Alexander K. Scheel

Interobserver reliability of rheumatologists performing musculoskeletal ultrasonography: results from a EULAR “Train the trainers” course

Objective: To evaluate the interobserver reliability among 14 experts in musculoskeletal ultrasonography (US) and to determine the overall agreement about the US results compared with magnetic resonance imaging (MRI), which served as the imaging “gold standard”. Methods: The clinically dominant joint regions (shoulder, knee, ankle/toe, wrist/finger) of four patients with inflammatory rheumatic diseases were ultrasonographically examined by 14 experts. US results were compared with MRI. Overall agreements, sensitivities, specificities, and interobserver reliabilities were assessed. Results: Taking an agreement in US examination of 10 out of 14 experts into account, the overall κ for all examined joints was 0.76. Calculations for each joint region showed high κ values for the knee (1), moderate values for the shoulder (0.76) and hand/finger (0.59), and low agreement for ankle/toe joints (0.28). κ Values for bone lesions, bursitis, and tendon tears were high (κ = 1). Relatively good agreement for most US findings, compared with MRI, was found for the shoulder (overall agreement 81%, sensitivity 76%, specificity 89%) and knee joint (overall agreement 88%, sensitivity 91%, specificity 88%). Sensitivities were lower for wrist/finger (overall agreement 73%, sensitivity 66%, specificity 88%) and ankle/toe joints (overall agreement 82%, sensitivity 61%, specificity 92%). Conclusion: Interobserver reliabilities, sensitivities, and specificities in comparison with MRI were moderate to good. Further standardisation of US scanning techniques and definitions of different pathological US lesions are necessary to increase the interobserver agreement in musculoskeletal US.

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.

Sagittal laser optical tomography for imaging of rheumatoid finger joints.

We present a novel optical tomographic imaging system that was designed to determine two-dimensional spatial distribution of optical properties in a sagittal plane through finger joints. The system incorporates a single laser diode and a single silicon photodetector into a scanning device that records spatially resolved light intensities as they are transmitted through a finger. These data are input to a model-based iterative image reconstruction (MOBIIR) scheme, which uses the equation of radiative transfer (ERT) as a forward model for light propagation through tissue. We have used this system to obtain tomographic images of six proximal interphalangeal finger joints from two patients with rheumatoid arthritis. The optical images were compared to clinical symptoms and ultrasound images.

First clinical evaluation of sagittal laser optical tomography for detection of synovitis in arthritic finger joints

Objective: To identify classifiers in images obtained with sagittal laser optical tomography (SLOT) that can be used to distinguish between joints affected and not affected by synovitis. Methods: 78 SLOT images of proximal interphalangeal joints II–IV from 13 patients with rheumatoid arthritis were compared with ultrasound (US) images and clinical examination (CE). SLOT images showing the spatial distribution of scattering and absorption coefficients within the joint cavity were generated. The means and standard errors for seven different classifiers (operator score and six quantitative measurements) were determined from SLOT images using CE and US as diagnostic references. For classifiers showing significant differences between affected and non-affected joints, sensitivities and specificities for various cut off parameters were obtained by receiver operating characteristic (ROC) analysis. Results: For five classifiers used to characterise SLOT images the mean between affected and unaffected joints was statistically significant using US as diagnostic reference, but statistically significant for only one classifier with CE as reference. In general, high absorption and scattering coefficients in and around the joint cavity are indicative of synovitis. ROC analysis showed that the minimal absorption classifier yields the largest area under the curve (0.777; sensitivity and specificity 0.705 each) with US as diagnostic reference. Conclusion: Classifiers in SLOT images have been identified that show statistically significant differences between joints with and without synovitis. It is possible to classify a joint as inflamed with SLOT, without the need for a reference measurement. Furthermore, SLOT based diagnosis of synovitis agrees better with US diagnosis than CE.

Knee Osteoarthritis Efficacy of a new method of contrast-enhanced musculoskeletal ultrasonography in detection of synovitis in patients with knee osteoarthritis in comparison with magnetic resonance imaging

