Three-tesla magnetic resonance imaging of the ventrolateral thalamus: a correlative anatomical description.
OBJECTIVE
Surgery for tremor targets the ventrolateral nuclei of the thalamus. An initial radiological estimation of this target can be further refined through intraoperative physiological confirmation. Direct visualization of these nuclei has not yet been described. The improved signal-to-noise ratio associated with 3-tesla (3T) magnetic resonance (MR) imaging makes increased spatial resolution possible, which may aid in the identification of subtle morphological features. This study was conducted to describe the anatomy of the nuclei and fiber projections within the ventral thalamus by using 3T MR imaging.


METHODS
Using a commercially available 3T MR unit, the authors obtained images of a formalin-fixed, paraffin-embedded brain. Slices with a 2-mm thickness and 0.2-mm gap were obtained parallel to the anterior commissure-posterior commissure (AC-PC) line. The brain was then sectioned through the cerebral hemispheres to obtain tissue slices encompassing the same levels. Adjacent 10-microm paraffin sections from the middle of each level were stained with Luxol fast blue and cresyl violet. The MR image and histological sections at the level of the AC-PC line were then compared in detail. In a separate study, the human thalamus was scanned in vivo using 3T and 1.5T MR imaging for anatomical comparison.


CONCLUSIONS
The anatomy of the nuclei and fiber projections within the ventrolateral thalamus in humans can be described using 3T MR imaging. The findings were reproducible in vivo with 3T but not 1.5T MR imaging. Additional studies are needed to confirm the accuracy of this observation for clinical purposes.
Mercado
Rodrigo
R
Surgical Centre for Movement Disorders, Division of Neurosurgery, University of British Columbia, Vancouver, British Columbia, Canada.
Mandat
Tomasz
T
Moore
G R Wayne
GR
Li
David
D
MacKay
Alex
A
Honey
Christopher R
CR
D016477:Artifacts; D001921:Brain / Q000473:pathology / Q000601:surgery; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009412:Nerve Fibers / Q000473:pathology; D009434:Neural Pathways / Q000473:pathology / Q000601:surgery; D012016:Reference Values; D012680:Sensitivity and Specificity; D013238:Stereotaxic Techniques; D014202:Tremor / Q000473:pathology* / Q000601:surgery; D020651:Ventral Thalamic Nuclei / Q000473:pathology* / Q000601:surgery