Q.  Identify 3 normal brain structures that will contrast enhance with gadolinium on T1-weighted MRI images.

A.  Trigeminal nerve, pituitary, choroid plexus

“Magnetic resonance imaging contrast enhancement of the trigeminal nerve in dogs without evidence of trigeminal neuropathy.”

Pettigrew R, Rylander H, Schwarz T.

Vet Radiol Ultrasound. 2009 May-Jun;50(3):276-8.

Abstract

Brain magnetic resonance images from 42 dogs imaged between 2002 and 2007 were reviewed retrospectively to establish the incidence of trigeminal nerve contrast enhancement. These dogs had otherwise normal MR images and no clinical evidence of trigeminal nerve disease. Contrast enhancement of the entire trigeminal nerve was seen in 39 dogs and in the region of the trigeminal ganglion in all 42 dogs. When contrast enhancement of the trigeminal nerve was observed, the intensity was subjectively less than or equal to that of the pituitary gland. Contrast enhancement of the trigeminal nerve was seen in 42 dogs with no clinical evidence of trigeminal nerve pathology.

“Dynamic magnetic resonance imaging of the normal canine pituitary gland.”

Graham JP, Roberts GD, Newell SM.

Vet Radiol Ultrasound. 2000 Jan-Feb;41(1):35-40.

Abstract

The pituitary glands of six normal dogs were evaluated using dynamic magnetic resonance imaging. T1 weighted images were obtained every 13 seconds for three minutes of three contiguous slices through the pituitary gland following a bolus intravenous injection of gadolinium-DTPA. Contrast enhancement was seen initially in the region of the pituitary stalk at 52-65 seconds followed by uniform enhancement at 104-143 seconds post injection. This pattern of enhancement was seen in all subjects and is similar to that reported in humans