UpToDate
Official reprint from UpToDate®
www.uptodate.com ©2016 UpToDate®

Noninvasive assessment of hepatic fibrosis: Ultrasound-based elastography

Author
Christoph F Dietrich, MD, MBA
Section Editor
Jonathan B Kruskal, MD, PhD
Deputy Editor
Anne C Travis, MD, MSc, FACG, AGAF

INTRODUCTION

Liver disease is an important problem worldwide. Accurately diagnosing liver fibrosis and inflammatory activity are the most important factors for determining the stage of the disease, assessing the patient's prognosis, and predicting treatment responses [1-7]. This is true for a wide range of disorders, including viral hepatitis, alcoholic and nonalcoholic fatty liver disease, drug-induced liver injury, primary biliary cirrhosis, and autoimmune hepatitis. Ultrasound-based elastography provides noninvasive approaches for assessing hepatic fibrosis.

This topic will review the use of ultrasound-based elastography for assessing liver fibrosis. Other methods for assessing liver fibrosis, including liver biopsy, magnetic resonance elastography, and serologic testing, are discussed separately. (See "Percutaneous, fine-needle aspiration, and laparoscopic liver biopsy" and "Histologic scoring systems for chronic liver disease" and "Noninvasive assessment of hepatic fibrosis: Overview of serologic and radiographic tests".)

ROLE OF ULTRASOUND-BASED ELASTOGRAPHY

Ultrasound-based elastography is primarily used as an alternative to liver biopsy for the assessment of hepatic fibrosis. It can also be used to predict complications in patients with cirrhosis. However, it is not yet widely available in the United States, where liver biopsy remains the standard for assessing hepatic fibrosis.

Ultrasound-based elastography has been studied for the evaluation of focal liver lesions, but because of limitations, such as limited depth of penetration, it is not recommended for this application.

Assessing hepatic fibrosis — Assessing hepatic fibrosis is often done with liver biopsy. However, liver biopsy has several disadvantages: it is invasive; it is associated with rare but serious complications; and it can only sample a small portion of the liver parenchyma, making it susceptible to sampling variation. To overcome these problems, alternative noninvasive serologic and radiographic methods have been developed to assess hepatic fibrosis (table 1). One of the more commonly used ultrasound-based techniques for assessing hepatic fibrosis is transient elastography. Other ultrasound-based techniques include point-shear wave elastography (SWE), two-dimensional (2D)-SWE, and strain elastography (sometimes referred to as real-time elastography).

                     

Subscribers log in here

To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information or to purchase a personal subscription, click below on the option that best describes you:
Literature review current through: Nov 2016. | This topic last updated: Thu Oct 15 00:00:00 GMT 2015.
The content on the UpToDate website is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health care professional regarding any medical questions or conditions. The use of this website is governed by the UpToDate Terms of Use ©2016 UpToDate, Inc.
References
Top
  1. Vergniol J, Foucher J, Terrebonne E, et al. Noninvasive tests for fibrosis and liver stiffness predict 5-year outcomes of patients with chronic hepatitis C. Gastroenterology 2011; 140:1970.
  2. Ngo Y, Munteanu M, Messous D, et al. A prospective analysis of the prognostic value of biomarkers (FibroTest) in patients with chronic hepatitis C. Clin Chem 2006; 52:1887.
  3. Parkes J, Roderick P, Harris S, et al. Enhanced liver fibrosis test can predict clinical outcomes in patients with chronic liver disease. Gut 2010; 59:1245.
  4. Parkes J, Guha IN, Harris S, et al. Systematic review of the diagnostic performance of serum markers of liver fibrosis in alcoholic liver disease. Comp Hepatol 2012; 11:5.
  5. Parkes J, Guha IN, Roderick P, et al. Enhanced Liver Fibrosis (ELF) test accurately identifies liver fibrosis in patients with chronic hepatitis C. J Viral Hepat 2011; 18:23.
