Enhancement patterns of focal liver masses: discordance between contrast-enhanced sonography and contrast-enhanced CT and MRI

Unique portal venous phase imaging discordance between CEUS and MRI: a valuable predictor of intrahepatic cholangiocarcinoma?

PURPOSE

We have long noted unique portal venous phase (PVP) imaging discordance of focal liver masses between CEUS, showing rapid marked washout, and MRI, showing progressive or sustained enhancement. We postulate association of this unique discordance with intrahepatic cholangiocarcinoma (ICC) and causal relationship to different contrast agent behavior. We investigate this unique discordance, propose its clinical significance for ICC diagnosis, and confirm further histologic associations.

METHODS

Cases were collected within our CEUS department and from pathology records over a ten-year interval. This retrospective review includes 99 patients, 73 with confirmed ICC and 26 other diagnoses, showing unique PVP discordance. The CEUS and MRI enhancement characteristics were compared for all patients.

RESULTS

Unique discordance is identified in 67/73 (92%) ICC and difference between the PVP appearance on MRI and CEUS is statistically significant (p <  0.0001). Arterial phase enhancement did not show statistically significant difference between CEUS and MRI, p >  0.05. Other diagnoses showing unique discordance include especially lymphoma (n = 7), sclerosed hemangioma (n = 6), HCC (n = 4), metastases (n = 2), and other rare entities.

CONCLUSION

ICC shows this discrepant intermodality enhancement pattern in a statistically significant number of cases and should be considered along with other LR-M features in at-risk patients. Discordance is also rarely seen in a number of other liver lesions.

The Role of Contrast-Enhanced Ultrasound (CEUS) in the Detection of Neoplastic Portal Vein Thrombosis in Patients with Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the principal primary liver cancer and one of the most frequent malignant tumors worldwide in patients with chronic liver disease. When diagnosed at an advanced stage, it is often associated with portal vein tumor thrombosis (PVTT), which heavily affects patients' prognosis. Imaging evaluation is crucial in PVTT detection and staging; computed tomography and magnetic resonance are the principal diagnostic tools. Contrast-enhanced ultrasound (CEUS) is a non-invasive and easily repeatable method that can also be used in patients with impaired renal function. It represents an important means for the identification of PVTT, particularly differentiating neoplastic and non-neoplastic thrombosis through the analysis of ultrasound enhancement characteristics of the thrombosis (arterial hyperenhancement and portal washout), thus allowing more refined disease staging, appropriate treatment planning, and response evaluation, along with prognosis assessment.

Differences between CEUS LI-RADS and CECT LI-RADS in the diagnosis of focal liver lesions in patients at risk for HCC

OBJECTIVES

To compare the inter-modality consistency and diagnostic performances of the contrast-enhanced ultrasound (CEUS) Liver Imaging Reporting and Data System (LI-RADS) and contrast-enhanced computed tomography (CECT) LI-RADS in patients at risk for hepatocellular carcinoma (HCC), so as to help clinicians to select a more appropriate modality to follow the focal liver lesions (FLLs).

METHODS

This retrospective study included untreated 277 FLLs from 247 patients who underwent both CEUS and CECT within 1 month. The ultrasound contrast medium used was SonoVue. FLL categories were independently assigned by two ultrasound physicians and two radiologists using CEUS LI-RADS v2017 and CECT LI-RADS v2018, respectively. The diagnostic performances of CEUS and CECT LI-RADS were evaluated using sensitivity, specificity, positive predictive value (PPV), and negative predictive value. Cohen's Kappa was employed to evaluate the concordance of the LI-RADS category.

RESULTS

The inter-modality consistency for CEUS and CECT LI-RADS was 0.31 (p < 0.001). HCC was more frequently observed in CECT LR-3 and LR-4 hepatic lesions than in CEUS (7.3% vs. 19.5%, p < 0.001). The specificity and PPV of CEUS and CECT LR-5 for the diagnosis of HCC were 89.5%, 95.0%, and 82.5%, 94.4%, respectively. The sensitivity of CEUS LR-5 + LR-M for the diagnosis of hepatic malignancies was higher than that of CECT (93.7% vs. 82.7%, p < 0.001). The specificity and PPV of CEUS LR-M for the diagnosis of non-HCC malignancies were lower than those of CECT (59.7% vs. 95.5%, p < 0.001; 23.4% vs. 70.3%, p < 0.001).

CONCLUSIONS

The inter-modality consistency between the CEUS and CECT LI-RADS categories is fair. CEUS LI-RADS was more sensitive than CECT LI-RADS in terms of identifying hepatic malignancies, but weaker in terms of separating HCC from non-HCC malignancies.

Characterization of hepatobiliary phase hypointense nodules without arterial phase hyperenhancement on gadoxetic acid-enhanced MRI via contrast-enhanced ultrasound using perfluorobutane

PURPOSE

Hepatobiliary phase (HBP) hypointense nodules without arterial phase hyperenhancement (APHE) on gadoxetic acid-enhanced MRI (GA-MRI) may be nonmalignant cirrhosis-associated nodules or hepatocellular carcinomas (HCCs). We aimed to characterize HBP hypointense nodules without APHE on GA-MRI by performing contrast-enhanced ultrasound using perfluorobutane (PFB-CEUS).

METHODS

In this prospective, single-center study, participants at high-risk of HCC having HBP hypointense nodules without APHE at GA-MRI were enrolled. All participants underwent PFB-CEUS; if APHE and late, mild washout or washout in the Kupffer phase were present, the diagnosis of HCC was established according to the v2022 Korean guidelines. The reference standard consisted of histopathology or imaging. The sensitivity, specificity, and positive/negative predictive values of PFB-CEUS for detecting HCC were calculated. Associations between clinical/imaging features and the diagnosis of HCC were evaluated with logistic regression analyses.

RESULTS

In total, 67 participants (age, 67.0 years ± 8.4; 56 men) with 67 HBP hypointense nodules without APHE (median size, 1.5 cm [range, 1.0-3.0 cm]) were included. The prevalence of HCC was 11.9% (8/67). The sensitivity, specificity, and positive and negative predictive values of PFB-CEUS for detecting HCC were 12.5%(1/8), 96.6%(57/59), 33.3%(1/3) and 89.1%(57/64), respectively. Mild-moderate T2 hyperintensity on GA-MRI (odds ratio, 5.756; P = 0.042) and washout in the Kupffer phase on PFB-CEUS (odds ratio, 5.828; P = 0.048) were independently associated with HCC.

CONCLUSION

Among HBP hypointense nodules without APHE, PFB-CEUS was specific for detecting HCC, which had a low prevalence. Mild-moderate T2 hyperintensity on GA-MRI and washout in the Kupffer phase on PFB-CEUS may be useful to detect HCC in those nodules.

Nodules Identified on Surveillance Ultrasound for HCC: CEUS or MRI as the Initial Test?

OBJECTIVES

Following positive surveillance ultrasound (US), magnetic resonance imaging (MRI) is recommended for further characterization. We propose contrast-enhanced ultrasound (CEUS) shows equivalent efficacy.

METHODS

This prospective institutional review board approved study recruited 195 consecutive at-risk patients with a positive surveillance US. All had CEUS and MRI. Biopsy (n = 44) and follow-up are gold standard. MRI and CEUS results are classified according to liver imaging reporting and data system (LI-RADS) and patient outcome.

