3D POWER DOPPLER SIGNAL PREDICTS PROGRESSION OF DISEASE IN EARLY RHEUMATOID ARTHRITIS

Background: Early identification of Rheumatoid Arthritis (RA) patients likely to develop erosive disease may permit more optimal targeting of pharmacological intervention. Musculoskeletal ultrasound may be a useful tool in the diagnosis and prognostication of early RA. Traditionally power Doppler ultrasound (PDUS) has been performed using 2D images which require skill and training to acquire optimum information. In comparison, acquisition of images in 3D mode is automated, can be performed by a relatively unskilled operator and potentially detects more vascular signal within the synovium. Thus 3D ultrasound promises to be a useful tool in the detection and monitoring of synovial inflammation whilst minimising margin of error. Objectives: To study the use of 2D and 3D PDUS as a predictor of erosive progression in early RA. Methods: 40 patients taking part in an ongoing study of prognostic markers in early seropositive RA underwent 2D high frequency grey scale US and PDUS of 10 MCP joints, and 3D PDUS of 10 MCP joints and wrists at 0 and 6 months. A single operator (DS) carried out all scans with a GE Logiq 9, using a multi-frequency linear probe (7-12MHz) and 4D16L 3D probe, under standardized settings. 2D images were scored for erosions at the MCP joints at each visit, and also scored qualitatively for vascularity and synovial hypertrophy where 0=none, 1=minimal, 2=mild, 3=moderate and 4=severe. 3D images were scored qualitatively for vascularity and also quantitatively where synovial power Doppler signal was calculated in mm. Results: At baseline 12 patients had a total of 22 erosions at the MCP joints. At six months 25 patients had a total of 62 erosions at the MCP joints. A statistically significant, strongly positive correlation was found between baseline total MCP 3D power Doppler volume (PDV) and erosive progression on high frequency grey scale ultrasound, (Spearman rank correlation coefficient 0.55, 95% CI 0.24-0.74, p=0.0002). There was also a strongly positive correlation found between baseline wrist 3D PDV and erosive progression, (Spearman rank 0.55, 95% CI 0.24-0.74, p=0.0002). A statistically significant, strongly positive correlation was also found between erosive progression at 6 months, and 3D PDV at the wrist and MCP joints combined at baseline, (Spearman rank 0.56, 95% CI 0.30-0.75, p=0.0002). On 2D ultrasound scores, a strongly positive correlation was found between synovial thickness scores and progression of erosive disease, (Spearman rank 0.52, 95% CI 0.24-0.72, p=0.0006), and also 2D power Doppler score at baseline and progression of erosive disease at 6 months, (Spearman rank 0.40, 95% CI 0.09-0.64, p=0.012). Conclusion: Erosive progression at the MCP joints in seropositive early RA is strongly correlated with baseline vascular signal seen in MCP and wrist joints on 3D power Doppler ultrasound. Significant positive correlation with erosive progression at 6 months is also seen with baseline 2D synovial thickness and vascular scores. These findings strongly implicate vascular tissue in the erosive phase of disease and may permit future stratification of patients into treatment strategies based on risk of tissue destruction. Acknowledgements: The Medical Research Council and AstraZeneca Disclosure of Interest: D. Sreerangaiah: None Declared, S. Abraham: None Declared, A. Fox: None Declared, C. McClinton: None Declared, M. Ho Employee of: AstraZeneca, P. Taylor Grant/Research Support from: Astra Zeneca, GlaxoSmithKline, Roche, Celgene, Nuon, Merck, Speakers Bureau: Abbott, Bristol-Myers Squibb, Centocor, Roche, Schering-Plough, Wyeth,UCBCitation: Annals of the Rheumatic Diseases, volume 69, supplement 3, year 2010, page 494Session: Rheumatoid arthritis – prognosis, predictors and outcome (Poster Presentations )