Liver Lesion-Initial Characterization

Variant: 1 Indeterminate, greater than 1 cm liver lesion on initial imaging with US. Normal liver. No suspicion or evidence of extrahepatic malignancy or underlying liver disease.

Procedure	Appropriateness Category	Relative Radiation Level
US abdomen with IV contrast	Usually Appropriate	O
MRI abdomen without and with IV contrast	Usually Appropriate	O
CT abdomen with IV contrast multiphase	Usually Appropriate	☢☢☢☢
MRI abdomen without IV contrast	May Be Appropriate	O
Image-guided biopsy liver	Usually Not Appropriate	Varies
CT abdomen without IV contrast	Usually Not Appropriate	☢☢☢
DOTATATE PET/CT skull base to mid-thigh	Usually Not Appropriate	☢☢☢
Liver spleen scan	Usually Not Appropriate	☢☢☢
RBC scan abdomen and pelvis	Usually Not Appropriate	☢☢☢
CT abdomen without and with IV contrast	Usually Not Appropriate	☢☢☢☢
FDG-PET/CT skull base to mid-thigh	Usually Not Appropriate	☢☢☢☢
Octreotide scan with SPECT or SPECT/CT chest and abdomen	Usually Not Appropriate	☢☢☢☢

Variant: 2 Indeterminate, greater than 1 cm liver lesion on initial imaging with CT (noncontrast or single-phase) or noncontrast MRI. Normal liver. No suspicion or evidence of extrahepatic malignancy or underlying liver disease.

Procedure	Appropriateness Category	Relative Radiation Level
MRI abdomen without and with IV contrast	Usually Appropriate	O
CT abdomen with IV contrast multiphase	Usually Appropriate	☢☢☢☢
US abdomen	May Be Appropriate (Disagreement)	O
US abdomen with IV contrast	May Be Appropriate	O
Image-guided biopsy liver	Usually Not Appropriate	Varies
DOTATATE PET/CT skull base to mid-thigh	Usually Not Appropriate	☢☢☢
Liver spleen scan	Usually Not Appropriate	☢☢☢
RBC scan abdomen and pelvis	Usually Not Appropriate	☢☢☢
CT abdomen without and with IV contrast	Usually Not Appropriate	☢☢☢☢
FDG-PET/CT skull base to mid-thigh	Usually Not Appropriate	☢☢☢☢
Octreotide scan with SPECT or SPECT/CT chest and abdomen	Usually Not Appropriate	☢☢☢☢

Variant: 3 Indeterminate, greater than 1 cm liver lesion on initial imaging with US. Known history of an extrahepatic malignancy.

Procedure	Appropriateness Category	Relative Radiation Level
MRI abdomen without and with IV contrast	Usually Appropriate	O
CT abdomen with IV contrast multiphase	Usually Appropriate	☢☢☢☢
US abdomen with IV contrast	May Be Appropriate	O
Image-guided biopsy liver	May Be Appropriate	Varies
MRI abdomen without IV contrast	May Be Appropriate	O
DOTATATE PET/CT skull base to mid-thigh	May Be Appropriate	☢☢☢
CT abdomen without and with IV contrast	May Be Appropriate	☢☢☢☢
FDG-PET/CT skull base to mid-thigh	May Be Appropriate	☢☢☢☢
Octreotide scan with SPECT or SPECT/CT chest and abdomen	May Be Appropriate	☢☢☢☢
CT abdomen without IV contrast	Usually Not Appropriate	☢☢☢
Liver spleen scan	Usually Not Appropriate	☢☢☢
RBC scan abdomen and pelvis	Usually Not Appropriate	☢☢☢

Variant: 4 Indeterminate, greater than 1 cm liver lesion on initial imaging with CT (noncontrast or single-phase) or noncontrast MRI. Known history of an extrahepatic malignancy.

Procedure	Appropriateness Category	Relative Radiation Level
MRI abdomen without and with IV contrast	Usually Appropriate	O
CT abdomen with IV contrast multiphase	Usually Appropriate	☢☢☢☢
FDG-PET/CT skull base to mid-thigh	Usually Appropriate	☢☢☢☢
US abdomen	May Be Appropriate	O
US abdomen with IV contrast	May Be Appropriate	O
Image-guided biopsy liver	May Be Appropriate	Varies
DOTATATE PET/CT skull base to mid-thigh	May Be Appropriate	☢☢☢
CT abdomen without and with IV contrast	May Be Appropriate	☢☢☢☢
Octreotide scan with SPECT or SPECT/CT chest and abdomen	May Be Appropriate	☢☢☢☢
Liver spleen scan	Usually Not Appropriate	☢☢☢
RBC scan abdomen and pelvis	Usually Not Appropriate	☢☢☢

Variant: 5 Incidental liver lesion, greater than 1 cm on US, noncontrast or single-phase CT, or noncontrast MRI. Known chronic liver disease.

Procedure	Appropriateness Category	Relative Radiation Level
US abdomen with IV contrast	Usually Appropriate	O
MRI abdomen without and with IV contrast	Usually Appropriate	O
CT abdomen with IV contrast multiphase	Usually Appropriate	☢☢☢☢
Image-guided biopsy liver	May Be Appropriate	Varies
DOTATATE PET/CT skull base to mid-thigh	Usually Not Appropriate	☢☢☢
Liver spleen scan	Usually Not Appropriate	☢☢☢
RBC scan abdomen and pelvis	Usually Not Appropriate	☢☢☢
CT abdomen without and with IV contrast	Usually Not Appropriate	☢☢☢☢
FDG-PET/CT skull base to mid-thigh	Usually Not Appropriate	☢☢☢☢
Octreotide scan with SPECT or SPECT/CT chest and abdomen	Usually Not Appropriate	☢☢☢☢

Variant: 6 Indeterminate, less than 1 cm liver lesion on initial imaging with US. Known history of an extrahepatic malignancy.

