2025+ACR适宜性标准：原发性肝癌的分期及随访

ACR Appropriateness Criteria® Staging and Follow-Up of Primary Liver Cancer

Expert Panel on Gastrointestinal Imaging: Elainea N. Smith, MDa', Mustafa R. Bashir, MDb',Alice Fung, MDc', Brooks D. Cash, MDd', Matthew Dixon, MDe', Elizabeth M. Hecht, MDf,Brendan M. McGuire, MDg', Anjana A. Pillai, MDh', Gregory K. Russo, MDi',Rachna T. Shroff, MD, MSj', Kiran H. Thakrar, MDk, Abhinav Vij, MD, MPH',Shaun A. Wahab, MDm', Terence Z. Wong, MD, PhD", Atif Zaheer, MD°,Kathryn J. Fowler, MDp

Abstract

Liver cancer is the sixth most common cancer worldwide, with 905,677 new cases in 2020, and the third leading cause of cancer-related deaths globally. Hepatocellular carcinoma(HCC) is the most common form of primary liver cancer and accounts for approximately 75% to 85% of cases. Ultimately, the management of HCC encompasses multiple disciplines including hepatologists,diagnostic radiologists, pathologists, transplant surgeons, surgical oncologists, radiation oncologists, and more. The development of a multidisciplinary clinic with dedicated tumor board review has been shown to increase survival in these patients with HCC. This

${}^{a}$ University of Alabama at Birmingham Medical Center, Birmingham,

${}^{b}$ Duke University Medical Center, Durham, North Carolina.

${}^{b}$ Panel Chair, Oregon Health & Science University, Portland, Oregon.${}^{4}$ University of Texas Health Science Center at Houston and McGovern Medical School, Houston, Texas; American Gastroenterological Association."Rush University Medical Center, Chicago, Illinois; Society of Surgical Oncology.

*Weill Cornell Medicine, New York, New York; ACR LI-RADS Committee.

${}^{8}$ University of Alabama at Birmingham, Birmingham, Alabama, Primary care physician.

${ }^{10}$ The University of Chicago Medical Center, Chicago, Illinois; American Association for the Study of Liver Diseases.

'Danbury Radiological Associates/Nuvance Health, Danbury, Connecticut.

University of Arizona Cancer Center, Tucson, Arizona; American Society of Clinical Oncology.

${}^{k}$ Endeavor Health, Evanston, Illinois.

`New York University Langone Medical Center, New York, New York.$mVanderbilt University Medical Center, Nashville, Tennessee.`

Ⓓuke University Medical Center, Durham, North Carolina; ACR Commission on Nuclear Medicine and Molecular Imaging.

°Johns Hopkins Hospital, Baltimore, Maryland

${}^{8}$ Specialy Chair, University of California San Diego, San Diego, California.Corresponding author: Elainea N. Smith, MD, 1230 Glen View Rd,Rirmingham,AL 35222; e-mail: elaineasmith@uabmc.edu.

The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness

Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document.Reprint requests to: publications@acr.org.

Mustafa R. Bashi, MD. reports relationships with Rectify Pharmaceuticals Inc,Miromatrix Medical, Inc, and ICON Clinical Research LLC that include consulting or advisory; relationships with Madrigal Pharmaceuticals Inc, Cor-cept Therapeutics Inc, NGM Biopharmaceuticals Inc, Siemens Healthineers AG, and Bayer HealthCare AG that include funding grants. Kathryn J. Fowler,MD, reports financial support was provided by Bayer Corporation; a relation-ship with Bayer AG that includes consulting or advisory, speaking and lecture fees, and travel reimbursement; and is a RSNA editorial board member. Rachna T. Shoff, MD, MS, reports relationships with Astra-Zeneca Pharmaceuticals LP, Genentech, Inc. Elevar Therapeutics, ICON Clinical Research LLC, Exelxis, Inc, Merck Research Laboratories, Boehringer Ingelheim GmbH, and Zymeworks Biopharmaceuticals, Inc that include consulting or advisory. The other authors state that they have no conflict of interest related to the material discussed in this article. Kathryn J. Fowler, MD,and Brendan M. McGuire, MD, are partners, and all other authors are non-partner/nonpartnership track/employees).

The ACR Appropriateness Criteria documents are updated regularly.Please go to the ACR website at http://www.acr.org/Clinical-Resources/Clinical-Tools-and-Reference/Appropriateness-Criteria to confirm that you are accessing the most current content.

Discipline: The ACR Committee on Appropriateness Criteria and its expert panels have developed criteria for determining appropriate 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.

document aims to guide the imaging of HCC, including screening, staging, active surveillance during liver-directed therapy,and in the setting of previously treated HCC.

The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RANDU/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Key Words: Appropriateness Criteria, Appropriate Use Criteria, AUC, cirrhosis screening, hepatocellular carcinoma(HCC), liver-directed therapy, primary liver cancer

J Am Coll Radiol 2025;22:S699-S712.© 2025 American College of Radiology. Published by Elsevier Inc. All rights are reserved, including those for text and data mining, Al training, and similar technologies.

ACR Appropriateness Criteria® Staging and Follow-up of Primary Liver Cancer. Variants 1 to 5 and Tables 1 and 2.

Variant 1. Adult. Primary liver cancer. Screening.

|Procedure|Appropriateness Category|Relative Radiation Level| |---|---|---| |US abdomen|Usually Appropriate|0| |MRI abdomen without and with IV contrast|May Be Appropriate|0| |MRI abdomen without IV contrast|May Be Appropriate|0| |CT abdomen with IV contrast multiphase|May Be Appropriate|0| |US abdomen with IV contrast|Usually Not Appropriate|0| |MRI abdomen without and with IV contrast|Usually Not Appropriate|0| |with MRCP|Usually Not Appropriate|0| |MRI abdomen without IV contrast with MRCP|Usually Not Appropriate|0| |CT abdomen with IV contrast|Usually Not Appropriate|0| |CT abdomen with IV contrast|Usually Not Appropriate|0| |CT abdomen without IV contrast|Usually Not Appropriate|0| |CT abdomen without and with IV contrast|Usually Not Appropriate|0| |FDG-PET/CT skull base to mid-thigh|Usually Not Appropriate|0|

Variant 2. Adult. Primary liver cancer. Staging.