  6. Lok AS, McMahon BJ. Chronic hepatitis B: update 2009. Hepatology 2009; 50:661.
  7. European Association for Study of Liver. EASL Clinical Practice Guidelines: management of hepatitis C virus infection. J Hepatol 2014; 60:392.
  8. Heide R, Strobel D, Bernatik T, Goertz RS. Characterization of focal liver lesions (FLL) with acoustic radiation force impulse (ARFI) elastometry. Ultraschall Med 2010; 31:405.
  9. Ying L, Lin X, Xie ZL, et al. Clinical utility of acoustic radiation force impulse imaging for identification of malignant liver lesions: a meta-analysis. Eur Radiol 2012; 22:2798.
  10. Guibal A, Boularan C, Bruce M, et al. Evaluation of shearwave elastography for the characterisation of focal liver lesions on ultrasound. Eur Radiol 2013; 23:1138.
  11. Ronot M, Di Renzo S, Gregoli B, et al. Characterization of fortuitously discovered focal liver lesions: additional information provided by shearwave elastography. Eur Radiol 2015; 25:346.
  12. Brunel T, Guibal A, Boularan C, et al. Focal nodular hyperplasia and hepatocellular adenoma: The value of shear wave elastography for differential diagnosis. Eur J Radiol 2015; 84:2059.
  13. Lu Q, Ling W, Lu C, et al. Hepatocellular carcinoma: stiffness value and ratio to discriminate malignant from benign focal liver lesions. Radiology 2015; 275:880.
  14. Marginean CO, Marginean C. Elastographic assessment of liver fibrosis in children: A prospective single center experience. Eur J Radiol 2012; 81:e870.
  15. Sporea I, Şirli R, Popescu A, et al. Is it better to use two elastographic methods for liver fibrosis assessment? World J Gastroenterol 2011; 17:3824.
  16. Sporea I, Sirli R, Bota S, et al. Is ARFI elastography reliable for predicting fibrosis severity in chronic HCV hepatitis? World J Radiol 2011; 3:188.
  17. Bota S, Sporea I, Sirli R, et al. Factors that influence the correlation of acoustic radiation force impulse (ARFI), elastography with liver fibrosis. Med Ultrason 2011; 13:135.
  18. Yoon KT, Lim SM, Park JY, et al. Liver stiffness measurement using acoustic radiation force impulse (ARFI) elastography and effect of necroinflammation. Dig Dis Sci 2012; 57:1682.
  19. Nahon P, Kettaneh A, Tengher-Barna I, et al. Assessment of liver fibrosis using transient elastography in patients with alcoholic liver disease. J Hepatol 2008; 49:1062.
  20. Fraquelli M, Rigamonti C, Casazza G, et al. Etiology-related determinants of liver stiffness values in chronic viral hepatitis B or C. J Hepatol 2011; 54:621.
  21. Coco B, Oliveri F, Maina AM, et al. Transient elastography: a new surrogate marker of liver fibrosis influenced by major changes of transaminases. J Viral Hepat 2007; 14:360.
  22. Arena U, Vizzutti F, Corti G, et al. Acute viral hepatitis increases liver stiffness values measured by transient elastography. Hepatology 2008; 47:380.
  23. Kuroda H, Takikawa Y, Onodera M, et al. Serial changes of liver stiffness measured by acoustic radiation force impulse imaging in acute liver failure: a case report. J Clin Ultrasound 2012; 40:99.
  24. Wong VW, Vergniol J, Wong GL, et al. Liver stiffness measurement using XL probe in patients with nonalcoholic fatty liver disease. Am J Gastroenterol 2012; 107:1862.
  25. de Lédinghen V, Wong VW, Vergniol J, et al. Diagnosis of liver fibrosis and cirrhosis using liver stiffness measurement: comparison between M and XL probe of FibroScan®. J Hepatol 2012; 56:833.
