J Korean Soc Radiol.  2014 Aug;71(2):97-100. 10.3348/jksr.2014.71.2.97.

MR Imaging of a Bilateral Lateral Segmental Anomalous Origin of the Lateral Head of the Gastrocnemius Muscles: A Case Report

• Kim JE
• Shim JC
• Lee GJ
• Lee KE
• Kim HK
• Suh JH

• KMID: 1819787
• DOI: http://doi.org/10.3348/jksr.2014.71.2.97

Abstract

A variety of anatomic variations of the gastrocnemius muscle have been identified, predominantly through cadaver studies. Magnetic resonance imaging (MRI) findings of anomalies of the medial head of the gastrocnemius muscle have also been well reported, but anomalies of the lateral head of the gastrocnemius muscle have been less frequently reported. We present a case of an anatomic variation of the lateral head of the gastrocnemius muscle detected as an incidental finding on MRI.

MeSH Terms

Anatomic Variation
Cadaver
Head*
Incidental Findings
Magnetic Resonance Imaging*
Muscle, Skeletal
Muscles*

Figure

• 

  Fig. 1 Axial MR images of the right knee. A. Right knee shows an anomalous muscle (asterisk) which originates from the iliotibial band (arrow). B. Inferiorly, this muscle (asterisk) combines with the body of the lateral head of gastrocnemius muscle (LGCM), which normally originates from the lateral condyle of the femur.

• 

  Fig. 2 Axial and coronal MR images of the left knee. A. Axial scan shows an anomalous muscle (asterisk) originating from the iliotibial band (arrow). This muscle also merges with the body of the lateral head of gastrocnemius muscle (LGCM), as is also the case in the right knee (not shown). B. Serial coronal scans from posterior to anterior confirm the body of the LGCM normally originating from the posterior aspect of the lateral femoral condyle, and the lateral segment of the muscle (asterisk) originating from the iliotibial band (arrow). Osteoarthrosis with lateral femoral condylar grade 2 cartilage lesions are also noted.

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