Calcific tendinitis of the longus colli muscle

• Amorphous calcifications in the superior fibers of longus colli muscle tendons at C1-C2 level on CT
• Hypo-attenuating edema within the longus colli muscles adjacent to the calcifications
• Small retropharyngeal effusion and prevertebral soft tissue edema without significant peripheral enhancement

• On CT, amorphous calcifications are typically seen in the superior fibers of the longus colli muscle tendons at the C1-C2 level, though occasionally the inferior fibers may be affected as low as T3.
• The longus colli muscles demonstrate hypo-attenuation on CT due to associated edema in the acute inflammatory phase.
• Small retropharyngeal effusions are commonly present with associated edema of the prevertebral soft tissues.
• Crucially, enhancement around the effusion is typically minimal or absent; if significant peripheral enhancement is present, retropharyngeal abscess should be suspected instead.
• On MRI, calcifications are difficult to visualize due to lack of water protons, making edema detection the primary finding rather than the calcium deposit itself.
• MRI demonstrates the edema within and around the longus colli muscle clearly on fluid-sensitive sequences.
• Localized marrow signal inflammatory changes in the adjacent vertebral bodies have been reported in at least one case.
• Absence of adenopathy and bone destruction helps confirm calcific tendinitis and excludes other serious pathology.

• Retropharyngeal abscess: distinguished by prominent peripheral enhancement around the collection, diffusion-restricting fluid within the collection, and associated cervical lymphadenopathy.
• Cervical trauma: acute fractures may present with prevertebral bone fragments that mimic calcifications; correlation with injury history and fracture line visibility helps distinguish.
• Cervical lymphadenopathy from malignancy or infection: solid mass with enhancement and associated lymph nodes rather than small effusion with minimal enhancement.
• Retropharyngeal hematoma: can present similarly but history of trauma, gradient echo susceptibility artifacts, and different temporal evolution help differentiate.
• Thyroid pathology: calcifications within thyroid gland and associated adenopathy would localize differently than longus colli pathology.

Report amorphous calcifications within the superior fibers of the longus colli tendons at C1-C2 level with associated hypo-attenuation edema and small retropharyngeal effusion, and specifically note that enhancement around any effusion is minimal or absent—if substantial rim enhancement is present, consider retropharyngeal abscess instead.

• Confusing calcific tendinitis with retropharyngeal abscess by misinterpreting surrounding edema as abscess; look for the presence or absence of significant peripheral enhancement which is characteristic of abscess.
• Misidentifying prevertebral bone fragments from acute fractures as calcifications within longus colli tendons; careful attention to location and correlation with fracture history prevents this error.
• Underestimating the severity of patient symptoms based on imaging findings alone, as symptoms can be debilitating despite minimal or moderate calcification on imaging.
• Missing the diagnosis on MRI because calcifications are not well visualized on fluid-sensitive sequences; high clinical suspicion is needed and CT should be performed for confirmation.