RESULTS

As an US-based modality, CEUS is superior in confirming findings from surveillance US, correlation in 189/195 (97%) on CEUS compared to 153/195 (79%) on MRI. Within these negative MRI examinations, there are 2 hepatocellular carcinoma (HCC) and 1 cholangiocarcinoma (iCCA) diagnosed on CEUS and proven by biopsy. From 195 patients, there are 71 malignant diagnoses from all sources, including 58 LR-5 (45 on MRI and 54 on CEUS) and 13 others, including HCC outside of LR-5 category, and LR-M with biopsy proven iCCA (3 on MRI and 6 on CEUS). CEUS and MRI show concordant results in the majority of patients (146/195, 75%), including 57/146 malignant and 89/146 benign diagnoses. There are 41/57 concordant LR-5 and 6/57 concordant LR-M. When CEUS and MRI are discordant, CEUS upgraded 20 (10 biopsy-proven) from MRI LR-3/4 to CEUS LR-5 or LR-M by showing washout (WO) that MRI failed to show. Additionally, CEUS characterized time and intensity of WO and diagnosed 13/20 LR-5 by showing late and weak WO and 7 LR-M by showing fast and marked WO. CEUS is 81% sensitive and 92% specific in diagnosing malignancy. MRI is 64% sensitive and 93% specific.

CONCLUSIONS

CEUS performance is at least equivalent if not superior to MRI for initial evaluation of lesions from surveillance US.

Multiparametric Dynamic Ultrasound Approach for Differential Diagnosis of Primary Liver Tumors

A correct differentiation between hepatocellular carcinoma (HCC) and intracellular cholangiocarcinoma (ICC) is essential for clinical management and prognostic prediction. However, non-invasive differential diagnosis between HCC and ICC remains highly challenging. Dynamic contrast-enhanced ultrasound (D-CEUS) with standardized software is a valuable tool in the diagnostic approach to focal liver lesions and could improve accuracy in the evaluation of tumor perfusion. Moreover, the measurement of tissue stiffness could add more information concerning tumoral environment. To explore the diagnostic performance of multiparametric ultrasound (MP-US) in differentiating ICC from HCC. Our secondary aim was to develop an US score for distinguishing ICC and HCC. Between January 2021 and September 2022 consecutive patients with histologically confirmed HCC and ICC were enrolled in this prospective monocentric study. A complete US evaluation including B mode, D-CEUS and shear wave elastography (SWE) was performed in all patients and the corresponding features were compared between the tumor entities. For better inter-individual comparability, the blood volume-related D-CEUS parameters were analyzed as a ratio between lesions and surrounding liver parenchyma. Univariate and multivariate regression analysis was performed to select the most useful independent variables for the differential diagnosis between HCC and ICC and to establish an US score for non-invasive diagnosis. Finally, the diagnostic performance of the score was evaluated by receiver operating characteristic (ROC) curve analysis. A total of 82 patients (mean age ± SD, 68 ± 11 years, 55 men) were enrolled, including 44 ICC and 38 HCC. No statistically significant differences in basal US features were found between HCC and ICC. Concerning D-CEUS, blood volume parameters (peak intensity, PE; area under the curve, AUC; and wash-in rate, WiR) showed significantly higher values in the HCC group, but PE was the only independent feature associated with HCC diagnosis at multivariate analysis (p = 0.02). The other two independent predictors of histological diagnosis were liver cirrhosis (p < 0.01) and SWE (p = 0.01). A score based on those variables was highly accurate for the differential diagnosis of primary liver tumors, with an area under the ROC curve of 0.836 and the optimal cut-off values of 0.81 and 0.20 to rule in or rule out ICC respectively. MP-US seems to be a useful tool for non-invasive discrimination between ICC and HCC and could prevent the need for liver biopsy at least in a subgroup of patients.

Multimodal ultrasound features of breast cancers: correlation with molecular subtypes

OBJECTIVES

To investigate whether multimodal intratumour and peritumour ultrasound features correlate with specific breast cancer molecular subtypes.

METHODS

From March to November 2021, a total of 85 patients with histologically proven breast cancer underwent B-mode, real-time elastography (RTE), colour Doppler flow imaging (CDFI) and contrast-enhanced ultrasound (CEUS). The time intensity curve (TIC) of CEUS was obtained, and the peak and time to peak (TTP) were analysed. Chi-square and binary logistic regression were used to analyse the connection between multimodal ultrasound imaging features and breast cancer molecular subtype.

RESULTS

Among 85 breast cancers, the subtypes were as follows: luminal A (36 cases, 42.4%), luminal B (20 cases, 23.5%), human epidermal growth factor receptor-2 positive (HER2+) (16 cases, 18.8%), and triple negative breast cancer (TNBC) (13 cases, 15.3%). Binary logistic regression models showed that RTE (P < 0.001) and CDFI (P = 0.036) were associated with the luminal A cancer subtype (C-index: 0.741), RTE (P = 0.016) and the peak ratio between intratumour and corpus mamma (P = 0.036) were related to the luminal B cancer subtype (C-index: 0.788). The peak ratio between peritumour and intratumour (P = 0.039) was related to the HER2 + cancer subtype (C-index: 0.859), and CDFI (P = 0.002) was associated with the TNBC subtype (C-index: 0.847).

CONCLUSIONS

Multimodal ultrasound features could be powerful predictors of specific breast cancer molecular subtypes. The intra- and peritumour CEUS features play assignable roles in separating luminal B and HER2 + breast cancer subtypes.

Contrast-enhanced ultrasonography for early prediction of response of neoadjuvant chemotherapy in breast cancer

Neoadjuvant chemotherapy (NAC) is widely accepted as a primary treatment for inoperable or locally advanced breast cancer before definitive surgery. However, not all advanced breast cancers are sensitive to NAC. Contrast-enhanced ultrasonography (CEUS) has been considered to assess tumor response to NAC as it can effectively reflect the condition of blood perfusion and lesion size. Therefore, this study aimed to evaluate the diagnostic performance of CEUS to predict early response in different regions of interest in breast tumors under NAC treatment. This prospective study included 82 patients with advanced breast cancer. Parameters of TIC (time-intensive curve) between baseline and after the first cycle of NAC were calculated for the rate of relative change (Δ), including Δpeak, ΔTTP (time to peak), ΔRBV (regional blood volume), ΔRBF (regional blood flow) and ΔMTT (mean transit time). The responders and non-responders were distinguished by the Miller-Payne Grading (MPG) system and parameters from different regions of tumors were compared in these two groups. For ROI 1(the greatest enhancement area in the central region of the tumor), there were significant differences in Δpeak1, ΔRBV1 and ΔRBF1 between responders and non-responders. For ROI 2 (the greatest enhancement area on edge of the tumor), there were significant differences in Δpeak2 and ΔRBF2 between the groups. The Δpeak1 and ΔRBF2 showed good prediction (AUC 0.798-0.820, p ≤ 0.02) after the first cycle of NAC. When the cut-off value was 0.115, the ΔRBF2 had the highest diagnostic accuracy and the maximum NPV. Quantitative TIC parameters could be effectively used to evaluate early response to NAC in advanced breast cancer.

A comparative study of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging and contrast-enhanced ultrasound in the detection of intrahepatic lesion

We evaluated the diagnostic performance of both gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (Gd-EOB-DTPA-MRI) and contrast-enhanced ultrasound (CEUS) for focal liver lesions, especially for the detection of small (<2 cm) intrahepatic lesions. We retrospectively reviewed patients who underwent Gd-EOB-DTPA-MRI and CEUS before liver resection and compared Gd-EOB-DTPA-MRI and CEUS in the detection of focal liver lesions. A total of 216 patients were included, and 309 lesions were found. The sensitivity values of MRI and CEUS for the main lesion were both more than 95%, and the coincidence rates were both more than 80%. Regarding lesions <2 cm, 135 such lesions were detected by MRI, whereas only 85 were detected by CEUS. For lesions <2 cm, the sensitivity, specificity, and coincidence rates of MRI were significantly better than those of CEUS. Among 27 patients, 50 more lesions were detected by MRI than CEUS, 56% (28/50) of which were malignant. For the large lesion, the diagnostic performance is similar between Gd-EOB-DTPA-MRI and CEUS, and the sensitivity and coincidence rates of both methods are high. Gd-EOB-DTPA-MRI is likely to detect small (<2 cm) focal intrahepatic lesions.

Application of the CT/MRI LI-RADS Treatment Response Algorithm to Contrast-Enhanced Ultrasound: A Feasibility Study

Purpose

The contrast-enhanced ultrasound (CEUS) Liver Imaging Reporting and Data System (LI-RADS) treatment response algorithm (TRA) is still in development. The aim of this study was to explore whether the CT/MRI LI-RADS TRA features were applicable to CEUS in evaluating the liver locoregional therapy (LRT) response.

Patients and Methods

This study was a retrospective review of a prospectively maintained database of patients with hepatocellular carcinoma undergoing ablation between July 2017 and December 2018. The standard criteria for a viable lesion were a histopathologically confirmed or typical viable appearance in the follow-up CT/MRI. Performance of the LI-RADS TRA assessing tumor viability was then compared between CEUS and CT/MRI. Inter-reader association was calculated.

Results

A total of 244 patients with 389 treated observations (118 viable) were evaluated. The sensitivity and specificity of the CEUS TRA and CT/MRI LI-RADS TRA viable categories for predicting viable lesions were 55.0% (65/118) versus 56.8% (67/118) (P = 0.480) and 99.3% (269/271) versus 96.3% (261/271) (P = 0.013), respectively. The PPV of CEUS was higher than that of CT/MRI (97.0% vs 87.0%). Subgroup analysis showed that the sensitivity was low in the 1-month assessment for both CEUS (38.1%, 16/42) and CT/MR (47.6%, 20/42) and higher in the 2–6-month assessment for both CEUS (65.7%, 23/35) and CT/MR (62.9%, 22/35). Interobserver agreements were substantial for both CEUS TRA and CT/MRI LI-RADS TRA (κ, 0.74 for both).

Conclusion

The CT/MRI LI-RADS TRA features were applicable to CEUS TRA for liver locoregional therapy. The CEUS TRA for liver locoregional therapy has sufficiently high specificity and PPV to diagnose the viability of lesions after ablation.

Contrast-enhanced US of the Liver and Kidney: A Problem-solving Modality

Contrast-enhanced US (CEUS) has an important role as a supplement to CT or MRI in clinical practice. The main established utilizations are in the liver and the kidney. The primary advantages of CEUS compared with contrast-enhanced CT or MRI relate to its superior contrast resolution, real-time continuous scanning, pure intravascular nature, portability, and safety-especially in patients with renal impairment or CT or MRI contrast agent allergy. This article focuses on the use of CEUS in the liver and kidney.

Characterization of Focal Liver Masses: A Multicenter Comparison of Contrast-Enhanced Ultrasound, Computed Tomography, and Magnetic Resonance Imaging

OBJECTIVES

To demonstrate the usefulness of contrast-enhanced ultrasound (CEUS) for the evaluation of focal liver masses via a direct comparison to standard ultrasound and computed tomography/magnetic resonance imaging (CT/MRI).

METHODS

A cohort of 214 patients with previously undiagnosed focal liver masses were included from 5 different centers. Each patient was imaged using CEUS and CT and/or MRI. Anonymized and randomized images were interpreted by 4 separate blind readers from 3 of the participating centers (2 readers for CEUS and 2 readers for CT/MRI). Readers were blinded to patient demographics and past medical history. Readers were asked to decide if the lesion was benign or malignant, provide a final diagnosis for the lesion, and provide a confidence interval. Results were compared to truth standard from pathology or expert consensus.

RESULTS

In determination of malignancy, CEUS had a sensitivity of 95%, specificity of 82%, PPV of 82%, NPV of 95%, statistically better than standard ultrasound (sensitivity 82%, specificity 56%, PPV 60%, NPV 78%) with P < .01 and not statistically different from CT (sensitivity 90%, specificity 73% PPV 81%, NPV 86%) or MRI (sensitivity 85%, specificity 79%, PPV 68%, NPV 91%) with P ≥ .01. In assigning a final diagnosis, CEUS had an accuracy of 78% statistically better than standard ultrasound (46%) with P < .01 and not statistically different from CT (68%) or MRI (71%) with P > .01.

CONCLUSIONS

In the evaluation of focal liver lesions, both for determination of malignancy and in accuracy of final diagnosis, CEUS performs better than standard ultrasound and at least equivalent to both CT and MRI.

Hepatocellular carcinoma in the non-cirrhotic liver

Liver cirrhosis is an established high-risk factor for HCC and the majority of patients diagnosed with HCC have cirrhosis. However, HCC also arises in non-cirrhotic livers in approximately 20 %of all cases. HCC in non-cirrhotic patients is often clinically silent and surveillance is usually not recommended. HCC is often diagnosed at an advanced stage in these patients. Current information about HCC in patients with non-cirrhotic liver is limited. Here we review the current knowledge on epidemiology, clinical features and imaging features of those patiens.

Contrast -Enhanced Ultrasound: State of the Art in North America

The Society of Radiologists in Ultrasound convened a panel of specialists in contrast-enhanced ultrasound (CEUS) to produce a white paper on noncardiac CEUS in North America. The panel met in Chicago, Illinois, on October 24 and 25, 2017. The recommendations are based on analysis of current literature and common practice strategies and are thought to represent a reasonable approach to introduce the advantages of this safe and noninvasive technique for the benefit of our patients. Characterization of liver nodules, and pediatric vascular and intravesicular applications comprise the approved indications for CEUS in the United States. They, along with the very successful off-label use of CEUS for the kidney, are included in this publication.Other off-label uses are presented with emphasis on their value and literature support in the online version.

Utility of contrast-enhanced ultrasound for solid mass surveillance and characterization in children with tuberous sclerosis complex: an initial experience

BACKGROUND

Patients with tuberous sclerosis complex (TSC) can develop solid kidney masses from childhood. Imaging surveillance is done to detect renal cell carcinoma (RCC) and angiomyolipomas (AML), including AMLs at risk for hemorrhage. Intravenous contrast-enhanced ultrasound (CEUS) may be useful for screening as ultrasound is well tolerated by children and ultrasound contrast agents (UCA) are not nephrotoxic.

METHODS

Retrospective review of kidney CEUS exams of pediatric TSC patients. Qualitative CEUS analysis by consensus of 3 radiologists assessed rate, intensity, and pattern of lesion enhancement. Quantitative CEUS analysis was performed using Vuebox®. Where available, abdominal MRI was analyzed qualitatively for the same features and quantitatively by in-house-developed software. Time-intensity curves were generated from both CEUS and MRI where possible. Appearance of lesions were compared between CEUS and MRI and histology where available.

RESULTS

Nine masses in 5 patients included one histologically proven RCC and 8 AMLs diagnosed by imaging. Quantitative CEUS of RCC showed malignant features including increased peak enhancement 162%, rapid wash-in rate 162%, and elevated washout rate 156% compared to normal kidney tissue; versus AML which was 68%, 105%, and 125%, respectively. All masses were hypoenhancing on MRI compared to normal kidney tissue; MR dynamic contrast study offered no distinction between RCC and AML. The only MRI feature differentiating RCC from AML was absence of fat.

CONCLUSION

Temporal resolution afforded by CEUS was useful to distinguish malignant from benign kidney masses. CEUS may prove useful for screening, characterizing, and follow-up of kidney lesions in pediatric TSC patients.

CT/MRI LI-RADS v2018 vs. CEUS LI-RADS v2017-Can Things Be Put Together?

Simple Summary

The LI-RADS system is nowadays the mainstream system used in classifying liver nodules in cirrhotic liver according to their risk of malignancy. Two main LI-RADS documents have been released—the CEUS LI-RADS v2017 document, and the CT/MRI LI-RADS v2018 document. In some circumstances, a nodule can be differently classified when using CEUS versus when using CT or MRI. In this paper, we also focus on the existing similitudes between the two documents but, essentially, on the differences between the two main documents and the complementarities between imaging techniques in characterizing liver nodules in cirrhotic livers. Awareness of the complementarity of imaging techniques may lead to an improvement in the characterization and classification of liver nodules and will reduce the number of liver biopsies. This paper proposes practical solutions in order to better classify and manage observations or nodules detected in cirrhotic livers.

Abstract

Different LI-RADS core documents were released for CEUS and for CT/MRI. Both documents rely on major and ancillary diagnostic criteria. The present paper offers an exhaustive comparison of the two documents focusing on the similarities, but especially on the differences, complementarity, and added value of imaging techniques in classifying liver nodules in cirrhotic livers. The major diagnostic criteria are defined, and the sensitivity and specificity of each major diagnostic criteria are presented according to the literature. The existing differences between techniques in assessing the major diagnostic features can be then exploited in order to ensure a better classification and a better clinical management of liver nodules in cirrhotic livers. Ancillary features depend on the imaging technique used, and their presence can upgrade or downgrade the LI-RADS score of an observation, but only as far as LI-RADS 4. MRI is the imaging technique that provides the greatest number of ancillary features, whereas CEUS has fewer ancillary features than other imaging techniques. In the final part of the manuscript, some recommendations are made by the authors in order to guidephysicians as to when adding another imaging technique can be helpful in managing liver nodules in cirrhotic livers.

MR versus CEUS LI-RADS for Distinguishing Hepatocellular Carcinoma from other Hepatic Malignancies in High-Risk Patients

Distinguishing between other hepatic malignancies (OMs) and hepatocellular carcinoma (HCC) is vital to allow clinicians to determine optimal treatment and assess prognosis in patients at high risk for HCC. This study evaluated the performance of the Liver Imaging Reporting and Data System (LI-RADS) using magnetic resonance imaging (MRI) versus contrast-enhanced ultrasonography (CEUS) for differentiating HCC from OMs in patients at high risk for HCC. This retrospective study consecutively enrolled 106 high-risk patients with HCC and 52 high-risk patients with OMs. Patients underwent both MRI and CEUS, with histologic diagnosis as a reference standard. The diagnostic performance of MR versus CEUS LI-RADS was calculated and compared. The performance of the modified CEUS LI-RADS criteria was also evaluated and compared. Our research found that MRI features significantly differed between patients with OMs and those with HCC (p < 0.05), with sensitivities of 34.6%-69.2% and specificities of 83.0%-95.3% for diagnosing OMs and an LI-RADS M (LR-M): definite or probable malignancy, not specific for hepatocellular carcinoma sensitivity of 90.4% and specificity of 83.0% for diagnosing OM. CEUS features also significantly differed between patients with OM and HCC (p < 0.05), with sensitivities of 11.5%-96.2% and specificities of 23.6%-100% for diagnosing OMs, and an LR-M sensitivity of 98.1% and specificity of 84.0% for diagnosing OMs. Accuracies of category LR-M did not significantly differ between MR and CEUS LI-RADS (85.4% vs. 88.6%, p = 0.724). After reclassification of category LR-M nodules to category LR-5 if they exhibited clear intratumoral non-enhanced area boundaries and no punched-out appearance before 5 min, accuracy increased from 88.6% to 96.8% for CEUS LR-M and from 84.8% to 91.1% for CEUS LR-5. LR-M accuracies were significantly higher for the modified version of the CEUS LI-RADS than for MR LI-RADS (96.8% vs. 85.4%, respectively, p = 0.04). CEUS LI-RADS and MR LI-RADS can effectively be used to distinguish HCC from OMs. In patients at high risk of HCC, performance may be further improved by using a modified CEUS LI-RADS classification system in which category LR-M lesions are considered LR-5 if they have clear intratumoral non-enhanced area boundaries and do not have a punched-out appearance.

Differentiation between hepatocellular carcinoma and intrahepatic cholangiocarcinoma using contrast-enhanced ultrasound: A systematic review and meta-analysis

AIM

To explore the diagnostic ability of contrast-enhanced ultrasound (CEUS) in distinguishing intrahepatic cholangiocarcinoma (ICC) from hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

PubMed, EMBASE, Cochrane Library, and Web of Science were systematically searched for studies reporting the diagnostic accuracy of CEUS in differentiating ICC from HCC. The diagnostic ability of CEUS was assessed based on the pooled sensitivity, specificity, diagnostic odds ratio (DOR), positive likelihood ratio (PLR), negative likelihood ratio (NLR) and area under the curve (AUC) with 95% confidence intervals (CIs). The methodologic quality was assessed by the QUADAS-2 tool. Subgroup analyses, meta-regression and investigation of publication bias were performed to identify the source of heterogeneity.

RESULTS

A total of eight studies were included, consisting of 1,116 patients with HCC and 529 with ICC. The general diagnostic performance of CEUS in distinguishing ICC and HCC were as follows: pooled sensitivity, 0.92 (95% CI: 0.84-0.96); pooled specificity, 0.87 (95% CI: 0.79-0.92); pooled PLR, 7.1 (95% CI: 4.1-12.0); pooled NLR, 0.09 (95% CI: 0.05-0.19); pooled DOR, 76 (95% CI: 26-220) and AUC, 0.95(95% CI: 0.93-0.97). Different liver background may be a potential factor that influenced the diagnostic accuracy of CEUS according to the subgroup analysis, with the pooled DOR of 89.67 in the mixed liver background group and 46.87 in the cirrhosis group, respectively. Six informative CEUS features that may help differentiate HCC from ICC were extracted. The three CEUS features favoring HCC were arterial phase hyperenhancement(APHE), mild washout and late washout (>60s); the three CEUS favoring ICC were arterial rim enhancement, marked washout and early washout(<60s). No potential publication bias was observed.

CONCLUSION

CEUS showed great diagnostic ability in differentiating ICC from HCC, which may be promising for noninvasive evaluation of these diseases.

Management consensus guideline for hepatocellular carcinoma: 2020 update on surveillance, diagnosis, and systemic treatment by the Taiwan Liver Cancer Association and the Gastroenterological Society of Taiwan

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality in Taiwan. The Taiwan Liver Cancer Association and the Gastroenterological Society of Taiwan had established a management consensus guideline in 2016. The current recommendations focus on updating critical issues regarding the management of HCC, including surveillance, diagnosis, and systemic treatment. For surveillance, the updated guideline suggests the role of dynamic computed tomography or magnetic resonance imaging and contrast-enhanced ultrasound (CEUS) in selected patients. For diagnosis, this update incorporates CEUS and recognizes the role of gadoxetic acid-enhanced magnetic resonance imaging. For systemic therapy, the updated guideline summarizes the multiple choices of targeted therapy, immune checkpoint inhibitors, and the combination of both. Through this update of the management consensus guideline, patients with HCC can benefit from receiving optimal diagnostic and therapeutic modalities.

A study on the inconsistency of arterial phase hypervascularity detection between contrast-enhanced ultrasound using sonazoid and gadolinium-ethoxybenzyl-diethylenetriamine penta-acetic acid magnetic resonance imaging of hepatocellular carcinoma lesions

PURPOSE

By analyzing possible factors contributing to imaging misevaluation of arterial phase (AP) vascularity, we aimed to provide a more proper way to detect AP hypervascularity of hepatocellular carcinomas (HCCs) using the noninvasive imaging modalities magnetic resonance imaging (MRI) and contrast-enhanced ultrasound (CEUS).

