Ultrasonographic findings and differential diagnosis of acute calcific periarthritis in hands.

Objectives: To explore the feasibility of using high-frequency ultrasound for the diagnosis and differential diagnosis of acute calcific periarthritis (ACP).

Method: A total of 35 ACP patients in Group A and 38 gouty patients in Group B underwent ultrasound examination. All the ultrasound images were observed and analysed, and the sizes of the tophi and calcifications in the hands were measured. The differences in ultrasound features between Group A and Group B were examined. A t test was used to determine significant differences in size between ACP calcifications and gouty tophi.

Results: The mean size of the tophus (9.54 ± 5.51 mm) was significantly larger than that of the ACP calcification (4.3 ± 1.51 mm). The double contour sign, bone erosion and synovitis were present in Group B (gout) but not in Group A (ACP). The calcification in all patients in Group A was almost completely resolved at the 1-month follow-up, as confirmed by ultrasound examination.

Conclusions: High-frequency ultrasound appears to be a useful diagnostic tool for identifying ACP and can reduce the use of unnecessary diagnostic tests, invasive procedures, inappropriate medications and surgery. Key Points • High-frequency ultrasound effectively differentiates between acute calcific periarthritis (ACP) and gout by identifying distinct ultrasound features. • This study revealed that the size of the tophus in gout patients was significantly larger than the calcification size in ACP patients. • Unique ultrasound signs, such as the double contour sign and bone erosion, were present in gout patients but absent in ACP patients, aiding in accurate diagnosis. • Follow-up ultrasound examinations revealed significant resolution of calcifications in ACP patients, reinforcing the utility of the tool in monitoring disease progression.