Effect of delayed acquisition times on Gadolinium-enhanced MRI of the presumably normal canine brain

Joslyn, S., Sullivan, M., Novellas Torroja, R., Brannan, N., Cameron, G. and Hammond, G. (2011) Effect of delayed acquisition times on Gadolinium-enhanced MRI of the presumably normal canine brain. Veterinary Radiology and Ultrasound, 52(6), (doi: 10.1111/j.1740-8261.2011.01847.x)

Abstract

A delay in imaging following intravenous contrast medium administration has been recommended to reduce misdiagnoses. However, the normal variation of contrast enhancement in dogs following a delay has not been characterized. Contrast enhanced MR imaging of 22 dogs was assessed, in terms of identification of normal anatomic structures, to investigate the variation associated with 10 minute delay between contrast medium administration and imaging. All dogs had a normal brain MR imaging study and unremarkable CSF. Specific ROIs were assessed both objectively, using computer software, and subjectively using three observers. Mean contrast enhancement greater than 10% was seen in the pituitary gland, choroid plexus, meninges, temporal muscle, trigeminal nerve and the trigeminal nerve root. Structures with an active blood-brain-barrier had minimal contrast enhancement (<6%). Enhancing structures had significantly more contrast enhancement at t=1min versus t=10min, except in temporal muscle, the trigeminal nerve and the trigeminal nerve root. Inter-observer agreement was moderate to good in favor of the initial post contrast T1w sequence. The observers found either no difference or poor agreement in identification of the non-vascular structures. Intra-observer agreement was very good with all vascular structures and most non-vascular structures. A degree of meningeal enhancement was a consistent finding. The initial acquisition had higher enhancement characteristics and observer agreement for some structures; however, contrast-to-noise was comparable in the delayed phase or not significantly different. We provide baseline references and suggest that the initial T1w post contrast sequence is preferable but not essential should a delayed post contrast T1w sequence be performed.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Sullivan, Professor Martin and Joslyn, Mr Stephen and Brannan, Mrs Nicola and Novellas Torroja, Dr Rosa and Hammond, Dr Gawain and Cameron, Mrs Gillian
• Authors: Joslyn, S., Sullivan, M., Novellas Torroja, R., Brannan, N., Cameron, G., and Hammond, G.
• Subjects: S Agriculture > SF Animal culture > SF600 Veterinary Medicine
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Veterinary Radiology and Ultrasound
• ISSN: 1058-8183
• Copyright Holders: Copyright © 2011 Veterinary Radiology and Ultrasound
• First Published: First published in Veterinary Radiology & Ultrasound 52(6)
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher