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

Contrast-enhanced ultrasound for the evaluation of liver lesions

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


Contrast-enhanced ultrasound (CEUS) is a well-established technique for imaging the liver and other organs [1-6]. It is used in most of Europe and Asia, as well as in many other countries worldwide. However, the contrast agents used for CEUS of the liver have not been approved by the US Food and Drug Administration, so its use in the United States is limited to research settings [1,2,7]. It is most often used for imaging the liver.

This topic will review the role of CEUS in evaluating liver lesions, including the indications for the procedure and findings associated with various lesions. The general evaluation of liver lesions is discussed in detail elsewhere. (See "Solid liver lesions: Differential diagnosis and evaluation" and "Diagnosis and management of cystic lesions of the liver".)


Standard CEUS — Contrast-enhanced ultrasound (CEUS) uses ultrasound contrast agents to improve visualization and characterization of anatomic structures and lesions. It is most often performed transcutaneously, though it can also be used intraoperatively. There are several contrast agents available for CEUS. Currently used ultrasound contrast agents are microbubbles consisting of gas bubbles stabilized by a shell. The most commonly used include sulfur hexafluoride with a phospholipid shell (SonoVue), octafluoropropane (perflutren with a lipid shell; Definity/Luminity), and perfluorobutane with a phospholipid shell (Sonazoid). Other ultrasound contrast agents are available, but they are not licensed for liver imaging or, in some cases (eg, Levovist), are no longer produced. (See "Contrast echocardiography: Contrast agents, safety, and imaging technique", section on 'Second generation contrast agents'.)

Ultrasound contrast agents are 1 to 10 microns in size (equal to or smaller than red blood cells) and permit visualization of both the macrovasculature and the microvasculature. The minute bubbles survive transpulmonary passage and recirculate, producing systemic ultrasound enhancement. This is an advantage over larger molecules that are retained in vascular beds [1,2,8]. Most ultrasound contrast agents are confined to the vascular space. By contrast, most of the contrast agents used for computed tomography or magnetic resonance imaging (MRI) are rapidly cleared from the blood pool into the extravascular space [2]. Because ultrasound contrast agents remain within the vascular space, only a small amount of contrast agent is required (typically 1 to 2 mL).

CEUS permits real-time visualization of contrast-enhancement patterns during all vascular phases (arterial, portal-venous, and late) [9]. This results in higher temporal resolution than can be achieved with other imaging modalities. The arterial phase provides information on the extent and pattern of the vascular supply. The arterial phase starts 10 to 20 seconds after contrast injection and lasts approximately 25 to 35 seconds. The portal-venous phase starts a few seconds after the arterial phase. It typically lasts until two minutes after contrast injection. The portal-venous phase is followed by the late phase, which lasts until the ultrasound contrast agents are cleared from the circulation (typically four to six minutes). In the case of the contrast agent Sonazoid, it is taken up by Kupffer cells, so there is an additional postvascular (or Kupffer) phase that starts 10 minutes after injection and lasts for an hour or more [1,2,10-13]. The images are analogous to those obtained with gadolinium-ethoxybenzyl-diethylenetriamine-enhanced MRI [9].


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: Sep 2016. | This topic last updated: Sep 26, 2014.
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.
  1. Claudon M, Dietrich CF, Choi BI, et al. Guidelines and good clinical practice recommendations for Contrast Enhanced Ultrasound (CEUS) in the liver - update 2012: A WFUMB-EFSUMB initiative in cooperation with representatives of AFSUMB, AIUM, ASUM, FLAUS and ICUS. Ultrasound Med Biol 2013; 39:187.
  2. Claudon M, Dietrich CF, Choi BI, et al. Guidelines and good clinical practice recommendations for contrast enhanced ultrasound (CEUS) in the liver--update 2012: a WFUMB-EFSUMB initiative in cooperation with representatives of AFSUMB, AIUM, ASUM, FLAUS and ICUS. Ultraschall Med 2013; 34:11.
  3. Albrecht T, Blomley M, Bolondi L, et al. Guidelines for the use of contrast agents in ultrasound. January 2004. Ultraschall Med 2004; 25:249.
