Differentiation of small (≤2 cm) hepatocellular carcinomas from small benign nodules in cirrhotic liver on gadoxetic acid-enhanced and diffusion-weighted magnetic resonance images

Modified LR-5 criteria based on gadoxetic acid can improve the sensitivity in the diagnosis of hepatocellular carcinoma

BACKGROUND

Currently, only tumors classified as LR-5 are considered definitive hepatocellular carcinoma (HCC), and no further pathologic confirmation is required to initiate therapy. Previous studies have shown that the sensitivity of LR-5 is modest, and lesions enhanced by gadoxetic acid (Gd-EOB-DTPA) may exhibit lower sensitivity than those enhanced by Gd-DTPA.

AIM

To identify malignant ancillary features (AFs) that can independently and significantly predict HCC in Liver Imaging Reporting and Data System version 2018, and to develop modified LR-5 criteria to improve diagnostic performance on Gd-EOB-DTPA - enhanced magnetic resonance imaging.

METHODS

Imaging data from patients with HCC risk factors who underwent abdominal Gd-EOB-DTPA - enhanced magnetic resonance imaging were collected. Univariate and multivariate logistic regression analyses were performed to determine AFs that could independently and significantly predict HCC. The modified LR-5 criteria involved reclassifying LR-4/LR-3 lesions based on major features combined with independently significant AFs for HCC, or by substituting threshold growth with significant AFs. McNemar's test was used to compare the diagnostic performance of the modified LR-5 criteria.

RESULTS

A total of 244 lesions from 216 patients were included. Transitional phase hypointensity, mild - moderate T2 hyperintensity, and fat in mass (more than adjacent liver) were identified as significant independent predictors of HCC. Using the modified LR-5 criteria (e.g., LR-5-M1: LR-4 + transitional phase hypointensity; LR-5-M4: LR-5 by transitional phase hypointensity instead of threshold growth; LR-5-M5: LR-5 by mild - moderate T2 hyperintensity instead of threshold growth; LR-5-M8: LR-3/LR-4 + any two features of transitional phase hypointensity/mild - moderate T2 hyperintensity/fat in mass), sensitivities were significantly increased (88.5%-89.1%) compared to the standard LR-5 (60.6%; all P values < 0.05), while specificities (84.8%-89.9%) remained largely unchanged (93.7%; all P values > 0.05). The LR-5-M8 criterion achieved the highest sensitivity.

CONCLUSION

Mild - moderate T2 hyperintensity, transitional phase hypointensity, and fat in mass are independent and significant predictors of HCC malignant AFs. The modified LR-5 criteria can improve sensitivity without significantly reducing specificity.

Diagnostic performance of gadoxetic acid-enhanced abbreviated magnetic resonance imaging protocol in small hepatocellular carcinoma (≤2 cm) in high-risk patients

BACKGROUND

Biannual Ultrasound showed insufficient sensitivity in detecting small or early-stage hepatocellular carcinoma (HCC). Abbreviated magnetic resonance imaging (A-MRI) protocols with fewer sequences demonstrated higher HCC detection sensitivity than ultrasound with acceptable cost and examination time.

PURPOSE

To compare the diagnostic performance of gadoxetic acid-enhanced A-MRI with a full sequence MRI (F-MRI) protocol for small HCC (≤2 cm) in cirrhotic or hepatitis B virus-infected high-risk patients.

MATERIAL AND METHODS

Two hundred and four consecutive patients with 166 pathologically confirmed small HCC who underwent preoperative gadoxetic acid-enhanced MRI were retrospectively included. A-MRI set comprised T1-weighted hepatobiliary phase imaging, T2-weighted imaging, diffusion-weighted imaging and apparent diffusion coefficient mapping. Two independent radiologists blinded to clinical data assessed the A-MRI set and F-MRI set. Per-patient HCC and per-lesion HCC diagnostic performance were compared.

RESULTS

Per-patient HCC detection sensitivity of A-MRI set was 93.8% and 91.2% for observer 1 and observer 2, and, for the F-MRI set, the per-patient HCC detection sensitivity was 96.6% and 95.2%, respectively. There was no significant difference in per-patient sensitivity, specificity and per-lesion HCC detection sensitivity between the two imaging sets for both readers. (P = 0.06-0.25) The A-MRI set showed higher sensitivity on HCC without arterial phase hyperenhancement, and the F-MRI set demonstrated with higher sensitivity on HCC with arterial phase hyperenhancement (P < 0.05).

