MRIs vs Other Imaging Modalities

The purpose of an advanced imaging modality is threefold:

  • To make a diagnosis.

  • To determine the best therapeutic option

  • To provide prognostic information for our clients so we can help them make the best decision for their pet

As a diagnostic tool, MRI has a lower incidence of false negative results than with other imaging modalities. MRI improves the ability to diagnose a variety of CNS diseases (i.e. vascular accidents, syringohydromyelia, inflammatory conditions, gliomas), orthopedic, soft tissue, and internal medicine cases that are difficult or impossible to diagnose with CT or myelography. For example, we have seen MRI images of some dogs with multifocal lesions consistent with encephalitis that have had negative CSF taps. These lesions would have been missed on CT and an inappropriate therapy may have been instituted.

MRI is a superior imaging modality for nervous system disease and many other organ systems. It not only is non-invasive but it produces multiplanar images (i.e. sagittal, axial, coronal) of the region evaluated and a variety of study sequences (i.e. T1WI, T2WI, PD, STIR, FLAIR, etc). This provides the specialist with more information than can be attained from other imaging modalities including myelography and CT scan. These MRI imaging features make it ideal for oncologic cases because of its utility in presurgical planning, treatment response with follow-up MRI scans and prognosis based on extent of disease.

MRI is also more versatile then CT or myelography. It allows the specialist to image the brainstem and cervical spine in one study thereby increasing the ability to make a diagnosis of an occasional tetraparetic animal that presents without intracranial deficits. Without MRI, one would be have to myelogram in such a patient and when found to be negative do a CT scan of the brain.

Magnetic Resonance Imaging for the neurologist is what the ultrasound is for the internist and the echocardiogram is for the cardiologist. It has elevated the quality of care that we can provide for our patients.