Ultrasound Elastography in Musculoskeletal Radiology: Past, Present, and Future.

Ultrasound elastography (USE) is becoming an important adjunct tool in the evaluation of various musculoskeletal (MSK) traumatic conditions and diseases, with an increasing number of applications and publications in recent years. This rapidly evolving technique enhances the conventional ultrasound (US) examination by providing information on the elastic properties of tissue alongside the morphological and vascular information obtained from B-mode US and Doppler imaging. Those performing USE must have basic knowledge of its proper imaging techniques and limitations. In this review article, we place the USE in historical perspective and discuss basic techniques and current applications of USE in the evaluation of various traumatic and pathologic conditions of fasciae, nerves, muscles, tendons, ligaments, and MSK soft tissue masses.

EFSUMB guidelines and recommendations on the clinical use of ultrasound elastography. Part 1: Basic principles and technology.

The technical part of these Guidelines and Recommendations, produced under the auspices of EFSUMB, provides an introduction to the physical principles and technology on which all forms of current commercially available ultrasound elastography are based. A difference in shear modulus is the common underlying physical mechanism that provides tissue contrast in all elastograms. The relationship between the alternative technologies is considered in terms of the method used to take advantage of this. The practical advantages and disadvantages associated with each of the techniques are described, and guidance is provided on optimisation of scanning technique, image display, image interpretation and some of the known image artefacts.

EFSUMB guidelines and recommendations on the clinical use of ultrasound elastography. Part 2: Clinical applications.

The clinical part of these Guidelines and Recommendations produced under the auspices of the European Federation of Societies for Ultrasound in Medicine and Biology EFSUMB assesses the clinically used applications of all forms of elastography, stressing the evidence from meta-analyses and giving practical advice for their uses and interpretation. Diffuse liver disease forms the largest section, reflecting the wide experience with transient and shear wave elastography . Then follow the breast, thyroid, gastro-intestinal tract, endoscopic elastography, the prostate and the musculo-skeletal system using strain and shear wave elastography as appropriate. The document is intended to form a reference and to guide clinical users in a practical way.

Real-time ultrasound elastography of the normal Achilles tendon: reproducibility and pattern description.

AIM: To investigate the feasibility and reproducibility of real-time freehand ultrasound elastography (RTE) of the normal Achilles tendon and to describe its elastographic appearances. MATERIALS AND METHODS: Fifty normal Achilles tendons were prospectively examined using RTE performed by tissue compression using the hand-held transducer. The information was colour-coded (red=soft, green=medium, blue=hard) and superimposed on the B-mode image. Each tendon was examined three times transversely and longitudinally by two radiologists and the ratio between tendon and retro-Achilles fat strain (strain index) was calculated. The reproducibility of the elastograms was assessed qualitatively and quantitatively using the strain index inter and intra observer variation coefficient (intra/inter-CV and intra/inter-CC, respectively). RESULTS: All tendons were clearly visualized on the elastograms. Nineteen tendons (19/50, 38%) appeared homogeneously green/blue (type 1). Thirty-one tendons (31/50, 62%) appeared green with longitudinal red stripes (type 2). The intra- and inter-CC values of the strain index were lower for the transverse plane than for the longitudinal plane (0.43, 0.45, 0.41 and 0.78, 0.66, 0.51, respectively). The intra-CV and inter-CV values were higher for the transverse than for the longitudinal plane measurements (39%, 37%, 30% and 30.50%, 30.10%, 29.60%, respectively). CONCLUSION: RTE of the normal Achilles tendon is a feasible method. The reproducibility of the strain index is good and higher for longitudinal elastograms. Qualitative assessment enables the discrimination of two distinct elastographic patterns. Further studies are required to assess the clinical value of this method.

Chest radiography and tuberculosis case-finding in asymptomatic native and immigrant populations in Greece.

SETTING: A university hospital in southern Greece. OBJECTIVE: To determine the prevalence of tuberculosis (TB) and other clinically significant conditions in routine chest X-rays (CXRs) of asymptomatic Greeks and immigrants in Greece. DESIGN: Prospective study. METHODS: CXRs of 4338 asymptomatic persons (56.8% Greeks, 43.2% immigrants, 18-74 years of age) were examined by two experienced chest radiologists blinded to identifying data. Abnormalities were recorded and the final radiological diagnosis was established by consensus. Results were statistically analysed. RESULTS: The majority (94.7%) of the CXRs were reported as normal. Clinically significant findings were reported in four cases (0.08%). No case of active TB was depicted. The incidence of old TB was higher in the Greek-born group than among the immigrants, although the difference was not statistically significant. CONCLUSION: The low prevalence of TB in the Greek-born group implies that radiographic screening in that group presents an unnecessary risk and should possibly be abandoned. Our study does not confirm noticeably higher rates of TB in immigrants in comparison to the native Greek population. However, larger prospective studies are required to confirm this finding.

Molecular genetic alterations and viral presence in ophthalmic pterygium.

Pterygium is a lesion of the corneoscleral limbus which tends to grow in size, often recurs after surgical excision and is associated with exposure to solar light. Additionally, a family history is frequently reported. Loss of heterozygosity (LOH), increased P53 expression and the presence of oncogenic viruses, such as human papilloma virus (HPV) and herpes simplex virus (HSV), have been detected in pterygia, supporting the possible neoplastic nature of the lesion. Co-infection by HSV and HPV as well as LOH at some loci have also been correlated with clinical features, such as postoperative recurrence and history of conjunctivitis. A possible model of pterygium formation is proposed, in which genetic predisposition, environmental factors and viral infection(s) participate in a multi-step process. Future research may lead to new ways of pterygium treatment such as anti-viral or gene therapy.

Ultrasound elastography for musculoskeletal applications.

Ultrasound elastography (EUS) is a method to assess the mechanical properties of tissue, by applying stress and detecting tissue displacement using ultrasound. There are several EUS techniques used in clinical practice; strain (compression) EUS is the most common technique that allows real-time visualisation of the elastographic map on the screen. There is increasing evidence that EUS can be used to measure the mechanical properties of musculoskeletal tissue in clinical practice, with the future potential for early diagnosis to both guide and monitor therapy. This review describes the various EUS techniques available for clinical use, presents the published evidence on musculoskeletal applications of EUS and discusses the technical issues, limitations and future perspectives of this method in the assessment of the musculoskeletal system.