|Procedure|Appropriateness Category|Relative Radiation Level| |---|---|---| |MRI abdomen without and with IV contrast|Usually Appropriate|O| |CT abdomen with IV contrast multiphase|Usually Appropriate|00| |MRI abdomen without and with IV contrast with MRCP|May Be Appropriate|O| |Bone scan whole body|May Be Appropriate|00| |CT abdomen and pelvis with IV contrast|May Be Appropriate (Disagreement)|00| |CT chest with IV contrast|May Be Appropriate (Disagreement)|00| |CT chest without IV contrast|May Be Appropriate (Disagreement)|00| |CT pelvis with IV contrast|May Be Appropriate|00| |US abdomen transabdominal|Usually Not Appropriate|O| |US abdomen with IV contrast|Usually Not Appropriate|O| |MRI abdomen without IV contrast|Usually Not Appropriate|O| |MRI abdomen without IV contrast with MRCP|Usually Not Appropriate|O| |CT abdomen and pelvis without IV contrast|Usually Not Appropriate|00| |CT chest without and with IV contrast|Usually Not Appropriate|00| |FDG-PET/MRI skull base to mid-thigh|Usually Not Appropriate|00| |CT abdomen and pelvis without and with IV contrast|Usually Not Appropriate|00| |CT pelvis without and with IV contrast|Usually Not Appropriate|00| |CT pelvis without and with IV contrast|Usually Not Appropriate|00|

Variant 3. Adult. Primary liver cancer. Liver observations under active surveillance.

|Procedure|Appropriateness Category|Relative Radiation Level| |---|---|---| |MRI abdomen without and with IV contrast|Usually Appropriate|O| |CT abdomen with IV contrast multiphase|Usually Appropriate|888| |MRI abdomen without and with IV contrast|May Be Appropriate|0| |with MRCP|May Be Appropriate|888| |CT abdomen without and with IV contrast|May Be Appropriate|888| |US abdomen transabdominal|Usually Not Appropriate|0| |US abdomen with IV contrast|Usually Not Appropriate|0| |MRI abdomen without IV contrast|Usually Not Appropriate|0| |MRI abdomen without IV contrast with MRCP|Usually Not Appropriate|888| |CT abdomen with IV contrast|Usually Not Appropriate|888| |FDG-PET/CT skull base to mid-thigh|May Be Appropriate|888| |CT abdomen without and with IV contrast|May Be Appropriate|888| |US abdomen without and with IV contrast|Uply Not Appropriate|0| |US abdomen transabdominal|Usually Not Appropriate|0| |US abdomen with IV contrast|Usually Not Appropriate|0| |MRI abdomen without IV contrast with MRCP|Usually Not Appropriate|0| |CT abdomen with IV contrast|Usually Not Appropriate|888| |HDG-PET/CT skull base to mid-thigh|Uply Not Appropriate|888|

Variant 4. Adult. Primary liver cancer. Posttreatment evaluation after liver-directed therapy or neoadjuvant chemotherapy.

|Procedure|Appropriateness Category|Relative Radiation Level| |---|---|---| |MRI abdomen without and with IV contrast|Usually Appropriate|O| |CT abdomen with IV contrast multiphase|Usually Appropriate|8888| |CT abdomen without and with IV contrast|Usually Appropriate|888| |MRI abdomen without and with IV contrast with MRCP|May Be Appropriate|0| |US abdomen transabdominal|Usually Not Appropriate|0| |US abdomen with IV contrast|Usually Not Appropriate|0| |MRI abdomen without IV contrast|Usually Not Appropriate|0| |MRI abdomen without IV contrast with MRCP|Usually Not Appropriate|0| |CT abdomen with IV contrast|Usually Not Appropriate|888| |CT abdomen without IV contrast|Usually Not Appropriate|888| |FDG-PET/CT skull base to mid-thigh|Usually Not Appropriate|888|

Variant 5. Adult. Primary liver cancer. Treated. Routine surveillance.

|Procedure|Appropriateness Category|Relative Radiation Level| |---|---|---| |MRI abdomen without and with IV contrast|Usually Appropriate|0| |CT abdomen with IV contrast multiphase|Usually Appropriate|0| |MRI abdomen without and with IV contrast with MRCP|May Be Appropriate|0| |CT abdomen without and with IV contrast|May Be Appropriate|0| |US abdomen transabdominal|Usually Not Appropriate|0| |US abdomen with IV contrast|Usually Not Appropriate|0| |MRI abdomen without IV contrast|Usually Not Appropriate|0| |MRI abdomen without IV contrast with MRCP|Usually Not Appropriate|0| |CT abdomen without IV contrast with MRCP|Usually Not Appropriate|0| |CT abdomen with IV contrast with IV contrast|Usually Not Appropriate|0| |US abdomen without IV contrast with MRCP|Usually Not Appropriate|0| |CT abdomen with IV contrast with MRCP|Usually Not Appropriate|0| |CT abdomen without IV contrast with IV contrast|Usually Not Appropriate|0| |FDG-PET/CT skull base to mid-thigh|Upou|Upou|

Table 1. Appropriateness category names and definitions

|Appropriateness Category|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.|

Table 2. Relative radiation level designations

|RRL|Adult Effective Dose Estimate Range (mSv)|Pediatric Effective Dose Estimate Range (mSv)| |---|---|---| |0|0|0| |8|<0.1|<0.03| |8|0.1-1|0.03-0.3| |8|1-10|0.3-3| |8|10-30|3-10| |8|30-100|10-30|

Note: Relative radiation level (RRL) assignments for some of the examinations cannot be made, because the actual patient doses in these procedures vary as a function of a number of factors (eg, region of the body exposed to ionizing radiation, the imaging guidance that is used). The RRLs for these examinations are designated as "varies."

SUMMARY OF LITERATURE REVIEW

Introduction/Background

<BeginOfPara>Liver cancer is an increasing challenge to global health with continually increasing incidence despite recent advancements.Liver cancer is the sixth most common cancer worldwide, with 905,677 new cases in 2020, and is the third leading cause of cancer-related deaths globally [1]. Hepatocellular carcinoma(HCC) is the most common form of primary liver cancer and accounts for approximately 75\% to 85\% of cases [1]. Of these cases, 90\% occur in the setting of chronic liver disease. Infection with hepatitis B virus is the leading risk factor for HCC development worldwide and is estimated to be responsible for approximately 56\% of cases [1]. In the United States, the most common risk factor is infection with hepatitis C. Despite advancements in oral therapies for the treatment of hepatitis C, patients with cirrhosis are at a persistent high risk after achieving sustained virologic response and clearance of the virus [2]. Metabolic dysfunction-associated steatohepatitis, previously nonalco-holic steatohepatitis (NASH), is now the fastest growing

<EndOfPara>etiology of HCC due to its increased prevalence. Chronic alcohol consumption is another leading risk factor. Less prevalent risk factors include primary biliary cholangitis, he-mochromatosis, andα1-antitrypsin deficiency. Surveillance Epidemiology End Results reported HCC as the fastest increasing cause of cancer-related death in the United States since 2000, and HCC is projected to become the third leading cause of cancer-related death if trends continue[2]. Prognosis varies widely, with a 5-year survival exceeding 70% in patients who are diagnosed with early-stage HCC, compared with a median survival of 1 to 2 years in those diagnosed at more advanced stages[3].