  26. de Lédinghen V, Vergniol J, Foucher J, et al. Non-invasive diagnosis of liver steatosis using controlled attenuation parameter (CAP) and transient elastography. Liver Int 2012; 32:911.
  27. de Lédinghen V, Vergniol J, Gonzalez C, et al. Screening for liver fibrosis by using FibroScan(®) and FibroTest in patients with diabetes. Dig Liver Dis 2012; 44:413.
  28. Palmeri ML, Wang MH, Rouze NC, et al. Noninvasive evaluation of hepatic fibrosis using acoustic radiation force-based shear stiffness in patients with nonalcoholic fatty liver disease. J Hepatol 2011; 55:666.
  29. Myers RP, Crotty P, Pomier-Layrargues G, et al. Prevalence, risk factors and causes of discordance in fibrosis staging by transient elastography and liver biopsy. Liver Int 2010; 30:1471.
  30. Castéra L, Foucher J, Bernard PH, et al. Pitfalls of liver stiffness measurement: a 5-year prospective study of 13,369 examinations. Hepatology 2010; 51:828.
  31. Millonig G, Reimann FM, Friedrich S, et al. Extrahepatic cholestasis increases liver stiffness (FibroScan) irrespective of fibrosis. Hepatology 2008; 48:1718.
  32. Millonig G, Friedrich S, Adolf S, et al. Liver stiffness is directly influenced by central venous pressure. J Hepatol 2010; 52:206.
  33. Popescu A, Bota S, Sporea I, et al. The influence of food intake on liver stiffness values assessed by acoustic radiation force impulse elastography-preliminary results. Ultrasound Med Biol 2013; 39:579.
  34. Goertz RS, Egger C, Neurath MF, Strobel D. Impact of food intake, ultrasound transducer, breathing maneuvers and body position on acoustic radiation force impulse (ARFI) elastometry of the liver. Ultraschall Med 2012; 33:380.
  35. Goldschmidt I, Streckenbach C, Dingemann C, et al. Application and limitations of transient liver elastography in children. J Pediatr Gastroenterol Nutr 2013; 57:109.
  36. Berzigotti A, De Gottardi A, Vukotic R, et al. Effect of meal ingestion on liver stiffness in patients with cirrhosis and portal hypertension. PLoS One 2013; 8:e58742.
  37. Mederacke I, Wursthorn K, Kirschner J, et al. Food intake increases liver stiffness in patients with chronic or resolved hepatitis C virus infection. Liver Int 2009; 29:1500.
  38. Ophir J, Céspedes I, Ponnekanti H, et al. Elastography: a quantitative method for imaging the elasticity of biological tissues. Ultrason Imaging 1991; 13:111.
  39. Parker KJ, Huang SR, Musulin RA, Lerner RM. Tissue response to mechanical vibrations for "sonoelasticity imaging". Ultrasound Med Biol 1990; 16:241.
  40. Parker KJ, Doyley MM, Rubens DJ. Imaging the elastic properties of tissue: the 20 year perspective. Phys Med Biol 2011; 56:R1.
  41. Bamber J, Cosgrove D, Dietrich CF, et al. EFSUMB guidelines and recommendations on the clinical use of ultrasound elastography. Part 1: Basic principles and technology. Ultraschall Med 2013; 34:169.
  42. Cui XW, Friedrich-Rust M, De Molo C, et al. Liver elastography, comments on EFSUMB elastography guidelines 2013. World J Gastroenterol 2013; 19:6329.
  43. Cosgrove D, Piscaglia F, Bamber J, et al. EFSUMB guidelines and recommendations on the clinical use of ultrasound elastography. Part 2: Clinical applications. Ultraschall Med 2013; 34:238.
  44. Castéra L, Vergniol J, Foucher J, et al. Prospective comparison of transient elastography, Fibrotest, APRI, and liver biopsy for the assessment of fibrosis in chronic hepatitis C. Gastroenterology 2005; 128:343.