  4. Claudon M, Cosgrove D, Albrecht T, et al. Guidelines and good clinical practice recommendations for contrast enhanced ultrasound (CEUS) - update 2008. Ultraschall Med 2008; 29:28.
  5. Piscaglia F, Nolsøe C, Dietrich CF, et al. The EFSUMB Guidelines and Recommendations on the Clinical Practice of Contrast Enhanced Ultrasound (CEUS): update 2011 on non-hepatic applications. Ultraschall Med 2012; 33:33.
  6. Dietrich CF, Averkiou MA, Correas JM, et al. An EFSUMB introduction into Dynamic Contrast-Enhanced Ultrasound (DCE-US) for quantification of tumour perfusion. Ultraschall Med 2012; 33:344.
  7. Wilson SR, Greenbaum LD, Goldberg BB. Contrast-enhanced ultrasound: what is the evidence and what are the obstacles? AJR Am J Roentgenol 2009; 193:55.
  8. Granada JF, Feinstein SB. Imaging of the vasa vasorum. Nat Clin Pract Cardiovasc Med 2008; 5 Suppl 2:S18.
  9. Jang JY, Kim MY, Jeong SW, et al. Current consensus and guidelines of contrast enhanced ultrasound for the characterization of focal liver lesions. Clin Mol Hepatol 2013; 19:1.
  10. Maruyama H, Takahashi M, Ishibashi H, et al. Contrast-enhanced ultrasound for characterisation of hepatic lesions appearing non-hypervascular on CT in chronic liver diseases. Br J Radiol 2012; 85:351.
  11. Arita J, Hasegawa K, Takahashi M, et al. Correlation between contrast-enhanced intraoperative ultrasound using Sonazoid and histologic grade of resected hepatocellular carcinoma. AJR Am J Roentgenol 2011; 196:1314.
  12. Salvatore V, Borghi A, Piscaglia F. Contrast-enhanced ultrasound for liver imaging: recent advances. Curr Pharm Des 2012; 18:2236.
  13. Nakano H, Ishida Y, Hatakeyama T, et al. Contrast-enhanced intraoperative ultrasonography equipped with late Kupffer-phase image obtained by sonazoid in patients with colorectal liver metastases. World J Gastroenterol 2008; 14:3207.
  14. Cui XW, Ignee A, Jedrzejczyk M, Dietrich CF. Dynamic Vascular Pattern (DVP), a quantification tool for contrast enhanced ultrasound. Z Gastroenterol 2013; 51:427.
  15. Blomley MJ, Albrecht T, Cosgrove DO, et al. Liver vascular transit time analyzed with dynamic hepatic venography with bolus injections of an US contrast agent: early experience in seven patients with metastases. Radiology 1998; 209:862.
  16. Tang A, Kim TK, Heathcote J, et al. Does hepatic vein transit time performed with contrast-enhanced ultrasound predict the severity of hepatic fibrosis? Ultrasound Med Biol 2011; 37:1963.
  17. Zhou X, Strobel D, Haensler J, Bernatik T. Hepatic transit time: indicator of the therapeutic response to radiofrequency ablation of liver tumours. Br J Radiol 2005; 78:433.
  18. Bernatik T, Becker D, Neureiter D, et al. Hepatic transit time of an echo enhancer: an indicator of metastatic spread to the liver. Eur J Gastroenterol Hepatol 2004; 16:313.
  19. Dietrich CF. [3D real time contrast enhanced ultrasonography,a new technique]. Rofo 2002; 174:160.
  20. Dietrich CF. Contrast-enhanced low mechanical index endoscopic ultrasound (CELMI-EUS). Endoscopy 2009; 41 Suppl 2:E43.
  21. Dietrich CF, Ignee A, Frey H. Contrast-enhanced endoscopic ultrasound with low mechanical index: a new technique. Z Gastroenterol 2005; 43:1219.
  22. Wilson SR, Burns PN. An algorithm for the diagnosis of focal liver masses using microbubble contrast-enhanced pulse-inversion sonography. AJR Am J Roentgenol 2006; 186:1401.
  23. Strobel D, Seitz K, Blank W, et al. Contrast-enhanced ultrasound for the characterization of focal liver lesions--diagnostic accuracy in clinical practice (DEGUM multicenter trial). Ultraschall Med 2008; 29:499.
