7 Feb 2024 • These new guidelines emphasize targeted imaging for crystal-induced arthritis. These are the first recommendations that encompass the major forms of CiA and guide the use of common imaging modalities in this disease group in clinical practice.

KEY RECOMMENDATIONS

• Recommendation 1: When performing imaging in CiAs, both symptomatic areas and disease-specific target sites (ie, first metatarsophalangeal in gout, knee and wrist in CPPD, shoulder in BCPD) should be considered.

• Recommendation 2: In the diagnostic assessment of gout, ultrasound and DECT are both recommended imaging modalities.

• Recommendation 3: When characteristic features of MSU crystal deposition on ultrasound (ie, double-contour sign or tophi) or on DECT are identified, synovial fluid analysis is not needed to confirm a diagnosis of gout.

• Recommendation 4: In the diagnostic assessment of CPPD, CR and ultrasound (or CT if axial involvement is suspected) are recommended imaging modalities.

• Recommendation 5: In the diagnostic assessment of BCPD, imaging is necessary; CR or ultrasound is the recommended modality.

• Recommendation 6: In gout, ultrasound and DECT can be used to monitor crystal deposition and in case of ultrasound, also inflammation. Both modalities provide additional information on top of clinical and biochemical assessment. In case ultrasound/DECT are not available, CR can be used to assess structural damage due to gout. The decision on when to repeat imaging depends on the clinical circumstances.

• Recommendation 7: In CPPD and BCPD, serial imaging is not recommended, unless there is an unexpected change in clinical characteristics.

• Recommendation 8: In gout, assessing the amount of MSU crystal deposition by ultrasound or DECT may be used to predict future flares.

• Recommendation 9: If synovial fluid analysis is required in the assessment of CiAs, ultrasound guidance should be used in cases where aspiration based on anatomical landmarks is challenging.

• Recommendation 10: Showing and explaining imaging findings of CiAs to people with such conditions may help them understand their condition and improve treatment adherence in gout.