LI-RADS v2017 for liver nodules: how we read and report

[Multiparametric magnetic resonance imaging for hepatocellular carcinoma, part 1 : Morphology and dynamic perfusion imaging in primary diagnostics and treatment monitoring]

Radiology plays a key role in the diagnosis and monitoring of hepatocellular carcinoma (HCC). Ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) are used to identify HCC lesions. Multiparametric MRI provides detailed insights into the tumor biology through the analysis of morphology, perfusion and diffusion. In this way preoperative decisions can be optimized. The guidelines recommend using contrast-enhanced MRI or ultrasound for the diagnosis of HCC. The preferred method is MRI due to its superiority in the detection of small lesions The treatment response is evaluated using modified response evaluation criteria for solid tumors (RECIST) and the European Association for the Study of the Liver (EASL) criteria. The use of multiparametric MRI in conjunction with the liver imaging reporting and data system (LI-RADS) plays overall a central role in the precise diagnosis and monitoring of the treatment of HCC.

Hepatocellular carcinoma: State of the art diagnostic imaging

Primary liver cancer is the fourth most common malignancy worldwide, with hepatocellular carcinoma (HCC) comprising up to 90% of cases. Imaging is a staple for surveillance and diagnostic criteria for HCC in current guidelines. Because early diagnosis can impact treatment approaches, utilizing new imaging methods and protocols to aid in differentiation and tumor grading provides a unique opportunity to drastically impact patient prognosis. Within this review manuscript, we provide an overview of imaging modalities used to screen and evaluate HCC. We also briefly discuss emerging uses of new imaging techniques that offer the potential for improving current paradigms for HCC characterization, management, and treatment monitoring.

Massive Hepatocellular Carcinoma with Situs Inversus Totalis Achieved a Complete Response Following Camrelizumab Plus Apatinib and Combined with Two-Stage Hepatectomy: A Case Report

Situs inversus totalis (SIT) is a rare congenital condition in which abdominal and thoracic organs are transposed from normal positions. Two-stage hepatectomy (TSH) combined with translational therapy for hepatocellular carcinoma (HCC) with SIT has been rarely reported. We report a 41-year-old man with giant hepatocellular carcinoma (71 mm × 55 mm × 51 mm) whose future residual liver (FLR) and standard liver volume (SLV) ratio at first diagnosis was 37.4%. Preoperative volume assessment of portal vein ligation (PVL) revealed inadequate hypertrophy of FLR. After a multidisciplinary group discussion (MDT), the patient decided to follow conversion therapy. Three months later, ratio of the FLR/SLV increased from 37.4% to 71% after operation, which met the surgical requirements. Second hepatectomy, right lobectomy was successful. There was no recurrence after six months of follow-up. In our case, conversion therapy appears to be effective in maintaining residual liver hyperplasia, reducing tumor load, and preventing tumor progression in patients with large HCC during TSH.

A Narrative Review on LI-RADS Algorithm in Liver Tumors: Prospects and Pitfalls

Liver cancer is the sixth most detected tumor and the third leading cause of tumor death worldwide. Hepatocellular carcinoma (HCC) is the most common primary liver malignancy with specific risk factors and a targeted population. Imaging plays a major role in the management of HCC from screening to post-therapy follow-up. In order to optimize the diagnostic-therapeutic management and using a universal report, which allows more effective communication among the multidisciplinary team, several classification systems have been proposed over time, and LI-RADS is the most utilized. Currently, LI-RADS comprises four algorithms addressing screening and surveillance, diagnosis on computed tomography (CT)/magnetic resonance imaging (MRI), diagnosis on contrast-enhanced ultrasound (CEUS) and treatment response on CT/MRI. The algorithm allows guiding the radiologist through a stepwise process of assigning a category to a liver observation, recognizing both major and ancillary features. This process allows for characterizing liver lesions and assessing treatment. In this review, we highlighted both major and ancillary features that could define HCC. The distinctive dynamic vascular pattern of arterial hyperenhancement followed by washout in the portal-venous phase is the key hallmark of HCC, with a specificity value close to 100%. However, the sensitivity value of these combined criteria is inadequate. Recent evidence has proven that liver-specific contrast could be an important tool not only in increasing sensitivity but also in diagnosis as a major criterion. Although LI-RADS emerges as an essential instrument to support the management of liver tumors, still many improvements are needed to overcome the current limitations. In particular, features that may clearly distinguish HCC from cholangiocarcinoma (CCA) and combined HCC-CCA lesions and the assessment after locoregional radiation-based therapy are still fields of research.

