Longus colli calcific acute tendinitis: typical features with distinct imaging modalities.

A 54-year-old male patient complained of recent acute onset of severe neck pain and stiffness. MR revealed a retropharyngeal effusion and edematous infiltration of the longus colli (Figure 1). Radiographs and CT demonstrated calcifications anterior to C1-C2 (Figure 2). The patient shortly recovered after treatment with corticosteroids. Tendinitis of the longus colli, also known as retropharyngeal tendinitis, is a rare nonsurgical condition caused by intratendinous deposition of hydroxyapatite calcium. Although CT may easily depict the pathognomonic calcification, it is important to recognize this benign disease with MR, because this is frequently becoming the first imaging modality for suspected spinal disease.