METHODS

We retrospectively recruited 164 pathologically confirmed HCC lesions from 128 patients. Using CEUS with Sonazoid (SCEUS) and gadolinium-ethoxybenzyl-diethylenetriamine penta-acetic acid MRI (EOB-MRI), AP vascularity of the lesions was evaluated and inconsistencies in interpretation were examined. Indicators of margin, echogenicity, and halo and mosaic signs of lesions on grayscale US; depth of lesions on SCEUS; and tumoral homogeneity, signal contrast ratio of lesions to the surrounding area on precontrast and AP images on EOB-MRI, and histological grade were investigated.

RESULTS

When precontrast images were used to adjust the AP enhancement ratio, the proportion of inconsistent interpretations of AP vascularity declined from 26.2% (43/164; 29 non-hypervascularity instances using EOB-MRI and 14 using SCEUS) to 16.5% (27/164; 7 using EOB-MRI and 20 using SCEUS). Greater lesion depth (P = 0.017), ill-defined tumoral margin (P = 0.028), absence of halo sign (P = 0.034), and histologically early HCC (P = 0.007) on SCEUS, and small size (P = 0.012) and heterogeneity (P = 0.013) of lesions and slight enhancement (low AP enhancement ratio) (P = 0.018 and 0.009 before and after adjustment) on EOB-MRI, may relate to undetectable hypervascularity.

CONCLUSIONS

SCEUS and EOB-MRI may show discrepancies in evaluating AP vascularity in the case of deep, ill-defined, heterogeneous, slightly enhanced lesions, and histologically early HCCs. We recommend adjusting AP with precontrast images in EOB-MRI, and combining both modalities to detect hypervascularity.

The AMANDUS Project PART II-Advanced Microperfusion Assessed Non-Union Diagnostics with Contrast-Enhanced Ultrasound (CEUS): A Reliable Diagnostic Tool for the Management and Pre-operative Detection of Infected Upper-Limb Non-unions

The management of upper-limb non-unions can be challenging, especially when infection is existent. Thus, pre-operative detection of infection plays a relevant role in non-union treatment. This study investigated in a large cohort the diagnostic potential of contrast-enhanced ultrasound (CEUS) as stand-alone method for differentiating between aseptic and infected upper-limb non-unions. Osseous perfusion of 50 upper-extremity non-unions (radius/ulna, n = 20; humerus, n = 22; clavicle, n = 8) was prospectively assessed with CEUS before revision surgery. The perfusion was quantified via time-intensity curves and peak enhancement (in arbitrary units). Significant perfusion differences between aseptic and infected non-unions could be detected (peak enhancement, p < 0.001). The sensitivity and specificity for the detection of infected upper-limb non-unions were 80% and 94.3% (cutoff peak enhancement: 130.8 arbitrary units). CEUS reliably differentiates between aseptic and infected upper-limb non-unions. Consequently, CEUS should be integrated into the daily diagnostic routine algorithm to plan non-union revision surgery more precisely as a single- or multi-step procedure.

The diagnostic performance of gadoxetic acid disodium-enhanced magnetic resonance imaging and contrast-enhanced ultrasound in detecting hepatocellular carcinoma: A meta-analysis

The purpose of this study was to identify and compare the diagnostic performance of gadolinium-ethoxybenzyl-diethyltriethylenetriacetic acid (Gd-EOB-DTPA) enhanced magnetic resonance imaging (MRI) and contrast-enhanced ultrasound (CEUS) in hepatocellular carcinoma (HCC).Two researchers searched PubMed, EMBASE, and Cochrane Library databases from the inception of each database to 10 February 2020, to find comparative studies of Gd-EOB-DTPA-MRI and CEUS in detection of HCC.The study included eight studies (374 patients). MRI is superior to CEUS in diagnostic sensitivity of HCC, P = .03. The diagnostic sensitivity of MRI in lesions with a diameter of less than 30 mm was significantly higher than that of CEUS, P = .04. MRI and CEUS had no significant difference in diagnostic specificity of HCC, P = .95. Summary Receiver Operating Characteristics (SROC) of MRI showed a larger than that of CEUS, but with P > .05.Gd-EOB-DTPA-MRI showed higher sensitivity than CEUS for hepatocellular carcinoma lesions, especially for lesions of less than 30 mm across.

Accuracy of contrast-enhanced ultrasound liver imaging reporting and data system: a systematic review and meta-analysis

BACKGROUND AND AIM

After the introduction of the contrast-enhanced ultrasound Liver Imaging Reporting and Data System (CEUS LI-RADS), several studies have reported on its performance, but the reported data vary considerably. Therefore, we performed a systematic review and meta-analysis to determine the diagnostic performance of CEUS LI-RADS in patients at risk for hepatocellular carcinoma (HCC) and investigate the causes of study heterogeneity.

METHODS

Original studies published until May 30, 2020, investigating the diagnostic performance of CEUS LI-RADS were identified in the MEDLINE, EMBASE, and Cochrane library databases. Study quality was assessed using the QUADAS-2 tool. Meta-analytic summary sensitivity and specificity for the diagnosis of HCC were calculated using a bivariate random-effects model. Meta-regression analysis was performed to explore the causes of study heterogeneity.

RESULTS

Of the 105 articles screened, eight studies were finally analyzed (5428 hepatic observations). The summary sensitivity and specificity of CEUS LI-RADS category 5 (LR-5) for diagnosing HCC were 73% [95% confidence interval (CI) 65-79%; I² = 93%] and 95% (95% CI 91-97%; I² = 89%), respectively. Substantial study heterogeneity was noted in both sensitivity and specificity. Study heterogeneity was significantly associated with the proportion of cases of HCC and the type of reference standard (p ≤ 0.05).

CONCLUSION

CEUS LI-RADS had high pooled specificity for diagnosing HCC but suboptimal pooled sensitivity. Substantial study heterogeneity was found, which was significantly associated with the proportion of cases of HCC and the type of reference standard.

Usefulness of Modified CEUS LI-RADS for the Diagnosis of Hepatocellular Carcinoma Using Sonazoid

The Contrast-Enhanced Ultrasound Liver Imaging Reporting and Data System (CEUS LI-RADS) was introduced for classifying suspected hepatocellular carcinoma (HCC). However, it cannot be applied to Sonazoid. We assessed the diagnostic usefulness of a modified CEUS LI-RADS for HCC and non-HCC malignancies based on sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Patients with chronic liver disease at risk for HCC were evaluated retrospectively. Nodules ≥1 cm with arterial phase hyperenhancement, no early washout (within 60 s), and contrast defects in the Kupffer phase were classified as LR-5. Nodules showing early washout, contrast defects in the Kupffer phase, and/or rim enhancement were classified as LR-M. A total of 104 nodules in 104 patients (median age: 70.0 years; interquartile range: 54.5-78.0 years; 74 men) were evaluated. The 48 (46.2%) LR-5 lesions included 45 HCCs, 2 high-flow hemangiomas, and 1 adrenal rest tumor. The PPV of LR-5 for HCC was 93.8% (95% confidence interval (CI): 82.8-98.7%). The 22 (21.2%) LR-M lesions included 16 non-HCC malignancies and 6 HCCs. The PPV of LR-M for non-HCC malignancies, including six intrahepatic cholangiocarcinomas, was 100% (95% CI: 69.8-100%). In conclusion, in the modified CEUS LI-RADS for Sonazoid, LR-5 and LR-M are good predictors of HCC and non-HCC malignancies, respectively.

