Congenital Muscular Torticollis: Magnetic Resonance Imaging and Ultrasound Diagnosis

The magnetic resonance imaging (MRI) and sonographic appearances of congenital muscular torticollis were studied in a 6‐week‐old female infant who presented with a firm mass in the right sternocleidomastoid muscle and clinical signs of torticollis. MRI and ultrasound were performed to exclude neoplasm. MRI showed a diffusely enlarged, right sternocleidomastoid muscle that was isointense to normal muscle on T1‐weighted conventional spin‐echo images. The muscle became progressively brighter and more heterogeneous in signal intensity on proton density‐ and T2‐weighted conventional spin‐echo sequences. A thin rim of bright signal intensity on the T2‐ weighted images surrounded most of the muscle. Ultrasound demonstrated fusi‐form enlargement with patchy inhomogeneous areas of increased echogenicity. At 14 weeks there were signs of clinical improvement, with softening of the mass and decreased torticollis.