Imaging of Hepatic Steatosis

ABSTRACT

Hepatic steatosis is a common finding encountered during cross-sectional imaging examinations. This article reviews the imaging findings of hepatic steatosis as revealed by sonography, computed tomography, magnetic resonance imaging, and magnetic resonance spectroscopy. Focal fatty sparing and focal hepatic steatosis are conditions that can create potential diagnostic challenges for the radiologist. The typical findings, distribution, and etiology of these focal processes are presented. In the setting of diffuse hepatic steatosis, hepatic mass lesions can be difficult to discern on both computed tomography and sonography, with reported decreased sensitivity and specificity of lesion detection. In such cases, magnetic resonance imaging may be the imaging procedure of choice for the detection and characterization of both hepatic steatosis and coexistent hepatic masses. Some hepatocellular neoplasms, particularly hepatic adenoma and well-differentiated hepatocellular carcinoma, can have intratumoral lipid. By demonstrating the lipid content of these masses, imaging can add specificity in characterizing them as hepatocellular in origin because nonhepatocellular neoplasms in general do not contain intracellular lipid.

KEYWORD

Magnetic resonance imaging - hepatic steatosis - magnetic resonance - chemical shift

REFERENCES

• 1 Quinn S F, Gosink B B. Characteristic sonographic signs of hepatic fatty infiltration.  AJR . 1985;  145 753-755
• 2 Sanford N L, Walsh P, Matis C. Is ultrasonography useful in the assessment of diffuse parenchymal liver disease?.  Gastroenterology . 1985;  89 186-191
• 3 Celle G, Savarino V, Picciotto A. Is hepatic ultrasonography a valid alternative tool to liver biopsy?.  <~>Report on 507 cases studied with both techniques. Dig Dis Sci . 1988;  33 467-471
• 4 Berrut C, Curati W, de Gautard R. [The role of ultrasonography in the diagnosis of diffuse liver disease].  Schweiz Med Wochenschr J Suisse Med . 1986;  116 215-218
• 5 Needleman L, Kurtz A B, Rifkin M D. Sonography of diffuse benign liver disease: accuracy of pattern recognition and grading.  AJR . 1986;  146 1011-1015
• 6 Kissin C M, Bellamy E A, Cosgrove D O. Focal sparing in fatty infiltration of the liver.  Br J Radiol . 1986;  59 25-28
• 7 Jacobs J E, Birnbaum B A, Shapiro M A. Diagnostic criteria for fatty infiltration of the liver on contrast-enhanced helical CT.  AJR . 1998;  171 659-664
• 8 Piekarski J, Goldberg H I, Royal S A. Difference between liver and spleen CT numbers in the normal adult: its usefulness in predicting the presence of diffuse liver disease.  Radiology . 1980;  137 727-729
• 9 Kawata R, Sakata K, Kunieda T. Quantitative evaluation of fatty liver by computed tomography in rabbits.  AJR . 1984;  142 741-746
• 10 Johnston R J, Stamm E R, Lewin J M. Diagnosis of fatty infiltration of the liver on contrast enhanced CT: limitations of liver-minus-spleen attenuation difference measurements.  Abdom Imaging . 1998;  23 409-415
• 11 Chambers T P, Baron R L, Lush R M. Hepatic CT enhancement: comparison of ionic and nonionic contrast agents in the same patients.  Radiology . 1994;  190 721-725
• 12 Fishbein M H, Gardner K G, Potter C J. Introduction of fast MR imaging in the assessment of hepatic steatosis.  Magn Reson Imaging . 1997;  15 287-293
• 13 Petersein J, Schima W, Saini S. Comparison of in-phase and out-of-phase gradient recalled echo T1-weighted pulse sequence for MR imaging of malignant liver masses following administration of paramagnetic gadolinium-chelate.  Abdom Imaging . 2000;  25 159-163