CONCLUSION

A-MRI using diagnostic criteria including hypointensity on hepatobiliary phase plus mild to moderate hyperintensity on T2-weighted imaging or restricted diffusion demonstrated comparable sensitivity and specificity for small HCC compared to the F-MRI protocol in high-risk patients.

Role of MRI-Derived Radiomics Features in Determining Degree of Tumor Differentiation of Hepatocellular Carcinoma

Background: To investigate radiomics ability in predicting hepatocellular carcinoma histological degree of differentiation by using volumetric MR imaging parameters. Methods: Volumetric venous enhancement and apparent diffusion coefficient were calculated on baseline MRI of 171 lesions. Ninety-five radiomics features were extracted, then random forest classification identified the performance of the texture features in classifying tumor degree of differentiation based on their histopathological features. The Gini index was used for split criterion, and the random forest was optimized to have a minimum of nine participants per leaf node. Predictor importance was estimated based on the minimal depth of the maximal subtree. Results: Out of 95 radiomics features, four top performers were apparent diffusion coefficient (ADC) features. The mean ADC and venous enhancement map alone had an overall error rate of 39.8%. The error decreased to 32.8% with the addition of the radiomics features in the multi-class model. The area under the receiver-operator curve (AUC) improved from 75.2% to 83.2% with the addition of the radiomics features for distinguishing well- from moderately/poorly differentiated HCCs in the multi-class model. Conclusions: The addition of radiomics-based texture analysis improved classification over that of ADC or venous enhancement values alone. Radiomics help us move closer to non-invasive histologic tumor grading of HCC.

Clinical value of contrast-enhanced ultrasound in early diagnosis of small hepatocellular carcinoma (≤ 2 cm)

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common type of primary liver malignancy. Contrast-enhanced ultrasound (CEUS) uses contrast microbubbles during ultrasound, allowing the detection and characterization of malignant focal liver lesions with much higher diagnostic accuracy than conventional ultrasound; however, there are few reports focusing on the pattern of enhancement of CEUS for the diagnosis of HCC smaller than 2 cm.

AIM

To investigate the clinical value of CEUS in the early detection of small HCC with high risk factors.

METHODS

A total of 395 patients with 632 nodules at high risk of HCC, who underwent regular follow-up at Xuhui Dahua Hospital from January 2007 to December 2021, were retrospectively examined. Conventional ultrasonography combined with CEUS was adopted to analyze the echo, size, location, and enhancement characteristics of benign and malignant nodules, as well as the enhancement methods for HCC with different diameters.

RESULTS

The follow-up rate and duration were 92.15% (364/395) and 51.28 ± 45.09 mo, respectively. Conventional ultrasonography combined with CEUS revealed 65 (11.80%) nodules with a follow-up diagnosis of HCC, 19 (3.45%) dysplastic nodules, and 467 (84.75%) benign cirrhotic hyperplastic nodules. Among 65 cases of confirmed HCC, 40 (61.54%) were transformed from hypoechoic nodules, 9 (13.85%) from hyperechoic nodules, and the remaining 16 (24.62%) from isoechoic nodules. Significant differences in CEUS characteristics were found among cirrhotic nodules, dysplastic nodules, and HCC nodules at each phase. Significant differences in the enhancement mode were observed between nodules ≤ 1 cm and those 1-2 cm. The smaller the HCC nodule, the later the contrast agent began to flush and the longer the duration of contrast enhancement.

CONCLUSION

Conventional ultrasonography combined with CEUS could identify small HCC and help monitor patients with an early diagnosis of HCC. Significant differences in the enhancement mode are noted between nodules ≤ 1 cm and those 1-2 cm.

The second Mexican consensus on hepatocellular carcinoma. Part I: Epidemiology and diagnosis

Hepatocellular carcinoma (HCC) is more frequently manifesting as one of the main complications of cirrhosis of the liver, its principal risk factor. There have been modifications in its incidence over the past decade, related to an epidemiologic transition in the etiology of cirrhosis, with a decrease in the prevalence of hepatitis C and an increase in nonalcoholic fatty liver disease (NAFLD) as a cause, as well as the development of HCC in the non-cirrhotic liver due to NAFLD. Genetic markers associated with the disease have been identified, and surveillance and diagnosis have improved. Regarding treatment, surgical techniques, in both resection and transplantation, have advanced and radiologic techniques, at the curative stage of the disease, have enhanced survival in those patients. And finally, there have been radical changes in the systemic approach, with much more optimistic expectations, when compared with the options available a decade ago. Therefore, the Asociación Mexicana de Hepatología decided to carry out the Second Mexican Consensus on Hepatocellular Carcinoma, which is an updated review of the available national and international evidence on the epidemiology, risk factors, surveillance, diagnosis, and treatment of the disease, to offer the Mexican physician current information on the different topics regarding hepatocellular carcinoma. In this first part of the document, the topics related to epidemiology and diagnosis are presented.