Several alternative HCC staging systems have been previously proposed. These include the Barcelona Clinic Liver Cancer (BCLC) criteria, Cancer of the Liver Italian Program, Japan Integrated Staging, and Chinese University Prognostic Index, among others. According to the 2018 Practice Guidance by the American Association for the Study of Liver Diseases (AASLD), the BCLC staging system should be used [4]. This system uses the patient's Child-

Pugh score, number and size of nodules, Eastern Cooperative Oncology Group score, portal vein invasion, nodal status,and extrahepatic metastatic disease to stratify patients into stages. In 2008, the first Liver Imaging-Reporting and Data System (LI-RADS) committee convened, with support from the ACR. This committee formed to standardize the lexicon,imaging interpretation, and the reporting of findings to improve communication and diagnosis of HCC in high-risk patients [5]. Since 2008, there have been several major updates to LI-RADS, most recently in 2018. The LI-RADS assigns a diagnostic category to each liver observa-tion, which reflects the level of suspicion for HCC. The only blood-based biomarker currently validated for HCC sur-veillance is a-fetoprotein (AFP). Of note, AFP can at times be nonspecific, with elevation also seen in acute hepatitis,cholangiocarcinoma, and extrahepatic pathologies, as well [6].Ultimately, the management of HCC encompasses multiple disciplines including hepatologists, diagnostic radiologists,pathologists, transplant surgeons, surgical oncologists,radiation oncologists, and more. The development of a multidisciplinary clinic with dedicated tumor board review has been shown to increase survival in these patients with HCC [4].

Special Imaging Considerations

Since 2011, LI-RADS has published technical guidelines for the performance and interpretation of multiphase CT,MRI, ultrasound (US), and contrast-enhanced US (CEUS)examinations. Please consult these technical guidelines for specific imaging considerations [7].

DISCUSSION OF PROCEDURES BY VARIANT

Variant 1: Adult. Primary liver cancer.

Screening

Pre-existing cirrhosis is found in $>80 \%$ of patients diag-nosed with HCC. Therefore, any etiology that can lead to chronic liver injury and eventually cirrhosis should be considered a risk factor for HCC. The decision to enter a patient into screening is determined by the level of risk for HCC, as well as the patient's age, overall health, functional status, and willingness to comply with surveillance re-quirements. Because the goal of imaging screening is to increase survival through early HCC diagnosis, screening should only be performed on patients who are eligible for HCC-related treatments. Guidelines across scientific soci-eties agree that screening should be performed semi-annually, as imaging at 6-month intervals yields improved survival [6].

CT Abdomen With IV Contrast. Despite high diag-nostic performance, there is a lack of evidence on the use of

contrast-enhanced CT for the screening of patients at risk for development of HCC. However, in select patients with inadequate US examinations, CT may be used [4]. The phenomenon of arterial hyperenhancement and delayed washout has a sensitivity of 89\% and specificity of 96\%for the diagnosis of HCC and is therefore considered the radiographic hallmark [5]. Because of these imaging characteristics, cross-sectional imaging with multiple post-contrast phases is ideal, whereas single-phase CT does not allow for adequate lesion characterization.

CT Abdomen With IV Contrast Multiphase. Despite high diagnostic performance, there is a lack of evidence on the use of contrast-enhanced CT for the screening of pa-tients at risk for development of HCC. However, in select patients with inadequate US examinations, CT may be used [4].

The phenomenon of arterial hyperenhancement and delayed washout has a sensitivity of 89% and specificity of 96% for the diagnosis of HCC and is therefore considered the radiographic hallmark [5]. Because of these imaging characteristics, cross-sectional imaging with multiple post-contrast phases is ideal.

CT Abdomen Without and With IV Contrast. Despite high diagnostic performance, there is a lack of evidence on the use of contrast-enhanced CT for the screening of pa-tients at risk for development of HCC [4]. There is a lack of evidence to support the addition of noncontrast phase in this setting.

CT Abdomen Without IV Contrast. Difficulties eval-uating for potential underlying masses without the use of intravenous(IV) contrast limit the usefulness of non-contrast CT in screening for HCC.

FDG-PET/CT Skull Base to Mid-Thigh. There is limited literature supporting the use of fluorine-18-2-fluoro-2-deoxy-D-glucose(FDG)-PET/CT in screening patients for primary liver cancer.

MRI Abdomen Without and With IV Contrast. Kim et al [8] published a cohort study of 407 patients with cirrhosis and compared US with MRI with liver-specific contrast for the surveillance of HCC. A total of 43 pa-tients developed HCC, with 1 detected by US only, 26 by MRI alone, 11 by both, and 5 missed by both modalities.MRI had a lower false-positive rate than US (3% versus 5.6%).

To maximize value, abbreviated MRI examination protocols have been developed and are being tested. One potential abbreviated protocol, which has been proposed and studied, includes obtaining only T1-weighted hep-atobiliary phase axial images in addition to T2-weighted

single-shot fast spin-echo axial images. These protocols can achieve sensitivities of 80% to 90% and specificities of 91%to 98% in small cohort studies [9,10].

Demirtas et al [11] evaluated the effectiveness of annual contrast-enhanced MRI in screening at-risk patients when compared with US, using the evidence of 294 patients with consistent annual contrast-enhanced MRI and biannual AFP surveillance between 2008 and 2017. Thirty-five(11.9%) HCCs were detected with annual surveillance MRI. Of these, 30 (85.8%) were early-stage and 15(42.9%) were very early-stage. MRI had a sensitivity of 83.3% and 80%, with a specificity of 95.4% and 91.4% for detecting early and very early-stage HCCs, respectively.

Kim et al[9] also evaluated screening using MRI with liver-specific contrast agents. A total of 407 eligible pa-tients received 1,100 screenings with paired US and MRI.HCCs were diagnosed in 43 patients: 1 detected by US only, 26 by MRI only, 11 by both, and 5 were missed by both. The HCC detection rate of MRI was 86.0%(37/43),significantly higher than the 27.9%(12/43) of US(P<.001). MRI showed a significantly lower rate of false-positive findings than US(3.0% versus 5.6%; P=.004).Of the 43 patients with HCC, 32(74.4%) had very early-stage HCC(a single nodule<2 cm), and 29(67.4%)received curative treatments.

As these studies demonstrate, MRI may be a screening option for patients with poor visualization on US screening examinations.

MRI Abdomen Without and With IV Contrast With MRCP. There is no evidence for the addition of MR cholangiopreatatography(MRCP) sequences to an MR abdomen without and with IV contrast for the purpose of screening for HCC.