• 14 Outwater E K, Blasbalg R, Siegelman E S. Detection of lipid in abdominal tissues with opposed-phase gradient-echo images at 1.5 T: techniques and diagnostic importance.  Radiographics . 1998;  18 1465-1480
• 15 Mendler M H, Bouillet P, Le Sidaner A. Dual-energy CT in the diagnosis and quantification of fatty liver: limited clinical value in comparison to ultrasound scan and single- energy CT, with special reference to iron overload.  J Hepatol . 1998;  28 785-794
• 16 Lipman J C, Stomper P C, Kaplan W D. Detection of hepatic metastases in diffuse fatty infiltration by CT: the complementary role of imaging.  Clin Nucl Med . 1988;  13 602-605
• 17 Debaere C, Rigauts H, Laukens P. Transient focal fatty liver infiltration mimicking liver metastasis.  J Belge Radiol . 1998;  81 174-175
• 18 Scott Jr W W, Sanders R C, Siegelman S S. Irregular fatty infiltration of the liver: diagnostic dilemmas.  AJR . 1980;  135 67-71
• 19 Onaya H, Itai Y, Kurosaki Y. Metastatic tumors in irregular fatty liver mimicking focal sparing.  Radiat Med . 1994;  12 69-73
• 20 Kato M, Saji S, Kanematsu M. A case of liver metastasis from colon cancer masquerading as focal sparing in a fatty liver.  Jpn J Clin Oncol . 1997;  27 189-192
• 21 Arita T, Matsunaga N, Honma Y. Focally spared area of fatty liver caused by arterioportal shunt.  J Comput Assist Tomogr . 1996;  20 360-362
• 22 Arai K, Matsui O, Takashima T. Focal spared areas in fatty liver caused by regional decreased portal flow.  AJR . 1988;  151 300-302
• 23 Sauerbrei E E, Lopez M. Pseudotumor of the quadrate lobe in hepatic sonography: a sign of generalized fatty infiltration.  AJR . 1986;  147 923-927
• 24 Kawamori Y, Matsui O, Takahashi S. Focal hepatic fatty infiltration in the posterior edge of the medial segment associated with aberrant gastric venous drainage: CT, US, and MR findings.  J Comput Assist Tomogr . 1996;  17 590-595
• 25 Gabata T, Matsui O, Kadoya M. Aberrant gastric venous drainage in a focal spared area of segment IV in fatty liver: demonstration with color Doppler sonography.  Radiology . 1997;  203 461-463
• 26 Matsui O, Kadoya M, Takahashi S. Focal sparing of segment IV in fatty livers shown by sonography and CT: correlation with aberrant gastric venous drainage.  AJR . 1995;  164 1137-1140
• 27 Matsui O, Takahashi S, Kadoya M. Pseudolesion in segment IV of the liver at CT during arterial portography: correlation with aberrant gastric venous drainage.  Radiology . 1994;  193 31-35
• 28 Itai Y. Peritumoral sparing of fatty liver: another important instance of focal sparing caused by a hepatic tumor (Letter; comment).  AJR . 2000;  174 868-870
• 29 Grossholz M, Terrier F, Rubbia L. Focal sparing in the fatty liver as a sign of an adjacent space-occupying lesion.  AJR . 1998;  171 1391-1395
• 30 Chen K, Hiramatsu Y, Yunoki M. [Focal sparing around the gallbladder in fatty liver: an useful sign in the diagnosis of borderline cases by CT].  Nippon Igaku Hoshasen Gakkai Zasshi . 1989;  49 146-152
• 31 Tochio H, Kudo M, Okabe Y. Association between a focal spared area in the fatty liver and intrahepatic efferent blood flow from the gallbladder wall: evaluation with color Doppler sonography.  AJR . 1999;  172 1249-1253
• 32 Yoshikawa J, Matsui O, Takashima T. Focal fatty change of the liver adjacent to the falciform ligament: CT and sonographic findings in five surgically confirmed cases.  AJR . 1987;  149 491-494
• 33 Baker M K, Wenker J C, Cockerill E M. Focal fatty infiltration of the liver: diagnostic imaging.  Radiographics . 1985;  5 923-929