Can modified LI-RADS increase the sensitivity of LI-RADS v2018 for the diagnosis of 10-19 mm hepatocellular carcinoma on gadoxetic acid-enhanced MRI?

PURPOSE

To evaluate whether the Liver Imaging Reporting and Data System (LI-RADS) v2018 LR-5 criteria can be modified to increase sensitivity without reducing specificity for diagnosing 10-19 mm hepatocellular carcinoma (HCC) on gadoxetic acid-enhanced magnetic resonance imaging (MRI).

METHODS

A total of 133 high-risk consecutive patients with 174 small observations (10-19 mm) detected on gadoxetic acid-enhanced MRI were retrospectively studied. LI-RADS MRI major features (MFs) and ancillary features (AFs) were reviewed by two independent radiologists in consensus. Observations were categorized using LI-RADS v2018 MFs. Independently significant AFs were identified through logistic regression analysis. Upgraded LR-5 criteria were developed by combining independently significant AFs with MFs of LR-3 or LR-4 v2018. The sensitivity and specificity of the new diagnostic criteria were compared with those of LR-5 v2018 using McNemar's test.

RESULTS

Three of the AFs favoring malignancy [mild-moderate T2 hyperintensity, transitional phase (TP) hypointensity and fat in mass] were independently significant features for diagnosing 10-19 mm HCC. The upgraded LR-5 criteria (mLI-RADS VII: LR-4 + mild-moderate T2 hyperintensity/TP hypointensity or LR-3 + fat in mass) yielded a significantly greater sensitivity than that of the LR-5 v2018 criteria (70.4% vs 55.1%; p < 0.001), whereas the specificity was not significantly different (94.7% vs 98.7%, p = 0.250).

CONCLUSIONS

Independently significant AFs may be used to upgrade an observation from LR-3/LR-4 to LR-5, which can improve the sensitivity without impairing the specificity for diagnosing 10-19 mm HCC on gadoxetic acid-enhanced MRI.

Whole tumor volumetric ADC analysis: relationships with histopathological differentiation of hepatocellular carcinoma

PURPOSE

The aim of this study was to investigate the relationships between values obtained from whole tumor volumetric apparent diffusion coefficient (ADC) measurements and histopathological grade in patients with hepatocellular carcinoma (HCC).

METHODS

Fifty-one naïve patients with HCC were included in the study. The tumors were classified according to the Edmondson-Steiner grade and separated as well-differentiated and non-well-differentiated (moderately and poorly differentiated). The ADC parameters of groups were compared by applying Mann-Whitney U test. The correlation between tumors' histopathological stage and whole tumor ADC parameters was investigated using Spearman's Rank Correlation Coefficient. The receiver operating characteristic curve analysis (ROC) was applied to calculate the area under curve (AUC) with intersection point of ADC parameters and curve.

RESULTS

Mean and percentile ADC values of well-differentiated tumors were significantly higher than those of non-well-differentiated tumors (p < 0.05). The strongest correlation between histopathological grade and ADC parameters was 75th percentile ADC (r = - 0.501), 50th percentile ADC (r = - 0.476) and mean ADC (r = - 0.465). Mean, 75th and 50th percentile ADC values used for the distinction of groups gave the highest AUC at ROC analysis (0.781, 0.781, 0.767, respectively). When threshold values of mean, 75th and 50th percentile ADC values were applied (1516 mm²/s, 1194 mm²/s, and 1035 mm²/s) sensitivity was calculated as 0.73, 0.91, 0.83, respectively, and specificity was calculated as 0.82, 0.61, and 0.68, respectively.

CONCLUSIONS

A correlation between whole tumor volumetric ADC values and HCCs' histopathological grade was detected in this study. 75th percentile, 50th percentile and mean ADC values are determined as highly sensitive and specific tests when the threshold values are applied for distinguishing between well-differentiated tumors and moderately/poorly differentiated tumors. When all these findings are evaluated together, HCCs' volumetric ADC values might be a useful noninvasive predictive parameters for histopathological grade in patients with HCC.

