Ultrasonography Helps Confirm Diagnosis of Early Arthritis

The presence of isolated synovial thickening in B-mode ultrasonography (US) or isolated bone erosion in US is not sufficient to confirm the diagnosis of early inflammatory arthritis. However, the presence of more than 1 case of joint synovitis or bone erosion is a strong argument for the diagnosis.

Millot and colleagues studied 127 healthy patients matched with the ESPOIR cohort of patients with early arthritis. US was used to assess the second and fifth metacarpophalangeal (MCP) joints and fifth metatarsophalangeal (MTP) joint of both hands and feet to detect bone erosion. The second, third, fourth, and fifth MCP joint and the fifth MTP joint were evaluated for synovial thickening in B-mode US and flow signal in power Doppler US.

Bone erosion and grade 2-3 synovial thickening in B-mode were seen in 11% and 9% of healthy patients, respectively. Receiver-operation characteristic curves revealed good discrimination and allowed a cutoff at 1 grade 2-3 synovial thickening in B-mode. To confirm the diagnosis of early arthritis with higher specificity, cutoff set at 2 joints with grade 2-3 synovial thickening in B-mode or 2 cases of bone
erosion gave optimal results.

The authors noted that there is no study of the diagnostic value of US in rheumatoid arthritis.