Decision Making with Ultrasound in Rheumatology

The _first aim_ of this thesis was to evaluate the added value of ultrasound in clinical decision making in patients with arthralgia, patients with psoriasis and monitoring RA patients. Our _second aim_ was to increase sensitivity of power Doppler ultrasound for MCP joints. Early diagnosis of rheumatoid arthritis and thereby facilitating early initiation of effective disease-modifying drugs can slow down disease progression and diminish joint damage. With the introduction of the 2010 ACR/EULAR classification criteria for RA we are able to classify patients as having RA at an earlier stage. We described which cut point of the 2010 criteria would enable us to earlier identify RA patients among recent onset inflammatory arthritis patients. _Part one – Ultrasound in clinical practice_ Since physical examination reached its maximum to identify synovitis, the first chapters of this thesis focus on the added value of ultrasound in daily clinical practice. Firstly, we described the association of ultrasound inflammation and the development of inflammatory arthritis in an early arthralgia cohort. Secondly, the frequency of ultrasound enthesitis in primary care psoriasis patients with musculoskeletal complaints was explored. The course of ultrasound inflammation and clinical findings in the feet in newly diagnosed RA patients was investigated next. In addition, the association of the presence of ultrasound synovitis and health status in RA patients who are in clinical remission was studied. And last we evaluated if ultrasound synovitis is a biomarker for clinical flare in RA patients who are tapering their medication. _Part two – Experimental technical research_ The performance of the power Doppler modality of several ultrasound machines was compared by a flow phantom. The same flow phantom was used to compare conventional ultrasound with high-frame rate Doppler ultrasound. And we also give the results of high-frame rate Doppler ultrasound imaging in RA patients to evaluate whether it was possible to detect higher levels of vascularisation than with conventional ultrasound