Traditionally, MRI has been used in veterinary medicine as a way
to diagnose brain diseases and make treatment recommendations.
While MRI is superior to other imaging techniques (for example CT)
in achieving this goal, it is not perfect. In one recent manuscript
(Rodendas et al Vet J 2009) about 30% of dogs with brain tumors had
the incorrect tumor type assigned through MRI and about 10% had
tumors misdiagnosed as other diseases.
Stereotactic biopsy is a minimally invasive surgical technique
whereby a small portion of a lesion can be removed to make a
definitive diagnosis. Very few veterinary clinics have this
technique available as equipment is costly and complex to quality
control. In cooperation with UT Houston Medical School and human
stereotactic neurosurgeons, Texas A&M University has developed
stereotactic biopsy techniques for dogs.
The image on the left is a transverse CT from
a dog with meningitis and nasal discharge. A black arrow points to
abnormal soft tissue within the right frontal sinus. Traditionally,
a 10 inch skin incision with a wide bone flap would need to be
created to access this lesion for biopsy. Stereotactic surgery
reduces the size of incisions and increases a surgeon's ability to
locate abnormal tissue. The image on the right comes from our
stereotactic equipment and depicts image-assisted targeting of this
frontal sinus mass. A biopsy was obtained through a 1 inch incision
and 3mm burr hole.