Søren Torp-Pedersen

Quantitative ultrasonography in rheumatoid arthritis: evaluation of inflammation by Doppler technique

OBJECTIVE To evaluate ultrasonographic methods, including the Doppler technique, as measures of synovial inflammation in finger joints of patients with rheumatoid arthritis. METHODS Ultrasonography was performed with a high frequency transducer (13 MHz).  Evaluation of the sonographic data was conducted by two independent observers and included measurement of synovial area and thickness (grey tone ultrasound), vascularisation (power/colour Doppler), and indices of the intra- and extrasynovial arterial flow (spectral Doppler). The flow pattern was estimated by the indices of pulsatility (PI) and resistance (RI). RESULTS The sonographic measurements of joint space were reproducible with intraobserver, intraclass correlation coefficients (ICC) 0.82–0.97 (p<0.0001) and interobserver ICC 0.81 (p<0.0001). The mean (SD) fraction of the synovium vascularised in the patients was 0.15 (0.15). The synovial blood flow was characterised by a diastolic flow—that is, the flow persisting during the diastole. The mean (SD) PI was 1.92 (1.18) and RI 0.70 (0.13). The estimated vascular fraction correlated with the erythrocyte sedimentation rate (ESR) (r s=0.53, p=0.03). The relative Pi (rPi), an estimate of an abnormally low resistance to vascularisation, correlated with both ESR (r s=−0.557, p<0.05) and Health Assessment Questionnaire score (r s=−0.584, p<0.05). After an injection of contrast Levovist the vascular fraction increased, while no difference in PI and RI was observed. CONCLUSION Ultrasonography is a reliable tool for estimating the size of the joint space and the synovial activity measured by the degree of vascularisation and pattern of flow. Ultrasonography may be useful in monitoring the synovial inflammation in rheumatoid arthritis.

Interobserver reliability in musculoskeletal ultrasonography: results from a “Teach the Teachers” rheumatologist course

Objective: To assess the interobserver reliability of the main periarticular and intra-articular ultrasonographic pathologies and to establish the principal disagreements on scanning technique and diagnostic criteria between a group of experts in musculoskeletal ultrasonography. Methods: The shoulder, wrist/hand, ankle/foot, or knee of 24 patients with rheumatic diseases were evaluated by 23 musculoskeletal ultrasound experts from different European countries randomly assigned to six groups. The participants did not reach consensus on scanning method or diagnostic criteria before the investigation. They were unaware of the patients’ clinical and imaging data. The experts from each group undertook a blinded ultrasound examination of the four anatomical regions. The ultrasound investigation included the presence/absence of joint effusion/synovitis, bony cortex abnormalities, tenosynovitis, tendon lesions, bursitis, and power Doppler signal. Afterwards they compared the ultrasound findings and re-examined the patients together while discussing their results. Results: Overall agreements were 91% for joint effusion/synovitis and tendon lesions, 87% for cortical abnormalities, 84% for tenosynovitis, 83.5% for bursitis, and 83% for power Doppler signal; κ values were good for the wrist/hand and knee (0.61 and 0.60) and fair for the shoulder and ankle/foot (0.50 and 0.54). The principal differences in scanning method and diagnostic criteria between experts were related to dynamic examination, definition of tendon lesions, and pathological v physiological fluid within joints, tendon sheaths, and bursae. Conclusions: Musculoskeletal ultrasound has a moderate to good interobserver reliability. Further consensus on standardisation of scanning technique and diagnostic criteria is necessary to improve musculoskeletal ultrasonography reproducibility.

Settings and artefacts relevant in colour/power Doppler ultrasound in rheumatology

The paper explains the most important parameters for the use of colour and power Doppler in rheumatology. Recommendations for machine settings are given. The commonly encountered artefacts and their importance for image interpretation are explained.

Estimation of inflammation by Doppler ultrasound: quantitative changes after intra-articular treatment in rheumatoid arthritis

Objective: To evaluate the use of ultrasound, including quantitative Doppler analysis of synovial vascularisation, before and after intra-articular treatment with glucocorticosteroids in patients with rheumatoid arthritis (RA). Methods: 51 patients with RA were followed prospectively after an intra-articular glucocorticosteroid injection. Disease modifying antirheumatic drug treatment was kept unchanged and no further injections given in this observation period. At baseline, disease activity was estimated clinically by target join pain on a 100 mm visual analogue scale, on which the target joint was scored 0–3 for swelling and tenderness, and by ultrasound measurements of grey scale pixels, colour Doppler pixels, and the spectral Doppler resistive index (RI) as indicators of synovial swelling and inflammation. After four weeks, the measurements were repeated on the same joint. An observer unaware of the sequence and patient number evaluated the ultrasound images. Results: At one month follow up after the glucocorticosteroid injection, a marked decrease in the fraction of colour pixels was seen in 41/51 patients (Student’s t test p<0.001). Correspondingly, the RI increased indicating a diminished flow to the synovium (Student’s t test p<0.01). Both the fraction of colour pixels and the RI values corresponded with the clinical evaluation and with the subjective effect of the treatment. The synovial membrane volume estimated by total amount of pixels showed a significant decrease by 31% after treatment. Conclusion: Ultrasound-Doppler seems to be a promising tool for the estimation of synovial activity in arthritis. After intra-articular glucocorticosteroid, changes in RI and fraction of colour pixels may both be used as quantitative measurements of the blood flow.

