Sonoelastography breaks new ground in musculoskeletal imaging

Researchers from Austria, Italy, and Egypt are taking a leap of faith to evaluate several possible ultrasound elastography applications in musculoskeletal radiology. Everyone from weekend warriors to elite athletes may benefit if the test is proven effective, according to papers released at the 2008 RSNA meeting.

Musculoskeletal radiologists seem keen on moving toward more quantitative, functional studies. But they need the right imaging tools to explain how MSK structures work instead of simply describing their appearance. Elastography -- performed by ultrasound or MRI -- has emerged as a way to characterize the mechanical properties of tissue. It has been praised as a useful diagnostic tool in breast, prostate, cervix, and thyroid applications.

Now musculoskeletal radiologists could also use real-time sonoelastography for diagnosis of tissue softening or tears of heel, elbow, and shoulder tendons.

Associate professor of radiology Dr. Andrea Klauser and colleagues at the Medical University of Innsbruck compared sonoelastography and standard sonography to assess Achilles tendons in 25 patients with chronic tendinopathy and 25 healthy subjects. They found elastography just as accurate to detect tendon abnormalities in symptomatic and asymptomatic patients.

"Clinical differentiation between tendinopathies and other debilitating conditions is sometimes difficult," said abstract presenter Dr. Tobias De Zordo, a researcher with the Sonoelastography Project Innsbruck. "Sonoelastography showed good sensitivity and specificity in the detection of alterations of Achilles tendinopathy in good correlation with conventional ultrasound."

During the same scientific session, investigators from the University of Genoa presented results of their own sonoelastography study of Achilles tendon degeneration in healthy athletes. They enrolled 16 patients referred for tendon pain associated with sport activity plus 24 healthy controls. They found sonoelastography useful for characterization of stiffness in symptomatic tendons compared to normal ones.

In another study by the Sonoelastography Project Innsbruck, researchers used the modality to assess 32 patients previously diagnosed with elbow tendon lesions and 28 healthy volunteers. They compared results with those of the clinical exam plus standard and Doppler sonography.

Sonoelastography provided sensitivity, specificity, accuracy, and positive and negative predictive values of 100%, 89%, 94%, 88%, and 100%, respectively, compared with 95%, 89%, 91%, 88%, and 95% for conventional sonography. Findings suggest that elastography could work as a diagnostic adjunct to power Doppler for a more detailed assessment of patients presenting with elbow tendon lesions.

Also getting a foothold in the MSK breakthrough, researchers from Giza, Egypt, used sonoelastography to assess the supraspinatus tendon in 20 healthy volunteers and 40 patients complaining of shoulder pain. They compared results with MRI and found that sonoelastography was a sensitive method for diagnosis of rotator cuff tears.

Further studies will tell how effective sonoelastography would be in diagnosing pathology, said session chair Dr. Jon A. Jacobson. Researchers need to define the diagnostic and prognostic benefit of elastography over gray-scale, color, or power Doppler imaging.

"There are potential applications," Jacobson told Diagnostic Imaging. "What remains to be seen is how much of that can be used clinically."

For more information from the Diagnostic Imaging archives:

Musculoskeletal radiology evolves from anatomic to functional imaging

Ultrasound unveils source of stump pain in amputees

Imaging helps in diagnosis of musculoskeletal masses

RSNA drops ultrasound subspecialty from its scientific program