A Multicenter Assessment of Interreader Reliability of LI-RADS Version 2018 for MRI and CT.

Background Various limitations have impacted research evaluating reader agreement for Liver Imaging Reporting and Data System (LI-RADS). Purpose To assess reader agreement of LI-RADS in an international multicenter multireader setting using scrollable images. Materials and Methods This retrospective study used deidentified clinical multiphase CT and MRI and reports with at least one untreated observation from six institutions and three countries; only qualifying examinations were submitted. Examination dates were October 2017 to August 2018 at the coordinating center. One untreated observation per examination was randomly selected using observation identifiers, and its clinically assigned features were extracted from the report. The corresponding LI-RADS version 2018 category was computed as a rescored clinical read. Each examination was randomly assigned to two of 43 research readers who independently scored the observation. Agreement for an ordinal modified four-category LI-RADS scale (LR-1, definitely benign; LR-2, probably benign; LR-3, intermediate probability of malignancy; LR-4, probably hepatocellular carcinoma [HCC]; LR-5, definitely HCC; LR-M, probably malignant but not HCC specific; and LR-TIV, tumor in vein) was computed using intraclass correlation coefficients (ICCs). Agreement was also computed for dichotomized malignancy (LR-4, LR-5, LR-M, and LR-TIV), LR-5, and LR-M. Agreement was compared between research-versus-research reads and research-versus-clinical reads. Results The study population consisted of 484 patients (mean age, 62 years ± 10 [SD]; 156 women; 93 CT examinations, 391 MRI examinations). ICCs for ordinal LI-RADS, dichotomized malignancy, LR-5, and LR-M were 0.68 (95% CI: 0.61, 0.73), 0.63 (95% CI: 0.55, 0.70), 0.58 (95% CI: 0.50, 0.66), and 0.46 (95% CI: 0.31, 0.61) respectively. Research-versus-research reader agreement was higher than research-versus-clinical agreement for modified four-category LI-RADS (ICC, 0.68 vs 0.62, respectively; P = .03) and for dichotomized malignancy (ICC, 0.63 vs 0.53, respectively; P = .005), but not for LR-5 (P = .14) or LR-M (P = .94). Conclusion There was moderate agreement for LI-RADS version 2018 overall. For some comparisons, research-versus-research reader agreement was higher than research-versus-clinical reader agreement, indicating differences between the clinical and research environments that warrant further study. © RSNA, 2023 Supplemental material is available for this article. See also the editorials by Johnson and Galgano and Smith in this issue.

The adoption of LI-RADS: a survey of non-academic radiologists.

PURPOSE: To understand the practice and determinants of non-academic radiologists regarding LI-RADS and the four current LI-RADS algorithms: CT/MRI, contrast-enhanced ultrasound (CEUS), ultrasound (US), and CT/MRI Treatment Response. MATERIALS AND METHODS: Seven themes were covered in this international survey, as follows: (1) demographics of participants and sub-specialty, (2) HCC practice and interpretation, (3) reporting practice, (4) screening and surveillance, (5) HCC imaging diagnosis, (6) treatment response, and (7) CT and MRI technique. RESULTS: Of the 232 participants, 69.4% were from the United States, 25.0% from Canada, and 5.6% from other countries and 45.9% were abdominal/body imagers. During their radiology training or fellowship, no formal HCC diagnostic system was used by 48.7% and LI-RADS was used by 44.4% of participants. In their current practice, 73.6% used LI-RADS, 24.7% no formal system, 6.5% UNOS-OPTN, and 1.3% AASLD. Barriers to LI-RADS adoption included lack of familiarity (25.1%), not used by referring clinicians (21.6%), perceived complexity (14.5%), and personal preference (5.3%). The US LI-RADS algorithm was used routinely by 9.9% of respondents and CEUS LI-RADS was used by 3.9% of the respondents. The LI-RADS treatment response algorithm was used by 43.5% of the respondents. 60.9% of respondents thought that webinars/workshops on LI-RADS Technical Recommendations would help them implement these recommendations in their practice. CONCLUSION: A majority of the non-academic radiologists surveyed use the LI-RADS CT/MR algorithm for HCC diagnosis, while nearly half use the LI-RADS TR algorithm for assessment of treatment response. Less than 10% of the participants routinely use the LI-RADS US and CEUS algorithms.

How to Use LI-RADS to Report Liver CT and MRI Observations.

