A New Framework for Musculoskeletal Ultrasound in Rheumatology

October 2, 2017

EULAR developed a comprehensive but practical update describing standardized procedures.

A consensus-based comprehensive but practical update describing standardized procedures for musculoskeletal ultrasound in rheumatologic practice was developed by the European League Against Rheumatism (EULAR).

Increasing numbers of rheumatologists are using musculoskeletal ultrasound in their practices to make diagnoses and monitor response to treatment as well as to direct local injections and take biopsies, the guideline authors noted. Ingrid Möller and colleagues representing EULAR pointed out that ultrasound has many benefits over other imaging techniques, the most important being safety and point-of-care convenience. The portability of smaller ultrasound machines has contributed to their widespread availability in the rheumatologist’s office.

Based on these facts and the remote nature of EULAR’s 2001 guidelines for musculoskeletal ultrasound, the authors presented an update to those guidelines in a recent Annals of the Rheumatic Diseases article.

Task force objectives

EULAR created a task force with the following objectives:

(1) To update the standardized scanning techniques for musculoskeletal ultrasound assessment of the joint areas accessible to ultrasound evaluation in rheumatologic musculoskeletal diseases.

(2) To produce standardized imaging procedures for ultrasound assessment of other structures important to rheumatology.

(3) To select and prioritize the abnormalities found with musculoskeletal ultrasound.

(4) To create an electronic illustrated manual (an App) of images and techniques accessible to everyone who has interest in performing musculoskeletal ultrasound in their clinical practice.

Methods

A comprehensive literature review was performed to look at 7706 articles; 176 were selected for detailed review. Surveys were completed by 227 international musculoskeletal ultrasound experts; the response rate was 49.8%.

Recommendations

Following are general recommended procedures for musculoskeletal ultrasound assessment in rheumatologic musculoskeletal disease:

• Musculoskeletal ultrasound includes 2 principal modes: B-mode (or grey scale) that provides morphological information of the anatomic structures and Doppler mode (color Doppler or power Doppler) that allows for evaluation of blood flow.

• Musculoskeletal ultrasound should be performed with high-resolution linear transducers (probes) with frequencies between 6 and 14 MHz for deep/intermediate areas to ≥ 15 MHz for superficial areas.

• Tissue harmonic imaging, spatial compound imaging, and extended field of view (panoramic) and virtual convex imaging are some of the software capabilities that may be useful in musculoskeletal ultrasound.

• When a joint is scanned, the probe should be oriented perpendicular or parallel to the bony cortical surface (bony acoustic landmark) so that the cortical margin appears bright, sharp, and hyperechoic.

• A dynamic scanning technique by means of slight movements of translation (side-to-side, back-to-front), angulation, and rotation of the probe should be carried out to allow for the best visualization of the structure or structures of interest.

• Musculoskeletal structures should be evaluated as they move smoothly, either actively or passively.

• To avoid anisotropy (hypoechoic/anechoic appearance
 of a normally hyperechoic structure that mainly affects tendons) and the common pitfalls that accompany it, the probe should be continuously adjusted to maintain the beam perpendicular to the tendon fibers, especially in insertional regions.

• When the long axis of the structure of interest corresponds to the cranial-caudal orientation of the anatomic position, the most proximal aspect of the structure is usually placed on the left-hand side of the screen. However, other options are acceptable as long as the movement of the image on the screen is kept parallel to the direction of the probe on the patient.

The authohrs’ preference for short axis is to align the structure of interest on the screen as if the observer is looking at the patient.

• Probe compression can be helpful in distinguishing a compressible liquid collection from a noncompressible solid. Little or no compression is important when performing Doppler examination to avoid cessation of flow in small vessels.

• A generous amount of gel should be used for superficial structures, especially when little or no pressure is indicated.

• The machine setting for B-mode and Doppler mode should be properly adjusted to optimize the US image acquisition process.

Authors’ expectations

• These enhanced practical, comprehensive, and consensus-based guidelines should provide a framework and reference for practitioners to perform musculoskeletal ultrasound.

• The guidelines should be a valuable educational tool and reference for practice and research in rheumatologic musculoskeletal disease.

• The Musculoskeletal Ultrasound App is available free of charge at the EULAR web page.

Disclosures:

This project was funded by a European League Against Rheumatism grant.

References:

Möller I, Janta I, Backhaus M, et al. “The 2017 EULAR standardised procedures for ultrasound imaging in rheumatology.” Ann Rheum Dis. 2017 Aug 16. pii: annrheumdis-2017-211585. doi: 10.1136/annrheumdis-2017-211585. [Epub ahead of print]