Study on clinical application of susceptibility weighted imaging ombined with diffusion weighted imaging in patients with Liver Cirrhosis complicated with small Hepatocellular Carcinoma

Objectives

To evaluate the clinical value of susceptibility weighted imaging (SWI) combined with diffusion weighted imaging (DWI) in patients with liver cirrhosis complicated with small hepatocellular carcinoma (SHCC).

Methods

A total of 40 patients with liver cirrhosis and 44 nodules were treated with conventional nuclear magnetic scanning (T1WI, T2WI) and SWI combined with DWI; the results were judged by two senior physicians; the t test, χ² test, rank sum test, and other methods were used for contrastive analysis of the pathological results of different scanning methods after operation or puncture.

Results

Contrast analysis of the different MRI scanning methods and pathological results showed that among the 32 nodules of small hepatocellular carcinoma, 24 cases were diagnosed by conventional MRI, with the coincidence rate being 75%, 30 cases were diagnosed by SWI DWI, with the coincidence rate being 96%; significant difference was found between the two groups (p=0. 04). Significant differences were found in the specificity, sensitivity and accuracy of different scanning methods in the diagnosis of small hepatocellular carcinoma (specificity, accuracy, p=0.04; sensitivity p=0.01). The SWI of small hepatocellular carcinoma nodules showed hyperintensity, and the degree of iron deposition was low. Significant difference was found between small hepatocellular carcinoma nodules and other nodules (comparison of SWI signal degree, p=0.01; comparison of iron deposition degree, p=0.00).

Conclusion

The SWI of small hepatocellular carcinoma nodules showed hyperintensity, and the degree of iron deposition was low. The coincidence rate of SWI+DWI scanning is higher than that of conventional scanning methods in the diagnosis of small hepatocellular carcinoma, and the difference in specificity, sensitivity and accuracy has obvious advantages. SWI+DWI scanning can improve the detection rate of liver cirrhosis complicated with small hepatocellular carcinoma.

Hepatobiliary phase hypointensity on gadobenate dimeglumine-enhanced magnetic resonance imaging may improve the diagnosis of hepatocellular carcinoma

Background

To determine the clinical value of hepatobiliary phase (HBP) hypointensity for noninvasive diagnosis of hepatocellular carcinoma (HCC).

Methods

A total of 246 high-risk patients with 263 selected nodules (126 HCCs, 137 non-HCCs) undergoing gadobenate dimeglumine (Gd-BOPTA)-enhanced magnetic resonance imaging (MRI) were included in the study. Imaging-based diagnoses of small (≤3 cm) and large (>3 cm) HCCs were made using the following 4 criteria: (I) non-rim arterial phase hyper-enhancement (APHE) plus hypointensity on the portal venous phase (PVP); (II) non-rim APHE plus hypointensity on the PVP and/or transitional phase (TP); (III) non-rim APHE plus hypointensity on the PVP and/or TP and/or HBP; (IV) criterion 3 plus non-LR-1/2/M. Based on typical imaging features, LR-1, LR-2, or LR-M (if definitely benign, probably benign, malignant but not HCC specific, respectively) were defined according to the Liver Imaging Reporting and Data System (LI-RADS). Sensitivities and specificities of imaging criteria were calculated and compared using McNemar’s test.

Results

Among the diagnostic criteria for small HCCs, criterion 3 and 4, which included HBP hypointensity, showed significantly higher sensitivities (96.4% and 94.6%, respectively) than criterion 1 (58.9%, P<0.001 for both). Moreover, criterion 4, which included HBP hypointensity and ancillary features, showed significantly higher specificity (94.7%) than criterion 3 (66.7%, P<0.001) and comparable specificity to criterion 1 (97.4%, P=0.375), achieving the highest accuracies (94.7%). The diagnostic performance of criterion 4 for large HCCs was similar to that for small HCCs.

Conclusions

HBP hypointensity acquired from Gd-BOPTA-MRI can improve sensitivity and maintain high specificity in the diagnosis of both small and large HCCs after excluding benignities or non-HCC malignancies according to characteristic imaging features.