  45. Shiina T, Nightingale KR, Palmeri ML, et al. WFUMB guidelines and recommendations for clinical use of ultrasound elastography: Part 1: basic principles and terminology. Ultrasound Med Biol 2015; 41:1126.
  46. Talwalkar JA, Kurtz DM, Schoenleber SJ, et al. Ultrasound-based transient elastography for the detection of hepatic fibrosis: systematic review and meta-analysis. Clin Gastroenterol Hepatol 2007; 5:1214.
  47. Rockey DC. Noninvasive assessment of liver fibrosis and portal hypertension with transient elastography. Gastroenterology 2008; 134:8.
  48. Friedrich-Rust M, Ong MF, Martens S, et al. Performance of transient elastography for the staging of liver fibrosis: a meta-analysis. Gastroenterology 2008; 134:960.
  49. Sarvazyan A, Hall TJ, Urban MW, et al. AN OVERVIEW OF ELASTOGRAPHY - AN EMERGING BRANCH OF MEDICAL IMAGING. Curr Med Imaging Rev 2011; 7:255.
  50. Sporea I, Sirli R, Bota S, et al. Comparative study concerning the value of acoustic radiation force impulse elastography (ARFI) in comparison with transient elastography (TE) for the assessment of liver fibrosis in patients with chronic hepatitis B and C. Ultrasound Med Biol 2012; 38:1310.
  51. Sporea I, Bota S, Peck-Radosavljevic M, et al. Acoustic Radiation Force Impulse elastography for fibrosis evaluation in patients with chronic hepatitis C: an international multicenter study. Eur J Radiol 2012; 81:4112.
  52. Lupsor M, Badea R, Stefanescu H, et al. Performance of a new elastographic method (ARFI technology) compared to unidimensional transient elastography in the noninvasive assessment of chronic hepatitis C. Preliminary results. J Gastrointestin Liver Dis 2009; 18:303.
  53. Bavu E, Gennisson JL, Couade M, et al. Noninvasive in vivo liver fibrosis evaluation using supersonic shear imaging: a clinical study on 113 hepatitis C virus patients. Ultrasound Med Biol 2011; 37:1361.
  54. Muller M, Gennisson JL, Deffieux T, et al. Quantitative viscoelasticity mapping of human liver using supersonic shear imaging: preliminary in vivo feasibility study. Ultrasound Med Biol 2009; 35:219.
  55. Dietrich CF, Cantisani V. Current status and perspectives of elastography. Eur J Radiol 2014; 83:403.
  56. Nightingale K, Bentley R, Trahey G. Observations of tissue response to acoustic radiation force: opportunities for imaging. Ultrason Imaging 2002; 24:129.
  57. Nightingale KR, Palmeri ML, Nightingale RW, Trahey GE. On the feasibility of remote palpation using acoustic radiation force. J Acoust Soc Am 2001; 110:625.
  58. Degos F, Perez P, Roche B, et al. Diagnostic accuracy of FibroScan and comparison to liver fibrosis biomarkers in chronic viral hepatitis: a multicenter prospective study (the FIBROSTIC study). J Hepatol 2010; 53:1013.
  59. Lupşor M, Badea R, Stefănescu H, et al. Analysis of histopathological changes that influence liver stiffness in chronic hepatitis C. Results from a cohort of 324 patients. J Gastrointestin Liver Dis 2008; 17:155.
  60. Zarski JP, Sturm N, Guechot J, et al. Comparison of nine blood tests and transient elastography for liver fibrosis in chronic hepatitis C: the ANRS HCEP-23 study. J Hepatol 2012; 56:55.
  61. European Association for the Study of the Liver. EASL Clinical Practice Guidelines: management of hepatitis C virus infection. J Hepatol 2011; 55:245.
  62. Ferraioli G, Tinelli C, Dal Bello B, et al. Performance of liver stiffness measurements by transient elastography in chronic hepatitis. World J Gastroenterol 2013; 19:49.
