Clinical Utility of Multi-Energy Spectral Photon-Counting Computed Tomography in Crystal Arthritis.

Abstract

OBJECTIVE:

To determine whether novel multi-energy spectral photon-counting computed tomography (SPCCT) imaging can detect and differentiate between monosodium urate (MSU), calcium pyrophosphate (CPP), and hydroxyapatite (HA) crystal deposits ex vivo.

METHODS:

A finger with a subcutaneous gouty tophus and a calcified knee meniscus excised at the time of surgery were obtained. The finger was imaged using plain x-ray, dual-energy CT (DECT), and multi-energy SPCCT. Plain x-ray and multi-energy SPCCT images of the meniscus were acquired. For validation purposes, samples of the crystals were obtained from the tophus and meniscus, and examined by polarized light microscopy and/or x-ray diffraction. As further validation, synthetic crystal suspensions of MSU, CPP, and HA were scanned using multi-energy SPCCT.

RESULTS:

Plain x-ray of the gouty finger revealed bone erosions with overhanging edges. DECT and multi-energy SPCCT both showed MSU crystal deposits; SPCCT was able to show finer detail. Plain x-ray of the calcified meniscus showed chondrocalcinosis consistent with CPP, while SPCCT showed and differentiated CPP and HA.

CONCLUSION:

Multi-energy SPCCT can not only detect, differentiate, and quantify MSU crystal deposits in a gouty finger ex vivo, but also specifically detect, identify, and quantify CPP within an osteoarthritic meniscus, and distinguish them from HA crystal deposits. There is potential for multi-energy SPCCT to become useful in the diagnosis of crystal arthropathies.

• Authors: Lisa K Stamp, Nigel G Anderson, Fabio Becce, Maya Rajeswari, Matthew Polson, Olivier Guyen, Anais Viry, Chloe Choi, Tracy E Kirkbride, Aamir Y Raja
• Journal: Arthritis & rheumatology (Hoboken, N.J.) (Arthritis Rheumatol) Vol. 71 Issue 7 Pg. 1158-1162 (07 2019) ISSN: 2326-5205 [Electronic] United States
• PMID: 30714678 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2019, American College of Rheumatology.

Chemical References

• Uric Acid
• Durapatite
• Calcium Pyrophosphate

Topics

• Calcium Pyrophosphate
• Chondrocalcinosis (diagnostic imaging)
• Crystal Arthropathies (diagnostic imaging)
• Diagnosis, Differential
• Durapatite
• Fingers (diagnostic imaging, pathology)
• Gout (diagnostic imaging)
• Humans
• Menisci, Tibial (diagnostic imaging, pathology)
• Radiography
• Tomography, X-Ray Computed (methods)
• Uric Acid