A meta-analysis of the added value of diffusion weighted imaging in combination with contrast-enhanced magnetic resonance imaging for the diagnosis of small hepatocellular carcinoma lesser or equal to 2 cm

Diffusion weighted imaging (DWI) has been found to increase the sensitivity in the diagnosis of small hepatocellular carcinoma (HCC), although additional studies are required to confirm its value. The aim of the present study was to explore the diagnostic performance of DWI combined with contrast-enhanced magnetic resonance imaging (MRI) for small HCC by performing a meta-analysis. Literature databases (PubMed, Embase, Web of Science and Cochrane Library databases) were searched to identify studies reporting the sensitivity and specificity of MRI with DWI for the diagnosis of small HCCs. Pooled sensitivity and specificity were generated using a bivariate random effect model. Multilevel mixed-effects logistic regression analysis was used to examine the value of DWI combined with conventional MRI. A total of 837 small HCCs and 545 benign liver lesions from 10 studies were included. The overall sensitivity and specificity of DWI combined with contrast-enhanced MRI was 0.88 (95% CI, 0.80-0.93) and 0.90 (95% CI, 0.81-0.95), respectively. Compared with that in contrast-enhanced MRI, DWI with contrast-enhanced MRI had a significantly higher sensitivity for the diagnosis of small HCC (P=0.01) while there was no significant difference in the specificity (P=0.603). The present meta-analysis suggests that DWI combined with contrast-enhanced MRI may increase the sensitivity, whilst maintaining high specificity for the diagnosis of small HCCs with a diameter ≤2 cm.

Current Opinion about Hepatocellular Carcinoma <10 mm

BACKGROUND

Early detection of hepatocellular carcinoma (HCC) is important. Advances in liver imaging techniques have facilitated the detection of HCC at an early stage. However, there is a controversial discussion on how to diagnose very small HCC by imaging. The aim of the current review is to present current published data on HCC ≤10 mm and discuss on how to best diagnose and treat such lesions.

SUMMARY

It is still challenging, however, to accurately characterize HCC <10 mm. The accuracy of contrast-enhanced ultrasound may be critical for early treatment decisions for cancer patients, particularly when CECT and/or CEMRI are inconclusive. Key Messages: The characterization of focal liver lesions <10 mm is frequently delayed until a follow-up imaging procedure demonstrates growth or stability. A repetition of ultrasound examination after 3 months for new nodules <1 cm should be recommended.

Comparison of extracellular and hepatobiliary MR contrast agents for the diagnosis of small HCCs

BACKGROUND & AIMS

The aim of this study was to use a head-to-head nodule comparison to compare the performance of extracellular contrast agent MRI (ECA-MRI) with that of hepatobiliary contrast agent MRI (HBA-MRI) for the non-invasive diagnosis of small hepatocellular carcinomas (HCCs).

METHODS

Between August 2014 and October 2017, 171 patients with cirrhosis, each with 1 to 3 nodules measuring 1-3 cm, were enrolled across 8 centers. All patients underwent both an ECA-MRI and an HBA-MRI within a month. A non-invasive diagnosis of HCC was made when a nodule exhibited arterial phase hyper-enhancement (APHE) with washout at the portal venous phase (PVP) and/or delayed phase (DP) for ECA-MRI, or the PVP and/or HB phase (HBP) for HBA-MRI. The gold standard was defined by using a previously published composite algorithm.

RESULTS

A total of 225 nodules, of which 153 were HCCs and 72 were not, were included. The sensitivites of both MRI techniques were similar. Specificity was 83.3% (95% CI 72.7-91.1) for ECA-MRI and 68.1% (95% CI 56.0-78.6) for HBA-MRI. In terms of HCC diagnosis on ECA-MRI, 138 nodules had APHE, 84 had washout at PVP, and 104 at DP; on HBA-MRI, 128 nodules had APHE, 71 had washout at PVP, and 99 at HBP. For nodules 2-3 cm in size, sensitivity and specificity were similar between the 2 approaches. For nodules 1-2 cm in size, specificity dropped to 66.1% (95% CI 52.2-78.2) for HBA-MRI vs. 85.7% (95% CI 73.8-93.6) for ECA-MRI.

CONCLUSIONS

HBA-MRI specificity is lower than that of ECA-MRI for diagnosing small HCCs in patients with cirrhosis. These results raise the question of the proper use of HBA-MRI in algorithms for the non-invasive diagnosis of small HCCs.

LAY SUMMARY

There are 2 magnetic resonance imaging (MRI)-based approaches available for the non-invasive diagnosis of hepatocellular carcinoma (HCC), using either extracellular or hepatobiliary contrast agents. The current results showed that the sensitivity of MRI with hepatobiliary contrast agents was similar to that with extracellular contrast agents, but the specificity was lower. Thus, hepatobiliary contrast agent-based MRI, although detailed in international guidelines, should be used with caution for the non-invasive diagnosis of HCC.