  63. Kim DY, Kim SU, Ahn SH, et al. Usefulness of FibroScan for detection of early compensated liver cirrhosis in chronic hepatitis B. Dig Dis Sci 2009; 54:1758.
  64. Chan HL, Wong GL, Choi PC, et al. Alanine aminotransferase-based algorithms of liver stiffness measurement by transient elastography (Fibroscan) for liver fibrosis in chronic hepatitis B. J Viral Hepat 2009; 16:36.
  65. Kim SU, Ahn SH, Park JY, et al. Liver stiffness measurement in combination with noninvasive markers for the improved diagnosis of B-viral liver cirrhosis. J Clin Gastroenterol 2009; 43:267.
  66. Kim SU, Han KH, Ahn SH. Transient elastography in chronic hepatitis B: an Asian perspective. World J Gastroenterol 2010; 16:5173.
  67. Afdhal NH, Bacon BR, Patel K, et al. Accuracy of fibroscan, compared with histology, in analysis of liver fibrosis in patients with hepatitis B or C: a United States multicenter study. Clin Gastroenterol Hepatol 2015; 13:772.
  68. Fraquelli M, Rigamonti C, Casazza G, et al. Reproducibility of transient elastography in the evaluation of liver fibrosis in patients with chronic liver disease. Gut 2007; 56:968.
  69. Zelber-Sagi S, Yeshua H, Shlomai A, et al. Sampling variability of transient elastography according to probe location. Eur J Gastroenterol Hepatol 2011; 23:507.
  70. Myers RP, Pomier-Layrargues G, Kirsch R, et al. Feasibility and diagnostic performance of the FibroScan XL probe for liver stiffness measurement in overweight and obese patients. Hepatology 2012; 55:199.
  71. Wong GL. Transient elastography: Kill two birds with one stone? World J Hepatol 2013; 5:264.
  72. Wong GL, Vergniol J, Lo P, et al. Non-invasive assessment of liver fibrosis with transient elastography (FibroScan®): applying the cut-offs of M probe to XL probe. Ann Hepatol 2013; 12:570.
  73. Engelmann G, Gebhardt C, Wenning D, et al. Feasibility study and control values of transient elastography in healthy children. Eur J Pediatr 2012; 171:353.
  74. Ferraioli G, Filice C, Castera L, et al. WFUMB guidelines and recommendations for clinical use of ultrasound elastography: Part 3: liver. Ultrasound Med Biol 2015; 41:1161.
  75. Adebajo CO, Talwalkar JA, Poterucha JJ, et al. Ultrasound-based transient elastography for the detection of hepatic fibrosis in patients with recurrent hepatitis C virus after liver transplantation: a systematic review and meta-analysis. Liver Transpl 2012; 18:323.
  76. Pavlov CS, Casazza G, Nikolova D, et al. Transient elastography for diagnosis of stages of hepatic fibrosis and cirrhosis in people with alcoholic liver disease. Cochrane Database Syst Rev 2015; 1:CD010542.
  77. Sandrin L, Fourquet B, Hasquenoph JM, et al. Transient elastography: a new noninvasive method for assessment of hepatic fibrosis. Ultrasound Med Biol 2003; 29:1705.
  78. Saito H, Tada S, Nakamoto N, et al. Efficacy of non-invasive elastometry on staging of hepatic fibrosis. Hepatol Res 2004; 29:97.
  79. Perazzo H, Fernandes FF, Gomes A, et al. Interobserver variability in transient elastography analysis of patients with chronic hepatitis C. Liver Int 2015; 35:1533.
  80. Boursier J, Konate A, Guilluy M, et al. Learning curve and interobserver reproducibility evaluation of liver stiffness measurement by transient elastography. Eur J Gastroenterol Hepatol 2008; 20:693.
  81. Singh S, Fujii LL, Murad MH, et al. Liver stiffness is associated with risk of decompensation, liver cancer, and death in patients with chronic liver diseases: a systematic review and meta-analysis. Clin Gastroenterol Hepatol 2013; 11:1573.