Primary liver cancer is the fourth leading cause of cancer-related deaths worldwide, with hepatocellular carcinoma (HCC) comprising the vast majority of primary liver malignancies. Imaging plays a central role in HCC diagnosis and management. As a result, the content and structure of radiology reports are of utmost importance in guiding clinical management. The Liver Imaging Reporting and Data System (LI-RADS) provides guidance for standardized reporting of liver observations in patients who are at risk for HCC. LI-RADS standardized reporting intends to inform patient treatment and facilitate multidisciplinary communication and decisions, taking into consideration individual clinical factors. Depending on the context, observations may be reported individually, in aggregate, or as a combination of both. LI-RADS provides two templates for reporting liver observations: in a single continuous paragraph or in a structured format with keywords and imaging findings. The authors clarify terminology that is pertinent to reporting, highlight the benefits of structured reports, discuss the applicability of LI-RADS for liver CT and MRI, review the elements of a standardized LI-RADS report, provide guidance on the description of LI-RADS observations exemplified with two case-based reporting templates, illustrate relevant imaging findings and components to be included when reporting specific clinical scenarios, and discuss future directions. An invited commentary by Yano is available online. Online supplemental material is available for this article. Work of the U.S. Government published under an exclusive license with the RSNA.

Clinicians and surgeon survey regarding current and future versions of CT/MRI LI-RADS.

PURPOSE: To determine preferences of clinicians and surgeons regarding radiology reporting of liver observations in patients at risk for hepatocellular carcinoma (HCC). METHODS: Members of the American College of Radiology Liver Imaging and Data Reporting System (LI-RADS) Outreach & Education Group (30 members) as well as Society of Abdominal Radiology Disease-Focused Panel on HCC diagnosis (27 members) created and distributed an 18-question survey to clinicians and surgeons, with focus on preferences regarding radiology reporting of liver observations in patients. The survey questions were directed to physician demographics, current use of LI-RADS by their local radiologists, their opinions about current LI-RADS and potential improvements. RESULTS: A total of 152 physicians responded, 66.4% (101/152) from North America, including 42 surgeons, 81 physicians and 29 interventional radiologists. Participants were predominantly from academic centers 83% (126/152), while 13.8% (21/152) worked in private/community centers and 3.2% (5/152) worked in a hybrid practice. Almost 90% (136/152) of participants preferred the use of LI-RADS (compared to nothing or other standardized reporting systems; OPTN and AASLD) to communicate liver-related observations. However, only 28.5% (43/152) of participants input was sought at the time of implementing LI-RADS in their institutions. Fifty-eight percent (88/152) of all participants found standardized LI-RADS management recommendations in radiology reports to be clinically helpful. However, a subgroup analysis of surgeons in academic centers showed that 61.8% (21/34) prefer not to receive standardized LI-RADS recommendations. CONCLUSIONS: Most participants preferred the use LI-RADS in reporting CT and MRI examination. When considering inclusion of management recommendations, radiologists should consult with their referring physicians, as preference may differ.

LI-RADS: a conceptual and historical review from its beginning to its recent integration into AASLD clinical practice guidance.

The Liver Imaging Reporting and Data System (LI-RADS®) is a comprehensive system for standardizing the terminology, technique, interpretation, reporting, and data collection of liver observations in individuals at high risk for hepatocellular carcinoma (HCC). LI-RADS is supported and endorsed by the American College of Radiology (ACR). Upon its initial release in 2011, LI-RADS applied only to liver observations identified at CT or MRI. It has since been refined and expanded over multiple updates to now also address ultrasound-based surveillance, contrast-enhanced ultrasound for HCC diagnosis, and CT/MRI for assessing treatment response after locoregional therapy. The LI-RADS 2018 version was integrated into the HCC diagnosis, staging, and management practice guidance of the American Association for the Study of Liver Diseases (AASLD). This article reviews the major LI-RADS updates since its 2011 inception and provides an overview of the currently published LI-RADS algorithms.

White paper of the Society of Abdominal Radiology hepatocellular carcinoma diagnosis disease-focused panel on LI-RADS v2018 for CT and MRI.