Guidelines and Good Clinical Practice Recommendations for Contrast Enhanced Ultrasound (CEUS) in the Liver - Update 2020 - WFUMB in Cooperation with EFSUMB, AFSUMB, AIUM, and FLAUS

The present, updated document describes the fourth iteration of recommendations for the hepatic use of contrast enhanced ultrasound (CEUS), first initiated in 2004 by the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB). The previous updated editions of the guidelines reflected changes in the available contrast agents and updated the guidelines not only for hepatic but also for non-hepatic applications.The 2012 guideline requires updating as previously the differences of the contrast agents were not precisely described and the differences in contrast phases as well as handling were not clearly indicated. In addition, more evidence has been published for all contrast agents. The update also reflects the most recent developments in contrast agents, including the United States Food and Drug Administration (FDA) approval as well as the extensive Asian experience, to produce a truly international perspective.These guidelines and recommendations provide general advice on the use of ultrasound contrast agents (UCA) and are intended to create standard protocols for the use and administration of UCA in liver applications on an international basis to improve the management of patients.

Guidelines and Good Clinical Practice Recommendations for Contrast-Enhanced Ultrasound (CEUS) in the Liver-Update 2020 WFUMB in Cooperation with EFSUMB, AFSUMB, AIUM, and FLAUS

The present, updated document describes the fourth iteration of recommendations for the hepatic use of contrast-enhanced ultrasound, first initiated in 2004 by the European Federation of Societies for Ultrasound in Medicine and Biology. The previous updated editions of the guidelines reflected changes in the available contrast agents and updated the guidelines not only for hepatic but also for non-hepatic applications. The 2012 guideline requires updating as, previously, the differences in the contrast agents were not precisely described and the differences in contrast phases as well as handling were not clearly indicated. In addition, more evidence has been published for all contrast agents. The update also reflects the most recent developments in contrast agents, including U.S. Food and Drug Administration approval and the extensive Asian experience, to produce a truly international perspective. These guidelines and recommendations provide general advice on the use of ultrasound contrast agents (UCAs) and are intended to create standard protocols for the use and administration of UCAs in liver applications on an international basis to improve the management of patients.

Emerging Role of Hepatobiliary Magnetic Resonance Contrast Media and Contrast-Enhanced Ultrasound for Noninvasive Diagnosis of Hepatocellular Carcinoma: Emphasis on Recent Updates in Major Guidelines

Hepatocellular carcinoma (HCC) can be noninvasively diagnosed on the basis of its characteristic imaging findings of arterial phase enhancement and portal/delayed “washout” on computed tomography (CT) and magnetic resonance imaging (MRI) in cirrhotic patients. However, different specific diagnostic criteria have been proposed by several countries and major academic societies. In 2018, major guideline updates were proposed by the Association for the Study of Liver Diseases, European Association for the Study of the Liver (EASL), Korean Liver Cancer Association and National Cancer Center (KLCA-NCC) of Korea. In addition to dynamic CT and MRI using extracellular contrast media, these new guidelines now include magnetic resonance imaging (MRI) using hepatobiliary contrast media as the first-line diagnostic test, while the KLCA-NCC and EASL guidelines also include contrast-enhanced ultrasound (CEUS) as the second-line diagnostic test. Therefore, hepatobiliary MR contrast media and CEUS will be increasingly used for the noninvasive diagnosis and staging of HCC. In this review, we discuss the emerging role of hepatobiliary phase MRI and CEUS for the diagnosis of HCC and also review the changes in the HCC diagnostic criteria in major guidelines, including the KLCA-NCC practice guidelines version 2018. In addition, we aimed to pay particular attention to some remaining issues in the noninvasive diagnosis of HCC.

Multimodality Approach in Detection and Characterization of Hepatic Metastases

Early detection of liver metastases is important in patients with known primary malignancies. This plays an important role in treatment planning and impacts on further management of certain primary malignancies.

Magnetic resonance imaging (MRI), computed tomography (CT), and positron emission tomography-computed tomography scans are reported to have high accuracy in the diagnosis of intrahepatic lesions. MRI in particular has the advantages of its high tissue sensitivity and its multiparametric approach.

Hepatic metastatic lesions have considerable overlap in their radiological appearance, and in this article the imaging appearance of various hepatic metastasis and approach is described.

Contrast-Enhanced Ultrasound of Focal Liver Masses: A Success Story

The epidemic of increasing fatty liver disease and liver cancer worldwide, and especially in Western society, has given new importance to non-invasive liver imaging. Contrast-enhanced ultrasound (CEUS) using microbubble contrast agents provides unique advantages over computed tomography (CT) and magnetic resonance imaging (MRI), the currently established methods. CEUS provides determination of malignancy and allows excellent differential diagnosis of a focal liver mass, based on arterial phase enhancement patterns and assessment of the timing and intensity of washout. Today, increased use of CEUS has provided safe and rapid diagnosis of incidentally detected liver masses, improved multidisciplinary management of nodules in a cirrhotic liver, facilitated ablative therapy for liver tumors and allowed diagnosis of hepatocellular carcinoma without biopsy. Benefits of CEUS include the dynamic real-time depiction of tumor perfusion and the fact that it is a purely intravascular agent, accurately reflecting tumoral and inflammatory blood flow. CEUS has many similarities to contrast-enhanced CT and MRI but also unique differences, which are described. The integration of CEUS into a multimodality imaging setting optimizes patient care.

Use of CEUS LI-RADS for the Accurate Diagnosis of Nodules in Patients at Risk for Hepatocellular Carcinoma: A Validation Study

Purpose

To validate the contrast agent-enhanced US Liver Imaging Reporting and Data System (CEUS LI-RADS) algorithm for accurate diagnosis of hepatocellular carcinoma (HCC) and categorization of all nodules encountered in patients at risk for HCC.

Materials and Methods

A single-center retrospective review of 196 nodules in 184 patients at risk for HCC (consisting of 139 HCCs, 18 non-HCC malignancies, and 39 benign nodules) was performed in a three-reader blinded read format, with the use of the CEUS LI-RADS algorithm. Pathologic confirmation was available for 143 nodules (122 HCCs, 18 non-HCC malignancies, and three benign nodules). Nodule sizes ranged between 1.0 and 16.2 cm. Nodules assessed with contrast-enhanced US were assigned various CEUS LI-RADS categories by three blinded readers. CEUS LI-RADS categorization was then compared against histopathologic findings, concurrent CT, and/or MR images or follow-up imaging to assess diagnostic accuracy of CEUS LI-RADS. In addition, the proportion of HCC in all LI-RADS (LR) categories, univariable and multivariable feature analysis, and interrater agreement using Light κ were determined.

Results

The LR-5 category, determined through radiologist categorization of nodules using the CEUS LI-RADS criteria, showed sensitivity, specificity, positive predictive value, and negative predictive value of 86% (119 of 139), 96% (55 of 57), 98% (119 of 121), and 73% (55 of 75), respectively, for the diagnosis of HCC. Two false-positive cases of LR-5 included a cholangiocarcinoma and a combined hepatocellular and cholangiocarcinoma. The remainder of the cholangiocarcinomas in the sample (n = 8) were appropriately categorized as LR-M. Multivariable logistic regression analysis showed that washout of greater than 60 seconds was the contrast-enhanced US feature most predictive of HCC diagnosis, whereas washout of less than 60 seconds was the feature most predictive of nonhepatocellular malignancy. The proportion of HCC nodules categorized in the LR-M and LR-4 categories was 35% and 20%, respectively. Light κ agreement between readers for LI-RADS categorization was 90%.

Conclusion

This study showed excellent specificity for the CEUS LI-RADS LR-5 category, allowing for confident imaging diagnosis of HCC, without necessity for pathologic confirmation. In addition, there was accurate differentiation of HCC from non-HCC malignancies and benign nodules. Only a single cholangiocarcinoma was misdiagnosed as category LR-5, with the remainder of the cholangiocarcinomas in the sample appropriately characterized as category LR-M.Keywords: Abdomen/GI, Evidence Based Medicine, Liver, Neoplasms-Primary, Ultrasound-Contrast© RSNA, 2020.