  82. Merchante N, Rivero-Juárez A, Téllez F, et al. Liver stiffness predicts clinical outcome in human immunodeficiency virus/hepatitis C virus-coinfected patients with compensated liver cirrhosis. Hepatology 2012; 56:228.
  83. Cescon M, Colecchia A, Cucchetti A, et al. Value of transient elastography measured with FibroScan in predicting the outcome of hepatic resection for hepatocellular carcinoma. Ann Surg 2012; 256:706.
  84. Castéra L, Le Bail B, Roudot-Thoraval F, et al. Early detection in routine clinical practice of cirrhosis and oesophageal varices in chronic hepatitis C: comparison of transient elastography (FibroScan) with standard laboratory tests and non-invasive scores. J Hepatol 2009; 50:59.
  85. Sporea I, Raţiu I, Sirli R, et al. Value of transient elastography for the prediction of variceal bleeding. World J Gastroenterol 2011; 17:2206.
  86. Pritchett S, Cardenas A, Manning D, et al. The optimal cut-off for predicting large oesophageal varices using transient elastography is disease specific. J Viral Hepat 2011; 18:e75.
  87. Roulot D, Czernichow S, Le Clésiau H, et al. Liver stiffness values in apparently healthy subjects: influence of gender and metabolic syndrome. J Hepatol 2008; 48:606.
  88. Gaia S, Carenzi S, Barilli AL, et al. Reliability of transient elastography for the detection of fibrosis in non-alcoholic fatty liver disease and chronic viral hepatitis. J Hepatol 2011; 54:64.
  89. Mueller S, Millonig G, Sarovska L, et al. Increased liver stiffness in alcoholic liver disease: differentiating fibrosis from steatohepatitis. World J Gastroenterol 2010; 16:966.
  90. Tapper EB, Cohen EB, Patel K, et al. Levels of alanine aminotransferase confound use of transient elastography to diagnose fibrosis in patients with chronic hepatitis C virus infection. Clin Gastroenterol Hepatol 2012; 10:932.
  91. Petta S, Maida M, Macaluso FS, et al. The severity of steatosis influences liver stiffness measurement in patients with nonalcoholic fatty liver disease. Hepatology 2015; 62:1101.
  92. Myers RP, Pomier-Layrargues G, Kirsch R, et al. Discordance in fibrosis staging between liver biopsy and transient elastography using the FibroScan XL probe. J Hepatol 2012; 56:564.
  93. Friedrich-Rust M, Nierhoff J, Lupsor M, et al. Performance of Acoustic Radiation Force Impulse imaging for the staging of liver fibrosis: a pooled meta-analysis. J Viral Hepat 2012; 19:212.
  94. Palmeri ML, Wang MH, Dahl JJ, et al. Quantifying hepatic shear modulus in vivo using acoustic radiation force. Ultrasound Med Biol 2008; 34:546.
  95. Guzmán-Aroca F, Frutos-Bernal MD, Bas A, et al. Detection of non-alcoholic steatohepatitis in patients with morbid obesity before bariatric surgery: preliminary evaluation with acoustic radiation force impulse imaging. Eur Radiol 2012; 22:2525.
  96. Bota S, Herkner H, Sporea I, et al. Meta-analysis: ARFI elastography versus transient elastography for the evaluation of liver fibrosis. Liver Int 2013; 33:1138.
  97. Friedrich-Rust M, Nierhoff J, Lupsor M, et al. Performance of Acoustic Radiation Force Impulse imaging for the staging of liver fibrosis: a pooled meta-analysis. J Viral Hepat 2012; 19:e212.
  98. Friedrich-Rust M, Wunder K, Kriener S, et al. Liver fibrosis in viral hepatitis: noninvasive assessment with acoustic radiation force impulse imaging versus transient elastography. Radiology 2009; 252:595.
