Contrast-enhanced Sonography for the Evaluation of Neovascularization in Tendinopathic Tissues

Evaluation of Tendon Disorders With Ultrasonography and Elastography

The frequency of musculoskeletal system ultrasonography (US) has increased over time. The most common reason for musculoskeletal US is the evaluation of tendons. The superficial location of tendons makes US the most suitable diagnostic tool, and US is generally the initial imaging modality for tendon disorders. The primary advantages of US are its low cost, easy accessibility, rapidity, repeatability, freedom from x-rays, and enabling of a dynamic inspection. In addition, Doppler US and elastography can be performed simultaneously with US. We aimed to demonstrate the US and elastographic findings of tendon disorders that we frequently encounter in different regions.

Contrast-Enhanced Ultrasound for Musculoskeletal Applications: A World Federation for Ultrasound in Medicine and Biology Position Paper

This World Federation for Ultrasound in Medicine and Biology position paper reviews the diagnostic potential of ultrasound contrast agents for clinical decision-making and provides general advice for optimal contrast-enhanced ultrasound performance in musculoskeletal issues. In this domain, contrast-enhanced ultrasound performance has increasingly been investigated with promising results, but still lacks everyday clinical application and standardized techniques; therefore, experts summarized current knowledge according to published evidence and best personal experience. The goal was to intensify and standardize the use and administration of ultrasound contrast agents to facilitate correct diagnoses and ultimately to improve the management and outcomes of patients.

In Achilles tendinopathy, the neovascularization, detected by contrast-enhanced ultrasound (CEUS), is abundant but not related to symptoms

PURPOSE AND HYPOTHESIS

Mid-portion Achilles tendinopathy is characterized by a proliferation of small vessels, called neovascularization, which can be demonstrated by power Doppler sonography (PD). Neovascularization can be correlated with diagnosis and consequent therapies focused on vascular supply. Published data regarding the relationship between neovascularisation and symptoms, such as pain and disability, are contradictory. The hypothesis that contrast-enhanced ultrasound (CEUS) could detect with more sensibility than PD the new vessel ingrowth in human degenerated Achilles tendons and therefore the correlation of neovascularization with pain and disability, was evaluated.

METHODS

Thirty consecutive patients of recalcitrant Achilles tendinopathy were studied with ultrasound greyscale (US), PD, CEUS and magnetic resonance imaging. Neovascularization was recorded as percentage on the whole extension of examined area. The vascularization time was recorded as venous and arterial type. Imaging data were classified both concurrently with the examination and in a secondary blinded assessment; any difference in the subjective assessment was discussed and a consensus view formed. Pain and disability were assessed by Western Ontario McMaster Universities Arthritis Index (WOMAC) and EuroQuality of life 5-dimension-5-level questionnaire and visual analogue scale (EQ-VAS). All results were analysed with suitable statistical methods.

RESULTS

76.7% of cases were degenerated; 23.3% had also partial discontinuity of the fibres. PD detected vascularization in 54% of cases, whereas CEUS in 83% of cases: in 13 cases, PD did not detect vascularization. The vascularization time was rapid (< 20 s, arterial type) in 60% of cases. WOMAC pain mean value is 6.4 and SD 3.4; WOMAC total score mean value is 21.6 and SD 12.8. EQ-VAS mean value is 56 and SD 18.3. No statistically significant correlation emerged between vascularization and pain/disability.

CONCLUSIONS

CEUS showed a greater ability to detect neovessels than PD in chronic Achilles tendinopathies. Nevertheless in 30 consecutive tendinopathies, no correlation between pain/disability and neovascularization was found: the role of multiple neovessels continue to be unclear. The possibility to discriminate arterial from venous vessels ('vascularization time') could be useful to understand the pathophysiology of tendinopathies and its healing process.

STUDY TYPE

Diagnostic study.

LEVEL OF EVIDENCE

II.