Failure in all steps of hepatocellular carcinoma surveillance process is frequent in daily practice

INTRODUCTION AND OBJECTIVES

Failures at any step in the hepatocellular carcinoma (HCC) surveillance process can result in HCC diagnostic delays and associated worse prognosis. We aimed to estimate the prevalence of surveillance failure and its associated risk factors in patients with HCC in Argentina, considering three steps: 1) recognition of at-risk patients, 2) implementation of HCC surveillance, 3) success of HCC surveillance.

METHODS

We performed a multi-center cross-sectional study of patients at-risk for HCC in Argentina seen between10.01.2018 and 10.30.2019. Multivariable logistic regression analysis was used to identify correlates of surveillance failure.

RESULTS

Of 301 included patients, the majority were male (74.8%) with a mean age of 64 years old. At the time of HCC diagnosis, 75 (25%) patients were unaware of their diagnosis of chronic liver disease, and only 130 (43%) patients were under HCC surveillance. Receipt of HCC surveillance was significantly associated with follow-up by a hepatologist. Of 119 patients with complete surveillance, surveillance failure occurred in 30 (25%) patients. Surveillance failure was significantly associated with alpha fetoprotein ≥20 ng/mL (OR 4.0, CI 95% 1.43-11.55).

CONCLUSIONS

HCC surveillance failure was frequent in all the evaluated steps. These data should help guide strategies to improve the implementation and results of HCC surveillance in our country.

Adapting the Utility of Lipiodol CT in Treating Small Hepatocellular Carcinoma

Introduction

Multiphase MRI liver is the gold-standard imaging modality for staging hepatocellular carcinoma (HCC) in patients with cirrhosis. Often, small HCCs diagnosed on multiphase MRI are occult on B-mode ultrasound and multiphase CT (MPCT) and thus pose a challenge for loco-regional therapy. We adapted the technique of lipiodol CT in treating two such patients of small HCC.

Methods

Lipiodol-CT involved an intra-arterial lipiodol injection through the hepatic artery followed by a noncontrast CT liver. CT delineated small, hyperdense, lipiodol-laden hepatic nodules, which served as a target for executing ablation of the nodule and also revealed the true disease stage by depicting the additional number of tumors in the liver.

Results

Case one was a 51-year female, known case of chronic hepatitis C who presented with ascites for two months. She was diagnosed with a small HCC (LI-RADS-4) in a cirrhotic liver on multiphase MRI. Percutaneous radiofrequency ablation was planned, but the mass was not located on ultrasound or multiphase CT. Lipiodol-CT was undertaken, which delineated the lipiodol-laden small HCC, which served as a target for executing ablation. Case 2 was a 55-year male, Child-Pugh A cirrhotic, who had undergone right extended hepatectomy for hepatitis B-related HCC. Follow-up MRI revealed a 5 mm segment III nodule, which had increased in size on repeat MRI at 3 months (LI-RADS-4). This nodule, too, was occult on both ultrasound and MPCT. Lipiodol CT revealed additional multiple, variable-sized lipiodol-laden nodules in the liver remnant. Treatment of trans-arterial chemoembolization was performed at one month. Both patients showed complete response to treatment. Conclusion: Lipiodol CT can be safely used in a new role of facilitating treatment of small HCCs diagnosed on MRI but occult on ultrasonography and MPCT.

Optimizing diagnostic imaging data using LI-RADS and the Likert scale in patients with hepatocellular carcinoma

Purpose

The study aimed to compare the diagnostic performance of the Liver Imaging Reporting and Data System (LI-RADS), which incorporates fixed criteria, and the Likert scale (LS), which mainly depends on an overall impression in liver lesion diagnosis.

Material and methods

Diagnostic data of 110 hepatic nodules in 103 high-risk patients for hepatocellular carcinoma (HCC) were included. Data including diameter, arterial hyperenhancement, washout, and capsule were reviewed by 2 readers using LI-RADS and LS (range, score 1-5). Inter-reader agreement (IRA), intraclass agreement (ICA), and diagnostic performance were determined by Fleiss, Cohen’s k, and logistic regression, respectively.