  24. Dietrich CF, Ignee A, Trojan J, et al. Improved characterisation of histologically proven liver tumours by contrast enhanced ultrasonography during the portal venous and specific late phase of SHU 508A. Gut 2004; 53:401.
  25. Brenner DJ, Hall EJ. Computed tomography--an increasing source of radiation exposure. N Engl J Med 2007; 357:2277.
  26. Hricak H, Brenner DJ, Adelstein SJ, et al. Managing radiation use in medical imaging: a multifaceted challenge. Radiology 2011; 258:889.
  27. Sirli R, Sporea I, Martie A, et al. Contrast enhanced ultrasound in focal liver lesions--a cost efficiency study. Med Ultrason 2010; 12:280.
  28. Piscaglia F, Leoni S, Cabibbo G, et al. Cost analysis of recall strategies for non-invasive diagnosis of small hepatocellular carcinoma. Dig Liver Dis 2010; 42:729.
  29. Wilson SR, Jang HJ, Kim TK, et al. Real-time temporal maximum-intensity-projection imaging of hepatic lesions with contrast-enhanced sonography. AJR Am J Roentgenol 2008; 190:691.
  30. Schinkel AF, Krueger CG, Tellez A, et al. Contrast-enhanced ultrasound for imaging vasa vasorum: comparison with histopathology in a swine model of atherosclerosis. Eur J Echocardiogr 2010; 11:659.
  31. Lanka B, Jang HJ, Kim TK, et al. Impact of contrast-enhanced ultrasonography in a tertiary clinical practice. J Ultrasound Med 2007; 26:1703.
  32. Leen E, Ceccotti P, Kalogeropoulou C, et al. Prospective multicenter trial evaluating a novel method of characterizing focal liver lesions using contrast-enhanced sonography. AJR Am J Roentgenol 2006; 186:1551.
  33. Ding H, Wang WP, Huang BJ, et al. Imaging of focal liver lesions: low-mechanical-index real-time ultrasonography with SonoVue. J Ultrasound Med 2005; 24:285.
  34. Quaia E, Degobbis F, Tona G, et al. [Differential patterns of contrast enhancement in different focal liver lesions after injection of the microbubble US contrast agent SonoVue]. Radiol Med 2004; 107:155.
  35. Wilson SR, Jang HJ, Kim TK, Burns PN. Diagnosis of focal liver masses on ultrasonography: comparison of unenhanced and contrast-enhanced scans. J Ultrasound Med 2007; 26:775.
  36. Wu W, Chen MH, Yin SS, et al. The role of contrast-enhanced sonography of focal liver lesions before percutaneous biopsy. AJR Am J Roentgenol 2006; 187:752.
  37. Dietrich CF, Kratzer W, Strobe D, et al. Assessment of metastatic liver disease in patients with primary extrahepatic tumors by contrast-enhanced sonography versus CT and MRI. World J Gastroenterol 2006; 12:1699.
  38. Hohmann J, Müller A, Skrok J, et al. Detection of hepatocellular carcinoma and liver metastases with BR14: a multicenter phase IIA study. Ultrasound Med Biol 2012; 38:377.
  39. Correas JM, Low G, Needleman L, et al. Contrast enhanced ultrasound in the detection of liver metastases: a prospective multi-centre dose testing study using a perfluorobutane microbubble contrast agent (NC100100). Eur Radiol 2011; 21:1739.
  40. Quaia E, D'Onofrio M, Palumbo A, et al. Comparison of contrast-enhanced ultrasonography versus baseline ultrasound and contrast-enhanced computed tomography in metastatic disease of the liver: diagnostic performance and confidence. Eur Radiol 2006; 16:1599.
  41. Torzilli G. Advances in the surgical treatment of colorectal cancer liver metastases through ultrasound. Surg Today 2011; 41:1184.
  42. Donadon M, Torzilli G. Intraoperative ultrasound in patients with hepatocellular carcinoma: from daily practice to future trends. Liver Cancer 2013; 2:16.
  43. Leen E, Ceccotti P, Moug SJ, et al. Potential value of contrast-enhanced intraoperative ultrasonography during partial hepatectomy for metastases: an essential investigation before resection? Ann Surg 2006; 243:236.
