Contrast-enhanced ultrasonography is more sensitive than grayscale and power Doppler ultrasonography compared to MRI in therapy monitoring of rheumatoid arthritis patients.

PURPOSE: To evaluate wrist and finger joints in patients with rheumatoid arthritis (RA) by grayscale, power Doppler (PD) and contrast-enhanced musculoskeletal ultrasonography (US) and to compare these findings with MRI, clinical (DAS28) and laboratory (ESR; CRP) data.

MATERIALS AND METHODS: US was performed at baseline (t0) and after three, six and twelve (t12) months before and after a change of medical treatment. MRI was carried out at t0 and t12 and used as the reference method. Contrast-enhanced US was used to assess one clinically most affected joint region. Different semiquantitative synovitis scores were calculated by grayscale and PD US.

RESULTS: Contrast-enhanced US results evaluated by enhancement, slope and semi-quantitative assessment significantly correlated to each other, to grayscale US, CRP, as well as to MRI with the highest correlation coefficients for the used contrast-enhanced US modes (r = 0.56, r = 0.55, r = 0.57; each p < 0.05). Sum scores evaluated by grayscale US showed that synovial inflammation in finger joints was detected significantly more frequently in the palmar aspect than on the dorsal side (p = 0.001). Using power Doppler US, the wrists were significantly more inflamed from dorsal than on the palmar side (p = 0.0004). Significant longitudinal correlations between grayscale and power Doppler US scores were detected.

CONCLUSION: Grayscale, power Doppler and contrast-enhanced US are accurate tools for the detection and follow-up of synovitis in RA wrist and finger joints, with contrast-enhanced US being most sensitive compared to MRI. All imaging methods reflected a good response to TNFα blocking therapy.