CLINICAL TRIAL NUMBER

NCT00848952.

Comparison of the diagnostic performance of imaging criteria for HCCs ≤ 3.0 cm on gadoxetate disodium-enhanced MRI

BACKGROUND AND PURPOSE

Imaging-based diagnostic systems play important roles in hepatocellular carcinoma (HCC). We aimed to compare the diagnostic performance of recently updated imaging criteria for HCCs ≤ 3.0 cm on gadoxetate disodium-enhanced magnetic resonance imaging (MRI).

METHODS

493 nodules (399 HCCs, 24 other malignancies, 70 benign) 1.0-3.0 cm from 400 patients, including 322 male (mean age 59.3 ± 9.4 years) and 78 female (mean age 61.2 ± 9.0 years), at risk for HCC who underwent gadoxetate disodium-enhanced MRI between July 2015 and December 2016 were retrospectively evaluated. Final diagnosis was determined histopathologically or clinically. The sensitivity and specificity in diagnosing HCC of the latest versions of four imaging criteria [Liver Imaging Reporting and Data System (LI-RADS), European Association for the Study of the Liver (EASL), Asian Pacific Association for the Study of the Liver (APASL), Korean Liver Cancer Association-National Cancer Center (KLCA-NCC)] were compared using generalized estimating equations.

RESULTS

In 331 only pathologically diagnosed nodules, the sensitivities of both the APASL (86.8%) and KLCA-NCC criteria (85.4%) were significantly higher than the sensitivities of the EASL (71.8%) and LR-5 (71.1%) criteria (p < 0.001 for each pairwise comparison). However, the specificity of LR-5 was significantly higher than that of APASL (92.2% vs. 70.6%, respectively; p = 0.011) but did not differ significantly from the specificities of EASL (84.3%; p = 0.634) and KLCA-NCC (78.4%; p = 0.107).

CONCLUSION

Of the four international imaging criteria, LI-RADS and EASL showed high specificity but suboptimal sensitivity for diagnosing HCCs ≤ 3 cm. However, APASL and KLCA-NCC had a higher sensitivity but a lower specificity than LI-RADS and EASL.

Arterial subtraction images of gadoxetate-enhanced MRI improve diagnosis of early-stage hepatocellular carcinoma

BACKGROUND & AIMS

Although gadoxetate disodium-enhanced magnetic resonance imaging (MRI) shows higher sensitivity for diagnosing hepatocellular carcinoma (HCC), its arterial-phase images may be unsatisfactory because of weak arterial enhancement. We investigated the clinical effectiveness of arterial subtraction images from gadoxetate disodium-enhanced MRI for diagnosing early-stage HCC using the Liver Imaging Reporting and Data System (LI-RADS) v2018.

METHODS

In 258 patients at risk of HCC who underwent gadoxetate disodium-enhanced MRI in 2016, a total of 372 hepatic nodules (273 HCCs, 18 other malignancies, and 81 benign nodules) of 3.0 cm or smaller were retrospectively analyzed. Final diagnosis was assessed histopathologically or clinically (marginal recurrence after treatment or change in lesion size on follow-up imaging). The detection rate for arterial hyperenhancement was compared between ordinary arterial-phase and arterial subtraction images, and the benefit of arterial subtraction images in diagnosing HCC using LI-RADS was assessed.

RESULTS

Arterial subtraction images had a significantly higher detection rate for arterial hyperenhancement than ordinary arterial-phase images, both for all hepatic nodules (72.3% vs. 62.4%, p <0.001) and HCCs (91.9% vs. 80.6%, p <0.001). Compared with ordinary arterial-phase images, arterial subtraction images significantly increased the sensitivity of LI-RADS category 5 for diagnosis of HCC (64.1% [173/270] vs. 55.9% [151/270], p <0.001), without significantly decreasing specificity (92.9% [91/98] vs. 94.9% [93/98], p = 0.155). For histopathologically confirmed lesions, arterial subtraction images significantly increased sensitivity to 68.8% (128/186) from the 61.3% (114/186) of ordinary arterial-phase images (p <0.001), with a minimal decrease in specificity to 84.8% (39/46) from 89.1% (41/46) (p = 0.151).

CONCLUSIONS

Arterial subtraction images of gadoxetate disodium-enhanced MRI can significantly improve the sensitivity of early-stage HCC diagnosis using LI-RADS, without a significant decrease in specificity.