Procedure	Appropriateness Category	Relative Radiation Level
MRI abdomen without and with IV contrast	Usually Appropriate	O
US abdomen with IV contrast	May Be Appropriate	O
MRI abdomen without IV contrast	May Be Appropriate	O
CT abdomen with IV contrast multiphase	May Be Appropriate	☢☢☢☢
Image-guided biopsy liver	Usually Not Appropriate	Varies
CT abdomen without IV contrast	Usually Not Appropriate	☢☢☢
DOTATATE PET/CT skull base to mid-thigh	Usually Not Appropriate	☢☢☢
Liver spleen scan	Usually Not Appropriate	☢☢☢
RBC scan abdomen and pelvis	Usually Not Appropriate	☢☢☢
CT abdomen without and with IV contrast	Usually Not Appropriate	☢☢☢☢
FDG-PET/CT skull base to mid-thigh	Usually Not Appropriate	☢☢☢☢
Octreotide scan with SPECT or SPECT/CT chest and abdomen	Usually Not Appropriate	☢☢☢☢

Variant: 7 Indeterminate, less than 1 cm liver lesion on initial imaging with CT (noncontrast or single-phase) or noncontrast MRI. Known history of an extrahepatic malignancy.

Procedure	Appropriateness Category	Relative Radiation Level
MRI abdomen without and with IV contrast	Usually Appropriate	O
CT abdomen with IV contrast multiphase	Usually Appropriate	☢☢☢☢
US abdomen with IV contrast	May Be Appropriate	O
Image-guided biopsy liver	May Be Appropriate	Varies
US abdomen	Usually Not Appropriate	O
DOTATATE PET/CT skull base to mid-thigh	Usually Not Appropriate	☢☢☢
Liver spleen scan	Usually Not Appropriate	☢☢☢
RBC scan abdomen and pelvis	Usually Not Appropriate	☢☢☢
CT abdomen without and with IV contrast	Usually Not Appropriate	☢☢☢☢
FDG-PET/CT skull base to mid-thigh	Usually Not Appropriate	☢☢☢☢
Octreotide scan with SPECT or SPECT/CT chest and abdomen	Usually Not Appropriate	☢☢☢☢

Variant: 8 Incidental liver lesion, less than 1 cm on US, noncontrast or single-phase CT, or noncontrast MRI. Known chronic liver disease.

Procedure	Appropriateness Category	Relative Radiation Level
MRI abdomen without and with IV contrast	Usually Appropriate	O
CT abdomen with IV contrast multiphase	Usually Appropriate	☢☢☢☢
US abdomen with IV contrast	May Be Appropriate	O
Image-guided biopsy liver	Usually Not Appropriate	Varies
DOTATATE PET/CT skull base to mid-thigh	Usually Not Appropriate	☢☢☢
Liver spleen scan	Usually Not Appropriate	☢☢☢
RBC scan abdomen and pelvis	Usually Not Appropriate	☢☢☢
CT abdomen without and with IV contrast	Usually Not Appropriate	☢☢☢☢
FDG-PET/CT skull base to mid-thigh	Usually Not Appropriate	☢☢☢☢
Octreotide scan with SPECT or SPECT/CT chest and abdomen	Usually Not Appropriate	☢☢☢☢

Panel Members

Summary of Literature Review

Introduction/Background

Special Imaging Considerations

Discussion of Procedures by Variant

Variant 1: Indeterminate, greater than 1 cm liver lesion on initial imaging with US. Normal liver. No suspicion or evidence of extrahepatic malignancy or underlying liver disease.

Variant 1: Indeterminate, greater than 1 cm liver lesion on initial imaging with US. Normal liver. No suspicion or evidence of extrahepatic malignancy or underlying liver disease.
A. CT Abdomen

Variant 2: Indeterminate, greater than 1 cm liver lesion on initial imaging with CT (noncontrast or single-phase) or noncontrast MRI. Normal liver. No suspicion or evidence of extrahepatic malignancy or underlying liver disease.

Variant 3: Indeterminate, greater than 1 cm liver lesion on initial imaging with US. Known history of an extrahepatic malignancy.

Variant 3: Indeterminate, greater than 1 cm liver lesion on initial imaging with US. Known history of an extrahepatic malignancy.
A. CT Abdomen

Variant 3: Indeterminate, greater than 1 cm liver lesion on initial imaging with US. Known history of an extrahepatic malignancy.
B. FDG-PET/CT Skull Base to Mid-Thigh

Variant 3: Indeterminate, greater than 1 cm liver lesion on initial imaging with US. Known history of an extrahepatic malignancy.
C. DOTATATE PET/CT Skull Base to Mid-Thigh

Variant 3: Indeterminate, greater than 1 cm liver lesion on initial imaging with US. Known history of an extrahepatic malignancy.
D. Octreotide Scan with SPECT or SPECT/CT Chest and Abdomen

Variant 3: Indeterminate, greater than 1 cm liver lesion on initial imaging with US. Known history of an extrahepatic malignancy.
E. MRI Abdomen

Variant 3: Indeterminate, greater than 1 cm liver lesion on initial imaging with US. Known history of an extrahepatic malignancy.
F. Image-Guided Biopsy Liver

Variant 3: Indeterminate, greater than 1 cm liver lesion on initial imaging with US. Known history of an extrahepatic malignancy.
G. RBC Scan Abdomen and Pelvis

Variant 3: Indeterminate, greater than 1 cm liver lesion on initial imaging with US. Known history of an extrahepatic malignancy.
H. Liver Spleen Scan

Variant 3: Indeterminate, greater than 1 cm liver lesion on initial imaging with US. Known history of an extrahepatic malignancy.
I. US Abdomen with Contrast

Variant 4: Indeterminate, greater than 1 cm liver lesion on initial imaging with CT (noncontrast or single-phase) or noncontrast MRI. Known history of an extrahepatic malignancy.