CEUS LI-RADS: a pictorial review

Contrast-enhanced ultrasound (CEUS) greatly improved the diagnostic accuracy of US in the detection and characterization of focal liver lesions (FLLs), and it is suggested and often included in many international guidelines as an important diagnostic tool in the imaging work-up of cirrhotic patients at risk for developing hepatocellular carcinoma (HCC). In particular, CEUS Liver Imaging Reporting and Data System (LI-RADS) provides standardized terminology, interpretation, and reporting for the diagnosis of HCC. The aim of this pictorial essay is to illustrate CEUS features of nodules discovered at US in cirrhotic liver according to LI-RADS categorization.

Additional value of contrast-enhanced ultrasound (CEUS) on arterial phase non-hyperenhancement observations (≥ 2 cm) of CT/MRI for high-risk patients: focusing on the CT/MRI LI-RADS categories LR-3 and LR-4

PURPOSE

To determine the added value of CEUS on arterial phase non-hyperenhancement (APNHE) observations (LR-3 and LR-4) of CT/MRI in high-risk patients.

METHODS

Forty-three patients with APNHE observations (≥ 2 cm) from CT/MRI were prospectively enrolled in this IRB-approved study and underwent CEUS. All observations were assessed by LI-RADS for CT/MRI and CEUS. The hemodynamic findings were compared. The mean follow-up period was 11.8 ± 2.1 months. Reference standard was made on 34-APNHE observations based on biopsy (n = 2), surgery (n = 2), and follow-up image (n = 30).

RESULTS

The median of observation size was 2.3 cm (IQR 2.0-2.5 cm). Among the 43-APNHE observations, 12-observations (27.9%) were further presented as arterial phase hyperenhancement (APHE) in CEUS with early (n = 1, CEUS LR-M), late (n = 10, CEUS LR-5), or no (n = 1, CEUS LR-4) washout. Compared to CT, CEUS presented concordant enhancement patterns in 16 (44.4%) in AP and 20 (55.6%) in PVP, respectively. Similarly, 13 (59.1%) and 14 (63.6%) observations showed concordant enhancement patterns between CEUS and MRI in AP and PVP, respectively. Of the 34-APNHE observations with final diagnosis (hepatocellular carcinoma [HCC] n = 12; intrahepatic cholangiocarcinoma [IHCC], n = 1; non-malignancy, n = 21), 4 HCCs (33.3%) and 1 IHCC (100%) were additionally diagnosed by CEUS, while 1 non-malignant lesion (4.5%) was misdiagnosed as HCC by CEUS.

CONCLUSION

Adding CEUS to APNHE observations from CT/MRI would be useful not only for definitely diagnosing HCC (CEUS LR-5) but also for other malignancies (CEUS LR-M). The discordance of dynamic features between the LI-RADS for CEUS and CT/MRI may reflect the different properties of contrast media, although the systems are not interchangeable.

Resolution of indeterminate MRI with CEUS in patients at high risk for hepatocellular carcinoma

PURPOSE

To show the contribution of CEUS to characterization of indeterminate MRI observations in high-risk patients for hepatocellular carcinoma (HCC).

METHODS

From July to December 2015, 42 consecutive patients referred to CEUS with indeterminate MRI scans comprise our study cohort. There are 50 indeterminate nodule-like observations and 10 arterial phase hyperenhancing foci, suggesting pseudolesions/arterio-portal shunts. MRI and CEUS lesions are classified according to their enhancement features in all phases and Liver Imaging and Reporting Data System (LI-RADS) in a blind read format. Clinical pathologic correlation and 24 months follow-up are performed.

RESULTS

A majority, 37/50 (74%), of indeterminate nodule-like observations have arterial phase enhancement without washout on MRI. CEUS further characterizes enhancement and shows washout in 14/37 (38%). In total, CEUS diagnoses 16 malignant lesions in 14 patients including 14 HCC and 2 ICC. 12/16 (75%) malignant lesions are confirmed by biopsy or follow-up. Ultrasound identification of a nodule differentiates real nodules from pseudolesions. Of the ten suspected arterial-portal shunts on MRI, two show a real nodule on ultrasound, confirmed as an HCC and a regenerative nodule. 15/42 (36%) patients have LI-RADS escalated from LR-3 or 4 on MRI to LR-4 or 5 on CEUS. Overall, the sensitivity of CEUS is (13/16) 81.3% and specificity is (37/37) 100% for malignant diagnosis.

CONCLUSION

Grayscale ultrasound detects true nodules. Dynamic CEUS detects and characterizes washout, correctly predicting HCC. CEUS is complimentary to MRI and can serve as a problem-solving tool when MRI is indeterminate.

Current Imaging Standards for Nonmetastatic Benign and Malignant Liver Tumors

The accurate diagnosis of a liver mass can usually be established with a thorough history, examination, laboratory inquiry, and imaging. The necessity of a liver biopsy to determine the nature of a liver mass is rarely necessary. Contrast-enhanced computed tomography and magnetic resonance are the standard of care for diagnosing liver lesions and high-quality imaging should be performed before performing a biopsy. This article discusses current consensus guidelines for imaging of liver masses, as well as masses found on surveillance imaging. The ability to accurately characterize lesions requires proper use and understanding of the technology and expert interpretation.

The AMANDUS Project-Advanced Microperfusion Assessed Non-Union Diagnostics With Contrast-Enhanced Ultrasound (CEUS) for the Detection of Infected Lower Extremity Non-Unions

The pre-operative determination of infection plays a decisive role in non-union treatment. This study investigated in a large cohort the diagnostic potential of contrast-enhanced ultrasound (CEUS) as stand-alone method for the differentiation between aseptic and infected non-unions. Of 109 patients with lower extremity non-unions (tibia n = 78, femur n = 31) osseous perfusion with CEUS was prospectively assessed before revision surgery. The perfusion was quantified via time-intensity curves and peak enhancement (PE) (arbitrary unit [au]). Significant perfusion differences between aseptic and infected non-unions were evident (PE, p < 0.001). The sensitivity and specificity for the detection of infected tibial and femoral non-unions could be determined with 85.1% and 88.7% (cutoff PE: 81.2 au). CEUS illustrates tibial and femoral non-union perfusion in real time and discriminates reliably between aseptic and infected non-unions. Consequently, when CEUS is integrated into the diagnostic routine algorithm, non-union revision surgery can be planned more accurately as a single or multistep procedure.

Contrast-enhanced US in Local Ablative Therapy and Secondary Surveillance for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) has a high incidence of recurrence following therapy. Therefore, secondary surveillance (scheduled follow-up imaging after treatment) is an important part of disease management. The recent approval in the United States for use of a microbubble-based contrast agent for US liver imaging promotes the increased use of contrast-enhanced US (CEUS) in patients with HCC. Although the criteria for the diagnosis of HCC at CEUS are well described, there is a paucity of published literature describing the role of CEUS in ablative therapy and secondary surveillance. In the setting of ablative therapy, CEUS can have vital roles, including patient selection, intraprocedural guidance, and immediate postprocedural assessment. Although CEUS is not widely used, the authors found that it can be used to accurately detect residual or recurrent tumor, characterize the geographic pattern of recurrence (intrazonal, extrazonal, segmental, or remote), and assess for tumor in vein. In addition, similar to primary surveillance, secondary surveillance includes assessment of the entire liver for evaluation of new nodules. Arterial phase hyperenhancement is the reference standard characteristic of disease recurrence at secondary surveillance with CEUS. ^©RSNA, 2019 See discussion on this article by Rodgers.

