||MRI can be used, but requires special sequences and expertise. In the future MR may be used more for the characterisation of abdominal masses and nodules in veterinary patients.
||CT is the current modality of choice providing good quality images and being much easier and faster to perform.
|Elbow and Hock
||MRI can provide additional information concerning soft tissue, bone oedema, tendon and cartilage pathology.
||CT is usually recommended. Complimentary to arthroscopy in elbow disease.
|Shoulder and Stifle
||MRI preferred modality - great potential for assessment of muscular, tendinous, ligamentous and meniscal injury.
||CT recommended for osseous disease only.
||MRI advantageous in neoplastic disease (such as bone tumours, infection etc.).
||CT useful for angular limb deformities and fracture repair planning.
|Patients with metallic implants
||In MRI non-ferrous implants may be placed into the magnet, but can create serious artefacts and hence non-diagnostic studies. The magnitude of these artefacts differ depending on the MR sequence used. Where Tungsten implants are used MRI can still provide useful information in the right circumstances.
||The artefacts identified on CT examinations in patients with metallic implants can also prevent interpretation, but on occasion the gantry can be angled to avoid the metallic region and certain slices and reconstructions can limit their effect on the final image.
|Central nervous system (CNS)
||Imaging modality of choice for CNS. Specific additional MRI sequences can be very useful – these include radient echo sequences (haemorrhage), diffusion weighted imaging (ischaemic disease), FLAIR sequences (perilesional oedema and identification of pure fluid) and STIR sequences (to evaluate muscle, bone and nerve root changes).
||CT myelography is necessary to identify significant sites of spinal cord compression. Intramedullary lesions are better recognized on MRI without the inherent risks of myelography. Use CT alone to diagnose brain dis-ease ONLY if MRI is not available. Not generally suitable for assessment of foramen magnum herniation.
|Nasal cavities and sinuses
||MRI is extremely useful in assessment of the nasal cavities and frontal sinuses. Effective in the assessment of turbinate, maxillary and palatine destruction, mass lesions, presence of fluid, osteomyelitis and contrast enhancing lesions. Unlike other imaging modalities MRI can also detect early infiltration/infection in the brain.
||CT is extremely useful in assessment of the nasal cavities and frontal sinuses. Effective in the assessment of turbinate, maxillary and palatine destruction, mass lesions, presence of fluid, osteomyelitis, and contrast enhancing lesions. CT can be used for guided FNA’s or biopsies.
|External, middle and inner ears
||MRI can detect the fluid or mass lesions within the tympanic bulla and external ear canal, sclerosis or erosion of the bulla wall, associated retropharyngeal or para-aural lesions and regional lymphadenopathy. MRI allows assessment of cranial nerves VII and VIII, the cochlea and semicircular canals and the adjacent brainstem.
||CT can detect the fluid or mass lesions within the tympanic bulla and external ear canal, sclerosis or erosion of the bulla wall, associated retropharyngeal or para-aural lesions and regional lymphadenopathy.
||MRI can be used for thoracic imaging in some situations. Useful for mediastinal masses, thoracic wall masses and pleural space disease.
||CT is the modality of choice. Superior metastatic screening when compared to radiographs.
||MRI is ideal for the evaluation of the pelvic organs and surrounding regions.
||CT evaluation of the pelvic region provides good quality images, being much easier and faster to perform.