Variant 4: Indeterminate, greater than 1 cm liver lesion on initial imaging with CT (noncontrast or single-phase) or noncontrast MRI. Known history of an extrahepatic malignancy.
A. CT Abdomen

Variant 5: Incidental liver lesion, greater than 1 cm on US, noncontrast or single-phase CT, or noncontrast MRI. Known chronic liver disease.

Variant 5: Incidental liver lesion, greater than 1 cm on US, noncontrast or single-phase CT, or noncontrast MRI. Known chronic liver disease.
A. CT Abdomen

Variant 5: Incidental liver lesion, greater than 1 cm on US, noncontrast or single-phase CT, or noncontrast MRI. Known chronic liver disease.
B. FDG-PET/CT Skull Base to Mid-Thigh

Variant 5: Incidental liver lesion, greater than 1 cm on US, noncontrast or single-phase CT, or noncontrast MRI. Known chronic liver disease.
C. DOTATATE PET/CT Skull Base to Mid-Thigh

Variant 5: Incidental liver lesion, greater than 1 cm on US, noncontrast or single-phase CT, or noncontrast MRI. Known chronic liver disease.
D. Octreotide Scan with SPECT or SPECT/CT Chest and Abdomen

Variant 5: Incidental liver lesion, greater than 1 cm on US, noncontrast or single-phase CT, or noncontrast MRI. Known chronic liver disease.
E. MRI Abdomen

Variant 5: Incidental liver lesion, greater than 1 cm on US, noncontrast or single-phase CT, or noncontrast MRI. Known chronic liver disease.
F. Image-Guided Biopsy Liver

Variant 5: Incidental liver lesion, greater than 1 cm on US, noncontrast or single-phase CT, or noncontrast MRI. Known chronic liver disease.
G. RBC Scan Abdomen and Pelvis

Variant 5: Incidental liver lesion, greater than 1 cm on US, noncontrast or single-phase CT, or noncontrast MRI. Known chronic liver disease.
H. Liver Spleen Scan

Variant 5: Incidental liver lesion, greater than 1 cm on US, noncontrast or single-phase CT, or noncontrast MRI. Known chronic liver disease.
I. US Abdomen with Contrast

Variant 6: Indeterminate, less than 1 cm liver lesion on initial imaging with US. Known history of an extrahepatic malignancy.

Variant 6: Indeterminate, less than 1 cm liver lesion on initial imaging with US. Known history of an extrahepatic malignancy.
A. CT Abdomen

Variant 6: Indeterminate, less than 1 cm liver lesion on initial imaging with US. Known history of an extrahepatic malignancy.
B. FDG-PET/CT Skull Base to Mid-Thigh

Variant 6: Indeterminate, less than 1 cm liver lesion on initial imaging with US. Known history of an extrahepatic malignancy.
C. DOTATATE PET/CT Skull Base to Mid-Thigh

Variant 6: Indeterminate, less than 1 cm liver lesion on initial imaging with US. Known history of an extrahepatic malignancy.
D. Octreotide Scan with SPECT or SPECT/CT Chest and Abdomen

Variant 6: Indeterminate, less than 1 cm liver lesion on initial imaging with US. Known history of an extrahepatic malignancy.
E. MRI Abdomen

Variant 6: Indeterminate, less than 1 cm liver lesion on initial imaging with US. Known history of an extrahepatic malignancy.
F. Image-Guided Biopsy Liver

Variant 6: Indeterminate, less than 1 cm liver lesion on initial imaging with US. Known history of an extrahepatic malignancy.
G. RBC Scan Abdomen and Pelvis

Variant 6: Indeterminate, less than 1 cm liver lesion on initial imaging with US. Known history of an extrahepatic malignancy.
H. Liver Spleen Scan

Variant 6: Indeterminate, less than 1 cm liver lesion on initial imaging with US. Known history of an extrahepatic malignancy.
I. US Abdomen with Contrast

Variant 7: Indeterminate, less than 1 cm liver lesion on initial imaging with CT (noncontrast or single-phase) or noncontrast MRI. Known history of an extrahepatic malignancy.

Variant 7: Indeterminate, less than 1 cm liver lesion on initial imaging with CT (noncontrast or single-phase) or noncontrast MRI. Known history of an extrahepatic malignancy.
A. CT Abdomen

Variant 7: Indeterminate, less than 1 cm liver lesion on initial imaging with CT (noncontrast or single-phase) or noncontrast MRI. Known history of an extrahepatic malignancy.
B. FDG-PET/CT Skull Base to Mid-Thigh

Variant 7: Indeterminate, less than 1 cm liver lesion on initial imaging with CT (noncontrast or single-phase) or noncontrast MRI. Known history of an extrahepatic malignancy.
E. MRI Abdomen

Variant 7: Indeterminate, less than 1 cm liver lesion on initial imaging with CT (noncontrast or single-phase) or noncontrast MRI. Known history of an extrahepatic malignancy.
I. US Abdomen

Variant 8: Incidental liver lesion, less than 1 cm on US, noncontrast or single-phase CT, or noncontrast MRI. Known chronic liver disease.

