Abstract
Objective Abnormalities within the spinal arachnoid space are often treated surgically, but
they can be challenging to detect with conventional magnetic resonance imaging (MRI)
sequences. 3D-CISS sequences are considered superior in evaluating structures surrounded
by cerebrospinal fluid (CSF) due to the high signal-to-noise ratio, high contrast-to-noise
ratio and intrinsic insensitivity to motion with minimal signal loss due to CSF pulsations.
Our objective was to describe findings and advantages in adding 3D-CISS sequences
to routine MRI in patients affected by spinal arachnoid diverticula (SAD) or arachnoid
adhesions.
Material and Methods This article is a retrospective review of medical records of 19 dogs admitted at
Fitzpatrick Referrals between 2013 and 2017 that were diagnosed with SAD and confirmed
surgically. Inclusion criterions were the presence of clinical signs compatible with
compressive myelopathy and an MRI diagnosis, which included the 3D-CISS sequence.
Our database was searched for additional 19 dogs diagnosed with other spinal lesions
other than SAD that had the same MR sequences. All MR images were anonymized and evaluated
by two assessors.
Conclusion and Clinical Relevance 3D-CISS sequence appears to improve confidence in diagnosing and surgical planning
(Mann–Whitney U-test: p < 0.0005), delineating SAD from other changes associated with abnormal CSF hydrodynamics
and providing more anatomical details than conventional MRI sequences. The clinical
data in combination with imaging findings would limit over interpretation, when concurrent
pathology within the arachnoid space is present.
Keywords
gradient echo sequence - 3D-CISS - magnetic resonance imaging - arachnoid web - spinal
arachnoid diverticulum
