Crowned dens syndrome mimicking GCA

The rheumatology and nuclear medicine units at Prince of Wales Hospital work closely together to diagnose and monitor patients with large vessel vasculitis. We use PET scans as our first line investigation for new and relapsed giant cell arteritis (GCA).

In some cases the PET scan not only excludes GCA but also identifies an alternative cause for  patients’ symptoms. We recently published a case of “crowned dens syndrome” mimicking GCA. Crowned dens is a condition where calcium pyrophosphate crystals deposit in a crown like configuration in ligaments around the dens at the top of the spine.  The crystals can periodically trigger an acute inflammatory reaction causing neck pain, headaches and low grade fevers. The article is available in open access format at Arthritis and Rheumatology journal.

This picture shows PET detected acute inflammation (tracer appears as green colour) in the upper cervical spine (boxes B, C and D) corresponding with the site of calcification in the ligaments adjacent to the dens (box A).