Page 6 - index
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Updates on Canine Brain tumors:
options to make the diagnosis (part 2)

➤ Continued from Page 6

and the risk of morbidity. Despite LIVS and chamber placement for electrophysiology.
utilizing the using the highest magnet It allows LIVS neurosurgeons to extend the
strength available in veterinary medicine, applicability of the system beyond neurosci-
the diagnostic specifcity of MRI remains ence research into more general veterinary ap-
insuffcient when compared with biopsy plications. Brainsight brings the same benefts
of tumors. of neuronavigation for biopsy guidance and
Non-neoplastic space-occupying le- surgery planning and guidance that is com-
sions may mimic the CT or MR appear- monplace for human treatment. This system
ance of a neoplasm and occasionally a has an error rate of 1.2 mm in dogs, meaning
metastasis may resemble a primary brain that it is very likely to provide diagnostic brain
tumor. Currently biopsy and/or surgical biopsies at minimal risk to the patient. In ad-
excision are the only methods available dition to its potential as a diagnostic tool, the
for the defnitive diagnosis of brain tumor Brainsight system has potential application
types. MIB methods used at LIVS include for gene therapy, in which a specifc gene is
ultrasound-guided biopsy, the Brainsight delivered to a specifc location in the brain in
®
MR-stereotactic biopsy system. The most order to control or cure a neurologic disorder.
recent advance in the biopsy of brain tu- (Figure 4)
mors has been the use of the Sanarus
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freeze core biopsy system for use in cats MHF-1 Intraoperative Ultrasound Scanner
and dogs, pioneered at LIVS. This biopsy Generation of images based on ultrasound
system provides a relatively rapid and ex- waves is not a new phenomenon in veterinary
tremely accurate means of tumor biopsy, or human medicine; however, the use of intra-
with a high diagnostic yield and a low rate operative ultrasound in facilitating brain and
of complications. spine surgery is largely limited to major hu-
man neurosurgery centers. At LIVS, we have
Brainsight MR-stereotactic been pioneering the use of this technology in
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biopsy system patients referred to us for neurosurgery for
Figure 3a-b Poor image resolution associated with low Brainsight is our neuronavigation sys- several years. With a probe footprint of 1cm,
feld magnet strength (a) compared with high resolution tem which allows the neurosurgeons at specialized high frequency probes allow our
image utilizing 3T magnet (b) LIVS to use the principles of frameless neurosurgeons to localize neoplastic masses,
stereotaxy to perform a variety of neuro- granulomas, hematomas, and abscesses with-
surgical procedures with accuracy, sim- in the deepest portions of the nervous system
a high feld strength magnet. MRI technologists plicity and improved subject comfort when and remove them safely. Ultrasound-guided
undergo a rigorous 2-year training program and compared to the stereotactic frame. Brainsight biopsies of masses deemed non-surgical can
are the most adept at operating (and trouble- has been used for a wide variety of applica-
shooting-in diffcult cases, or if the machine tions, including cannula and needle placement Continued on Page 8 ➤
experiences problems). MRI machines are very
complex and successful image acquisition is
dependent on an individual or individuals who
understand the physics of MR imaging as well
as the machinery involved. Optimum image
acquisition is most likely to occur when a high
feld strength magnet is being operated by a
fully-trained MRI technologist. At LIVS, we
employ two certifed MRI technologists with
over a decade of experience.

Minimally Invasive Biopsy
Techniques (MIB)
Several studies have shown that MR imaging
may render a specifc diagnosis of some canine
brain tumors, however, as in human patients,
the accuracy varies substantially. Histopathol-
ogy remains the gold standard for making a
defnitive diagnosis with an intracranial le-
sion and is often a necessary component for
accurate treatment planning. Unfortunately,
permission to biopsy is not always granted Figure 4 Brainsight MR-stereotactic biopsy system brings the same benefts of human neuro-navigation systems for
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by owners because of financial limitations biopsy guidance and surgery planning.

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