  44. Ignee A, Baum U, Schuessler G, Dietrich CF. Contrast-enhanced ultrasound-guided percutaneous cholangiography and cholangiodrainage (CEUS-PTCD). Endoscopy 2009; 41:725.
  45. Seitz K, Bernatik T, Strobel D, et al. Contrast-enhanced ultrasound (CEUS) for the characterization of focal liver lesions in clinical practice (DEGUM Multicenter Trial): CEUS vs. MRI--a prospective comparison in 269 patients. Ultraschall Med 2010; 31:492.
  46. Konopke R, Kersting S, Bergert H, et al. Contrast-enhanced ultrasonography to detect liver metastases : a prospective trial to compare transcutaneous unenhanced and contrast-enhanced ultrasonography in patients undergoing laparotomy. Int J Colorectal Dis 2007; 22:201.
  47. Trillaud H, Bruel JM, Valette PJ, et al. Characterization of focal liver lesions with SonoVue-enhanced sonography: international multicenter-study in comparison to CT and MRI. World J Gastroenterol 2009; 15:3748.
  48. Dietrich CF, Maddalena ME, Cui XW, et al. Liver tumor characterization--review of the literature. Ultraschall Med 2012; 33 Suppl 1:S3.
  49. Strobel D, Bernatik T, Blank W, et al. Diagnostic accuracy of CEUS in the differential diagnosis of small (≤ 20  mm) and subcentimetric (≤ 10  mm) focal liver lesions in comparison with histology. Results of the DEGUM multicenter trial. Ultraschall Med 2011; 32:593.
  50. Guang Y, Xie L, Ding H, et al. Diagnosis value of focal liver lesions with SonoVue®-enhanced ultrasound compared with contrast-enhanced computed tomography and contrast-enhanced MRI: a meta-analysis. J Cancer Res Clin Oncol 2011; 137:1595.
  51. Westwood M, Joore M, Grutters J, et al. Contrast-enhanced ultrasound using SonoVue® (sulphur hexafluoride microbubbles) compared with contrast-enhanced computed tomography and contrast-enhanced magnetic resonance imaging for the characterisation of focal liver lesions and detection of liver metastases: a systematic review and cost-effectiveness analysis. Health Technol Assess 2013; 17:1.
  52. Tranquart F, Correas JM, Ladam Marcus V, et al. [Real-time contrast-enhanced ultrasound in the evaluation of focal liver lesions: diagnostic efficacy and economical issues from a French multicentric study]. J Radiol 2009; 90:109.
  53. Albrecht T, Blomley MJ, Burns PN, et al. Improved detection of hepatic metastases with pulse-inversion US during the liver-specific phase of SHU 508A: multicenter study. Radiology 2003; 227:361.
  54. Catala V, Nicolau C, Vilana R, et al. Characterization of focal liver lesions: comparative study of contrast-enhanced ultrasound versus spiral computed tomography. Eur Radiol 2007; 17:1066.
  55. Harvey CJ, Blomley MJ, Eckersley RJ, et al. Hepatic malignancies: improved detection with pulse-inversion US in late phase of enhancement with SH U 508A-early experience. Radiology 2000; 216:903.
  56. Wilson SR, Kim TK, Jang HJ, Burns PN. Enhancement patterns of focal liver masses: discordance between contrast-enhanced sonography and contrast-enhanced CT and MRI. AJR Am J Roentgenol 2007; 189:W7.
  57. Kono Y, Steinbach GC, Peterson T, et al. Mechanism of parenchymal enhancement of the liver with a microbubble-based US contrast medium: an intravital microscopy study in rats. Radiology 2002; 224:253.
  58. Dietrich CF, Cui XW, Boozari B, et al. Contrast-enhanced ultrasound (CEUS) in the diagnostic algorithm of hepatocellular and cholangiocellular carcinoma, comments on the AASLD guidelines. Ultraschall Med 2012; 33 Suppl 1:S57.
  59. Barreiros AP, Piscaglia F, Dietrich CF. Contrast enhanced ultrasound for the diagnosis of hepatocellular carcinoma (HCC): comments on AASLD guidelines. J Hepatol 2012; 57:930.
  60. Dietrich CF, Mertens JC, Braden B, et al. Contrast-enhanced ultrasound of histologically proven liver hemangiomas. Hepatology 2007; 45:1139.
