Real-time sonoelastography is a relatively new technique that can assess the elastic properties of tissues.1 Elastography is based on the principle that the compression of tissue produces strain (displacement). This strain is lower in tissue that is hard and higher in tissue that is soft.
The principle of strain imaging, or elastography, was first described in 1991.2 A fast cross-sectional technique, based on real-time elastographical imaging, was described in 1999.3 Real-time sonoelastography (RTSE) allows this strain to be measured and displayed in real-time (Figures 1 and 2).4
It is sometimes difficult, or even impossible, to distinguish pathological tissue from surrounding healthy tissue on conventional ultrasound. The two regions often present with the same echogenicity.5 Changes in the tissue's elasticity that are due to inflammation and tumors can, however, be detected on RTSE.5
Although RTSE is not yet used in routine clinical practice, it has been shown to be useful in the differential diagnosis of breast,4 thyroid,6 and prostate cancers.7 Researchers are also looking at the role of this technology in lymph node and liver characterization.8,9 Our group is the first to apply RTSE to musculoskeletal disorders.
Tendinopathy is a pathology found most commonly in athletes. Systemic disorders, such as psoriasis, rheumatoid arthritis, and spondyloarthropathies, can also affect tendons. Although the etiology is believed to be multifactorial,10 pathogenesis is mainly the same in all pathologies. Repetitive microtrauma, vascular alterations, and autoimmune processes produce histopathological changes in tendons, such as hypoxic, mucoid, calcifying, or lipoid degenerations.11,12 These microscopic alterations may result in tendon thickening, which in turn can lead to partial tears or full-thickness ruptures.