MRI Abdomen Without IV Contrast. Sutherland et al[12] evaluated an abbreviated noncontrast MRI protocol compared with screening US. Patients with chronic liver disease referred for US screening underwent a liver US and a liver MRI comprising free breathing diffusion-weighted imaging. One hundred ninety-two patients were recruited, and HCC was diagnosed in 6 patients(3%), all of whom were detected at US screening, and 5 detected at MRI screening. US had false-positive studies 20 times(10%), whereas diffusion-weighted MRI had 3 false-positive examinations(2%, P\geq.\.05). The sensitivity,specificity, positive predictive value, and negative predictive values for US are 100%, 90%, 23%, and 100%, respec-tively, although for MRI they were 839%, 98%, 63%, and 99%, respectively.

Kim et al [8] are currently conducting the magnetic resonance imaging as surveillance tools for hepatocellular

carcinoma (MAGNUUS-HCC) trial, which is the comparison of biannual US and annual noncontrast MRI as surveillance tools. The date of trial registration was September 15, 2015, and evidence collection is still ongoing.

MRI Abdomen Without IV Contrast With MRCP.

screening for HCC.US Abdomen. The AASLD currently recommends sur-veillance using US, with serum AFP, every 6 months[4].The European Association for the Study of the Liver guidelines also recommend surveillance with US every 6 months[13].

Zhang et al[14] conducted a large randomized controlled trial of 18,000+ patients with hepatitis B. The screened group completed 58.2% of the screening offered. When the screening group was compared with the control group,the number of HCC was 86 versus 67; subclinical HCC being 52(60.5%) versus 0; small HCC 39(45.3%) versus 0; resection achieved 40(46.5%) versus 5(7.5%); 1-, 3-,and 5-year survival rate 65.9%, 52.6%, 46.4% versus 31.2%,7.2%,0%,respectively.Thirty-two people died from HCC in the screened group versus 54 in the control group,and the HCC mortality rate was significantly lower in the screened group than in controls, being 83.2/100,000 and 131.5/100,000, respectively, with a mortality rate ratio of 0.63(95% confidence interval, 0.41-0.98). Overall findings indicated that biannual screening reduced HCC mortality by 37%.

Moon et al [15] found in a matched case-control study of the Veterans Affairs health care system that screening patients with cirrhosis using US, a measurement of serum AFP, either test, or both tests was not associated with decreased HCC-related mortality.

Recent evidence has suggested that US is operator-dependent and has poor performance in patient sub-groups such as those with obesity and NASH[16]. In these patients with poor visualization, CT or MRI can be considered.

US LI-RADS provides a unified lexicon, precise inter-pretive criteria, standardized reporting, and follow-up rec-ommendations for US surveillance in patients at-risk for HCC[17].

US Abdomen With IV Contrast. CEUS is not useful as a sole means of screening for HCC but may be a valuable screening modality in the future. Notably, this modality could help reduce the number of return visits for a follow-up examination if an incidental liver lesion is detected on grayscale US, with potential immediate administration of US contrast for lesion characterization [18]. However,

contrast-enhanced studies often have limitations in com-plete visualization of the liver; there is limited evidence to demonstrate the usefulness of CEUS as a main screening examination.

Variant 2: Adult. Primary liver cancer. Staging

Because HCC occurs in an identifiable at-risk patient pop-ulation, many patients are diagnosed with a suspicious lesion during screening. However, due to under-implementation of screening, particularly in developing countries, up to 50% of cases are diagnosed incidentally, usually identified on cross-sectional imaging performed for other reasons[6]. Once a suspicious lesion is identified, patients often undergo further testing to establish a diagnosis. With multiphase CT and MRI, observations are assigned LI-RADS cate-gories reflecting their relative probability of being benign,HCC, or other hepatic neoplasms. LI-RADS 5 lesions are definite HCC-and these imaging criteria are consistent with the Organ Procurement and Transplantation Network(OPTN) Class 5 criteria and the 2011 AASLD criteria [4].After imaging or pathological diagnosis of HCC has been established, for complete staging and consideration for liver transplantation, OPTN requires a chest CT to rule out metastatic disease [19].

Bone Scan Whole Body. If there is a suspicious osseous lesion on cross-sectional imaging, a bone scan may be of benefit to confirm osseous metastatic disease. There is no literature to support the routine usage of bone scans for the staging of every patient with primary liver cancer. Bone is the third most common site of metastasis, following the lung and abdominal lymph nodes [19].

CT Abdomen With IV Contrast Multiphase. The phenomenon of arterial hyperenhancement and delayed washout has a sensitivity of 89% and specificity of 96% for the diagnosis of HCC and is therefore considered the radiographic hallmark [5]. Because of these imaging characteristics, cross-sectional imaging with multiple postcontrast phases is ideal.The AASLD recommends multiphase CT or multiphase MRI with extracellular or hepatobiliary agents for diagnostic eval-uation because of similar performance characteristics [4].

If a CT abdomen with IV contrast multiphase or an MRI abdomen without and with IV contrast has been performed to diagnose HCC, a repeat of these examinations is unnecessary for staging purposes. However, if the diag-nosis of HCC was made by CEUS or current multiphase imaging of the entire liver has not been performed, then CT abdomen with IV contrast multiphase or an MRI abdomen without and with IV contrast may be appropriate.

CT Abdomen and Pelvis With IV Contrast. During the initial characterization of a liver lesion, due to the

diagnostic hallmarks of HCC, a single postcontrast phase would be of less benefit.

For complete staging and consideration for liver trans-plantation, OPTN requires a chest CT to rule out meta-static disease [19].

CT Abdomen and Pelvis Without and With IV Contrast. The addition of a noncontrast sequence is usually most beneficial in the setting of postliver-directed therapy, and there is limited evidence on its usefulness in pretreatment staging.

For complete staging and consideration for liver trans-plantation, OPTN requires a chest CT to rule out meta-static disease [19].

CT Abdomen and Pelvis Without IV Contrast. Dif-ficulties evaluating for potential underlying masses without the use of IV contrast limit the usefulness of noncontrast CT for HCC staging.

For complete staging and consideration for liver trans-plantation, OPTN requires a chest CT to rule out meta-static disease [19].

CT Chest With IV Contrast. For complete staging and consideration for liver transplantation, OPTN requires a chest CT to rule out metastatic disease [19]. There is insufficient evidence regarding the use of IV contrast in evaluating for thoracic metastases in the setting of HCC; however, the advantage of IV contrast when imaging the chest relates to the improved conspicuity of thoracic adenopathy.

CT Chest Without and With IV Contrast. For com-plete staging and consideration for liver transplantation, Dif-jecting and consideration evidence in the literature on the usage of contrast to suggest a without phase would be beneficial in this staging.

CT Chest Without IV Contrast. For complete staging and consideration for liver transplantation, OPTN requires a chest CT to rule out metastatic disease [19]. There is insufficient evidence regarding the use of IV contrast in evaluating for thoracic metastases in the setting of HCC;however, the advantage of IV contrast when imaging the chest relates to the improved conspicuity of thoracic adenopathy.

