas de convulsão pós-mielografia (BARONE et al, 2002;ISRAEL et al, 2009).…”