AIUM Standard for MSK Ultrasound: Indications, Technique, and Protocol

What the AIUM Document Regulates

The AIUM Practice Parameter for the Performance of the Musculoskeletal Ultrasound Examination describes the minimum requirements for performing, documenting, and interpreting musculoskeletal ultrasound. The parameter is intended for the study of muscles, tendons, ligaments, joints, bursae, superficial soft tissues, peripheral nerves, and a range of ultrasound-guided interventions. It is not an anatomy textbook or a list of all possible pathologies, but a practical quality standard: what should be checked, recorded, and reflected in the report.

The key principle of AIUM: the scope of the study is determined by the clinical question, anatomical area, and real-time findings. If necessary, the protocol is expanded, dynamic tests are performed, comparison with the opposite side and Doppler assessment are conducted.

Indications for MSK Ultrasound

According to AIUM, the study is appropriate for pain, injury, functional limitation, palpable mass, suspicion of inflammation, effusion, tendon or ligament injury, muscle pathology, bursae, fascia, peripheral nerve, foreign body, infectious process, or postoperative complication. Ultrasound is also used to monitor previously identified changes and to guide diagnostic or therapeutic procedures.

It is particularly important that MSK ultrasound is a dynamic method. It is especially useful when the symptom is reproduced by movement: click, impingement, tendon subluxation, ligament complex instability, nerve compression, or changes in soft tissue relationships under load.

Clinical Request and Preparation

The referral should include the clinical question, side, anatomical area, presumed diagnosis, significant surgeries, injuries, results of previous imaging, and examination data. An unclear request reduces reproducibility: “joint ultrasound” is less useful than “pain on the lateral surface of the elbow, rule out common extensor tendinopathy and lateral ligament complex injury.”

The patient's position is chosen to provide access to the area of interest, relaxation or tension of the required structure, and the possibility of dynamic testing. The study is performed in longitudinal and transverse planes; due to the anisotropy of tendons and nerves, the angle of insonation must be constantly adjusted.

Equipment and Settings

AIUM indicates the need to use an ultrasound system suitable for superficial high-resolution structures. The main probe for most MSK tasks is a high-frequency linear one. For deep structures, large patients, or the hip area, a probe with greater penetration depth may be required. Grayscale imaging and Doppler modes should be available, and for interventions, real-time needle visualization is necessary.

Settings are adjusted to the structure: depth minimally sufficient, focus at the level of interest, gain without “overexposure,” Doppler with sensitive parameters for low-velocity blood flow. Measurements are performed only when they answer the clinical question or are needed for dynamic observation.

General Scanning Algorithm

The standard approach includes identifying the anatomical landmark, assessing the structure in two mutually perpendicular planes, checking the integrity of fibers or the capsuloligamentous complex, analyzing surrounding bursae and soft tissues, searching for effusion, synovial thickening, calcifications, erosive changes of the bone surface, hematoma, or collection. Doppler is used when hyperemia or active inflammation is suspected.

Comparison with the contralateral side is not mandatory for every case but is recommended when anatomical variability or minimal changes may affect the conclusion. Dynamic maneuvers are performed when impingement, instability, snapping phenomena, tendon subluxations, and nerve compression are suspected.

Protocols by Anatomical Areas

Ultrasound-Guided Procedures

AIUM includes MSK ultrasound not only as a diagnostic but also as a navigational tool. Under ultrasound guidance, fluid aspiration, injection into a joint, bursa, or tendon sheath, biopsy of a soft tissue mass, removal or localization of a foreign body, and other manipulations can be performed if they are within the specialist's competence and allowed by local practice.

For procedures, visualization of the target, adjacent vessels and nerves, needle trajectory, and distribution of the injected substance are critical. The protocol records the indication, access, target structure, fact of ultrasound guidance, and complications if they occur.

Image Documentation

Documentation must confirm that the declared area was examined and the pathological conclusion is based on images. Representative grayscale images of normal and altered structures, measurements of significant findings, Doppler frames when assessing blood flow, images before and after dynamic testing when relevant, and frames demonstrating needle position or procedure result are preserved.

If the study is limited by pain, dressing, postoperative changes, inability to position, or technical conditions, this should be indicated. Limiting the protocol without explanation makes the conclusion less suitable for clinical decision-making.

Structure of the Report

The report should be clinically targeted: area and side of the study, reason for referral, additional modes or dynamic tests applied, description of normal and pathological structures, sizes of significant masses or collections, degree of confidence, differential range if necessary, and final answer to the referral question.

AIUM does not require inserting universal “norms” for each structure in the report. If local scales or classifications are used, they must be validated in the institution's practice and not replace morphological description: integrity, echostructure, thickening, fluid, hyperemia, retraction, relation to adjacent tissues.

Qualification, Safety, and Quality Control

The study should be performed and interpreted by a specialist trained in MSK ultrasound, anatomy, and artifact recognition. Regular equipment maintenance, adherence to the principle of reasonable use of acoustic energy, infection control, probe cleaning, and sterile technique for invasive procedures are necessary.

The practical implementation of the AIUM parameter in the department is conveniently formatted as a local checklist: clinical request, mandatory structures by area, dynamics or comparison when indicated, saved images, report with an answer to the question and indication of limitations.