Power Doppler sonography in the assessment of synovial tissue of the knee joint in RA: a preliminary experience

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Ann Rheum Dis 2002 Oct;61(10):877-82

Power Doppler sonography in the assessment of synovial tissue of the

knee joint in rheumatoid arthritis: a preliminary experience.

Carotti M, Salaffi F, Manganelli P, Salera D, Simonetti B, Grassi W.

Department of Radiology, University of Ancona, Italy Department of

Rheumatology, University of Ancona Rheumatic Disease Unit, Hospital of

Parma, Italy.

OBJECTIVE: To investigate the intra-articular vascularisation of the

synovial pannus in the knee of patients with rheumatoid arthritis (RA)

with power Doppler ultrasonography (PDS) and an echo contrast agent and

correlate the area under the time-intensity curves with the clinical

findings and laboratory measures of disease activity. METHOD: Forty two

patients with RA (31 women, 11 men) with history and signs of knee

arthritis, classified according to a modified index of synovitis

activity (active, moderately active, and inactive), were studied.

Clinical and functional assessment (number of swollen joints, intensity

of pain, general health-visual analogue scale, disability index-Health

Assessment Questionnaire, Ritchie articular index) and a laboratory

evaluation were made on all patients. Disease activity was evaluated

using the disease activity score (DAS) and the chronic arthritis

systemic index (CASI) for each patient. All patients were examined with

conventional ultrasonography and PDS before injection of intravenous

ultrasound contrast agent (Levovist). The quantitative estimation of the

vascularisation of the synovial membrane was performed with

time-intensity curves and calculation of the area under the curves.

RESULTS: The mean (SD) value of the area underlying time-intensity

curves was 216.2 (33.4) in patients with active synovitis, 186.8 (25.8)

in patients with moderately active synovitis, and 169.6 (20.6) in those

with inactive synovitis. The mean value of the areas differed

significantly between the patients with active and those with inactive

synovitis (p<0.01). The mean value of the area under the curve of the

entire group was weakly correlated with the number of swollen joints

(p=0.038), but a strong correlation was found with composite indexes of

disease activity such as the DAS (p=0.006) and CASI (p=0.01). No

correlation was found with age, disease duration, and other laboratory

and clinical variables.

CONCLUSION: PDS may be a valuable tool to detect

fractional vascular volume and to assist clinicians in distinguishing

between inflammatory and non-inflammatory pannus. The transit of

microbubbles of ultrasound contrast across a tissue can be used to

estimate haemodynamic alterations and may have a role in assessing

synovial activity and the therapeutic response to treatment of synovitis

of the knee joint.

PMID: 12228155