  61. Jeong MG, Yu JS, Kim KW. Hepatic cavernous hemangioma: temporal peritumoral enhancement during multiphase dynamic MR imaging. Radiology 2000; 216:692.
  62. Piscaglia F, Venturi A, Mancini M, et al. Diagnostic features of real-time contrast-enhanced ultrasound in focal nodular hyperplasia of the liver. Ultraschall Med 2010; 31:276.
  63. Dietrich CF, Schuessler G, Trojan J, et al. Differentiation of focal nodular hyperplasia and hepatocellular adenoma by contrast-enhanced ultrasound. Br J Radiol 2005; 78:704.
  64. Dietrich CF, Jenssen C. [Focal liver lesion, incidental finding]. Dtsch Med Wochenschr 2012; 137:2099.
  65. Kim TK, Jang HJ, Burns PN, et al. Focal nodular hyperplasia and hepatic adenoma: differentiation with low-mechanical-index contrast-enhanced sonography. AJR Am J Roentgenol 2008; 190:58.
  66. Ignee A, Piscaglia F, Ott M, et al. A benign tumour of the liver mimicking malignant liver disease--cholangiocellular adenoma. Scand J Gastroenterol 2009; 44:633.
  67. Dietrich CF, Ignee A, Greis C, et al. Artifacts and pitfalls in contrast-enhanced ultrasound of the liver. Ultraschall Med 2014; 35:108.
  68. Hirche TO, Ignee A, Hirche H, et al. Evaluation of hepatic steatosis by ultrasound in patients with chronic hepatitis C virus infection. Liver Int 2007; 27:748.
  69. Dietrich CF. Letter to the editor: Kratzer W et al. Prevalence and risk factors of focal sparing in hepatic steatosis. Ultraschall in Med 2010; 31: 37 - 42. Ultraschall Med 2010; 31:417.
  70. Janica J, Ustymowicz A, Lukasiewicz A, et al. Comparison of contrast-enhanced ultrasonography with grey-scale ultrasonography and contrast-enhanced computed tomography in diagnosing focal fatty liver infiltrations and focal fatty sparing. Adv Med Sci 2013; 58:408.
  71. Kim SH, Lee JM, Lee JY, et al. Value of contrast-enhanced sonography for the characterization of focal hepatic lesions in patients with diffuse liver disease: receiver operating characteristic analysis. AJR Am J Roentgenol 2005; 184:1077.
  72. Catalano O, Sandomenico F, Nunziata A, et al. Transient hepatic echogenicity difference on contrast-enhanced ultrasonography: sonographic sign and pitfall. J Ultrasound Med 2007; 26:337.
  73. Catalano O, Sandomenico F, Raso MM, Siani A. Low mechanical index contrast-enhanced sonographic findings of pyogenic hepatic abscesses. AJR Am J Roentgenol 2004; 182:447.
  74. Liu GJ, Lu MD, Xie XY, et al. Real-time contrast-enhanced ultrasound imaging of infected focal liver lesions. J Ultrasound Med 2008; 27:657.
  75. Thorelius L. Contrast-enhanced ultrasound in trauma. Eur Radiol 2004; 14 Suppl 8:P43.
  76. Thorelius L. Contrast-enhanced ultrasound: beyond the liver. Eur Radiol 2003; 13 Suppl 3:N91.
  77. Nilsson A, Lorén I, Nirhov N, et al. Power Doppler ultrasonography: alternative to computed tomography in abdominal trauma patients. J Ultrasound Med 1999; 18:669.
  78. Cagini L, Gravante S, Malaspina CM, et al. Contrast enhanced ultrasound (CEUS) in blunt abdominal trauma. Crit Ultrasound J 2013; 5 Suppl 1:S9.
  79. Badea R, Seicean A, Procopet B, et al. Pseudoaneurysm of splenic artery ruptured in pancreatic pseudocyst and complicated by wirsungorrhagia: the role of the ultrasound techniques and contrast substances. Ultraschall Med 2011; 32:205.
  80. Stryckers M, Voet D, Vogelaers D, et al. Contrast-enhanced ultrasonography in hepatosplenic sarcoidosis. Acta Clin Belg 2011; 66:429.