The Liver Imaging and Reporting Data System (LI-RADS) is a comprehensive system for standardizing the terminology, technique, interpretation, reporting, and data collection of liver imaging with the overarching goal of improving communication, clinical care, education, and research relating to patients at risk for or diagnosed with hepatocellular carcinoma (HCC). In 2018, the American Association for the Study of Liver Diseases (AASLD) integrated LI-RADS into its clinical practice guidance for the imaging-based diagnosis of HCC. The harmonization between the AASLD and LI-RADS diagnostic imaging criteria required minor modifications to the recently released LI-RADS v2017 guidelines, necessitating a LI-RADS v2018 update. This article provides an overview of the key changes included in LI-RADS v2018 as well as a look at the LI-RADS v2018 diagnostic algorithm and criteria, technical recommendations, and management suggestions. Substantive changes in LI-RADS v2018 are the removal of the requirement for visibility on antecedent surveillance ultrasound for LI-RADS 5 (LR-5) categorization of 10-19 mm observations with nonrim arterial phase hyper-enhancement and nonperipheral "washout", and adoption of the Organ Procurement and Transplantation Network definition of threshold growth (≥ 50% size increase of a mass in ≤ 6 months). Nomenclatural changes in LI-RADS v2018 are the removal of -us and -g as LR-5 qualifiers.

Evidence Supporting LI-RADS Major Features for CT- and MR Imaging-based Diagnosis of Hepatocellular Carcinoma: A Systematic Review.

The Liver Imaging Reporting and Data System (LI-RADS) standardizes the interpretation, reporting, and data collection for imaging examinations in patients at risk for hepatocellular carcinoma (HCC). It assigns category codes reflecting relative probability of HCC to imaging-detected liver observations based on major and ancillary imaging features. LI-RADS also includes imaging features suggesting malignancy other than HCC. Supported and endorsed by the American College of Radiology (ACR), the system has been developed by a committee of radiologists, hepatologists, pathologists, surgeons, lexicon experts, and ACR staff, with input from the American Association for the Study of Liver Diseases and the Organ Procurement Transplantation Network/United Network for Organ Sharing. Development of LI-RADS has been based on literature review, expert opinion, rounds of testing and iteration, and feedback from users. This article summarizes and assesses the quality of evidence supporting each LI-RADS major feature for diagnosis of HCC, as well as of the LI-RADS imaging features suggesting malignancy other than HCC. Based on the evidence, recommendations are provided for or against their continued inclusion in LI-RADS. © RSNA, 2017 Online supplemental material is available for this article.

Hepatocellular carcinoma imaging systems: why they exist, how they have evolved, and how they differ.

Over the past 16 years, several scientific organizations have proposed systems that incorporate imaging for surveillance, diagnosis, staging, treatment, and monitoring of treatment response of hepatocellular carcinoma (HCC). These systems are needed to standardize the acquisition, interpretation, and reporting of liver imaging examinations; help differentiate benign from malignant observations; improve consistency between radiologists; and provide guidance for management of HCC. This review article discusses the historical evolution of HCC imaging systems. We indicate the features differentiating these systems, including target population, screening and surveillance algorithm, diagnostic imaging modalities, diagnostic scope, expertise and technical requirements, terminology, major and ancillary imaging features, staging and transplant eligibility, and assessment of treatment response. We highlight the potential benefits of unifying the systems, which we anticipate will enable sharing, pooling, and meta-analysis of data; facilitate multi-center trials; and accelerate dissemination of knowledge.

Biliary Leak in the Postsurgical Abdomen: A Primer to HIDA Scan Interpretation.

Postsurgical bile leaks can be associated with significant morbidity and even mortality, if not identified and treated at an early phase. Hepatobiliary iminodiacetic acid (HIDA) scan is an important test for detection of bile leaks in the postoperative abdomen. However, the lack of anatomical details on planar images can make interpretation difficult, especially in the setting of altered postsurgical anatomy. Familiarity with the expected postoperative appearance on HIDA scan and correlation with SPECT/CT or other imaging modalities when available are very important. The purpose of this review is to describe the expected findings on HIDA scan after common major abdominal surgeries that involve a change in biliary tree anatomy, and illustrate how to identify biliary leaks and avoid interpretation pitfalls.

Overview of the Novel and Improved Pulmonary Ventilation-Perfusion Imaging Applications in the Era of SPECT/CT.

OBJECTIVE: In this article, we describe the concepts of ventilation-perfusion planar, SPECT, and SPECT/CT and outline the advantages of integrated ventilation-perfusion SPECT/CT over planar imaging. We present an overview of the traditional and new applications of ventilation-perfusion scintigraphy. CONCLUSION: SPECT/CT has improved the diagnostic accuracy of ventilation-perfusion imaging and opened the door for a new spectrum of applications.

Diagnostic Accuracy of Preoperative Gadoxetic Acid-enhanced 3-T MR Imaging for Malignant Liver Lesions by Using Ex Vivo MR Imaging-matched Pathologic Findings as the Reference Standard.