LAY SUMMARY

Gadoxetate disodium-enhanced magnetic resonance imaging is an imaging technique with a high sensitivity for the diagnosis of hepatocellular carcinoma. However, arterial-phase images may be unsatisfactory because of weak arterial enhancement. We found that using arterial subtraction images led to clinically meaningful improvements in the diagnosis of early-stage hepatocellular carcinoma.

Gadoxetic Acid-enhanced MRI of Hepatocellular Carcinoma: Value of Washout in Transitional and Hepatobiliary Phases

Background Current Liver Imaging Reporting and Data System guidelines define the washout appearance of gadoxetic acid-enhanced MRI only during the portal venous phase. Defining washout only during the portal venous phase may lead to lower sensitivity for diagnosis of hepatocellular carcinoma (HCC). Purpose To compare the diagnostic performances of three gadoxetic acid-enhanced MRI criteria for HCC according to the phases during which washout appearance was determined. Materials and Methods In this retrospective study, patients with a hepatic nodule detected at US surveillance for HCC from January to December 2012 underwent gadoxetic acid-enhanced MRI. Three diagnostic MRI criteria for HCC were defined according to the phases during which washout appearance was observed, with the presence of arterial phase hyperenhancement and hypointensity noted (a) only during the portal venous phase, with washout confined to the portal venous phase; (b) during the portal venous phase or transitional phase, with washout extended to the transitional phase; or (c) during the portal venous, transitional, or hepatobiliary phase, with washout extended to the hepatobiliary phase. If a nodule showed marked T2 hyperintensity or a targetoid appearance, it was precluded from the diagnosis of HCC. The sensitivity and specificity were compared by using a generalized estimating equation. Results A total of 178 patients were included (mean age ± standard deviation, 55.3 years ± 9.1) with 203 surgically confirmed hepatic nodules (186 HCCs and 17 non-HCCs) measuring 3.0 cm or smaller. The sensitivity with washout extended to the hepatobiliary phase (95.2% [177 of 186]) was better than that with washout extended to the transitional phase (90.9% [169 of 186]; P = .01) and washout confined to the portal venous phase (75.3% [140 of 186]; P < .01). The specificity with extensions of washout to the transitional phase and hepatobiliary phase (82% [14 of 17] for both) was similar to that obtained with washout confined to the portal venous phase (94.1% [16 of 17]) (P = .47). Conclusion After exclusion of typical hemangiomas and nodules with a targetoid appearance, extending washout appearance to the transitional or hepatobiliary phase (instead of restricting it to the portal venous phase) allowed higher sensitivity without a reduction in specificity. © RSNA, 2019 See also the editorial by Fowler and Sirlin in this issue.

Combining the Arterial Phase of Contrast-Enhanced Ultrasonography, Gadoxetic Acid-Enhanced Magnetic Resonance Imaging and Diffusion-Weighted Imaging in the Diagnosis of Hepatic Nodules ≤20 mm in Patients with Cirrhosis

Contrast-enhanced ultrasonography (CEUS) and gadoxetic acid-enhanced magnetic resonance imaging (EOB-MRI) were compared with respect to diagnostic efficacy in the detection of small hepatocellular carcinoma. A new diagnostic strategy that combines the arterial phase of CEUS, the hepatobiliary phase of EOB-MRI and diffusion-weighted MR imaging (DWI) is described. One hundred sixteen nodules were enrolled to validate the performance of the strategy. For lesions ≤20 mm in size, the areas under the receiver operating characteristic curves (Az) of CEUS and EOB-MRI were 0.930 (95% confidence interval [CI]: 0.867-0.969) and 0.920 (95% CI: 0.855-0.962) (p = 0.796), respectively. The Az value of the new diagnostic strategy was 0.985 (95% CI: 0.942-0.999) (vs. CEUS, p = 0.026; vs. EOB-MRI, p = 0.014). The sensitivity, specificity and diagnostic accuracy of the new strategy were 95.5% (95% CI: 88.9%-98.8%), 96.3% (95% CI: 81.0%-99.9%) and 95.7% (95% CI: 91.9%-99.4%), respectively. The new diagnostic strategy based on the arterial phase of CEUS, hepatobiliary phase of EOB-MRI and DWI represents an appealing solution for distinguishing small hepatocellular carcinomas from benign lesions, especially when the nodules present atypical enhancement patterns.