  99. Rizzo L, Calvaruso V, Cacopardo B, et al. Comparison of transient elastography and acoustic radiation force impulse for non-invasive staging of liver fibrosis in patients with chronic hepatitis C. Am J Gastroenterol 2011; 106:2112.
  100. Kircheis G, Sagir A, Vogt C, et al. Evaluation of acoustic radiation force impulse imaging for determination of liver stiffness using transient elastography as a reference. World J Gastroenterol 2012; 18:1077.
  101. Friedrich-Rust M, Buggisch P, de Knegt RJ, et al. Acoustic radiation force impulse imaging for non-invasive assessment of liver fibrosis in chronic hepatitis B. J Viral Hepat 2013; 20:240.
  102. Ye XP, Ran HT, Cheng J, et al. Liver and spleen stiffness measured by acoustic radiation force impulse elastography for noninvasive assessment of liver fibrosis and esophageal varices in patients with chronic hepatitis B. J Ultrasound Med 2012; 31:1245.
  103. Yoneda M, Suzuki K, Kato S, et al. Nonalcoholic fatty liver disease: US-based acoustic radiation force impulse elastography. Radiology 2010; 256:640.
  104. Friedrich-Rust M, Romen D, Vermehren J, et al. Acoustic radiation force impulse-imaging and transient elastography for non-invasive assessment of liver fibrosis and steatosis in NAFLD. Eur J Radiol 2012; 81:e325.
  105. Zhang D, Li P, Chen M, et al. Non-invasive assessment of liver fibrosis in patients with alcoholic liver disease using acoustic radiation force impulse elastography. Abdom Imaging 2015; 40:723.
  106. Piscaglia F, Salvatore V, Di Donato R, et al. Accuracy of VirtualTouch Acoustic Radiation Force Impulse (ARFI) imaging for the diagnosis of cirrhosis during liver ultrasonography. Ultraschall Med 2011; 32:167.
  107. Toshima T, Shirabe K, Takeishi K, et al. New method for assessing liver fibrosis based on acoustic radiation force impulse: a special reference to the difference between right and left liver. J Gastroenterol 2011; 46:705.
  108. Karlas T, Pfrepper C, Wiegand J, et al. Acoustic radiation force impulse imaging (ARFI) for non-invasive detection of liver fibrosis: examination standards and evaluation of interlobe differences in healthy subjects and chronic liver disease. Scand J Gastroenterol 2011; 46:1458.
  109. Bercoff J, Pernot M, Tanter M, Fink M. Monitoring thermally-induced lesions with supersonic shear imaging. Ultrason Imaging 2004; 26:71.
  110. Bercoff J, Tanter M, Fink M. Supersonic shear imaging: a new technique for soft tissue elasticity mapping. IEEE Trans Ultrason Ferroelectr Freq Control 2004; 51:396.
  111. Sporea I, Bota S, Gradinaru-Taşcău O, et al. Which are the cut-off values of 2D-Shear Wave Elastography (2D-SWE) liver stiffness measurements predicting different stages of liver fibrosis, considering Transient Elastography (TE) as the reference method? Eur J Radiol 2014; 83:e118.
  112. Cassinotto C, Lapuyade B, Mouries A, et al. Non-invasive assessment of liver fibrosis with impulse elastography: comparison of Supersonic Shear Imaging with ARFI and FibroScan®. J Hepatol 2014; 61:550.
  113. Ferraioli G, Tinelli C, Zicchetti M, et al. Reproducibility of real-time shear wave elastography in the evaluation of liver elasticity. Eur J Radiol 2012; 81:3102.
  114. Ophir J, Garra B, Kallel F, et al. Elastographic imaging. Ultrasound Med Biol 2000; 26 Suppl 1:S23.
  115. Itoh A, Ueno E, Tohno E, et al. Breast disease: clinical application of US elastography for diagnosis. Radiology 2006; 239:341.
  116. Berg WA, Cosgrove DO, Doré CJ, et al. Shear-wave elastography improves the specificity of breast US: the BE1 multinational study of 939 masses. Radiology 2012; 262:435.