Late Gadolinium Hyperintensity of Suspected Colorectal Liver Metastases on Gadofosveset-Enhanced Magnetic Resonance Imaging: A Predictor of Benignity and a Potential Problem-Solving Tool

PURPOSE

Late gadolinium hyperintensity (LGH) is sometimes seen in colorectal liver metastasis (CRLM) and represents a significant diagnostic pitfall due to overlap with LGH in benign hemangiomas; therefore, the objective of this study was to determine the prevalence of LGH and the ability of LGH to differentiate between CRLM and benign lesions with intravascular (gadofosveset) vs extracellular contrast agents (gadobutrol).

METHODS

Patients with known colorectal cancer and suspected liver lesions were prospectively recruited into this institutional review board-approved, single institution study and received magnetic resonance imaging of the liver with gadofosveset and gadobutrol. The prevalence of LGH for CRLMs and solid benign lesions was determined. Receiver operating characteristics curves were determined for the presence of LGH as a predictor of benignity. The utility of LGH to differentiate between CRLM and solid benign lesions using gadofosveset vs gadobutrol was compared using the generalized estimating equation.

RESULTS

Twenty-five patients with 131 solid focal liver lesions were recruited. The prevalence of LGH of CRLMs was 11.2% (95% confidence interval [CI]: 0.5%-21.8%) with gadofosveset vs 63.7% (95% CI: 45.7%-81.7%) with gadobutrol. The area under the receiver operating characteristic curve for the presence of LGH as a predictor of benignity was 0.86 using gadofosveset vs 0.75 using gadobutrol. Both LGH (P = .003) and the interaction of contrast agent and LGH (P = .003) statistically significantly differentiated CRLM from benign lesions.

CONCLUSION

LGH is more common with extracellular than with intravascular contrast agents and is statistically significantly associated with benign lesions rather than metastases.

Contrast-enhanced ultrasound of hepatocellular carcinoma: where do we stand?

Contrast-enhanced ultrasound (CEUS) represents a significant breakthrough in ultrasonography (US), and it is being increasingly used for the evaluation of focal liver lesions (FLLs). CEUS is unique in that it allows non-invasive assessment of liver perfusion in real time throughout the vascular phase, which has led to dramatic improvements in the diagnostic accuracy of US in the detection and characterization of FLLs, the choice of therapeutic procedures, and the evaluation of response. Currently, CEUS is included as a part of the suggested diagnostic work-up of FLLs, including in cirrhotic patients with hepatocellular carcinoma, resulting in better patient management and cost-effective delivery of therapy.

Imaging of combined hepatocellular-cholangiocarcinoma in cirrhosis and risk of false diagnosis of hepatocellular carcinoma

BACKGROUND

Diagnosis of hepatocellular carcinoma can be achieved by imaging in cirrhotic patients. Combined hepatocellular-cholangiocarcinoma is a primary liver tumor and its imaging patterns have been poorly investigated. Misdiagnosis for either hepatocellular carcinoma or benign lesions can occur. We aimed to evaluate the enhancement pattern of combined hepatocellular-cholangiocarcinoma in cirrhosis with imaging techniques and to estimate the risk of misdiagnosis for hepatocellular carcinoma.

METHODS

All histology-confirmed combined hepatocellular-cholangiocarcinoma in cirrhosis seen in two Italian centers between 2003 and 2016, in which at least one imaging technique had been performed, was retrospectively collected. The enhancement pattern was analyzed for all available imaging modalities.

RESULTS

A total of 37 combined hepatocellular-cholangiocarcinoma nodules were identified. Contrast-enhanced ultrasound, computed tomography, and magnetic resonance imaging had been performed in 27, 34, and 17 nodules, respectively. Contrast-enhanced ultrasound was at higher risk of misdiagnosis for pure hepatocellular carcinoma than computed tomography (p = 0.005) or magnetic resonance imaging (p = 0.040). Only six of 24 combined hepatocellular-cholangiocarcinoma lesions submitted to both contrast-enhanced ultrasound and computed tomography showed coincident patterns; contrast-enhanced ultrasound correctly suggested a condition of malignancy in a higher number of cases than computed tomography (p < 0.001) and magnetic resonance imaging (p = 0.002).

CONCLUSIONS

Contrast-enhanced ultrasound misdiagnosed a higher number of combined hepatocellular-cholangiocarcinoma as hepatocellular carcinoma than computed tomography and magnetic resonance imaging. However, the latter techniques were able to identify features of malignancy less often.

Hepatocellular carcinoma in non-cirrhotic liver: A comprehensive review

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, which in turns accounts for the sixth most common cancer worldwide. Despite being the 6^th most common cancer it is the second leading cause of cancer related deaths. HCC typically arises in the background of cirrhosis, however, about 20% of cases can develop in a non-cirrhotic liver. This particular subgroup of HCC generally presents at an advanced stage as surveillance is not performed in a non-cirrhotic liver. HCC in non-cirrhotic patients is clinically silent in its early stages because of lack of symptoms and surveillance imaging; and higher hepatic reserve in this population. Interestingly, F3 fibrosis in non-alcoholic fatty liver disease, hepatitis B virus and hepatitis C virus infections are associated with high risk of developing HCC. Even though considerable progress has been made in the management of this entity, there is a dire need for implementation of surveillance strategies in the patient population at risk, to decrease the disease burden at presentation and improve the prognosis of these patients. This comprehensive review details the epidemiology, risk factors, clinical features, diagnosis and management of HCC in non-cirrhotic patients and provides future directions for research.

Contrast-enhanced ultrasound patterns of hepatocellular adenoma: an Italian multicenter experience

PURPOSE

Hepatocellular adenoma (HCA) is a rare benign monoclonal neoplasm, recently categorized on genetic and histopathological basis into four subtypes with different biological behaviors. Since contrast-enhanced ultrasonography (CEUS) is nowadays a well-established technique for liver nodule characterization, the aim of our study was to assess CEUS features of HCAs to identify criteria that correlate with different HCA subtypes as compared to histopathologic examination and other imaging modalities.

METHODS

We retrospectively analyzed data of patients with histology-proven HCA who underwent CEUS, computed tomography or magnetic resonance imaging (MRI) in seven different Italian ultrasound units.

RESULTS

The study enrolled 19 patients (16 females; 69% with concomitant/prior use of oral contraceptives): the mean size of all HCAs was 4.2 cm (range 1.6-7.1 cm); 14/19 had inflammatory HCAs (I-HCA), 1/19 β-catenin-activated HCA, and the others unclassified HCAs. On CEUS, during the arterial phase, all but one HCA displayed a rapid enhancement, with 89% of these showing centripetal and 11% centrifugal filling pattern, whereas during the portal and late venous phase 58% of HCA showed washout and the remaining 42% displayed persistent enhancement. In particular, among I-HCAs 7/14 showed no washout, 3/14 and 4/14 showed washout in the portal or late phase, respectively.

CONCLUSIONS

This dataset represents one of the few published experiences on HCAs and CEUS in Italy and shows that HCAs are hypervascularized in the arterial phase usually with a centripetal flow pattern and have a heterogeneous behavior in portal and late phase. In particular, occurrence of delayed washout on CEUS but not on MRI is frequently observed in the subtype of I-HCA.

Practical advantages of contrast-enhanced ultrasound in abdominopelvic radiology

Computed tomography (CT) and magnetic resonance imaging (MRI) are two of the workhorse modalities of abdominopelvic radiology. However, these modalities are not without patient- and technique-specific limitations that may prevent a timely and accurate diagnosis. Contrast-enhanced ultrasound (CEUS) is an effective, rapid, and cost-effective imaging modality with expanding clinical utility in the United States. In this pictorial essay, we provide a case-based discussion demonstrating the practical advantages of CEUS in evaluating a variety of pathologies in which CT or MRI was precluded or insufficient. Through these advantages, CEUS can serve a complementary role with CT and MRI in comprehensive abdominopelvic radiology.