Objective: To develop a new method of digital synovial vascularisation quantification by using contrast-enhanced musculoskeletal ultrasonography (MUS) in detecting synovitis in patients with knee osteoarthritis (OA) compared with healthy subjects and MRI. Methods: Evaluation of 41 patients with painful knee OA and 6 healthy subjects. The severity of knee pain was evaluated. All patients and all 6 healthy subjects underwent contrast medium-enhanced (CE)-MUS with SonoVue®, and 36 patients additionally underwent CE-MRI with Magnevist. Joint effusion, synovial thickening and pain were assessed and compared with B-mode and Power Doppler sonography (PDS) as well as contrast medium enhancement. Results: Pain evaluated by the visual analogue scale (VAS) hardly correlated with other markers of disease activity measured by ultrasound (US) in B-mode or MRI. US of the superior recess revealed an effusion or synovial thickening in 58%. PDS findings were positive in 63%, and CE-MUS in the superior knee recess was positive in 95%. MRI showed effusion in the superior recess in 61% and showed positive findings in 82% when using contrast medium. The kappa value was 0.48 between US and MRI with regard to the effusion in the superior recess, and 0.53 between PD signal in the superior recess and effusion in the superior recess by US. Using MRI as the reference standard, there was a sensitivity of 72% for assessing effusion in the superior recess and 81% for assessing effusion in the lateral recess. Conclusion: Assessment of disease activity (synovitis) in knee OA by VAS is not sufficient. US PDS was more sensitive than B-mode, and CE-MUS was more sensitive than PDS and CE-MRI in detecting synovitis in patients with painful knee OA. Also, CE-MRI was more sensitive in detecting inflammatory changes in the superior recess than without contrast medium. Using CE-MUS and performing time/intensity analysis has shown to be a good model for evaluation of an inflammatory process in the setting of knee OA in the superior recess.

Contrast-enhanced ultrasound in monitoring the efficacy of a bradykinin receptor 2 antagonist in painful knee osteoarthritis compared with MRI

Objectives: To evaluate contrast-enhanced ultrasound (CE-US) as a monitoring tool to assess hypervascularisation of synovial processes in knee osteoarthritis (OA) treated with intra-articular injections of the bradykinin-receptor 2 antagonist icatibant compared to contrast-enhanced magnetic resonance imaging (CE-MRI). Patients and methods: In a randomised, double-blind, placebo-controlled trial, 41 patients with painful knee OA underwent US (12.5 MHz for B-mode and 3–8 MHz for CE-US), and 36 of the patients underwent additional MRI (0.2T) at baseline and after 3 injections of the study drug (after a mean of 22.2 days). A total of 15 patients received placebo (group A), 12 patients 500 μg icatibant (group B) and 14 patients 2000 μg icatibant (group C). Pain and the synovial process (B-mode, power Doppler US (PD-US), CE-US, CE-MRI) were assessed at both time points. Results: At baseline, the placebo group showed more activity in terms of effusion in the superior and lateral recess in ultrasound as well as in PD-US in the lateral recess. Pain improved significantly in all subgroups. Effect sizes were 0.43 (pain at rest) and 0.52 (pain during activity) in group B vs 0.48 and 1.11 in group C. There was no change of US and MRI parameters. We found moderate to good correlation (r) and kappa values (κ) for effusion in the superior recess (r = 0.591, k = 0.453), effusion in the lateral recess (r = 0.304, k = 0.440) and contrast enhancement (r = 0.601, k = 0.242) between US and MRI. Conclusions: Our results show that CE-US and CE-MRI have good agreement in assessing inflammatory changes in knee OA. For the 41 patients with OA, an analgesic effect of icatibant could clearly be shown, especially for pain during activity in the high dose icatibant group. However, we could not find an anti-inflammatory effect of icatibant by CE-US compared to CE-MRI.

Diagnostic quality and scoring of synovitis, tenosynovitis and erosions in low-field MRI of patients with rheumatoid arthritis: a comparison with conventional MRI

Objective: To compare dedicated low-field MRI (lfMRI) with conventional MRI (cMRI) in the detection and scoring of synovitis, tenosynovitis and erosions in patients with rheumatoid arthritis. Patients and methods: The wrist and finger joints of 17 patients with rheumatoid arthritis (median (range) disease duration 8 years (7–12); Disease Activity Score 3.3 (2.6–4.5)) were examined by 0.2 T lfMRI and 1.5 TcMRI. The protocols comprised coronal spin-echo and three-dimensional gradient-echo sequences before and after contrast medium administration. Synovitis of the metacarpophalangeal and proximal interphalangeal joints 2–5 and the wrist joints was scored according to Outcome Measures in Rheumatology recommendations. Tenosynovitis and erosions were scored using 4-point and 6-point scales, respectively. The results were analysed by calculating κ values and performing McNemar’s test intra-individually on a joint-by-joint basis. Results: Agreement between the two MRI techniques was good to excellent for synovitis and erosions, and moderate for tenosynovitis. Of the 306 joints evaluated, 245 and 200 joints showed synovitis in lfMRI and cMRI, respectively. Scoring of synovitis of the finger joints yielded κ values from 0.69 to 0.94. Of the 68 flexor tendons evaluated, tenosynovitis was diagnosed by lfMRI in 24 and by cMRI in 33 instances. Of the 391 bones evaluated, 154 and 139 showed erosions in lfMRI and cMRI, respectively. κ values for erosion scores were between 0.65 and 1. Conclusion: Dedicated, lfMRI shows high agreement with cMRI in diagnosing and scoring synovitis, tenosynovitis and erosions in rheumatoid arthritis when using standardised scoring systems.