• 34 Dao T H, Mathieu D, Thu N T. Value of MR imaging in evaluating focal fatty infiltration of the liver: preliminary study.  Radiographics . 1991;  11 1003-1012
• 35 Brawer M K, Austin G E, Lewin K J. Focal fatty change of the liver, a hitherto poorly recognized entity.  Gastroenterology . 1980;  78 247-252
• 36 Kawashima A, Suehiro S, Murayama S. Focal fatty infiltration of the liver mimicking a tumor: sonographic and CT features.  J Comput Assist Tomogr . 1986;  10 329-331
• 37 Layfield L J. Focal fatty change of the liver: cytologic findings in a radiographic mimic of metastases.  Diagn Cytopathol. 1994;  11 385-387 387 discussion-389 discussion
• 38 Outwater E K, Bhatia M, Siegelman E S. Lipid in renal clear cell carcinoma: detection on opposed-phase gradient-echo MR images.  Radiology . 1997;  205 103-107
• 39 Schlund J F, Kenney P J, Brown E D. Adrenocortical carcinoma: MR imaging appearance with current techniques.  J Magn Reson Imaging . 1995;  5 171-174
• 40 Mathieu D, Paret M, Mahfouz A E. Hyperintense benign liver lesions on spin-echo T1-weighted MR images: pathologic correlations.  Abdom Imaging . 1997;  22 410-417
• 41 Martin J, Puig J, Falco J. Hyperechoic liver nodules: characterization with proton fat-water chemical shift MR imaging [published erratum appears in Radiology 1998 Aug;208(2):556].  Radiology . 1998;  207 325-330
• 42 Martin J, Sentis M, Zidan A. Fatty metamorphosis of hepatocellular carcinoma: detection with chemical shift gradient-echo MR imaging.  Radiology . 1995;  195 125-130
• 43 Mortele K J, Stubbe J, Praet M. Intratumoral steatosis in focal nodular hyperplasia coinciding with diffuse hepatic steatosis: CT and MRI findings with histologic correlation.  Abdom Imaging . 2000;  25 179-181
• 44 Castillo M, Kwock L, Mukherji S K. Clinical application of proton MR spectroscopy.  AJNR . 1996;  17 1-15
• 45 Kurhanewicz J, Vigneron D B, Hricak H. Three-dimensional H-1 MR spectroscopic imaging of the in situ human prostate with high (0.24-0.7-cm³) spatial resolution.  Radiology . 1996;  198 795-805
• 46 Longo R, Ricci C, Masutti F. Fatty infiltration of the liver. Quantification by ¹H localized magnetic resonance spectroscopy and comparison with computed tomography.  Invest Radiol . 1993;  28 297-302
• 47 Longo R, Pollesello P, Ricci C. Proton MR spectroscopy in quantitative in vivo determination of fat content in human liver steatosis.  J Magn Reson Imaging . 1995;  5 281-285
• 48 Thomsen C, Becker U, Winkler K. Quantification of liver fat using magnetic resonance spectroscopy.  Magn Reson Imaging . 1994;  12 487-495
• 49 Rosen B R, Carter E A, Pykett I L. Proton chemical shift imaging: an evaluation of its clinical potential using an in vivo fatty liver model.  Radiology . 1985;  154 469-472
• 50 McKenzie A, Gill G, McIntosh R. Computed tomographic and ultrasound appearances of focal spared areas in fatty infiltration of the liver.  Australas Radiol . 1991;  35 166-168
• 51 Martin J, Sentis M, Puig J. Comparison of in-phase and opposed-phase GRE and conventional SE MR pulse sequences in T1-weighted imaging of liver lesions.  J Comput Assist Tomogr . 1996;  20 890-897
• 52 Rofsky N M, Weinreb J C, Ambrosino M M. Comparison between in-phase and opposed-phase T1-weighted breath-hold FLASH sequences for hepatic imaging.  J Comput Assist Tomogr . 1996;  20 230-235
• 53 Siegelman E S, Outwater E K. MR imaging techniques of the liver.  Radiol Clin North Am . 1998;  36 263-286
• 54 Mitchell D G, Palazzo J, Hann H W. Hepatocellular tumors with high signal on T1-weighted MR images: chemical shift MR imaging and histologic correlation.  J Comput Assist Tomogr . 1991;  15 762-769