The “Crowned Dens” Revisited: Imaging Findings in Calcium Crystal Deposition Diseases Around the Odontoid

Abstract

The so-called "crowned dens" is a peculiar manifestation of calcium crystal deposition diseases, either caused by calcium pyrophosphate dihydrate or caused by calcium hydroxiapatite crystals, characterized by the presence of calcific deposits around the odontoid, often showing a crown-like configuration on imaging. It has protean clinical and radiological pictures, and care should be taken to avoid misinterpretation and diagnostic errors. Although asymptomatic in many patients, this entity may present as a predominantly algic or febrile condition, and in some cases, signs of compression of the spinal cord may be the major complaint. The detection of calcifications in the periodontoid tissues is the key to the diagnosis, erosive osseous changes, and variably calcified soft-tissue masses being occasionally associated. Computed tomography is the most important imaging study to be performed in this setting.

Crowned Dens Syndrome

“…Previous reports of CDS have been based on radiographic evidence of calcium deposits around the odontoid process (1), but neck CT is now considered to be the reference standard for making such a diagnosis. The use of radiography this diagnosis is limited due to the superposition of the osseous structure (2). Magnetic resonance imaging is also less useful for the detection of small deposits (2).…”

Acute Pseudogout of the Neck: "Crowned Dens" Revisited

“…CT is more sensitive and accurate than conventional plain radiography in detecting calcific depositis and bony change. Up to 90% of CT imaging comprises posterior, posterolateral, or circular periodontoid calcification, configuring the "crowned dens" appearance [8]. Plain radiography is often not helpful.…”

A rare acute neck pain cause that can have misdiagnosis or missed diagnosis-crowned dens syndrome: description of two cases and a literature analysis

“…A rare condition, CDS is caused by calcium salt crystal deposition, especially CPPD (1), and a few cases have been reported as having been caused by HA deposition (2). Epidemiology shows that the disease is prevalent in elderly patients, especially in older women (3), and CPPD deposition occurs easily in elderly patients, while HA deposition is more common in younger age groups (40-70 years) (4,5). A review of the published literature revealed that most cases reported are over 60 years old.…”