PURPOSE: To determine per-lesion sensitivity and positive predictive value (PPV) of gadoxetic acid-enhanced 3-T magnetic resonance (MR) imaging for the diagnosis of malignant lesions by using matched (spatially correlated) hepatectomy pathologic findings as the reference standard. Materials and METHODS: In this prospective, institutional review board-approved, HIPAA-compliant study, 20 patients (nine men, 11 women; mean age, 59 years) with malignant liver lesions who gave written informed consent underwent preoperative gadoxetic acid-enhanced 3-T MR imaging for surgical planning. Two image sets were independently analyzed by three readers to detect liver lesions (set 1 without and set 2 with hepatobiliary phase [HBP] images). Hepatectomy specimen ex vivo MR imaging assisted in matching gadoxetic acid-enhanced 3-T MR imaging findings with pathologic findings. Interreader agreement was assessed by using the Cohen κ coefficient. Per-lesion sensitivity and PPV were calculated. RESULTS: Cohen κ values were 0.64-0.76 and 0.57-0.84, and overall per-lesion sensitivity was 45% (42 of 94 lesions) to 56% (53 of 94 lesions) and 58% (55 of 94 lesions) to 64% (60 of 94 lesions) for sets 1 and 2, respectively. The addition of HBP imaging did not affect interreader agreement but significantly improved overall sensitivity for one reader (P < .05) and almost for another (P = .05). Sensitivity for 0.2-0.5-cm lesions was 0% (0 of 26 lesions) to 8% (two of 26 lesions) for set 1 and 4% (one of 26 lesions) to 12% (three of 26 lesions) for set 2. Sensitivity for 0.6-1.0-cm lesions was 28% (nine of 32 lesions) to 59% (19 of 32 lesions) for set 1 and 66% (21 of 32 lesions) to 69% (22 of 32 lesions) for set 2. Sensitivity for lesions at least 1.0 cm in diameter was at least 81% (13 of 16 lesions) for set 1 and was not improved for set 2. PPV was 98% (56 of 57 lesions) to 100% (60 of 60 lesions) for all readers without differences between image sets or lesion size. CONCLUSION: Gadoxetic acid-enhanced 3-T MR imaging provides high per-lesion sensitivity and PPV for preoperative malignant liver lesion detection overall, although sensitivity for 0.2-0.5-cm malignant lesions is poor.

Risk of nephrogenic systemic fibrosis is low in patients with chronic liver disease exposed to gadolinium-based contrast agents.

PURPOSE: To determine the risk of nephrogenic systemic fibrosis (NSF) in a cohort of patients with chronic liver disease. MATERIALS AND METHODS: This retrospective, Institutional Review Board (IRB)-approved, Health Insurance Portability and Accountability Act (HIPAA)-compliant study was performed at a single tertiary liver center. The study cohort comprised 1167 patients with chronic liver disease followed in a liver clinic and exposed to gadolinium-based contrast agents (GBCAs) between February 2004 and October 2007. A retrospective review of medical records was performed. For each patient, data were collected on demographics, history of GBCA exposure, presence of purported risk factors for NSF, and histopathological evidence of NSF. RESULTS: Of the 1167 patients with chronic liver disease, 58% (n = 678) had cirrhosis. The patients had a total of 2421 separate GBCA exposures. Fifty-five percent (n = 646) had a single exposure, 19% (n = 218) had two exposures, and 26% (n = 303) had three or more exposures. Seventy-two percent (n = 843) of patients had renal insufficiency, 25 patients (2.1%) had hepatorenal syndrome, 80 patients (6.8%) were in the perioperative liver transplant period, and 49 patients (4.2%) had one or more additional risk factors for NSF. None of the 1167 patients developed NSF. CONCLUSION: Chronic liver disease does not appear to be a significant risk factor for NSF.

Understanding LI-RADS: a primer for practical use.

The Liver Imaging-Reporting and Data System (LI-RADS) is a comprehensive system for standardized interpretation and reporting of computed tomography and magnetic resonance examinations performed in patients at risk for hepatocellular carcinoma. LI-RADS includes a diagnostic algorithm, lexicon, and atlas as well as suggestions for reporting, management, and imaging techniques. This primer provides an introduction to LI-RADS for radiologists including an explanation of the diagnostic algorithm, descriptions of the categories, and definitions of the major imaging features used to categorize observations with case examples.

Correlation of transesophageal ultrasound of the pericardium with computed tomography.

