Spinal cord MRI in cats with myelopathy

Why cats need their own differential list

Spinal disease in cats is not a smaller version of disc disease in dogs. In 221 cats referred for spinal disease (Mella et al., Journal of Feline Medicine and Surgery, 2020), the diagnoses were:

Diagnosis	Cats
Non-lymphoid neoplasia	44
Intervertebral disc disease	42
Fracture or luxation	34
Ischaemic myelopathy	22
Feline infectious peritonitis (FIP) myelitis	18
Lymphoma	16
Thoracic vertebral canal stenosis	11
Acute non-compressive nucleus pulposus extrusion	11
Traumatic contusion	8
Spinal arachnoid diverticula	7
Lumbosacral stenosis	5
Spinal empyema	3

The history narrows this list before the scan, according to the same study:

Clinical picture	Most associated with
Middle-aged purebred cat, normal general examination, acute onset, painful and progressive	Intervertebral disc disease
Older cat, stable or improving, non-painful, lateralised, C6–T2 localisation	Ischaemic myelopathy
Younger cat, peracute onset, painful, non-ambulatory	Fracture or luxation
Concurrent systemic abnormalities on general examination	FIP myelitis, lymphoma or spinal empyema

Feline spinal MRI protocol at a glance

Two points from the evidence shape the field of view in cats. When lymphoma is on the list, including the lumbosacral plexus and paravertebral tissues is worth discussing, because in a series of 31 cats with nervous system lymphoma (Durand et al., Journal of Veterinary Internal Medicine, 2022) 6 of 12 spinal cases involved the conus medullaris and lumbosacral plexuses, and 11 of 31 cats had infiltration of adjacent extra-neural tissue. When FIP is suspected in a cat with spinal signs, imaging the brain as well as the spine is usually worth considering, because several typical MRI findings of neurologic FIP are intracranial (Crawford et al., Journal of Veterinary Internal Medicine, 2017).

What the radiologist looks at

Spinal lymphoma

In 27 cats with spinal lymphoma (Lorenzo et al., Frontiers in Veterinary Science, 2022), the most frequent signs were rapidly progressive paraparesis (62.9%) or paraplegia (22.2%). Age was bimodal: 40.7% of cats were 2.5 years or younger (63.6% of them FeLV positive) and 44.4% were 8 years or older (16.7% FeLV positive).

Typical MRI findings in that series:

• an ill-defined epidural lesion with moderate to severe cord compression, extending over more than one vertebral body
• most often in the lumbar segment and circumferential to the cord
• hyperintense on T2-weighted and isointense on T1-weighted images, with variable contrast enhancement
• other patterns: paravertebral masses extending into the vertebral canal, and lesions centred on spinal nerve roots
• involvement of vertebrae and adjacent soft tissues in 74%, with cortical sparing

Beyond the cord. In the 31-cat series, lymphoma also reached the conus medullaris, lumbosacral plexuses and adjacent extra-neural tissue, so the radiologist checks these areas when they are in the field of view.

FIP myelitis

In 24 cats with histopathologically confirmed neurologic FIP, 3 presented with a T3–L3 myelopathy. MRI was abnormal in all 24, with:

• meningeal contrast enhancement (22)
• ependymal enhancement (20)
• ventriculomegaly (20)
• syringomyelia (17)
• foramen magnum herniation (14)

Ischaemic myelopathy and non-compressive extrusions

• Ischaemic myelopathy. In 19 cats with a clinical and MRI diagnosis of ischaemic myelopathy (Theobald et al., Journal of Feline Medicine and Surgery, 2013), lesions were in the C1–C5 (30%), C6–T2 (30%), T3–L3 (25%) and L4–S1 (15%) segments. Possible inciting causes were found in 12 cats, including exertion, trauma, general anaesthesia, renal disease, hyperthyroidism, hypertension and hypertrophic cardiomyopathy.
• Fibrocartilaginous embolism in cats affects the cervical cord more often than other regions (De Risio, Frontiers in Veterinary Science, 2015).
• Non-compressive and intramedullary extrusions. In these, the disc space is often narrowed and the intramedullary T2 hyperintensity lies over the affected disc. A linear tract from the disc into the cord is highly suggestive of an intramedullary extrusion.
• The history. In 11 cats with presumptive acute non-compressive nucleus pulposus extrusion (Taylor-Brown and De Decker, Journal of Feline Medicine and Surgery, 2017), all had a peracute onset, and 8 had witnessed or suspected trauma.

Compressive disc disease: is it the cause?

In 114 cats with suspected myelopathy that had spinal MRI (Soteras et al., Journal of the American Veterinary Medical Association, 2024), 70% had at least one degenerative spinal change:

• disc extrusion was always responsible for the signs
• degenerative lumbosacral stenosis was commonly considered incidental
• disc protrusion was infrequently related to the signs

A useful report states whether a disc lesion explains the neurological findings, not only that it is present.

What your report will include

Every Veheri case is read by a radiologist or neurologist, and when you order you can choose Diplomate-only reporting or the full specialist panel. Neurology reporting covers CT and MRI. You can chat directly with the specialist assigned to your case, and a simplified pet owner report helps you explain the findings to the owner.

When you take the report forward:

• Suspected lymphoma often needs tissue. Spinal lymphoma looks heterogeneous, and CSF alone confirmed the diagnosis in 4 of 27 cats (14.8%), so tissue sampling guided by imaging was often needed.
• Ischaemic myelopathy is presumptive. It is based on clinical and MRI findings, and separating it from non-compressive extrusions can be difficult.
• Talking to the owner: in ischaemic myelopathy, median time to ambulation was 3.5 days, and 15 cats (79%) had a favourable outcome. In presumptive non-compressive extrusion, all cats that presented non-ambulatory regained ambulation.

What to include when you request a spinal MRI report

• signalment: age, breed and sex
• onset (peracute, acute or chronic), progression, pain and lateralisation
• trauma or exertion before onset
• general examination findings, systemic signs and FeLV status
• ambulatory status, nociception and continence
• blood pressure, cardiac, thyroid and renal findings where known

How Veheri can help

Veheri works with veterinary radiologists and neurologists and reports spinal MRI studies remotely for clinics. For the brain side of FIP and lymphoma, see brain MRI in cats, and for disc disease in the thoracolumbar region, see MRI of the thoracolumbar spine in cats.