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

Evaluating Fallopian Tube Patency: What the Radiologist Needs to Know

Impaired tubal patency accounts for up to 35% of cases of subfer-tility and infertility. Hysterosalpingography (HSG) or hysterosal-pingo-contrast sonography (HyCoSy) represents a first-line test in evaluating fallopian tube patency. Despite the association of HSG with ionizing radiation, HSG is a reference standard in assessing fallopian tube patency and tubal conditions such as tubal occlusion, salpingitis isthmica nodosa, and hydrosalpinx. HSG is widely available and utilizes either a water-soluble contrast medium (WSCM) or an oil-soluble contrast medium (OSCM). Compared with WSCM, HSG with OSCM results in a higher incidence of non–in vitro fertilization pregnancies and, therefore, may be pre-ferred in women younger than 38 years with unexplained subfer-tility. HSG may also be helpful in assessment after sterilization or before fallopian tube recanalization. US-based tubal tests are free of ionizing radiation and include HyCoSy, with either air-saline or microbubble US contrast material, and hysterosalpingo-foam sonography (HyFoSy), a tubal patency test that utilizes a gel foam. A comprehensive US infertility evaluation of the pelvis and fallopian tubes can be achieved in one setting by adding coronal three-dimensional imaging of the uterus, saline infusion sonohysterogra-phy, and HyCoSy or HyFoSy to routine pelvic US. MR HSG and virtual CT HSG also depict tubal patency and uterine and adnexal pathologic conditions and may be considered in select patients. While laparoscopic chromopertubation remains the standard for tubal patency evaluation, its disadvantages are its invasiveness and cost. Knowledge of the different fallopian tube tests and radiologic appearance of normal and abnormal fallopian tubes results in fewer pitfalls, accurate interpretation, and optimal patient care

Role of US LI-RADS in the LI-RADS Algorithm.

The US Liver Imaging Reporting and Data System (LI-RADS) was released in 2017 and is the newest of the four American College of Radiology (ACR) LI-RADS algorithms. US LI-RADS provides standardized terminology, technical recommendations, and a reporting framework for US examinations performed for screening or surveillance in patients at risk for developing hepatocellular carcinoma (HCC). The appropriate patient population for screening and surveillance includes individuals who are at risk for developing HCC but do not have known or suspected cancer. This includes patients with cirrhosis from any cause and subsets of patients with chronic hepatitis B virus infection in the absence of cirrhosis. In an HCC screening or surveillance study, US LI-RADS recommends assigning two scores that apply to the entire study: the US category, which determines follow-up, and a visualization score, which communicates the expected level of sensitivity of the examination but does not affect management. Three US categories are possible: US-1 negative, a study with no evidence of HCC; US-2 subthreshold, a study in which an observation less than 10 mm is depicted that is not definitely benign; and US-3 positive, a study in which an observation greater than or equal to 10 mm or a new thrombus in vein is identified, for which diagnostic contrast material-enhanced imaging is recommended. Three visualization scores are possible: A (no or minimal limitations), B (moderate limitations), and C (severe limitations). ©RSNA, 2019

Clinical validation of contrast-enhanced ultrasound liver imaging reporting and data system in a prospective multinational study in North America and Europe.

BACKGROUND AIMS: The objective of this study is to determine diagnostic accuracy of the American College of Radiology Contrast-Enhanced Ultrasound (CEUS) Liver Imaging Reporting and Data System (LI-RADS) LR-5 characterization for HCC diagnosis in North American or European patients. APPROACH RESULTS: Prospective multinational cohort study was performed from 01/2018 through 11/2022 at 11 academic and nonacademic centers in North America and Europe. Patients at risk for HCC with at least one liver observation not previously treated, identified on ultrasound (US) or multiphase CT or MRI performed as a part of standard clinical care were eligible for the study. All participants were examined with CEUS of the liver within 4 weeks of CT / MRI or tissue diagnosis to characterize up to 2 liver nodules per participant using ACR CEUS LI-RADS. Definite HCC diagnosis on the initial CT/MRI, imaging follow-up, or histology for CT/MRI-indeterminate nodules were used as reference standard. A total 545 nodules had confirmed reference standard in 480 patients, 73.8% were HCC, 5.5% other malignancy, and 20.7% were non-malignant. The specificity of CEUS LR-5 for HCC was 95.1% (95% CI 90.1% - 97.7%), sensitivity 62.9% (95% CI 57.9%-67.7%), Positive Predictive Value (PPV) 97.3% (95% CI 94.5% - 98.7%), and Negative Predictive Value (NPV) 47.7% (95% CI 41.7% - 53.8%). In addition, benign CEUS characterization (LR-1 or LR-2) had 100% specificity and 100% PPV for non-malignant liver nodules. CONCLUSIONS: CEUS LI-RADS characterization provides accurate categorization of liver nodules in participants at risk for HCC. ClinicalTrials.gov ID NCT03318380

Clinical validation of contrast-enhanced ultrasound liver imaging reporting and data system in a prospective multinational study in North America and Europe.

BACKGROUND AIMS The objective of this study is to determine diagnostic accuracy of the American College of Radiology Contrast-Enhanced Ultrasound (CEUS) Liver Imaging Reporting and Data System (LI-RADS) LR-5 characterization for HCC diagnosis in North American or European patients. APPROACH RESULTS Prospective multinational cohort study was performed from 01/2018 through 11/2022 at 11 academic and nonacademic centers in North America and Europe. Patients at risk for HCC with at least one liver observation not previously treated, identified on ultrasound (US) or multiphase CT or MRI performed as a part of standard clinical care were eligible for the study. All participants were examined with CEUS of the liver within 4 weeks of CT / MRI or tissue diagnosis to characterize up to 2 liver nodules per participant using ACR CEUS LI-RADS. Definite HCC diagnosis on the initial CT/MRI, imaging follow-up, or histology for CT/MRI-indeterminate nodules were used as reference standard. A total 545 nodules had confirmed reference standard in 480 patients, 73.8% were HCC, 5.5% other malignancy, and 20.7% were non-malignant. The specificity of CEUS LR-5 for HCC was 95.1% (95% CI 90.1% - 97.7%), sensitivity 62.9% (95% CI 57.9%-67.7%), Positive Predictive Value (PPV) 97.3% (95% CI 94.5% - 98.7%), and Negative Predictive Value (NPV) 47.7% (95% CI 41.7% - 53.8%). In addition, benign CEUS characterization (LR-1 or LR-2) had 100% specificity and 100% PPV for non-malignant liver nodules. CONCLUSIONS CEUS LI-RADS characterization provides accurate categorization of liver nodules in participants at risk for HCC. ClinicalTrials.gov ID NCT03318380