Dr. Barr is a Professor of Radiology, Northeastern Ohio
Medical University, and a Diagnostic Radiologist at Radiology
Consultants Inc., Youngstown, OH.
Case summary
A
42-year-old male who is an avid runner had an injury 2 months prior.
The pain at his heel area persisted despite conservative management and
was increasing when he presented. The patient had no other medical
problems, but a history of 2 torn ligaments in the past. The patient
underwent a magnetic resonance imaging (MRI) scan of his hind foot.
Imaging findings
The
proton-density weighted MRI (Figure 1) demonstrates the presence of an
abnormal signal involving the Achilles tendon. The diagnosis of Achilles
tendinitis was made. There was no evidence of a significant tear,
although minimal tears could not be excluded. There was no evidence of
bone-marrow edema, ankle-joint effusion, or fluid surrounding the
Achilles tendon.
An ultrasound (Figure 2) of the Achilles tendon
was performed, including strain elastography at the same time. The
B-mode ultrasound showed an area of decreased echogenicity within the
tendon, which on elastography is soft (red) compared to the normal
tendon, which is hard (blue).
Fusing the MRI and ultrasound images (Figure 3) shows the area of tendinitis is similarly identified on both techniques.
Diagnosis
The patient’s MRI confirmed the diagnosis of Achilles tendinitis. The
patient was placed in a cast for 4 weeks with significant symptomatic
improvement. A follow-up ultrasound (Figure 4) shows that the area of
soft (red) tendinitis has resolved and a small area of green
(intermediate hardness) is present, consistent with a scar/healing area.
Discussion
Musculoskeletal elastography is in its infancy.1-4 Current
studies show that tendons are one of the stiffest tissues in the body.
Pathologies, such as tendinitis or tears, can cause the relative
stiffness to lessen. MRI is considered the standard technique for
evaluating these changes. However, ultrasound elastography may be able
to evaluate these changes at a lower cost than MRI and allows monitoring
of healing. By monitoring the relative softness as well as the size of
the area affected, one can monitor treatment and may be able to better
tailor treatment to the patient’s healing. In addition, ultrasound is
useful for demonstrating dynamics of muscle and tendons. It is also easy
to obtain the contralateral images for comparison.
Conclusion
Strain elastography is a promising new technology that has the
potential to change the present clinical patterns in diagnosis and
patient management in musculoskeletal imaging. Ongoing studies will help
to define the role of strain elastography in musculoskeletal imaging.
References
-
De Zordo T, Fink C, Feuchtner GM, et al. Real-time sonoelastography
findings in healthy Achilles tendons. AJR Am J Roentgenol.
2009;193:W134-W137.
- Trombetti J. Sonoelastography and
musculoskeletal imaging. http://www.dotmed.com/news/story/7760/?lang=en.
Updated December 23, 2008. Accessed August 28, 2012.
-
Schreiber V, Smekal V, De Zordo T, et al. Real-time sonoelastography in
rotator cuff imaging and comparison to magnetic resonance imaging as
gold standard. RSNA 2009. http://
rsna2009.rsna.org/search/event_display.cfm?em_id=8016421&printmode=Y&autoprint=N.
Updated 2009. Accessed August 29, 2012.
- De Zordo T. Value of
real-time sonoelastography in lateral epicondylitis: Comparison with
clinical examination, ultrasound, and power Doppler ultrasound.
Radiological Society of North America 94th Scientific Assembly and
Annual Meeting; November 30th - December 5th, 2008; Chicago, USA.
Updated 2008. Accessed August 29, 2012.