CT Pelvis With IV Contrast. For complete staging and consideration for liver transplantation, OPTN requires a chest CT to rule out metastatic disease [19]. In patients whose imaging has been limited to the abdomen, the addition of a pelvic CT may be indicated for complete staging purposes. IV contrast may be helpful to identify metastatic adenopathy and peritoneal implants.

CT Pelvis Without and With IV Contrast. For com-plete staging and consideration for liver transplantation,OPTN requires a chest CT to rule out metastatic disease[19]. In patients whose imaging has been limited to the abdomen, the addition of a pelvic CT may be indicated for complete staging purposes. There is insufficient evidence in the literature on the usage of contrast to suggest a without phase would be beneficial in this staging.

CT Pelvis Without IV Contrast. For complete staging and consideration for liver transplantation, OPTN requires a chest CT to rule out metastatic disease [19]. In patients whose imaging has been limited to the abdomen, the addition of a pelvic CT may be indicated for complete staging purposes. IV contrast may be helpful to identify metastatic adenopathy and peritoneal implants.

FDG-PET/MRI Skull Base to Mid-Thigh. Staging according to the BCLC classification is based on conven-tional imaging. FDG-PET has been proposed to play a role in the detection of poorly differentiated HCC; however, its use is limited by its inability to detect well-differentiated HCC. Therefore, it is not currently recommended for HCC staging [20,21].

Dual tracer PET/CT has been validated for pretrans-plant staging for HCC. C11-acetate is used, as it is sensitive for well-differentiated HCC, in conjunction with FDG[22].

MRI Abdomen Without and With IV Contrast. The phenomenon of arterial hyperenhancement and delayed washout has a sensitivity of 89% and specificity of 96% for the diagnosis of HCC and is therefore considered the radiographic hallmark [5]. Because of these imaging characteristics, cross-sectional imaging with multiple postcontrast phases is ideal.The AASLD recommends multiphase CT or multiphase MRI with extracellular or hepatobiliary agents for diagnostic eval-uation because of similar performance characteristics [4].

A recent meta-analysis reported that the sensitivity of MRI with extracellular or hepatobiliary agents exceeded that of CT [23]. For all tumor sizes, the 19 comprehensive comparisons showed significantly higher sensitivity (82%versus 66%) and lower negative likelihood ratio (0.20 versus 0.37) for MRI over CT. However, this advantage was not sufficient to definitively recommend MRI due to low quality of reviewed evidence and many factors that go into modality selection for each patient [23].

There is currently insufficient evidence to recommend either extracellular contrast or hepatobiliary contrast over the other [4].

If a CT abdomen with IV contrast multiphase or an MRI abdomen without and with IV contrast has been performed to diagnose HCC, a repeat of these examinations

is unnecessary for staging purposes. However, if the diag-nosis of HCC was made by CEUS or current multiphase imaging of the entire liver has not been performed, then CT abdomen with IV contrast multiphase or an MRI abdomen without and with IV contrast may be appropriate.

MRI Abdomen Without and With IV Contrast With MRCP. There is a lack of evidence for the addition of MRCP sequences to an MR abdomen without and with IV contrast for the purpose of staging HCC.

MRI Abdomen Without IV Contrast. HCC staging requires the use of IV contrast.

MRI Abdomen Without IV Contrast With MRCP.

There is a lack of evidence for the addition of MRCP se-quences to an MR abdomen without IV contrast for the purpose of staging HCC.

US Abdomen Transabdominal. There is no evidence to support the use of transabdominal US in pretreatment staging of HCC.

US Abdomen With IV Contrast. CEUS does not pro-vide a complete evaluation for nodal and distant metastatic disease and would not adequately stage a patient according to the BCLC criteria. It is also not suitable for staging the entire liver [17].

Variant 3: Adult. Primary liver cancer. Liver observations under active surveillance

The designation of LI-RADS 3 for an observation, indicates a low probability of HCC. The differential diagnosis for these lesions includes benign and malignant entities, such as vascular pseudolesions and small HCCs. LI-RADS 4 lesions indicate probable HCC but do not meet all imaging criteria for definitive HCC diagnosis by imaging. The differential of these lesions includes dysplastic nodules, other benign entities, and rarely, non-HCC malignancies[4]. Because these lesions could represent small HCCs, but do not meet imaging criteria for definite HCC diagnosis and treatment, it is recommended that lesions>10 mm merit close cross-sectional imaging follow-up for a maximum of 18 months. The choice of observation with follow-up im-aging versus treatment depends on several factors, including patient preference, anticipated follow-up time, rate of growth of the lesion, degree of liver decompensation, and AFP [4]. When active surveillance is elected, the goal of imaging is to identify any changes in a LI-RADS 3 lesion that would confirm HCC or to identify enlarging LI-RADS 4 lesions as early as possible.

CT Abdomen With IV Contrast. The phenomenon of arterial hyperenhancement and delayed washout has a

sensitivity of 89% and specificity of 96% for the diagnosis of HCC and is therefore considered the radiographic hall-mark [5]. Because of these imaging characteristics, cross-sectional imaging with multiple postcontrast phases is ideal, whereas single-phase CT does not allow for adequate lesion characterization.

CT Abdomen With IV Contrast Multiphase. The phenomenon of arterial hyperenhancement and delayed washout has a sensitivity of 89% and specificity of 96% for the diagnosis of HCC and is therefore considered the radiographic hallmark [5]. Because of these imaging characteristics, cross-sectional imaging with multiple post-contrast phases is ideal.

CT Abdomen Without and With IV Contrast. There is a lack of evidence supporting CT abdomen without and with IV contrast usefulness in the setting of active surveillance of the liver. However, in patients who have undergone prior liver-directed therapy, the addition of a noncontrast series may be appropriate.

CT Abdomen Without IV Contrast. Difficulties eval-uating for potential underlying masses without the use of IV contrast limits the usefulness of noncontrast CT in the surveillance of LI-RADS 3 and 4 lesions.

FDG-PET/CT Skull Base to Mid-Thigh. There is a lack of evidence supporting the use of FDG-PET in active surveillance for HCC.

MRI Abdomen Without and With IV Contrast. The phenomenon of arterial hyperenhancement and delayed washout has a sensitivity of 89% and specificity of 96% for the diagnosis of HCC and is therefore considered the radiographic hallmark [5]. Because of these imaging characteristics, cross-sectional imaging with multiple post-contrast phases is ideal.

MRI Abdomen Without and With IV Contrast With MRCP. There is no relevant literature to support the addition of MRCP sequences to an MRI abdomen without and with IV contrast in active surveillance for HCC. In patients with a history of biliary disease, an MRCP sequence may be appropriate to include.

MRI Abdomen Without IV Contrast. Difficulties evaluating for potential underlying masses without the use of IV contrast limit the usefulness of noncontrast MRI in the surveillance of LI-RADS 3 and 4 lesions.