Assessing the intra- and inter-reader reliability of dynamic ultrasound images in power Doppler ultrasonography

Objective: To assess the intra-reader and inter-reader reliabilities of interpreting ultrasonography by several experts using video clips. Method: 99 video clips of healthy and rheumatic joints were recorded and delivered to 17 physician sonographers in two rounds. The intra-reader and inter-reader reliabilities of interpreting the ultrasound results were calculated using a dichotomous system (normal/abnormal) and a graded semiquantitative scoring system. Results: The video reading method worked well. 70% of the readers could classify at least 70% of the cases correctly as normal or abnormal. The distribution of readers answering correctly was wide. The most difficult joints to assess were the elbow, wrist, metacarpophalangeal (MCP) and knee joints. The intra-reader and inter-reader agreements on interpreting dynamic ultrasound images as normal or abnormal, as well as detecting and scoring a Doppler signal were moderate to good (κ = 0.52–0.82). Conclusions: Dynamic image assessment (video clips) can be used as an alternative method in ultrasonography reliability studies. The intra-reader and inter-reader reliabilities of ultrasonography in dynamic image reading are acceptable, but more definitions and training are needed to improve sonographic reproducibility.

Fasciculations : clinical, electromyographic, and ultrasonographic assessment

Widespread fasciculations are an important clinical sign in, for example, degenerative lower motor neuron diseases (LMND). Usually they are detected by clinical inspection and electromyography. Recently myosonography has been proposed for the detection of fasciculations. This prospective study compares the value of these three modes of examination in patients with degenerative LMND. Seventy healthy control persons and 34 patients (11 women, 23 men; aged 43–78 years; median age 60.5) with LMND were included in the study. All participants were subjected to thorough visual screening for the presence of fasciculations. Fourteen muscles were examined bilaterally by myosonography and a median of 8 muscles were screened electromyographically (only in the patients); the investigators were blinded to the other findings. Clinical inspection and ultrasonography exhibited fasciculations in up to 5 and 8 muscles, respectively, in 8 healthy persons. Ultrasonography demonstrated fasciculations in all patients, clinical inspection in all but 2, and electromyography in 26 of 33 patients (1 patient was not examined electromyographically). Comparing the three methods, clinical observation revealed fasciculations in 42%, electromyography in 39%, and ultrasonography in 67% of all muscles. Thus, ultrasonography was significantly more sensitive than the other techniques (P < 0.001). The interrater agreement (correlation coefficient)r in respect of the presence or absence of fasciculation was 0.71 for the clinical, 0.85 for the electromyographic and 0.84 for the myosonographic examinations. Ultrasonography and electromyography were more reliable than the clinical examination (P < 0.001 andP < 0.01, respectively). Our study indicates that ultrasonography is more sensitive than clinical and electromyographic examination in visualizing fasciculations in patients with LMND. Additionally, it is more reliable than clinical examination.

Low‐field MRI for assessing synovitis in patients with rheumatoid arthritis. Impact of Gd‐DTPA dose on synovitis scoring

Objective: To investigate the impact of a double dose compared to a single dose of contrast material in low‐field magnetic resonance imaging (MRI) on semi‐quantitative scoring of synovitis in patients with rheumatoid arthritis (RA). Methods: This prospective study included 38 RA patients (23 women and 15 men, mean age 51 years). All patients underwent low‐field MRI of the hand before administration of contrast medium, after intravenous injection of 0.1 mmol/kg gadolinium diethylenetriaminepentaacetic acid (Gd‐DTPA), and after another dose of 0.1 mmol/kg Gd‐DTPA. Two readers (A and B) blinded to dosage independently scored the single dose and double dose image sets for synovitis according to outcome measures in rheumatology (OMERACT) recommendations. Contrast‐to‐noise ratio (CNR) and signal‐to‐noise ratio (SNR) were also calculated for each set. Results: 149 metacarpophalangeal (MCP) joints were evaluated. There was good inter‐reader agreement for each of the two sets (intra‐class correlation coefficient of 0.75 for the single dose set and 0.83 for the double dose). Median CNR and SNR values were 5.4 and 15.9, respectively, for the single dose set and 8.5 and 16.6, respectively, for the double dose set (p<0.0001). Single dose set mean synovitis scores were 1.7 and 1.6 for readers A and B, respectively. Double dose set scores were 1.9 and 2.0, respectively. Thus, higher synovitis scores were recorded for the double dose sets than the single dose sets (p<0.005). Conclusion: In low‐field MRI, when evaluating RA, the dose of the contrast material influences synovitis scoring. Therefore, dosage of contrast material should be taken into consideration when using extremity dedicated low‐field MRI.