Metacarpophalangeal joints in rheumatoid arthritis: laser Doppler imaging--initial experience

Laser Doppler imaging is a noninvasive method yielding a spatial perfusion map. With use of a near-infrared laser, elevated perfusion associated with the metacarpophalangeal joints was detectable in patients with active rheumatoid arthritis. Findings at laser Doppler imaging correlated with pain scores and synovitis detected at ultrasonography, whereas the power Doppler sign (red pixels inside the active green box) did not. Laser Doppler imaging has the potential to help assess soft-tissue inflammation.

Intraobserver repeatability and interobserver reproducibility in musculoskeletal ultrasound imaging measurements

OBJECTIVE

To assess the repeatability and reproducibility of ultrasonographic measurements at the anterior surface of the femoral neck and iliofemoral ligament and on a human tissue-mimicking phantom.

METHODS

Two independent investigators studied 22 consecutive hips. One investigator had previous experience in musculoskeletal ultrasonography (US). The other investigator had undergone a short course in hip sonography (only 3 hours). Both investigators were blinded to their own and each other's results. On the phantom both observers had taken 10 vertical measurements at 6 cm deep where two objects were placed at 2 cm from each other. Calculation of measurement errors, percent errors and the Bland-Altman graphic technique were used for analysis of data.

RESULTS

After 132 examinations the first investigator's within-subject standard deviation was 0.4 mm. The intraobserver error was 4.75%. The second investigator's within-subject standard deviation was 0.6 mm and his intraobserver error was 7.00%. The interobserver error was 10.91%. After 20 phantom examinations the first investigators's intraobserver error was 1.11% and the second investigator's intraobserver error was 1.47%.

CONCLUSION

An inexperienced musculoskeletal sonographer can achieve an acceptable performance if given appropriate training.

Inflamed retrocalcaneal bursa and Achilles tendonitis in psoriatic arthritis demonstrated by ultrasonography

OBJECTIVE

To demonstrate the use of high resolution ultrasound measurements and power Doppler mode in the diagnosis and follow up of a patient with psoriatic arthritic with retrocalcaneal bursitis and Achilles tendonitis.

METHODS

An outpatient based ATL HDI 3000 ultrasound equipment was used with a CL10-5 MHZ 26 mm probe and musculoskeletal software. Real time B mode and power Doppler mode were used to detect changes in structure and blood flow.

RESULTS

Unilateral retrocalcaneal bursitis and Achilles tendonitis were demonstrated by sonography. Power Doppler mode was useful to demonstrate an increased blood flow around an abnormal retrocalcaneal bursa. A follow up examination showed marginal thickening of the Achilles tendon without any bursitis.

CONCLUSIONS

Ultrasonography is an objective method in the confirmation of clinical diagnosis after physical examination. During the examination it is possible to gain not only qualitative but also quantitative data. A comparative study with quantitative data is possible in longitudinal studies.

Novel use of laser Doppler imaging for investigating epicondylitis

OBJECTIVE

This investigation evaluated a novel form of tissue perfusion measurement, laser Doppler imaging (LDI), in a case of lateral epicondylitis to establish if it might have applications in assessing soft tissue lesions. LDI was used in conjunction with ultrasonography to provide information about tissue oedema as well as the power Doppler signal as an alternative method of assessing blood flow.

METHODS

A laser Doppler imager with a near-infrared (NIR) laser source was used to improve tissue penetration and yield measurements of perfusion (flux) from structures under the skin. Skin temperature over the lateral epicondylar region was also measured. Ultrasonography was used in both grey-scale and power Doppler modes. LDI, temperature measurements and ultrasonographic data were obtained before treatment and serially after local injection of methylprednisolone.

RESULTS

Before treatment there was increased perfusion and skin temperature and the presence of a power Doppler sign associated with the right lateral epicondyle as well as oedema at the extensor origin. None of these was present at the asymptomatic contralateral epicondylar region. Twenty-four hours after methylprednisolone administration, both perfusion and skin temperature had increased, and they declined over the subsequent 48 h. Although skin temperature had declined to normal (referenced to the contralateral epicondyle) by the third day after injection, it took until the eleventh day after injection for perfusion to normalize.

CONCLUSIONS

LDI using an NIR laser source appears to be an effective non-invasive method for the examination of inflammatory responses in soft tissue, with greater sensitivity than thermally based methods. In addition, LDI was found to correlate with power Doppler ultrasonography.