ROUNDS IN VETERINARY DIAGNOSTIC IMAGING

Nov 2025

Fraser McConnell

CASE 1�2 y.o. M Cane Corso X Mastiff

• History: One month history of intermittent pain and ataxia. Presented with per acute onset paraparesis (worse on left) progressive over last 24-48 hours
• Images: MRI of the T Spine
• Please write a report which includes an organized description of your findings, summary/radiographic diagnosis and ddx/conclusion
• Evaluation of the technical quality and artefacts is not necessary

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T2w

T2w

T1w

T1w+C

Subtraction

T2w

Findings

• Left caudal thoracic wall mass arising from the left 8th rib -probable neoplasia
• Dilated thoracic vertebral venous sinuses,  intervertebral veins and azygous vein with thrombosis 
• Dilated pulmonary arteries with thrombosis

Outcome

• Paraplegia improved for 1 week
• Peracute right thoracic limb paresis 1 week later
• Euthanased
• Biopsy of thoracic wall mass – poorly differentiated sarcoma

Pulmonary artery thrombosis

Vertebral venous sinus and azygous thrombosis

Variables affecting vessel signal

• Decreased signal
• High velocity
• Turbulent flow
• Flow within imaging plane

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• Saturation pulses
• Multislice acquisition
• Slices deep within imaging volume

• Increased signal
• Low velocity
• Laminar flow
• Flow perpendicular to slice

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• Gradient motion nulling (Flow comp)
• Slices at end of imaging volume
• Gadolinium

Contrast mechanisms of flow

• Signal from blood
• Long T1
• Long T2

Large T2/T1 ratio (bSSFP)

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• Inflow
• Time of flight (flow related enhancement) (esp. GRE)
• Flow voids (esp. T2w FSE)
• Phase effects
• Flowing blood acquires phase shift

bFFE

Appearance of bulk flow

• Flow effects always present
• Complex
• May mimic pathology
• Recognising normal flow important

T2* GRE without flow comp

T2w

T2* GRE with flow comp

Vertebral venous sinus thrombosis

• Rarely diagnosed
• Spinal pain

+/- Neurological deficits

• Signal similar to parenchymal haemorrhage
• T2* GRE useful

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Vertebral venous sinus dilation

• 11/93 sighthounds

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• Majority right sided

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• 10/11 unilateral

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• Caudal cervical spine most common

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• ? Significance

Sighthound venous sinus dilation

• 11 dogs -venous sinus dilation

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• 9 Sighthounds

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• Only 3 with clinical signs of spinal pain/neurological signs

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• 2 with thrombi in sinuses

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Case example 2018

• 2.5 y.o. Deerhound

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• Finlay had shown signs of neck pain over the previous two months however had an acute increase in pain over the past day. This included becoming increasingly head shy and crying out when his head was touched.

T2* GRE C4/5

T2* GRE C6/7

T2W C4/5

Case example - 2022

T2* GRE 2018

T2* GRE C6/7

T1W C6/7

T2W C6/7

bFFE C6/7

• 5 y.o. Mn Deerhound

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• Recurrence of cervical pain

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CT 2022

Case Example “Blossom” �8 y.o. Newfie

T2* GRE

T2w

T1w

T1w+C

CT

Differential diagnoses of dilated sinuses

• Sinus thrombosis

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• Increased venous pressure (e.g. CrVC obstruction etc )

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• Neoplasia – e.g. Lymphoma

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• Vascular malformations

CASE 2�7 y.o. F Cocker Spaniel�

• History: Acute onset tetraplegia. Localises C6-T2 based on reduced thoracic limb withdrawal bilaterally
• Images: MRI of the C spine
• Please write a report which includes an organized description of your findings, summary/radiographic diagnosis and ddx/conclusion
• Evaluation of the technical quality and artefacts is not necessary

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T2w

T2w

T1w

T1w+C

Subtraction

T2* GRE

Findings

• Extradural cystic lesion dorsal C1

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Haemorrhage on T2* GRE

8ms

16ms

24ms

32ms

40ms

Appearance of haemorrhage on SWI/T2*GRE

• Peracute = SWI hyperintense
• Late subacute – T1 shine through – SWI hyperintense
• Most stages SWI hypointense rim

Diagnosis

• Subperiosteal haematoma
• Confirmed surgically
• No underlying cause found
• Normal coagulation
• Angiostrongylus negative �

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Subperiosteal Haematoma

• Sighthounds most commonly

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• Lumbar spine most commonly

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• Acute onset signs

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• Lesions confined to periosteal/dural limits

CASE 3�13 y.o. FN DSH�

• History: Acute onset ataxia, nystagmus, right facial paresis
• Images: MRI of the head
• Please write a report which includes an organized description of your findings, summary/radiographic diagnosis and ddx/conclusion
• Evaluation of the technical quality and artefacts is not necessary

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T2w

FLAIR

T1w

T1w+C

Findings

• Otitis media
• Abnormal signal right inner ear

Post contrast FLAIR

Pre-contrast FLAIR

Post contrast 3D-T1w mDIXON 1mm slice

Post contrast T1w

Diagnosis and outcome

• Right sided otitis media/interna
• Localised meningitis
• Abnormal enhancement right facial nerve

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• Tx Pred, ear drops
• Improved but persistent facial paresis
• Relapsed 3 months later with recurrence of vestibular signs

Diagnosis Otitis Interna/Vestibular disease

• Failure of endo/perilymph suppression on FLAIR

- Haemorrhage

- Elevated protein

- Breakdown blood-labyrinth barrier

- Artefact

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Delayed post-contrast FLAIR

• Investigation of inner ear pathologies

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• 3D FLAIR post-contrast

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• 4 hour delay

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• Increased signal in abnormal inner ear

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Post-Contrast FLAIR

• 3D FLAIR recommended

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• At least 5 mins post-contrast

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• ?Long TE

Delayed post-contrast FLAIR

• 10 y.o. SBT

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• Right sided facial paresis and nystagmus

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• Idiopathic facial and vestibulocochlear neuropathy

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• Abnormal right inner ear

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T1w+C

FLAIR pre-contrast

FLAIR post-contrast

3D T1w TSE mDIXON +C

Facial and Vestibular neuropathy

• Need high resolution and FATSAT

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• Sensitivity ~90%
• Specificity ~90%

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• Concurrent involvement of vestibulococlear nerve common

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• Possible link with abnormal inner ear signal on FLAIR

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4mm T1+C

1mm 3DT1+C/FATSAT

Dorsal T2W

1mm 3DT1+C/FATSAT

Acknowledgements

• Neurology team SATH, University of Liverpool
• Rory Fentem, Northwest Veterinary Specialists, UK
• Nadia Shihab, Fitzpatrick Referrals , UK

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