  81. Lantinga MA, Gevers TJ, Drenth JP. Evaluation of hepatic cystic lesions. World J Gastroenterol 2013; 19:3543.
  82. Schuessler G, Fellbaum C, Fauth F, et al. [The infammatory pseudotumour -- an unusual liver tumour]. Ultraschall Med 2006; 27:273.
  83. Weiss D, Marti G, Mouton W, et al. [Infection with fasciola hepatica - a case series]. Ultraschall Med 2010; 31:175.
  84. Wang ZL, Tang J, Weskott HP, et al. Undetermined focal liver lesions on gray-scale ultrasound in patients with fatty liver: characterization with contrast-enhanced ultrasound. J Gastroenterol Hepatol 2008; 23:1511.
  85. Barreiros AP, Braden B, Schieferstein-Knauer C, et al. Characteristics of intestinal tuberculosis in ultrasonographic techniques. Scand J Gastroenterol 2008; 43:1224.
  86. Xu HX, Xie XY, Lu MD, et al. Unusual benign focal liver lesions: findings on real-time contrast-enhanced sonography. J Ultrasound Med 2008; 27:243.
  87. Kim SH, Lee JM, Kim WH, et al. Focal peliosis hepatis as a mimicker of hepatic tumors: radiological-pathological correlation. J Comput Assist Tomogr 2007; 31:79.
  88. Leinung S, Gütz U, Stölzel U, et al. [Peliosis hepatis: problems of differential diagnosis]. Rontgenpraxis 2000; 52:295.
  89. Okuda K, Omata M, Itoh Y, et al. Peliosis hepatis as a late and fatal complication of thorotrast liver disease. Report of five cases. Liver 1981; 1:110.
  90. Wang Z, Xu HX, Xie XY, et al. Imaging features of hepatic angiomyolipomas on real-time contrast-enhanced ultrasound. Br J Radiol 2010; 83:411.
  91. Rickes S, Wermke T, Ocran K, et al. [Contrast behaviour of a angiomyolipoma of the liver at echo-enhanced power-Doppler sonography]. Ultraschall Med 2002; 23:338.
  92. Trojan J, Hammerstingl R, Engels K, et al. Contrast-enhanced ultrasound in the diagnosis of malignant mesenchymal liver tumors. J Clin Ultrasound 2010; 38:227.
  93. Badea R, Chiorean L, Matei D, et al. Accidentally ingested foreign body associated with liver actinomycosis: the diagnostic value of imaging. J Gastrointestin Liver Dis 2013; 22:209.
  94. Hohmann J, Loddenkemper C, Albrecht T. Assessment of a biliary hamartoma with contrast-enhanced sonography using two different contrast agents. Ultraschall Med 2009; 30:185.
  95. Faust D, Fellbaum C, Zeuzem S, Dietrich CF. Nodular regenerative hyperplasia of the liver: a rare differential diagnosis of cholestasis with response to ursodeoxycholic acid. Z Gastroenterol 2003; 41:255.
  96. Ehrhardt AR, Reuter S, Buck AK, et al. Assessment of disease activity in alveolar echinococcosis: a comparison of contrast enhanced ultrasound, three-phase helical CT and [(18)F] fluorodeoxyglucose positron emission tomography. Abdom Imaging 2007; 32:730.
  97. Braden B, Helm B, Fabian T, Dietrich CF. [Bacillary angiomatosis of the liver, a suspected ultrasound diagnosis?]. Z Gastroenterol 2000; 38:785.
  98. Braden B, Thalhammer A, Schwarz W, Dietrich CF. Bleeding complications from hepatic mucoidal aneurysmata: value of color duplex sonography after liver transplantation. Liver Transpl 2002; 8:636.
  99. Dietrich CF, Sharma M, Gibson RN, et al. Fortuitously discovered liver lesions. World J Gastroenterol 2013; 19:3173.
  100. Bernatik T, Seitz K, Blank W, et al. Unclear focal liver lesions in contrast-enhanced ultrasonography--lessons to be learned from the DEGUM multicenter study for the characterization of liver tumors. Ultraschall Med 2010; 31:577.
  101. Omata M, Lesmana LA, Tateishi R, et al. Asian Pacific Association for the Study of the Liver consensus recommendations on hepatocellular carcinoma. Hepatol Int 2010; 4:439.