Variant 8: Incidental liver lesion, less than 1 cm on US, noncontrast or single-phase CT, or noncontrast MRI. Known chronic liver disease.
A. CT Abdomen

Variant 8: Incidental liver lesion, less than 1 cm on US, noncontrast or single-phase CT, or noncontrast MRI. Known chronic liver disease.
B. FDG-PET/CT Skull Base to Mid-Thigh

Variant 8: Incidental liver lesion, less than 1 cm on US, noncontrast or single-phase CT, or noncontrast MRI. Known chronic liver disease.
C. DOTATATE PET/CT Skull Base to Mid-Thigh

Variant 8: Incidental liver lesion, less than 1 cm on US, noncontrast or single-phase CT, or noncontrast MRI. Known chronic liver disease.
D. Octreotide Scan with SPECT or SPECT/CT Chest and Abdomen

Variant 8: Incidental liver lesion, less than 1 cm on US, noncontrast or single-phase CT, or noncontrast MRI. Known chronic liver disease.
E. MRI Abdomen

Variant 8: Incidental liver lesion, less than 1 cm on US, noncontrast or single-phase CT, or noncontrast MRI. Known chronic liver disease.
F. Image-Guided Biopsy Liver

Variant 8: Incidental liver lesion, less than 1 cm on US, noncontrast or single-phase CT, or noncontrast MRI. Known chronic liver disease.
G. RBC Scan Abdomen and Pelvis

Variant 8: Incidental liver lesion, less than 1 cm on US, noncontrast or single-phase CT, or noncontrast MRI. Known chronic liver disease.
H. Liver Spleen Scan

Variant 8: Incidental liver lesion, less than 1 cm on US, noncontrast or single-phase CT, or noncontrast MRI. Known chronic liver disease.
I. US Abdomen with Contrast

Summary of Recommendations

Supporting Documents

The evidence table, literature search, and appendix for this topic are available at https://acsearch.acr.org/list. The appendix includes the strength of evidence assessment and the final rating round tabulations for each recommendation.

For additional information on the Appropriateness Criteria methodology and other supporting documents, please go to the ACR website at https://www.acr.org/Clinical-Resources/Clinical-Tools-and-Reference/Appropriateness-Criteria.

Appropriateness Category Names and Definitions

Appropriateness Category Name	Appropriateness Rating	Appropriateness Category Definition
Usually Appropriate	7, 8, or 9	The imaging procedure or treatment is indicated in the specified clinical scenarios at a favorable risk-benefit ratio for patients.
May Be Appropriate	4, 5, or 6	The imaging procedure or treatment may be indicated in the specified clinical scenarios as an alternative to imaging procedures or treatments with a more favorable risk-benefit ratio, or the risk-benefit ratio for patients is equivocal.
May Be Appropriate (Disagreement)	5	The individual ratings are too dispersed from the panel median. The different label provides transparency regarding the panel’s recommendation. “May be appropriate” is the rating category and a rating of 5 is assigned.
Usually Not Appropriate	1, 2, or 3	The imaging procedure or treatment is unlikely to be indicated in the specified clinical scenarios, or the risk-benefit ratio for patients is likely to be unfavorable.

