Recommendations of the ESSR Arthritis Subcommittee on Ultrasonography in Inflammatory Joint Disease.

This article presents the recommendations of the European Society of Musculoskeletal Radiology Arthritis Subcommittee on the use of ultrasonography (US) in rheumatic disease, focused on the examination of joints in the adult population. The recommended examination technique and protocols used in a radiologic work-up are discussed. The main US features that can lead to a final diagnosis in the most common rheumatic diseases are addressed. The differential diagnosis that should be considered at image interpretation is presented. The role of US in interventional procedures and clinically important recent developments is also discussed.

Carpal tunnel syndrome.

Ultrasound (US) of the carpal tunnel adds value to the usual electrophysiology diagnosis by confirming doubtful results or evaluating patients who do not improve after surgery. US sometimes provides the surgeon or the referring physician with important information about normal variants or common or even rare causes of the nerve compression. The size of the median nerve must be calculated in the short axis by measuring the nerve cross-sectional area where the nerve is the thickest, in most cases at the proximal entrance of the carpal tunnel. Because the threshold of the nerve size varies in the literature, it is best to consider the cross-sectional median nerve area <8 mm(2) to rule out and ≥12 mm(2) to rule in the diagnosis of carpal tunnel syndrome.

Differentiation of focal liver lesions: usefulness of parametric imaging with contrast-enhanced US.

PURPOSE: To evaluate whether parametric imaging with contrast material-enhanced ultrasonography (US) is superior to visual assessment for the differential diagnosis of focal liver lesions (FLLs). MATERIALS AND METHODS: This study had institutional review board approval, and verbal patient informed consent was obtained. Between August 2005 and October 2008, 146 FLLs in 145 patients (63 women, 82 men; mean age, 62.5 years; age range, 22-89 years) were imaged with real-time low-mechanical-index contrast-enhanced US after a bolus injection of 2.4 mL of a second-generation contrast agent. Clips showing contrast agent uptake kinetics (including arterial, portal, and late phases) were recorded and subsequently analyzed off-line with dedicated image processing software. Analysis of the dynamic vascular patterns (DVPs) of lesions with respect to adjacent parenchyma allowed mapping DVP signatures on a single parametric image. Cine loops of contrast-enhanced US and results from parametric imaging of DVP were assessed separately by three independent off-site readers who classified each lesion as benign, malignant, or indeterminate. Sensitivity, specificity, accuracy, and positive and negative predictive values were calculated for both techniques. Interobserver agreement (κ statistics) was determined. RESULTS: Sensitivities for visual interpretation of cine loops for the three readers were 85.0%, 77.9%, and 87.6%, which improved significantly to 96.5%, 97.3%, and 96.5% for parametric imaging, respectively (P < .05, McNemar test), while retaining high specificity (90.9% for all three readers). Accuracy scores of parametric imaging were higher than those of conventional contrast-enhanced US for all three readers (P < .001, McNemar test). Interobserver agreement increased with DVP parametric imaging compared with conventional contrast-enhanced US (change of κ from 0.54 to 0.99). CONCLUSION: Parametric imaging of DVP improves diagnostic performance of contrast-enhanced US in the differentiation between malignant and benign FLLs; it also provides excellent interobserver agreement.

Developments in musculoskeletal ultrasound and clinical applications.

OBJECTIVE: Ultrasound (US) technologies are rapidly advancing, offering several refined transducer technologies as well as soft and hardware facilities. The aim of this article is to outline US developments, from B-mode technologies over Doppler advances to more sophisticated technologies, and their potential clinical impact in the field of musculoskeletal (MSK) imaging. NEW ADVANCES: When using B-mode ultrasound, compound imaging and beam-steering are of help to decrease anisotropy in tendons and ligaments, that are less well depicted due to their oblique course. Doppler imaging has become sensitive in the detection of flow in small vessels, which is of particular value in rheumatologic conditions, tumour and overuse assessment. The use of US microbubble contrast agents improves detection of low-volume blood flow in smaller vessels by increasing the signal-to-noise ratio and thereby facilitating detection of angiogenetic vessels in inflammatory conditions or tumours. The use of US blood pool contrast agents enables molecular imaging in real-time, and thus the diagnostic potential of US is expanded, opening up a new field of US applications. Objective quantification of altered tissue (e.g., synovial proliferation, tumours) is still demanding and might be improved by the use of three-dimensional imaging and software tools as parametric evaluation. Real-time sonoelastography (EUS) is a new development for visualization of tissue elasticity by measurement of tissue displacement in terms of tissue stiffness changes, promising new insights into tendon disorders. Image fusion is an exciting development that enables superimposition of CT/MRI data sets on real-time US scanning. This technique might be helpful in guiding injections under real-time conditions even in regions less easily accessible by US as, for instance, the axial skeleton, and can additionally provide an interesting tool for teaching MSK imaging and ways to guide interventions. CONCLUSION: In summary, exciting developments are expanding the applications of US in the MSK field, offering the advantages of real-time performance, high tissue resolution and relative speed at a reasonable cost.

Acromioclavicular joint injury: enhanced technique of examination with dynamic maneuver.

Acromioclavicular (AC) sprains can be graded in 3 to 6 different types according to Tossy or Rockwell, respectively. In mild sprains (Tossy and Rockwell I), movements in the AC joint are minimal, because the coraco-clavicular ligaments are intact. In these patients, stress radiography is usually normal, and sonographic examination at rest can be normal as well, showing minimal or no displacement between the 2 extremities of the bones. We present a simple dynamic maneuver to enhance the diagnosis of these mild sprains known as the cross-arm maneuver, in which the hand is placed on the opposite shoulder. The dynamic sonographic examination during this maneuver clearly shows abnormal movements in the clavicle's extremity, which "falls down" to the acromion in the cross-arm position and is raised and pulled from the acromion at rest. The maneuver is very easy to perform and may be useful when a mild AC joint sprain is suspected.

Ultrasonography of anterosuperior calcaneal process fracture: report of 2 cases.

OBJECTIVE: The purpose of this series is to describe the ultrasonographic findings of anterosuperior calcaneal process (ASCP) fracture. METHODS: Two patients with ASCP fractures were examined with ultrasonography. Both of them had pain over the lateral aspect of the ankle 10 to 13 months after an injury. Initial radiographs had shown no evidence of bone fracture or bone avulsion. RESULTS: In both cases, ultrasonography revealed the presence of a bone fragment adjacent to the ASCP suggestive of a misdiagnosed fracture. The latter was confirmed by radiographs. In 1 case, a hypoechoic thickening of the calcaneocuboid component of the bifurcate ligament was also identified on ultrasonographic scans. CONCLUSIONS: Ultrasonography is potentially valuable in detecting clinically or radiographically occult ASCP fractures.