Objectives: To determine how settings for power and color Doppler sensitivity varies
on different high and intermediate range ultrasound (US) machines and to evaluate
the impact of these changes on Doppler scoring of inflammatory joints Methods: Six
different types of ultrasound machine were used. On each machine, the factory setting
(FS) for superficial musculoskeletal scanning was used unchanged for both color and
power Doppler modalities. The settings were then adjusted for increased Doppler sensitivity
- study settings (SS). Eleven RA patients with wrist involvement were scanned on the
6 machines each with 4 settings generating 264 Doppler images for scoring and color
quantification. Doppler sensitivity was measured with a quantitative assessment of
Doppler activity - color fraction (CF) - higher CF indicated higher sensitivity. Results:
Power Doppler was more sensitive on half of the machines whereas color Doppler was
more sensitive on the other half with both FS and SS. There was an average increase
in Doppler sensitivity despite modality of 78% when SS were applied. Over the 6 machines,
2 Doppler modalities, and 2 settings, 7 patients varied between grades 0 and 3 with
the other 4 patients between grades 0 and 2. Conclusion: The effect of using different
machines, Doppler modalities, and settings has a considerable influence on the quantification
of inflammation in RA patients and this must be taken into account in multi-centre
studies. (c) 2014 American College of Rheumatology.