Relative Radiation Level Information

References

1.	Kaltenbach TE, Engler P, Kratzer W, et al. Prevalence of benign focal liver lesions: ultrasound investigation of 45,319 hospital patients. Abdom Radiol. 41(1):25-32, 2016 Jan.
2.	Taimr P, Jongerius VL, Pek CJ, et al. Liver Contrast-Enhanced Ultrasound Improves Detection of Liver Metastases in Patients with Pancreatic or Periampullary Cancer. Ultrasound in Medicine & Biology. 41(12):3063-9, 2015 Dec.
3.	Horowitz JM, Kamel IR, Arif-Tiwari H, et al. ACR Appropriateness Criteria R Chronic Liver Disease. J. Am. Coll. Radiol.. 14(11S):S391-S405, 2017 Nov.
4.	Gore RM, Pickhardt PJ, Mortele KJ, et al. Management of Incidental Liver Lesions on CT: A White Paper of the ACR Incidental Findings Committee. J. Am. Coll. Radiol.. 14(11):1429-1437, 2017 Nov.
5.	Hope TA, Petkovska I, Saranathan M, Hargreaves BA, Vasanawala SS. Combined parenchymal and vascular imaging: High spatiotemporal resolution arterial evaluation of hepatocellular carcinoma. J Magn Reson Imaging. 43(4):859-65, 2016 Apr.
6.	American College of Radiology: Liver Imaging Reporting and Data System. http://nrdr.acr.org/lirads/ 2014.
7.	D'Onofrio M, Crosara S, De Robertis R, Canestrini S, Mucelli RP. Contrast-Enhanced Ultrasound of Focal Liver Lesions. [Review]. AJR. American Journal of Roentgenology. 205(1):W56-66, 2015 Jul.AJR Am J Roentgenol. 205(1):W56-66, 2015 Jul.
8.	Mojtahedi A, Thamake S, Tworowska I, Ranganathan D, Delpassand ES. The value of (68)Ga-DOTATATE PET/CT in diagnosis and management of neuroendocrine tumors compared to current FDA approved imaging modalities: a review of literature. [Review]. Am J Nucl Med Mol Imaging. 4(5):426-34, 2014.
9.	Moriyasu F, Itoh K. Efficacy of perflubutane microbubble-enhanced ultrasound in the characterization and detection of focal liver lesions: phase 3 multicenter clinical trial. AJR Am J Roentgenol. 2009; 193(1):86-95.
10.	Chung YE, Kim MJ, Kim YE, Park MS, Choi JY, Kim KW. Characterization of incidental liver lesions: comparison of multidetector CT versus Gd-EOB-DTPA-enhanced MR imaging. PLoS ONE. 8(6):e66141, 2013.
11.	Margolis NE, Shaver CM, Rosenkrantz AB. Indeterminate liver and renal lesions: comparison of computed tomography and magnetic resonance imaging in providing a definitive diagnosis and impact on recommendations for additional imaging. J Comput Assist Tomogr. 37(6):882-6, 2013 Nov-Dec.
12.	Zech CJ, Grazioli L, Breuer J, Reiser MF, Schoenberg SO. Diagnostic performance and description of morphological features of focal nodular hyperplasia in Gd-EOB-DTPA-enhanced liver magnetic resonance imaging: results of a multicenter trial. Invest Radiol 2008; 43(7):504-511.
13.	Seitz K, Strobel D, Bernatik T, et al. Contrast-Enhanced Ultrasound (CEUS) for the characterization of focal liver lesions - prospective comparison in clinical practice: CEUS vs. CT (DEGUM multicenter trial). Parts of this manuscript were presented at the Ultrasound Dreilandertreffen 2008, Davos. Ultraschall Med. 2009; 30(4):383-389.
14.	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(30):3748-3756.
15.	Holzapfel K, Eiber MJ, Fingerle AA, Bruegel M, Rummeny EJ, Gaa J. Detection, classification, and characterization of focal liver lesions: Value of diffusion-weighted MR imaging, gadoxetic acid-enhanced MR imaging and the combination of both methods. Abdom Imaging. 37(1):74-82, 2012 Feb.
16.	Purysko AS, Remer EM, Coppa CP, Obuchowski NA, Schneider E, Veniero JC. Characteristics and distinguishing features of hepatocellular adenoma and focal nodular hyperplasia on gadoxetate disodium-enhanced MRI. AJR Am J Roentgenol. 2012; 198(1):115-123.
17.	Agarwal S, Fuentes-Orrego JM, Arnason T, et al. Inflammatory hepatocellular adenomas can mimic focal nodular hyperplasia on gadoxetic acid-enhanced MRI. AJR Am J Roentgenol. 203(4):W408-14, 2014 Oct.
18.	Fang L, Zhu Z, Huang B, et al. A comparative study of contrast enhanced ultrasound and contrast enhanced magnetic resonance imaging for the detection and characterization of hepatic hemangiomas. Biosci. trends. 9(2):104-10, 2015 Apr.
19.	Miller FH, Hammond N, Siddiqi AJ, et al. Utility of diffusion-weighted MRI in distinguishing benign and malignant hepatic lesions. J Magn Reson Imaging. 2010; 32(1):138-147.
20.	Bai YF, Liu JM, Zhang XM, Jiang CZ, Xu X, Zheng SS. Percutaneous liver biopsy: retrospective study of primary and secondary hepatic lymphoma in twenty-one patients. Hepatobiliary Pancreat Dis Int. 16(1):58-64, 2017 Feb.
21.	Eso Y, Takai A, Takeda H, et al. Sonazoid-enhanced ultrasonography guidance improves the quality of pathological diagnosis in the biopsy of focal hepatic lesions. European Journal of Gastroenterology & Hepatology. 28(12):1462-1467, 2016 Dec.Eur J Gastroenterol Hepatol. 28(12):1462-1467, 2016 Dec.
22.	Sparchez Z, Radu P, Kacso G, Sparchez M, Zaharia T, Al Hajjar N. Prospective comparison between real time contrast enhanced and conventional ultrasound guidance in percutaneous biopsies of liver tumors. Med. ultrasonography. 17(4):456-63, 2015 Dec.
23.	Tacher V, Le Deley MC, Hollebecque A, et al. Factors associated with success of image-guided tumour biopsies: Results from a prospective molecular triage study (MOSCATO-01). Eur J Cancer. 59:79-89, 2016 May.
24.	Partovi S, Lu Z, Kessner R, et al. Contrast enhanced ultrasound guided biopsies of liver lesions not visualized on standard B-mode ultrasound-preliminary experience. J. gastrointest. oncol.. 8(6):1056-1064, 2017 Dec.
25.	Park HJ, Lee MW, Lee MH, et al. Fusion imaging-guided percutaneous biopsy of focal hepatic lesions with poor conspicuity on conventional sonography. J Ultrasound Med. 32(9):1557-64, 2013 Sep.
