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True Pathologic Abnormality versus Artifact

Foot Position and Magic Angle Artifact in the Peroneal Tendons with 3T Imaging

Deena B. Horn Department of Orthopaedic Surgery, Inova Fairfax Hospital, Orthopaedic/Podiatry Department, Falls Church, VA.

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Steven Meyers Fairfax Radiological Consultants, Fairfax, VA.

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William Astor Fairfax Radiological Consultants, Fairfax, VA.

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Magnetic resonance imaging is a commonly ordered examination by many foot and ankle surgeons for ankle pain and suspected peroneal tendon pathologic abnormalities. Magic angle artifact is one of the complexities associated with this imaging modality. Magic angle refers to the increased signal on magnetic resonance images associated with the highly organized collagen fibers in tendons and ligaments when they are orientated at a 55° angle to the main magnetic field. We present several examples from a clinical practice setting using 3T imaging illustrating a substantial reduction in magic angle artifact of the peroneal tendon in the prone plantarflexed position compared with the standard neutral (right angle) position.

Corresponding author: Deena Blair Horn, DPM, Department of Orthopaedic Surgery, Inova Fairfax Hospital, 3300 Gallows Rd, Orthopaedic/Podiatry Department, Falls Church, VA 22042. (E-mail: deenahorn@gmail.com)