  102. Kudo M, Izumi N, Kokudo N, et al. Management of hepatocellular carcinoma in Japan: Consensus-Based Clinical Practice Guidelines proposed by the Japan Society of Hepatology (JSH) 2010 updated version. Dig Dis 2011; 29:339.
  103. International Consensus Group for Hepatocellular NeoplasiaThe International Consensus Group for Hepatocellular Neoplasia. Pathologic diagnosis of early hepatocellular carcinoma: a report of the international consensus group for hepatocellular neoplasia. Hepatology 2009; 49:658.
  104. Boozari B, Soudah B, Rifai K, et al. Grading of hypervascular hepatocellular carcinoma using late phase of contrast enhanced sonography - a prospective study. Dig Liver Dis 2011; 43:484.
  105. Liu GJ, Xu HX, Lu MD, et al. Correlation between enhancement pattern of hepatocellular carcinoma on real-time contrast-enhanced ultrasound and tumour cellular differentiation on histopathology. Br J Radiol 2007; 80:321.
  106. Nicolau C, Catalá V, Vilana R, et al. Evaluation of hepatocellular carcinoma using SonoVue, a second generation ultrasound contrast agent: correlation with cellular differentiation. Eur Radiol 2004; 14:1092.
  107. Jang HJ, Kim TK, Burns PN, Wilson SR. Enhancement patterns of hepatocellular carcinoma at contrast-enhanced US: comparison with histologic differentiation. Radiology 2007; 244:898.
  108. Bhayana D, Kim TK, Jang HJ, et al. Hypervascular liver masses on contrast-enhanced ultrasound: the importance of washout. AJR Am J Roentgenol 2010; 194:977.
  109. Kim TK, Lee KH, Khalili K, Jang HJ. Hepatocellular nodules in liver cirrhosis: contrast-enhanced ultrasound. Abdom Imaging 2011; 36:244.
  110. Piscaglia F, Cucchetti A, Dietrich CF, Salvatore V. Towards new tools for refined management of patients with advanced hepatocellular carcinoma under systemic therapy: some enthusiasm with a word of caution. J Hepatol 2013; 59:924.
  111. Mörk H, Ignee A, Schuessler G, et al. Analysis of neuroendocrine tumour metastases in the liver using contrast enhanced ultrasonography. Scand J Gastroenterol 2007; 42:652.
  112. Dörffel Y, Wermke W. Neuroendocrine tumors: characterization with contrast-enhanced ultrasonography. Ultraschall Med 2008; 29:506.
  113. Rickes S, Ocran KW, Gerstenhauer G, et al. Evaluation of diagnostic criteria for liver metastases of adenocarcinomas and neuroendocrine tumours at conventional ultrasound, unenhanced power Doppler sonography and echo-enhanced ultrasound. Dig Dis 2004; 22:81.
  114. Piscaglia F, Bolondi L, Italian Society for Ultrasound in Medicine and Biology (SIUMB) Study Group on Ultrasound Contrast Agents. The safety of Sonovue in abdominal applications: retrospective analysis of 23188 investigations. Ultrasound Med Biol 2006; 32:1369.
  115. Bokor D, Chambers JB, Rees PJ, et al. Clinical safety of SonoVue, a new contrast agent for ultrasound imaging, in healthy volunteers and in patients with chronic obstructive pulmonary disease. Invest Radiol 2001; 36:104.
  116. Schreiber-Dietrich D, Dietrich CF. Contrast enhanced ultrasound (CEUS) and off-label use (in children). Ultraschall Med 2012; 33:295.
  117. Dietrich CF, Ignee A, Hocke M, et al. Pitfalls and artefacts using contrast enhanced ultrasound. Z Gastroenterol 2011; 49:350.
  118. Nguyen BN, Fléjou JF, Terris B, et al. Focal nodular hyperplasia of the liver: a comprehensive pathologic study of 305 lesions and recognition of new histologic forms. Am J Surg Pathol 1999; 23:1441.
  119. Ignee A, Weiper D, Schuessler G, et al. Sonographic characterisation of hepatocellular carcinoma at time of diagnosis. Z Gastroenterol 2005; 43:289.
  120. Cui XW, Ignee A, Hocke M, et al. Prolonged heterogeneous liver enhancement on contrast-enhanced ultrasound. Ultraschall Med 2014; 35:246.