26.	Sainani NI, Schlett CL, Hahn PF, Gervais DA, Mueller PR, Arellano RS. Computed tomography-guided percutaneous biopsy of isoattenuating focal liver lesions. Abdominal Imaging. 39(3):633-44, 2014 Jun.
27.	Sandrasegaran K, Thayalan N, Thavanesan R, et al. Risk factors for bleeding after liver biopsy. Abdom Radiol. 41(4):643-9, 2016 04.
28.	Kang TW, Lee MW, Choi D, et al. Safety of Percutaneous Biopsy for Hepatic Angiosarcoma: Results of a Multicenter Korean Survey. J Vasc Interv Radiol. 27(6):846-51, 2016 Jun.
29.	Wang WP, Wu Y, Luo Y, et al. Clinical value of contrast-enhanced ultrasonography in the characterization of focal liver lesions: a prospective multicenter trial. Hepatobiliary Pancreat Dis Int. 2009; 8(4):370-376.
30.	Sporea I, Martie A, Bota S, Sirli R, Popescu A, Danila M. Characterization of focal liver lesions using contrast enhanced ultrasound as a first line method: a large monocentric experience. J. Gastrointestinal Liver Diseases. 23(1):57-63, 2014 Mar.
31.	Sporea I, Badea R, Martie A, et al. Contrast enhanced ultrasound for the characterization of focal liver lesions. Med Ultrason. 2011; 13(1):38-44.
32.	Sporea I, Sirli R, Martie A, Popescu A, Danila M. How useful is contrast enhanced ultrasonography for the characterization of focal liver lesions? J Gastrointestin Liver Dis. 2010; 19(4):393-398.
33.	Corvino A, Catalano O, Setola SV, Sandomenico F, Corvino F, Petrillo A. Contrast-enhanced ultrasound in the characterization of complex cystic focal liver lesions. Ultrasound Med Biol. 41(5):1301-10, 2015 May.
34.	Sirli R, Sporea I, Popescu A, et al. Contrast enhanced ultrasound for the diagnosis of liver hemangiomas in clinical practice. Med Ultrason. 2011; 13(2):95-101.
35.	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. 31(5):492-9, 2010 Oct.
36.	Sirli R, Sporea I, Sandulescu DL, et al. Contrast enhanced ultrasound for the diagnosis of liver hemangiomas - results of a Romanian multicentre study. Med. ultrasonography. 17(4):444-50, 2015 Dec.
37.	Celli N, Gaiani S, Piscaglia F, et al. Characterization of liver lesions by real-time contrast-enhanced ultrasonography. Eur J Gastroenterol Hepatol. 2007; 19(1):3-14.
38.	Phongkitkarun S, Srianujata T, Jatchavala J. Supplement value of magnetic resonance imaging in small hepatic lesion (< or = 20 mm) detected on routine computed tomography. J Med Assoc Thai. 92(5):677-86, 2009 May.
39.	Quaia E, De Paoli L, Angileri R, Cabibbo B, Cova MA. Indeterminate solid hepatic lesions identified on non-diagnostic contrast-enhanced computed tomography: assessment of the additional diagnostic value of contrast-enhanced ultrasound in the non-cirrhotic liver. Eur J Radiol. 83(3):456-62, 2014 Mar.
40.	Jolepalem P, Rydberg JN, Wong CO. Improvement of hepatic lesion characterization by 18F-FDG PET/CT with the use of the lesion to background liver activity ratio. Clin Nucl Med. 38(11):869-73, 2013 Nov.
41.	van Kessel CS, van Leeuwen MS, van den Bosch MA, et al. Accuracy of multislice liver CT and MRI for preoperative assessment of colorectal liver metastases after neoadjuvant chemotherapy. Dig Surg. 2011; 28(1):36-43.
42.	D'Souza M M, Sharma R, Mondal A, et al. Prospective evaluation of CECT and 18F-FDG-PET/CT in detection of hepatic metastases. Nucl Med Commun. 2009; 30(2):117-125.
43.	Sadigh G, Nandwana SB, Moreno C, et al. Assessment of Added Value of Noncontrast to Contrast-Enhanced Abdominal Computed Tomography Scan for Characterization of Hypervascular Liver Metastases. Curr Probl Diagn Radiol. 45(6):373-379, 2016 Nov - Dec.
44.	Sadigh G, Applegate KE, Baumgarten DA. Comparative accuracy of intravenous contrast-enhanced CT versus noncontrast CT plus intravenous contrast-enhanced CT in the detection and characterization of patients with hypervascular liver metastases: a critically appraised topic. [Review]. Academic Radiology. 21(1):113-25, 2014 Jan.
45.	Sundin A, Vullierme MP, Kaltsas G, Plockinger U. ENETS Consensus Guidelines for the Standards of Care in Neuroendocrine Tumors: radiological examinations. Neuroendocrinology. 2009;90(2):167-183.
46.	Kwekkeboom DJ, Krenning EP, Scheidhauer K, et al. ENETS Consensus Guidelines for the Standards of Care in Neuroendocrine Tumors: somatostatin receptor imaging with (111)In-pentetreotide. [46 refs]. Neuroendocrinology. 90(2):184-9, 2009.
47.	Haimerl M, Wachtler M, Platzek I, et al. Added value of Gd-EOB-DTPA-enhanced Hepatobiliary phase MR imaging in evaluation of focal solid hepatic lesions. BMC med. imaging. 13:41, 2013 Dec 01.
48.	Huf S, Platz Batista da Silva N, Wiesinger I, et al. Analysis of Liver Tumors Using Preoperative and Intraoperative Contrast-Enhanced Ultrasound (CEUS/IOCEUS) by Radiologists in Comparison to Magnetic Resonance Imaging and Histopathology. ROFO Fortschr Geb Rontgenstr Nuklearmed. 189(5):431-440, 2017 May.
49.	Chung WS, Kim MJ, Chung YE, et al. Comparison of gadoxetic acid-enhanced dynamic imaging and diffusion-weighted imaging for the preoperative evaluation of colorectal liver metastases. J Magn Reson Imaging. 2011; 34(2):345-353.
50.	Testa ML, Chojniak R, Sene LS, et al. Is DWI/ADC a useful tool in the characterization of focal hepatic lesions suspected of malignancy?. PLoS ONE. 9(7):e101944, 2014.
51.	Elsayes KM, Ellis JH, Elkhouly T, et al. Diagnostic yield of percutaneous image-guided tissue biopsy of focal hepatic lesions in cancer patients: ten percent are not metastases from the primary malignancy. Cancer. 117(17):4041-8, 2011 Sep 01.
52.	Szpakowski JL, Drasin TE, Lyon LL. Rate of seeding with biopsies and ablations of hepatocellular carcinoma: A retrospective cohort study. Hepatol. commun.. 1(9):841-851, 2017 11.