  117. Lee SH, Chang JM, Cho N, et al. Practice guideline for the performance of breast ultrasound elastography. Ultrasonography 2014; 33:3.
  118. Sun J, Cai J, Wang X. Real-time ultrasound elastography for differentiation of benign and malignant thyroid nodules: a meta-analysis. J Ultrasound Med 2014; 33:495.
  119. Giovannini M, Thomas B, Erwan B, et al. Endoscopic ultrasound elastography for evaluation of lymph nodes and pancreatic masses: a multicenter study. World J Gastroenterol 2009; 15:1587.
  120. Janssen J, Papavassiliou I. Effect of aging and diffuse chronic pancreatitis on pancreas elasticity evaluated using semiquantitative EUS elastography. Ultraschall Med 2014; 35:253.
  121. Dudea SM, Botar-Jid C, Dumitriu D, et al. Differentiating benign from malignant superficial lymph nodes with sonoelastography. Med Ultrason 2013; 15:132.
  122. Friedrich-Rust M, Ong MF, Herrmann E, et al. Real-time elastography for noninvasive assessment of liver fibrosis in chronic viral hepatitis. AJR Am J Roentgenol 2007; 188:758.
  123. Tatsumi C, Kudo M, Ueshima K, et al. Noninvasive evaluation of hepatic fibrosis using serum fibrotic markers, transient elastography (FibroScan) and real-time tissue elastography. Intervirology 2008; 51 Suppl 1:27.
  124. Havre RF, Elde E, Gilja OH, et al. Freehand real-time elastography: impact of scanning parameters on image quality and in vitro intra- and interobserver validations. Ultrasound Med Biol 2008; 34:1638.
  125. Morikawa H, Fukuda K, Kobayashi S, et al. Real-time tissue elastography as a tool for the noninvasive assessment of liver stiffness in patients with chronic hepatitis C. J Gastroenterol 2011; 46:350.
  126. Friedrich-Rust M, Schwarz A, Ong M, et al. Real-time tissue elastography versus FibroScan for noninvasive assessment of liver fibrosis in chronic liver disease. Ultraschall Med 2009; 30:478.
  127. Sandulescu L, Rogoveanu I, Gheonea IA, et al. Real-time elastography applications in liver pathology between expectations and results. J Gastrointestin Liver Dis 2013; 22:221.
  128. Sporea I, Bota S, Săftoiu A, et al. Romanian national guidelines and practical recommendations on liver elastography. Med Ultrason 2014; 16:123.
  129. Fujimoto K, Kato M, Tonomura A, et al. Non-invasive evaluation method of the liver fibrosis using real-time tissue elastograpy - usefulness of judgment liver fibrosis stage by liver fibrosis index (LF index). Kanzo 2010; 51:539.
  130. Kobayashi K, Nakao H, Nishiyama T, et al. Diagnostic accuracy of real-time tissue elastography for the staging of liver fibrosis: a meta-analysis. Eur Radiol 2015; 25:230.
  131. Colombo S, Buonocore M, Del Poggio A, et al. Head-to-head comparison of transient elastography (TE), real-time tissue elastography (RTE), and acoustic radiation force impulse (ARFI) imaging in the diagnosis of liver fibrosis. J Gastroenterol 2012; 47:461.
  132. Sãftoiu A, Gheonea DI, Ciurea T. Hue histogram analysis of real-time elastography images for noninvasive assessment of liver fibrosis. AJR Am J Roentgenol 2007; 189:W232.
  133. Ferraioli G, Gulizia R, Filice C. Real-time elastography in the assessment of liver fibrosis. AJR Am J Roentgenol 2007; 189:W170.
  134. Koizumi Y, Hirooka M, Kisaka Y, et al. Liver fibrosis in patients with chronic hepatitis C: noninvasive diagnosis by means of real-time tissue elastography--establishment of the method for measurement. Radiology 2011; 258:610.