Veterinary Shoulder MRI Guide

By: Scott Johnson MS RT (R)(MR) The original file: shouldermriguide.pdf

Suggested Protocol courtesy of Dr. Layla Shaikh:

Sagittal PD FatSat

Dorsal T1

Dorsal T2

Axial PD

Axial T2

Optional Contrast

Axial T1

Sagittal T1

Dorsal T1

Tips, Tricks, and Notes

Use of Gadolinium

If there is a suspicion for neoplastia or infection, it may be helpful to include post contrast imaging

Magic Angle Artifact

In tissues with linearly oriented fibers, it is possible that they may sit obliquely in the bore of the scanner in relation to the main magnetic field. Near a certain 'magical' angle of about 54 degrees, tissue T2 time may be prolonged, and appear artefactually bright on short TE sequences. To ensure any hyperintensity is real, include at least one T2 weighted imaged with a long TE of at least 90-100. The artifact is not dependent on imaging plane, but rather the position of the patient in the bore, so choose a plane for the T2 that best visualizes the anatomy of interest.

Imaging Parameters

Due to small anatomy, it is important to maintain high resolution and high fidelity imaging. Where possible, minimize the number of sequences, and maximize the quality of each sequence.

~ .5mmx.5mm in plane resolution; keep the matrix square!

Use thin slices of 2 or 3mm

Short ETL (7 for PD, 16 for T2)

Use a higher bandwidth; shorter echo spacing will maintain good edge details and minimize chemical shift

Add NEX/Averages as needed to regain SNR; it's OK if the sequence is 7 minutes long; quality over quantity.