53.	Ahn DW, Shim JH, Yoon JH, et al. Treatment and clinical outcome of needle-track seeding from hepatocellular carcinoma. Korean J Hepatol. 17(2):106-12, 2011 Jun.
54.	Chen QW, Cheng CS, Chen H, et al. Effectiveness and complications of ultrasound guided fine needle aspiration for primary liver cancer in a Chinese population with serum alpha-fetoprotein levels <=200 ng/ml--a study based on 4,312 patients. PLoS ONE. 9(8):e101536, 2014.
55.	Chernyak V, Santillan CS, Papadatos D, Sirlin CB. LI-RADS R algorithm: CT and MRI. [Review]. Abdominal Radiology. 43(1):111-126, 2018 01.
56.	Mita K, Kim SR, Kudo M, et al. Diagnostic sensitivity of imaging modalities for hepatocellular carcinoma smaller than 2 cm. World J Gastroenterol. 16(33):4187-92, 2010 Sep 07.
57.	Ichikawa T, Saito K, Yoshioka N, et al. Detection and characterization of focal liver lesions: a Japanese phase III, multicenter comparison between gadoxetic acid disodium-enhanced magnetic resonance imaging and contrast-enhanced computed tomography predominantly in patients with hepatocellular carcinoma and chronic liver disease. Invest Radiol. 2010; 45(3):133-141.
58.	Iannaccone R, Laghi A, Catalano C, et al. Hepatocellular carcinoma: role of unenhanced and delayed phase multi-detector row helical CT in patients with cirrhosis. Radiology. 234(2):460-7, 2005 Feb.
59.	Jang HJ, Kim TK, Khalili K, et al. Characterization of 1-to 2-cm liver nodules detected on hcc surveillance ultrasound according to the criteria of the American Association for the Study of Liver Disease: is quadriphasic CT necessary?. AJR Am J Roentgenol. 201(2):314-21, 2013 Aug.
60.	Kornberg A, Freesmeyer M, Barthel E, et al. 18F-FDG-uptake of hepatocellular carcinoma on PET predicts microvascular tumor invasion in liver transplant patients.[Erratum appears in Am J Transplant. 2009 May;9(5):1255. Note: Settmacher, U [added]]. Am J Transplant. 9(3):592-600, 2009 Mar.
61.	Becker-Weidman DJ, Kalb B, Sharma P, et al. Hepatocellular carcinoma lesion characterization: single-institution clinical performance review of multiphase gadolinium-enhanced MR imaging--comparison to prior same-center results after MR systems improvements. Radiology. 2011; 261(3):824-833.
62.	Di Martino M, Anzidei M, Zaccagna F, et al. Qualitative analysis of small (<=2 cm) regenerative nodules, dysplastic nodules and well-differentiated HCCs with gadoxetic acid MRI. BMC med. imaging. 16(1):62, 2016 Nov 11.
63.	Kwon S, Kim YK, Park HJ, Jeong WK, Lee WJ, Choi D. Is gadoxetic acid-enhanced MRI limited in tumor characterization for patients with chronic liver disease?. Magn Reson Imaging. 32(10):1214-22, 2014 Dec.
64.	Chou CT, Chen YL, Wu HK, Chen RC. Characterization of hyperintense nodules on precontrast T1-weighted MRI: utility of gadoxetic acid-enhanced hepatocyte-phase imaging. J Magn Reson Imaging. 2011; 33(3):625-632.
65.	Chou CT, Chen YL, Su WW, Wu HK, Chen RC. Characterization of cirrhotic nodules with gadoxetic acid-enhanced magnetic resonance imaging: the efficacy of hepatocyte-phase imaging. J Magn Reson Imaging. 2010; 32(4):895-902.
66.	Orlacchio A, Chegai F, Fabiano S, et al. Role of MRI with hepatospecific contrast agent in the identification and characterization of focal liver lesions: pathological correlation in explanted livers. Radiologia Medica. 121(7):588-96, 2016 Jul.
67.	Bashir MR, Gupta RT, Davenport MS, et al. Hepatocellular carcinoma in a North American population: does hepatobiliary MR imaging with Gd-EOB-DTPA improve sensitivity and confidence for diagnosis?. J Magn Reson Imaging. 37(2):398-406, 2013 Feb.
68.	Khouri Chalouhi C, Vernuccio F, Rini F, et al. Hepatobiliary phase in cirrhotic patients with different Model for End-stage Liver Disease score: comparison of the performance of gadoxetic acid to gadobenate dimeglumine. Eur Radiol. 29(6):3090-3099, 2019 Jun.
69.	Torrisi C, Picone D, Cabibbo G, Matranga D, Midiri M, Brancatelli G. Gadoxetic acid-enhanced MRI of transient hepatic enhancement differences: Another cause of hypointense observation on hepatobiliary phase. Eur J Radiol. 107:39-45, 2018 Oct.
70.	Yang D, Zhang J, Han D, Jin E, Yang Z. The role of apparent diffusion coefficient values in characterization of solid focal liver lesions: a prospective and comparative clinical study. Sci China Life Sci. 60(1):16-22, 2017 Jan.
71.	Shin SK, Kim YS, Choi SJ, et al. Characterization of small (<=3 cm) hepatic lesions with atypical enhancement feature and hypointensity in hepatobiliary phase of gadoxetic acid-enhanced MRI in cirrhosis: A STARD-compliant article. Medicine (Baltimore). 96(29):e7278, 2017 Jul.
72.	Takahashi M, Maruyama H, Shimada T, et al. Characterization of hepatic lesions (<= 30 mm) with liver-specific contrast agents: a comparison between ultrasound and magnetic resonance imaging. European Journal of Radiology. 82(1):75-84, 2013 Jan.
73.	Xu PJ, Yan FH, Wang JH, Shan Y, Ji Y, Chen CZ. Contribution of diffusion-weighted magnetic resonance imaging in the characterization of hepatocellular carcinomas and dysplastic nodules in cirrhotic liver. J Comput Assist Tomogr. 34(4):506-12, 2010 Jul.
74.	Santillan C, Chernyak V, Sirlin C. LI-RADS categories: concepts, definitions, and criteria. [Review]. Abdominal Radiology. 43(1):101-110, 2018 01.
75.	Silva MA, Hegab B, Hyde C, Guo B, Buckels JA, Mirza DF. Needle track seeding following biopsy of liver lesions in the diagnosis of hepatocellular cancer: a systematic review and meta-analysis. [Review] [50 refs]. Gut. 57(11):1592-6, 2008 Nov.
76.	Wu W, Chen M, Yan K, et al. Evaluation of contrast-enhanced ultrasound for diagnosis of dysplastic nodules with a focus of hepatocellular carcinoma in liver cirrhosis patients. Chin. J. Cancer Res.. 27(1):83-9, 2015 Feb.