Results

There were 53 triphasic enhanced computed tomography (CT) and 50 dynamic magnetic resonance (MR) examinations. Overall, IRA was excellent (k = 0.898). IRA was good for arterial hyperenhancement (k = 0.705), washout (k = 0.763), and capsule (k = 0.771) and excellent for diameter (k = 0.981) and tumour embolus (k = 0.927). Overall, ICA between LI-RADS and LS was fair 0.32; ICA was good for scores of 1 (k = 0.682), fair for scores of 2 (k = 0.36), moderate for scores of 5 (k = 0.52), but no agreement was found for scores of 3 (k = –0.059) and 4 (k = –0.022). LIRADS produced relatively high accuracy (87.3% vs. 80%), relatively low sensitivity (84.3% vs. 98%), and significantly higher specificity (89.83% vs. 64.4%) and positive likelihood ratio (+LR: 8.29 vs. 2.75) compared to LS approach.

Conclusions

LI-RADS revealed higher diagnostic accuracy as compared to LS with statistical proof higher specificity and +LR showing its ability to foretell malignancy in high-risk patients. We recommend the practical application of the LI-RADS system in the detection and treatment response monitoring of patients with HCC.

Contrast-Enhanced Ultrasonography for Screening and Diagnosis of Hepatocellular Carcinoma: A Case Series and Review of the Literature

Background: Contrast-enhanced ultrasound (CEUS) is a safe and noninvasive imaging technique that can characterize and evaluate liver lesions, and has been approved for this use in the Unites States since 2016. CEUS has been shown to be similar in accuracy to computed tomography (CT) and magnetic resonance imaging (MRI) for noninvasive diagnosis of hepatocellular carcinoma (HCC) and offers several advantages in certain patient populations who have contraindications for CT or MRI. However, CEUS has inherent limitations and has not been widely employed for evaluation of HCC. Methods: We present three retrospective cases of liver lesions in patients with cirrhosis, who underwent screening for HCC using concurrent, well-timed CT and CEUS. Results: In these cases, the liver lesions were better visualized and then diagnosed as malignancy via CEUS, whereas the lesions were best appreciated on CT only in retrospect. Conclusions: In some cirrhotic patients, a focal lesion may be more easily identifiable via CEUS than on CT and thus accurately characterized, suggesting an important and complementary role of CEUS with CT or MRI. Further studies are indicated to support the use of CEUS for the diagnosis and characterization of liver lesions in screening patients at risk for developing HCC.

Contrast imaging techniques to diagnose hepatocellular carcinoma in cirrhotics outside regular surveillance

INTRODUCTION AND AIM

The American Association for the Study of the Liver (AASLD) recommends contrast computerized tomography (CT-scan) and magnetic resonance (MRI) to diagnose hepatocellular carcinoma (HCC) arising in cirrhotic patients under semiannual surveillance with abdominal ultrasound (US). A US guided fine needle biopsy (FNB) serves the same purpose in radiologically undiagnosed tumors and incidentally detected nodules in cirrhotics outside surveillance. In this population, we evaluated the performance of radiological diagnosis of HCC according to 2010 AASLD recommendations.

MATERIALS AND METHODS

All cirrhotic patients with a liver nodule incidentally detected by US were prospectively investigated with a sequential application of CT-scan/MRI examination and a FNB.

RESULTS

Between 2011 and 2015, 94 patients (mean age 67 years) had a liver nodule (total 120) detected by US in the context of histologically confirmed cirrhosis. Mean nodules diameter was 40 (10-160) mm, 87 (73%) <5cm. At histology, 84 (70%) nodules were HCC, 8 (7%) intrahepatic cholangiocarcinoma, 6 (5%) metastases, 2 (2%) neuroendocrine tumors and 20 (16%) benign lesions. Hyperenhancement in arterial phase followed by wash-out in venous phases on at least one radiological technique was demonstrated in 62 nodules (61 HCC, 1 high grade dysplastic nodule), with a specificity of 97% (IC95%: 85-100%), sensitivity 73% (IC95%: 62-81%) and diagnostic accuracy 80%, being 64% for ≥5cm HCC. Sensitivity of AFP >200ng/mL was 12% (IC95%: 6-23%).

CONCLUSION

A single contrast imaging technique showing a typical contrast pattern confidently identifies HCC also in cirrhotic patients with an incidental liver nodule, thereby reducing the need for FNB examinations.