MRI Abdomen Without IV Contrast With MRCP.There is no relevant literature to support the addition of MRCP sequences to an MRI abdomen without IV contrast in active surveillance for HCC.

US Abdomen Transabdominal. In the setting of a mass lesion $<1~cm$ in diameter detected on US screening, short-term follow-up with repeat US in 3 months is sufficient due to the small size, which makes characterization on cross-sectional imaging difficult[6]. However, for lesions $\geq 1$cm, there is insufficient evidence to support the use of US for active surveillance.

US Abdomen With IV Contrast. Surveillance with CEUS can be evaluated for changes in lesion microcircu-lation and can show evolving hepatocarcinogenesis. CEUS also has the added benefit of superior temporal resolution compared with that of CT and MRI. CEUS LI-RADS was developed to standardize imaging technique, interpretation,and reporting[17]. However, CEUS is limited for certain patients because only one or two lesions can be evaluated during the examination, and there may be incomplete visualization of the entire liver.

Variant 4: Adult. Primary liver cancer.Posttreatment evaluation after liver-directed therapy or neoadjuvant chemotherapy

Patients with early-stage HCC as characterized by the BCLC staging system are preferred candidates for resection,transplantation, and local ablation. Ablation includes radi-ofrequency ablation, microwave ablation, and additional ablation techniques such as irreversible electroporation.Patients with intermediate stage are first candidates for transarterial chemoembolization (TACE) or transarterial radiotherapy. Those with advanced disease will receive systemic therapy [6]. Additionally, neoadjuvant therapies such as TACE or ablation are sometimes used to prevent tumor progression as patients await transplantation("bridging therapy"). External beam radiation therapy can also play a role in select patients, particularly in those with small tumors and who are not amenable to resection or transplantation [6].

In the setting of liver-directed or neoadjuvant systemic therapy, short-term immediate serial follow-up imaging is performed to evaluate treatment response and to determine whether patients may require retreatment. Response to postliver-directed therapy can be evaluated on imaging using the LI-RADS posttreatment response algorithm,whereas the response to neoadjuvant systemic therapy is usually evaluated using the modified Response Evaluation Criteria in Solid Tumors.

CT Abdomen With IV Contrast. According to the LI-RADS posttreatment response algorithm, an observation can be scored as “nonevaluable” in the setting of omission of multiphase imaging [17].

CT Abdomen With IV Contrast Multiphase. Patients postablation are at a high risk for recurrence, and surveillance should be performed with contrast-enhanced CT or MRI every 3 to 6 months [4]. The National Comprehensive Cancer Network (NCCN) guidelines recommend follow-up imaging after locoregional therapy with CT or MRI every 3 to 6 months for 2 years, and every 6 to 12 months thereafter [24].

CT Abdomen Without and With IV Contrast. The addition of a noncontrast series can assist in the evaluation for enhancement following some liver-directed therapies.This is especially true in the setting of postprocedural hemorrhage and in the setting of TACE using lipiodol,which is hyperdense on CT.

CT Abdomen Without IV Contrast. Difficulties eval-uating for potential underlying masses without the use of IV contrast limit the usefulness of noncontrast CT in screening for HCC. The current reference standard for monitoring treatment response is with contrast-enhanced CT or MRI[7].

FDG-PET/CT Skull Base to Mid-Thigh. There is no relevant literature supporting the use of FDG-PET in the setting of follow-up after liver-directed therapy.

MRI Abdomen Without and With IV Contrast. Pa-tients postablation are at a high risk for recurrence, and sur-veillance should be performed with contrast-enhanced CT or MRI every 3 to 6 months [4]. The NCCN guidelines recommend follow-up imaging after resection, transplant, or locoregional therapy with CT or MRI every 3 to 6 months for 2 years, and every 6 to 12 months thereafter [24].

MRI may be preferable to CT after iodized oil-TACE because high-density oil within an embolized tumor may obscure residual or recurrent enhancement [25].

MRI Abdomen Without and With IV Contrast With MRCP. There is a lack of evidence for the addition of MRCP sequences to an MR abdomen without and with IV contrast in follow-up after liver-directed therapy. In patients with a history of biliary disease, clinicians may elect to add an MRCP sequence.

MRI Abdomen Without IV Contrast. Difficulties evaluating for potential underlying masses without the use of IV contrast limit the usefulness of noncontrast MRI in the posttreatment evaluation after liver-directed therapy or neoadjuvant chemotherapy. Current reference standard for monitoring treatment response is with contrast-enhanced MRI or CT [7].

MRI Abdomen Without IV Contrast With MRCP.

There is a lack of evidence for the addition of MRCP

sequences to an MR abdomen without IV contrast in follow-up after liver-directed therapy.

US Abdomen Transabdominal. There is no relevant literature to support the role of transabdominal US in follow-up after liver-directed therapy.

US Abdomen With IV Contrast. An alternative to contrast-enhanced CT or MRI, CEUS can be used to evaluate treatment response and assess for viable HCC. A CEUS LI-RADS treatment response algorithm has been released in 2024[26]. However, CEUS is limited for certain patients because only one or two lesions can be evaluated during the examination, and there may be incomplete visualization of the entire liver.

Variant 5: Adult. Primary liver cancer.Treated. Routine surveillance

Surgical treatment for HCC is accepted as the most curative treatment. This includes both hepatic resection and liver transplantation. These treatments yield the best outcomes,with 5-year survivals averaging approximately 70% to 80%[27]. Recurrence rates after resection alone can be as high as 70% at 5 years; these can occur early(<2 years) most likely secondary to micrometastases or late(>2 years), likely a result of the development of a separate de novo HCC [6].The recurrence rates following transplant are approximately 10% to 15% at 5 years [6].The use of "bridging therapies"as mentioned previously has been shown to reduce transplant list dropout as well as posttransplant recurrence [28].

The decision for the patient to undergo surgical resection versus transplantation is a complex multidisciplinary decision that is beyond the scope of these guidelines. Because of the recurrence rates with both surgical options, patients undergo postresection and posttransplant imaging surveillance to identify any potentially recurrent disease early.

This variant also includes patients who have undergone liver-directed therapy and have completed the immediate period of close follow-up imaging, with lesions being effectively treated fully and who are now ready to return to routine surveillance.

CT Abdomen With IV Contrast. Because of HCCs'imaging characteristics, cross-sectional imaging with multi-ple postcontrast phases is ideal, whereas single-phase CT does not allow for adequate lesion detection or characterization.

Both LI-RADS and OPTN provide technical recommen-dations for dynamic contrast-enhanced CT and MRI [19].