77.	Jang HJ, Kim TK, Wilson SR. Small nodules (1-2 cm) in liver cirrhosis: characterization with contrast-enhanced ultrasound. Eur J Radiol. 72(3):418-24, 2009 Dec.
78.	Wildner D, Bernatik T, Greis C, Seitz K, Neurath MF, Strobel D. CEUS in hepatocellular carcinoma and intrahepatic cholangiocellular carcinoma in 320 patients - early or late washout matters: a subanalysis of the DEGUM multicenter trial. Ultraschall Med. 36(2):132-9, 2015 Apr.
79.	Wildner D, Pfeifer L, Goertz RS, et al. Dynamic contrast-enhanced ultrasound (DCE-US) for the characterization of hepatocellular carcinoma and cholangiocellular carcinoma. Ultraschall Med. 35(6):522-7, 2014 Dec.
80.	Kamaya A, Maturen KE, Tye GA, Liu YI, Parti NN, Desser TS. Hypervascular liver lesions. [Review] [140 refs]. Semin Ultrasound CT MR. 30(5):387-407, 2009 Oct.
81.	Jang HJ, Lim HK, Lee WJ, Lee SJ, Yun JY, Choi D. Small hypoattenuating lesions in the liver on single-phase helical CT in preoperative patients with gastric and colorectal cancer: prevalence, significance, and differentiating features. J Comput Assist Tomogr. 26(5):718-24, 2002 Sep-Oct.
82.	Schwartz LH, Gandras EJ, Colangelo SM, Ercolani MC, Panicek DM. Prevalence and importance of small hepatic lesions found at CT in patients with cancer. Radiology. 1999; 210(1):71-74.
83.	Elnahal SM, Shinagare AB, Szymonifka J, Hong TS, Enzinger PC, Mamon HJ. Prevalence and significance of subcentimeter hepatic lesions in patients with localized pancreatic adenocarcinoma. Pract Radiat Oncol. 2(4):e89-e94, 2012 Oct-Dec.
84.	Holzapfel K, Bruegel M, Eiber M, et al. Characterization of small (</=10 mm) focal liver lesions: value of respiratory-triggered echo-planar diffusion-weighted MR imaging. Eur J Radiol. 2010;76(1):89-95.
85.	Khalil HI, Patterson SA, Panicek DM. Hepatic lesions deemed too small to characterize at CT: prevalence and importance in women with breast cancer. Radiology. 235(3):872-8, 2005 Jun.
86.	Holalkere NS, Sahani DV, Blake MA, Halpern EF, Hahn PF, Mueller PR. Characterization of small liver lesions: Added role of MR after MDCT. J Comput Assist Tomogr. 2006; 30(4):591-596.
87.	Niekel MC, Bipat S, Stoker J. Diagnostic imaging of colorectal liver metastases with CT, MR imaging, FDG PET, and/or FDG PET/CT: a meta-analysis of prospective studies including patients who have not previously undergone treatment. Radiology. 2010;257(3):674-684.
88.	Laghi F, Catalano O, Maresca M, Sandomenico F, Siani A. Indeterminate, subcentimetric focal liver lesions in cancer patients: additional role of contrast-enhanced ultrasound. Ultraschall Med. 2010; 31(3):283-288.
89.	Chernyak V, Fowler KJ, Kamaya A, et al. Liver Imaging Reporting and Data System (LI-RADS) Version 2018: Imaging of Hepatocellular Carcinoma in At-Risk Patients. [Review]. Radiology. 289(3):816-830, 2018 12.
90.	Golfieri R, Marini E, Bazzocchi A, et al. Small (<or=3 cm) hepatocellular carcinoma in cirrhosis: the role of double contrast agents in MR imaging vs. multidetector-row CT. Radiol Med (Torino). 114(8):1239-66, 2009 Dec.
91.	Bottcher J, Hansch A, Pfeil A, et al. Detection and classification of different liver lesions: comparison of Gd-EOB-DTPA-enhanced MRI versus multiphasic spiral CT in a clinical single centre investigation. Eur J Radiol. 82(11):1860-9, 2013 Nov.
92.	Forner A, Vilana R, Ayuso C, et al. Diagnosis of hepatic nodules 20 mm or smaller in cirrhosis: Prospective validation of the noninvasive diagnostic criteria for hepatocellular carcinoma. Hepatology. 47(1):97-104, 2008 Jan.
93.	Kojiro M.. Pathological diagnosis at early stage: reaching international consensus. Oncology. 78 Suppl 1:31-5, 2010 Jul.
94.	Zheng SG, Xu HX, Liu LN, et al. Parametric imaging with contrast-enhanced ultrasound: usefulness for characterization of dynamic effects of microvascularization for hepatocellular carcinoma and focal nodular hyperplasia.[Erratum appears in Clin Hemorheol Microcirc. 2014;58(4):559]. Clin Hemorheol Microcirc. 55(3):375-89, 2013.
95.	American College of Radiology. ACR Appropriateness Criteria® Radiation Dose Assessment Introduction. Available at: https://edge.sitecorecloud.io/americancoldf5f-acrorgf92a-productioncb02-3650/media/ACR/Files/Clinical/Appropriateness-Criteria/ACR-Appropriateness-Criteria-Radiation-Dose-Assessment-Introduction.pdf.

Disclaimer

The ACR Committee on Appropriateness Criteria and its expert panels have developed criteria for determining appropriate imaging examinations for diagnosis and treatment of specified medical condition(s). These criteria are intended to guide radiologists, radiation oncologists and referring physicians in making decisions regarding radiologic imaging and treatment. Generally, the complexity and severity of a patient’s clinical condition should dictate the selection of appropriate imaging procedures or treatments. Only those examinations generally used for evaluation of the patient’s condition are ranked. Other imaging studies necessary to evaluate other co-existent diseases or other medical consequences of this condition are not considered in this document. The availability of equipment or personnel may influence the selection of appropriate imaging procedures or treatments. Imaging techniques classified as investigational by the FDA have not been considered in developing these criteria; however, study of new equipment and applications should be encouraged. The ultimate decision regarding the appropriateness of any specific radiologic examination or treatment must be made by the referring physician and radiologist in light of all the circumstances presented in an individual examination