Alba Farré Mariné (1)
Alejandro Luján Feliu-pascual (1)
Syringohydromyelia has been defined as a dilation of the centromedullary canal surrounded by a layer of ependymal cells (hydromyelia) or a fluid-filled cavity within the medullary parenchyma (syringomyelia). In human medicine, Magnetic Resonance Imaging (MRI) is the gold standard for the diagnosis of syringohydromyelia while Computed Tomography myelography (myelo-CT) is considered obsolete1 despite its superior sensitivity to detect small cavities.2,3 In veterinary medicine, the imaging characteristics of syringohydromyelia have been defined by MRI and plain CT4,5 but it has not been defined by myeloCT despite the fact that small intramedullary cavities have only been shown when they are filled with contrast.1
In this descriptive retrospective study, nine animals with intramedullary cavities consistent with syringohydromyelia were diagnosed following myeloCT between 2016-2019. Iohexol was injected in the subarachnoid space, and 16-slice helical CT with RadiAnt DICOM Viewer computer program were used for image evaluation. The diagnostic criteria were extrapolated from MRI and myeloCT human and veterinary studies.1-8
In all animals, a linear intramedullary cavity of variable length (from one vertebral body to extend along the entire spinal cord), and diameter (height range 1-4,5mm) between animals, and within the syringohydromyelia of each animal was seen. The cavity was filled with iodinated contrast appearing as a uniform hyperattenuating lesion with or without subjective increase in the diameter of the spinal cord.
To the authors’ knowledge, this is the first study describing the imaging characteristics of syringohydromyelia using myeloCT in veterinary medicine and demonstrates the usefulness of this imaging modality for the diagnosis.
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