CT Abdomen With IV Contrast Multiphase. The NCCN guidelines recommend routine surveillance after resection, transplant, or locoregional therapy with CT or

MRI every 3 to 6 months for 2 years, and every 6 to 12 months thereafter [24]. Because of HCCs' imaging characteristics, cross-sectional imaging with multiple post-contrast phases is ideal.

CT Abdomen Without and With IV Contrast. There is a lack of evidence for the addition of a noncontrast phase to a contrast-enhanced CT in the setting of routine sur-veillance after liver-directed therapy, resection, or trans-plant. However, a noncontrast sequence can be of benefit to evaluate for the presence of postcontrast enhancement,especially in the setting of prior wedge resection with hyperdense surgical material, or prior TACE with the uti-lization of lipiodol.

CT Abdomen Without IV Contrast. Difficulties eval-uating for potential underlying masses without the use of IV contrast limit the usefulness of noncontrast CT in routine surveillance of treated HCC.

FDG-PET/CT Skull Base to Mid-Thigh. There is a lack of evidence for FDG-PET/CT and its usefulness in the routine surveillance of treated HCC.

MRI Abdomen Without and With IV Contrast. The NCCN guidelines recommend follow-up imaging after resection, transplant, or locoregional therapy with CT or MRI every 3 to 6 months for 2 years, and every 6 to 12 months thereafter [24].

MRI Abdomen Without and With IV Contrast With MRCP. There is a lack of evidence for the addition of MRCP sequences to an MRI abdomen without and with IV contrast in the routine surveillance of treated HCC. In patients with a history of biliary disease, clinicians may elect to add an MRCP sequence.

MRI Abdomen Without IV Contrast. Difficulties evaluating for potential underlying masses without the use of IV contrast limit the usefulness of noncontrast MRI in the routine surveillance of treated HCC. Both LI-RADS and OPTN provide technical recommendations for dy-namic contrast-enhanced CT and MRI [19].

MRI Abdomen Without IV Contrast With MRCP.

There is a lack of evidence for the addition of MRCP se-quences to an MRI abdomen without IV contrast in routine surveillance of treated HCC.

US Abdomen Transabdominal. There is no relevant literature to support the use of US transabdominal in this clinical scenario.

US Abdomen With IV Contrast. There is no relevant literature to support the use of US abdomen with IV contrast in this clinical scenario.

SUMMARY OF HIGHLIGHTS

This is a summary of the key recommendations from the variant tables. Refer to the complete narrative document for more information.

■Variant 1:For screening patients at an increased risk of primary liver cancer, US abdomen is the recommended study. In certain patients, MRI abdomen either without and with IV contrast or without IV contrast, as well as CT abdomen with IV contrast multiphase may be appropriate. This is generally in the setting of poor-quality US, either due to body habitus or hepatic steatosis.

■Variant 2:In patients with known primary liver cancer presenting for staging, MRI abdomen without and with IV contrast or alternatively CT abdomen with IV contrast multiphase is the recommended examinations for complete evaluation of the extent of the primary liver lesion(s), vascular involvement, and abdominal extrahepatic metastatic disease. The inclusion of an MRCP sequence may be appropriate, if there is concern for biliary involvement or in the setting of known primary sclerosing cholangitis or primary biliary cholangitis. A bone scan whole body may be appropriate, if there are suspicious osseous lesions. A CT pelvis with IV contrast may be of benefit for complete staging purposes. There was panel disagreement on the appropriateness of CT chest with IV contrast or CT chest without IV contrast; a chest CT is usually needed for complete staging purposes,and the disagreement between use of IV contrast is likely due to institutional differences.

■Variant 3: If there are known liver lesions undergoing active surveillance (LI-RADS 3 or 4 lesions), MRI abdomen without and with IV contrast or alternatively CT abdomen with IV contrast or multiphase is the recommended modalities for short-term follow-up of these lesions. The addition of an MRCP sequence may be appropriate, usually if there is concern for biliary pathology or involvement. In the setting of a multiphase CT, the addition of a non-contrast may be appropriate.

■Variant 4: In patients who have undergone liver-directed therapy or neoadjuvant chemotherapy, MRI abdomen without and with IV contrast, CT abdomen with IV contrast multiple phase, and CT abdomen without and with IV contrast are alternatives recom-mended for the evaluation of treatment response. The addition of the noncontrast phase for CT is most

beneficial in the setting of liver-directed therapy. The addition of an MRCP sequence may be appropriate in the setting of biliary involvement or known pathology.

■Variant 5: After a patient has completed treatment for primary liver cancer, either remote liver-directed therapy or after liver transplant, and is undergoing surveillance, MRI abdomen without and with IV contrast or alternatively CT abdomen with IV contrast multiphase is recommended. The addition of an MRCP sequence may be of benefit in the setting of biliary involvement or known pathology.For CT, the addition of a noncontrast series may be appropriate in the setting of prior liver-directed therapy.

SUPPORTING DOCUMENTS

The evidence table, literature search, and appendix for this topic are available at https://acsearch.acr.org/list. The ap-pendix 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, visit www.acr.org/Clinical-Resources/Clinical-Tools-and-Reference/Appropriateness-Criteria.

GENDER EQUALITY AND INCLUSIVITY CLAUSE

The ACR acknowledges the first inuiliying inclu-sive language when citing research studies that predates the use of the current understanding of language inclusive of diversity in sex, intersex, gender, and gender-diversse people. The data variables regarding sex and gender used in the cited literature will not be changed. However, this guideline will use the terminology and definitions as proposed by the National Institutes of Health [29].

RELATIVE RADIATION LEVEL INFORMATION

<BeginOfPara>Potential adverse health effects associated with radiation exposure are an important factor to consider when selecting the appropriate imaging procedure. Because there is a wide range of radiation exposures associated with different diagnostic procedures, a relative radiation level (RRL)indication has been included for each imaging examination.The RRLs are based on effective dose, which is a radiation dose quantity that is used to estimate population total ra -radiation risk associated with an imaging procedure. Patients in the pediatric age group are at inherently higher risk from exposure, because of both organ sensitivity and longer life expectancy (relevant to the long latency that appears to

accompany radiation exposure). For these reasons, the RRL dose estimate ranges for pediatric examinations are lower as compared with those specified for adults (see Table 2).Additional information regarding radiation dose assessment for imaging examinations can be found in the ACR Appropriateness Criteria $\rangle$ Radiation Dose Assessment Introduction document [30].

ACKNOWLEDGMENTS

The ACR is the sole funding source of the ACR AC.

REFERENCES

1. Sung H, Ferlay J, Siegel RL, et al. Global cancer statistics 2020:GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin 2021;71:209-49.

2. Rahib L, Smith BD, Aizenberg R, Rosenzweig AB, Fleshman JM,Matrisian LM. Projecting cancer incidence and deaths to 2030: the unexpected burden of thyroid, liver, and pancreas cancers in the United States. Cancer Res 2014;74:2913-21.