OBJECTIVE: In this study, we assess the sensitivity and specificity of ultrasound and computed tomography (CT) for pericardial effusion and constrictive pericarditis. MATERIALS AND METHODS: This was a retrospective, institutional review board-approved, and health insurance privacy accountability act compliant study performed at a single tertiary center over a 10-year period (2001-2011) for patients who had clinical symptoms of pericarditis and had undergone both cardiac CT imaging and transesophageal echocardiogram (TEE) in a span of 2 weeks. INCLUSION CRITERIA: Inclusion criteria included patients with clinical symptoms of pericarditis, pericardial thickness measuring more than 2 mm on CT, and patients who had both cardiac CT imaging and TEE performed within 2 weeks. EXCLUSION CRITERIA: Exclusion criteria included patients with pericardial thickness measuring 2 mm or less on CT, no TEE, TEE not done within 2 weeks of the thoracic CT, and calcified pericardium on CT.Computed tomographic images were retrospectively reviewed by 2 radiologists who were unaware of the TEE findings. Pericardial effusion on CT was deemed present if there was obliteration of the fat plane in the left pulmonic recess. STATISTICAL ANALYSIS: Statistical analysis was performed using the R statistical environment (Rstat). Intraobserver and interobserver variability was estimated using Cohen κ- statistic (Cohen). RESULTS: Forty-three cases constituted the study population (28 men and 15 women; mean age, 55 years; age range, 22-82 years). Twenty-one patients had pathologic confirmation of pericarditis.The findings for CT and TEE were discrepant in 10 cases. Intraobserver variability Cohen κ statistic was 0.855. Interobserver variability Cohen κ statistics were 0.54 and 0.49. CONCLUSIONS: Computed tomography is sensitive to pericardial effusion and pericardial thickening, whereas TEE seems insensitive to isolated pericardial thickening.

A comprehensive review of the retroperitoneal anatomy, neoplasms, and pattern of disease spread.

A clear understanding of the normal anatomy and pattern of disease spread is important in evaluating many retroperitoneal disorders. Primary retroperitoneal tumors are uncommon, accounting for 0.1%-0.2% of all malignancies in the body; 80%-90% of all primary retroperitoneal tumors are malignant. The primary retroperitoneal neoplasms can be divided into solid or cystic masses. The solid neoplasms can be classified according to their tissue of origin into 3 main categories: mesodermal tumors, neurogenic tumors, and extragonadal germ cell tumors. Computed tomography and magnetic resonance imaging play a vital role in the localization, characterization, evaluation of the extent of local invasion, assessment of metastases, and determination of treatment response for these tumors. The diagnosis of a primary retroperitoneal malignancy is often challenging owing to overlap of imaging findings. A definitive diagnosis can be established only at histopathologic analysis. However, knowledge of the important tumor characteristics, growth pattern, and vascularity can assist in narrowing the differential diagnosis.

An update on criteria for assessing tumor response to treatment.

Standardized tumor response criteria have been developed over time since the advent of cytotoxic anticancer therapies. The criteria have evolved and continue to do so as the understanding of the therapeutic basis of various anticancer agents increases and as novel therapeutic agents are developed. Currently, the criteria can be divided into the following main categories: anatomical-based criteria; tumor- and therapy-specific criteria; metabolic-based criteria; and response assessment of lymphomas. The standardized criteria are critical to the successful conduct of clinical trials during the development of cancer therapeutic agents as they offer uniform end points that facilitate comparison of therapeutic agents and interpretation of studies. The criteria are also relevant in clinical practice as they standardize how radiologists select, measure, and report lesions in oncology patients, and they provide standardized definitions for tumor response categories. To remain relevant in a rapidly evolving oncology field and provide up-to-date imaging information that meets the needs of oncologists in both research trials and clinical practice, radiologists need to familiarize themselves with the various standardized tumor response criteria.

Imaging-based diagnostic systems for hepatocellular carcinoma.

OBJECTIVE: Noninvasive imaging plays critical roles in the treatment of patients with cirrhosis or other risk factors for the development of hepatocellular carcinoma. In recognition of the critical roles played by imaging, numerous international scientific organizations and societies have, in the past 12 years, proposed diagnostic systems for the interpretation of liver imaging examinations performed of at-risk patients. CONCLUSION: Although these imaging-based diagnostic systems represent important advances, they have limitations and they are not perfectly consistent with each other. The limitations and inconsistencies potentially cause confusion and may impair the integration of the systems into clinical practice as well as their utilization in research studies. The purpose of this article is to synthesize and critically appraise the current published imaging-based diagnostic systems endorsed by major societies for the noninvasive diagnosis and staging of hepatocellular carcinoma and to propose future directions that we hope may be helpful in further advancing the field.