Hepatocellular carcinoma: Can LI-RADS v2017 with gadoxetic-acid enhancement magnetic resonance and diffusion-weighted imaging improve diagnostic accuracy?

BACKGROUND

The Liver Imaging Reporting and Data System (LI-RADS), supported by the American College of Radiology (ACR), has been developed for standardizing the acquisition, interpretation, reporting, and data collection of liver imaging examinations in patients at risk for hepatocellular carcinoma (HCC). Diffusion-weighted imaging (DWI), which is described as an ancillary imaging feature of LI-RADS, can improve the diagnostic efficiency of LI-RADS v2017 with gadoxetic acid-enhanced magnetic resonance imaging (MRI) for HCC.

AIM

To determine whether the use of DWI can improve the diagnostic efficiency of LI-RADS v2017 with gadoxetic acid-enhanced magnetic resonance MRI for HCC.

METHODS

In this institutional review board-approved study, 245 observations of high risk of HCC were retrospectively acquired from 203 patients who underwent gadoxetic acid-enhanced MRI from October 2013 to April 2018. Two readers independently measured the maximum diameter and recorded the presence of each lesion and assigned scores according to LI-RADS v2017. The test was used to determine the agreement between the two readers with or without DWI. In addition, the sensitivity (SE), specificity (SP), accuracy (AC), positive predictive value (PPV), and negative predictive value (NPV) of LI-RADS were calculated. Youden index values were used to compare the diagnostic performance of LI-RADS with or without DWI.

RESULTS

Almost perfect interobserver agreement was obtained for the categorization of observations with LI-RADS (kappa value: 0.813 without DWI and 0.882 with DWI). For LR-5, the diagnostic SE, SP, and AC values were 61.2%, 92.5%, and 71.4%, respectively, with or without DWI; for LR-4/5, they were 73.9%, 80%, and 75.9% without DWI and 87.9%, 80%, and 85.3% with DWI; for LR-4/5/M, they were 75.8%, 58.8%, and 70.2% without DWI and 87.9%, 58.8%, and 78.4% with DWI; for LR- 4/5/TIV, they were 75.8%, 75%, and 75.5% without DWI and 89.7%, 75%, and 84.9% with DWI. The Youden index values of the LI-RADS classification without or with DWI were as follows: LR-4/5: 0.539 vs 0.679; LR-4/5/M: 0.346 vs 0.467; and LR-4/5/TIV: 0.508 vs 0.647.

CONCLUSION

LI-RADS v2017 has been successfully applied with gadoxetate-enhanced MRI for patients at high risk for HCC. The addition of DWI significantly increases the diagnostic efficiency for HCC.

Distinguishing Tumor From Bland Portal Vein Thrombus in Liver Transplant Candidates With Hepatocellular Carcinoma: the A-VENA Criteria

Differentiating tumor versus bland portal vein thrombosis (PVT) is essential in determining liver transplantation (LT) candidacy for patients with hepatocellular carcinoma (HCC). We aimed to evaluate radiographic and clinical features that could noninvasively distinguish tumor PVT from bland PVT in HCC patients. Of 467 patients with HCC listed for LT from 2004 to 2011, 59 (12.6%) had PVT and 12 of 59 (20.3%) were deemed malignant. When comparing tumor versus bland PVT, thrombus enhancement was seen in 100% versus 8.5%; venous expansion was seen in 91.7% versus 10.6%; neovascularity was seen in 58.3% versus 2.1%; and being adjacent to HCC or prior treatment site was seen in 100% versus 21.3% (all P < 0.001). Combining these 4 imaging characteristics with alpha-fetoprotein (AFP) >1000 ng/dL, the presence of ≥3 criteria best characterized tumor PVT with 100% sensitivity, 93.6% specificity, 80% positive predictive value, and 100% negative predictive value. No LT recipients with presumed bland PVT had macrovascular invasion on explant. There were no differences in post-LT survival or HCC recurrence with bland PVT versus no PVT. In conclusion, we proposed noninvasive criteria that could accurately differentiate tumor PVT from bland PVT called A-VENA, which is based on the presence of ≥3 of the following: AFP >1000 ng/dL; venous expansion; thrombus enhancement; neovascularity; and adjacent to HCC. Use of the A-VENA criteria can assist in standardizing the evaluation of PVT in patients with HCC being considered for LT.