Effects of treatment with etanercept (Enbrel, TNRF:Fc) on rheumatoid arthritis evaluated by Doppler ultrasonography

Objective: to estimate and visualise the efficacy of treatment with etanercept (Enbrel) in patients with rheumatoid arthritis (RA) using colour Doppler and spectral Doppler ultrasonography to determine the possible changes in synovial perfusion during a one year observation period. Methods: Eleven patients from the European multicentre trial of the efficacy and safety of etanercept were included in this study when transferred into the open label, long term safety, and efficacy study. Before a scheduled dosage increase to 50 mg/week they were examined clinically, serologically, and by ultrasonography using the colour Doppler pixels and the spectral Doppler resistance index (RI) as indicators of inflammation. The patients were re-examined at two weeks and at one year follow up Results: The clinical activity decreased significantly from baseline to week 2, but no significant changes were seen from baseline to one year. The number of coloured pixels in each region of interest decreased from baseline to week 2 with a median reduction of 60% (p=0.005). This effect on the perfusion in the synovium could not be found after one year of treatment. During the initial treatment we detected an increase in synovial RI by spectral Doppler. The median increase in peripheral resistance from baseline to week 2 as estimated by the mean RI was 22.6% (p=0.005). The increase in peripheral resistance was maintained to some extent after one year (mean RI increased by 18.8% p=0.074). Conclusion: Ultrasonography seems to be a promising tool for the detection of treatment response using spectral Doppler and pixel estimation.

Ultrasound and Power Doppler findings in jumper's knee - preliminary observations.

OBJECTIVE to examine a group of high risk athletes, for signs of inflammation in jumpers knee (JK) by gray-scale ultrasonography (US) and color/Power Doppler findings in JK. SUBJECTS AND METHODS eighteen high-elite basketball players participated in the investigation after a match. Seven players were examined by ultrasound before the match as well. The players were clinically examined for signs of JK and filled in a questionnaire concerning previous and present knee symptoms. RESULTS clinical signs of JK were found in 13 knees. Of these knees, ten had hypoechoic areas and six had Power Doppler flow. Four players reported symptoms of JK and clinical examination suspected the same. Three of them had both hypoechoic areas and Power Doppler flow. Fourteen players were asymptomatic at the time of examination but both hypoechoic areas and Power Doppler flow was found in the patellar tendons of four players. No correlation was found between clinical findings, symptoms of JK and US findings - including Power Doppler. The risk of type II error in this material is considerable. CONCLUSION an association between gray-scale US and color/Power Doppler was found in JK which may suggest an inflammatory component to be a part of the pathogenesis of JK.

Tendinopathy and Doppler activity: the vascular response of the achilles tendon to exercise

Background: Intratendinous Doppler activity has been interpreted as an equivalent of neovessels in the Achilles tendon and as a sign of tendinosis (AT).

Ultrasonically Guided Fine Needle Aspiration Biopsy of Renal Masses

A consecutive series of 301 ultrasonically guided fine needle aspiration biopsies of renal masses was reviewed. The retrieval rate was 95 per cent and a correct cytological diagnosis was established in 82 per cent of the cases. There were 14 false positive aspirates, for a predictive value of a malignant aspirate of only 93 per cent. All false positive results were misinterpreted as relatively well differentiated adenocarcinoma. We conclude that renal fine needle aspiration biopsy may add information but the risk of a false positive finding must always be considered.

A randomized, controlled study of a single intra-articular injection of etanercept or glucocorticosteroids in patients with rheumatoid arthritis.

Objective: Glucocorticosteroids are used successfully for both systemic and intra‐articular treatment of arthritis. Inhibitors of tumour necrosis factor alpha (TNF‐α) are effective when administered systemically and this study was performed to compare the effect of intra‐articular injection of these two substances. Design: A randomized, parallel‐group, double‐blind study with an independent observer. Thirty‐eight patients with flare of arthritis in a single joint (wrist, elbow, or knee) were given intra‐articular 25 mg etanercept or 40 mg methylprednisolone guided by ultrasound. The primary end‐point was the 4‐week change in pain in the target joint. The study complied with Good Clinical Practice (GCP) and the Consolidated Standards for Reporting of Trials (CONSORT) statement. Results: At 4 weeks no difference in pain outcome between treatment groups was demonstrated by analysis of covariance (ANCOVA). Pain on the Visual Analogue Scale (VAS) for etanercept was baseline mean 40.9 (SD 19.6) mm, follow‐up 32.7 (29.1) mm (p = 0.29), methylprednisolone baseline mean 47.1 (29.6) mm, follow‐up 25.3 (24.7) mm (p<0.001). The investigators evaluation was for etanercept baseline 30.6 (21.2) mm, follow‐up 17.1 (15.5) mm (p = 0.054) and for methylprednisolone baseline 35.4 (26.4) mm, follow‐up 11.9 (14.6) mm (p = 0.012). Joint swelling was for etanercept baseline 1.78 (0.73), follow‐up 1.25 (0.77) (p = 0.015) and for methylprednisolone baseline 1.74 (0.73), follow‐up 0.71 (0.77) (p<0.001). One serious adverse event was seen in a patient treated with methylprednisolone injection. Conclusion: Although no difference between groups was demonstrated, the within‐group effect of methylprednisolone was more marked than that of etanercept. Injections with 25 mg etanercept were well tolerated. However, the cost of etanercept will presumably limit its use to patients with adverse reactions to steroid.

Preliminary results of colour Doppler-guided intratendinous glucocorticoid injection for Achilles tendonitis in five patients.

Background: It is debated as to whether Achilles tendonitis (AT) has an inflammatory component. The intratendinous hyperaemia demonstrated with colour Doppler has been interpreted as neovascularisation. Glucocorticoid injection around the tendon is a common therapeutic procedure.