Diagnostic utility of computed tomography imaging in equine intracranial conditions

Abstract

CT was an excellent neurodiagnostic tool in identifying skull fractures, intracranial space-occupying lesions (e.g. neoplasia) and acute haemorrhage and allows to rule in intracranial disorders. However, CT showed limited sensitivity in identifying inflammatory disorders and small parenchymal lesions in the equine brain, which was not further detectable after contrast administration.

Use of contrast media in computed tomography and magnetic resonance imaging in horses: Techniques, adverse events and opportunities

“…administration of ICM with CT (usually via the jugular vein) is used to evaluate the equine skull [39,40]. Low case numbers likely biased this conclusion as multiple equine reports agree that contrast-enhanced CT provides more information about lesion aetiology than precontrast CT [41][42][43][44]. Low case numbers likely biased this conclusion as multiple equine reports agree that contrast-enhanced CT provides more information about lesion aetiology than precontrast CT [41][42][43][44].…”

“…The usefulness of contrastenhanced CT over precontrast CT has been questioned [41]. Inflammation, sinonasal neoplasia, ethmoid haematomas, parapharyngeal aneurysms and abscess capsules typically enhance (Fig 2) [39][40][41][45][46][47][48]; although cholesterinic granulomata may [42,43], or may not [41] contrast-enhance. Inflammation, sinonasal neoplasia, ethmoid haematomas, parapharyngeal aneurysms and abscess capsules typically enhance (Fig 2) [39][40][41][45][46][47][48]; although cholesterinic granulomata may [42,43], or may not [41] contrast-enhance.…”

“…Inflammation, sinonasal neoplasia, ethmoid haematomas, parapharyngeal aneurysms and abscess capsules typically enhance (Fig 2) [39][40][41][45][46][47][48]; although cholesterinic granulomata may [42,43], or may not [41] contrast-enhance. Brain neoplasias have variable degrees of contrast enhancement due to variability in breakdown of the blood-brain-barrier and the tissue type of origin [39,41,47]. The pituitary gland enhances following i.v.…”

“…Acute traumatic head injuries do not require contrast media as haemorrhage is hyperattenuating on precontrast images [47]. Despite the added information on aetiology, not all lesions require ICM to provide a diagnosis and precontrast images are always indicated [41,50]. administration, but the degree of enhancement is not different between horses with and without pituitary pars intermedia dysfunction [49].…”

Acquired epilepsy in a horse associated with colic surgery

“…As the aetiology could not be determined more precisely and considering the interictal signs of amaurosis present, due to a forebrain lesion most likely acquired, the authors assumed a case of acquired epilepsy. In horses, MRI is more sensitive for detecting cranial disorders associated with seizures than CT (Sogaro and others 2009, Lacombe and others 2010) and could have given interesting information about the intracranial lesion, even though in another study on seizures in horses only 2 out of 31 cases had detectable abnormalities in MRI of the head (Manso-Díaz and others 2014). MRI or CT have not been performed in this case because of limited availability.…”