3.Singal AG, Reddy S, Radadiya Aka Patel H, et al. Multicenter ran-domized clinical trial of a mailed outreach strategy for hepatocellular carcinoma surveillance. Clin Gastroenterol Hepatol 2022;20:2818-28125.e1.

4. Marrero JA, Kulik LM, Sirlin CB, et al. Diagnosis, staging, and management of hepatocellular carcinoma: 2018 practice guidance by the American Association for the Study of Liver Diseases. Hepatology 2018;68:723-50.

5. van der Pol CB, Lim CS, Sirlin CB, et al. Accuracy of the Liver Imaging Reporting and Data System in computed tomography and magnetic resonance image analysis of hepatocellular carcinoma or overall malignancy-a systematic review. Gastroenterology 2019;156:976-86.

6. Llovet JM, Zucman-Rossi J, Pikarsky E, et al. Hepatocellular carci-noma. Nat Rev Dis Primers 2016;2:16018.

7. Polikoff A, Wessner CE, Balasubramanya R, et al. Imaging appear-ance of residual HCC following incomplete trans-arterial chemo-embolization on contrast-enhanced imaging. Abdom Radiol (NY)2022;47:152-60.

8.Kim HA, Kim KA, Choi JI, et al. Comparison of biannual ultraso-nography and annual non-contrast liver magnetic resonance imaging as surveillance tools for hepatocellular carcinoma in patients with liver cirrhosis (MAGNUS-HCC): a study protocol. BMC Cancer 2017;17:877.

9. Kim SY, An J, Lim YS, et al. MRI with liver-specific contrast for surveillance of patients with cirrhosis at high risk of hepatocellular carcinoma. JAMA Oncol 2017;3:456-63.

10.Marks RM, Ryan A, Heba ER, et al. Diagnostic per-patient accuracy of an abbreviated hepatobiliary phase gadoexetic acid-enhanced MRI for hepatocellular carcinoma surveillance. AJR Am J Roentgenol 2015;204:527-35.

11. Demirtas CO, Gundzur F, Tuney D, et al. Annual contrast-enhanced magnetic resonance imaging is highly effective in the surveillance of hepatocellular carcinoma among cirrhotic patients. Eur J Gastro-enterol Hepatol 2020;32:517-23.

12. Sutherland T, Watts J, Ryan M, et al. Diffusion-weighted MRI for hepatocellular carcinoma screening in chronic liver disease: direct comparison with ultrasound screening. J Med Imaging Radiat Oncol 2017;61:34-9.

13. Bruix J, Sherman M, Llovet JM, et al. Clinical management of he-patocellular carcinoma. Conclusions of the Barcelona-2000 EASL

conference. European Association for the Study of the Liver.J Hepatol 2001;35:421-30.

14. Zhang BH, Yang BH, Tang ZY. Randomized controlled trial of screening for hepatocellular carcinoma. J Cancer Res Clin Oncol 2004;130:417-22.

15. Moon AM, Weiss NS, Beste LA, et al. No association between screening for hepatocellular carcinoma and reduced cancer-related mortality in patients with cirrhosis. Gastroenterology 2018;155:1128-11239.e6.

16. Atiq O, Tiro J, Yopp AC, et al. An assessment of benefits and harms of hepatocellular carcinoma surveillance in patients with cirrhosis.Hepatology 2017;65:1196-205.

17. Nguyen SA, Merrill CD, Burrowes DP, Medellin GA, Wilson SR. Hepatocellular carcinoma in evolution: correlation with CEUS LI-RADS. Radiographics 2022;42:1028-42.

18. Motz VL, White R, Lee R, Vu T, Shin B, McGill NL. Contrast-enhanced ultrasound for screening hepatocellular carcinoma: an implemented program at a semi-rural academic center. Abdom Radiol (NY) 2021;46:4170-7.

19. Fang, Fowler KJ, Chernyak V, Chapman WC, Sirlin CB. LI-RADS and transplantation for hepatocellular carcinoma. Abdom-Radiol (NY) 2018;43:193-202.

20. Chalaye J, Costentin CE, Luciani, A et. Positron emission to-mography/computed tomography with 18F-fluorocholine improve tumor staging and treatment allocation in patients with hepatocellular carcinoma. J. Hepatol 2018;69:336-44.

21. Khan MA, Combs CS, Brunt EM, et al. Positron emission tomog-raphy scanning in the evaluation of hepatocellular carcinoma.J Hepatol 2000;32:792-7.

22. Au KP, Chok SKH. Multidisciplinary approach for post-liver trans-plant recurrence of hepatocellular carcinoma: a proposed management algorithm. World J Gastroenterol 2018;24:5081-94.

23. Roberts LR, Sirlin CB, Zaiem F, et al. Imaging for the diagnosis of hepatocellular carcinoma: a systematic review and meta-analysis.Hepatology 2018;67:401-21.

24. Mirdad RS, Madison Hyer J, Diaz A, et al. Postoperative imaging surveillance for hepatocellular carcinoma: how much is enough?J Surg Oncol 2021;123:1568-77.

25. American College of Radiology Committee on LI-RADS®. Liver Imaging Reporting & Data System (LI-RADS®). Available at: https://www.acr.org/Clinical-Resources/Clinical-Tools-and-Reference/Reporting-and-Data-Systems/LI-RADS. Accessed March 31,2025.

26. American College of Radiology. LI-RADS® CEUS nonradiation TRA. v2024 Core. Available at: https://edge.sitecorecloud.io.americancoldf-facorgf92a-productioncb02-3650/media/ACR/File/Rads/RDS/LI-RADS/CEUS-Nonradiation-TRA-v2024-Core.pdf. Accessed March 31,2025.

27. European Association for the Study of the Liver. EASL Clinical practice guidelines: management of hepatocellular carcinoma.J Hepatol 2018;69:182-236.

28. Kulik L., Heimbach JK., Zaiem F, et al. Therapies for patients with hepatocellular carcinoma awaiting liver transplantation: a systematic review and meta-analysis. Hepatology 2018;67:381-400.

29. National Academies of Sciences. Engineering and Medicine; Division of Behavioral and Social Sciences and Education; Committee on National Statistics; Committee on Measuring Sex, Gender Identity, and Sexual Orientation. Measuring sex, gender identity, and sexual orientation. In:Becker T, Chin M, Bates N, eds. Measuring sex, gender identity, and sexual orientation. Washington, DC: National Academies Press; 2022.

30. American College of Radiology. ACR Appropriateness Criteria radiation dose assessment introduction. Available at: https://edge-sitecorecloud.io/americanoldf5f-acrgf92a-productioncb02-3650/media ACR/Files/Clinical/Appropriateness-Criteria/ACRAppropriateness-Criteria-Radiation-Dose-Assessment-Introduction.pdf. Accessed March 31,2025.