Comparison of gadoxetic acid versus gadopentetate dimeglumine for the detection of hepatocellular carcinoma at 1.5 T using the liver imaging reporting and data system (LI-RADS v.2017)

PURPOSE

The goal of this study was to investigate the Liver Imaging Reporting and Data System (LI-RADS) v.2017 for the categorization of hepatocellular carcinomas (HCCs) with gadoxetic acid compared with gadopentetate dimeglumine-enhanced 1.5-T magnetic resonance imaging (MRI).

MATERIAL AND METHODS

We included 141 high-risk patients with 145 pathologically-confirmed HCCs who first underwent gadopentetate dimeglumine-enhanced 1.5-T followed by gadoxetic acid-enhanced 1.5-T MRI. Two independent radiologists evaluated the presence or absence of major HCC features and assigned LI-RADS categories after considering ancillary features on both MRIs. Finally, the sensitivity of LI-RADS category 5 (LR-5) and the frequencies of major HCC features were compared between gadoxetic acid- and gadopentetate dimeglumine-enhanced 1.5-T MRI using the Wilcoxon test.

RESULTS

The sensitivity of LR-5 for diagnosing HCCs was significantly different between gadoxetic acid- and gadopentetate dimeglumine-enhanced MRI (73.8% [107/145] vs 26.2% [38/145], P < 0.001; 71% [103/145] vs 29% [42/145], P < 0.001 for reviewers 1 and 2, respectively). Among the major HCC LI-RADS features, capsule appearance was less frequently demonstrated on gadoxetic acid-enhanced MRI than on gadopentetate dimeglumine-enhanced MRI (3.4% [5/145] vs 5.5% [8/145], P = 0.793; 4.1% [6/145] vs 5.5% [8/145], P = 0.87 for reviewers 1 and 2, respectively), and the frequency of arterial hyperenhancement was not significantly different between gadoxetic acid and gadopentetate dimeglumine (89% [129/145] vs 89% [129/145], P = 1.000). In addition, the frequency of a washout appearance was less in the transitional phase (TP) than in the portal venous phase (PVP) on gadoxetic acid-enhanced MRI (43% [46/107] vs 57% [61/107], P = 0.367).

CONCLUSION

Gadoxetic acid-enhanced MRI showed a comparable sensitivity to gadopentetate dimeglumine-enhanced MRI for the diagnosis of HCCs, and LI-RADS category 4 (LR-4) hepatic nodules were upgraded to LR-5 when taking into account the major features according to LI-RADS v.2017.

New hallmark of hepatocellular carcinoma, early hepatocellular carcinoma and high-grade dysplastic nodules on Gd-EOB-DTPA MRI in patients with cirrhosis: a new diagnostic algorithm

OBJECTIVE

Many improvements have been made in diagnosing hepatocellular carcinoma (HCC), but the radiological hallmarks of HCC have remained the same for many years. We prospectively evaluated the imaging criteria of HCC, early HCC and high-grade dysplastic nodules (HGDNs) in patients under surveillance for chronic liver disease, using gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) MRI and diffusion-weighted imaging.

DESIGN

Our study population included 420 nodules >1 cm in 228 patients. The MRI findings of each nodule were collected in all sequences/phases. The diagnosis of HCC was made according to the American Association for the Study of Liver Diseases (AASLD) criteria; all atypical nodules were diagnosed using histology.

RESULTS

A classification and regression tree was developed using three MRI findings which were independently significant correlated variables for early HCC/HCC, and the best sequence of their application in a new diagnostic algorithm (hepatobiliary hypointensity, arterial hyperintensity and diffusion restriction) was suggested. This algorithm demonstrated, both in the entire study population and for nodules ≤2 cm, higher sensitivity (96% [95% CI 93.5% to 97.6%] and 96.6% [95% CI 93.9% to 98.5%], P<0.001, respectively) and slightly lower specificity (91.8% [95% CI 88.6% to 94.1%], P=0.063, and 92.7% [95% CI 88.9% to 95.4%], P=0.125, respectively) than those of the AASLD criteria. Our new diagnostic algorithm also showed a very high sensitivity (94.7%; 95% CI 92% to 96.6%) and specificity (99.3%; 95% CI 97.7% to 99.8%) in classifying HGDN.

CONCLUSION

Our new diagnostic algorithm demonstrated significantly higher sensitivity and comparable specificity than those of the AASLD imaging criteria for HCC in patients with cirrhosis evaluated using Gd-EOB-DTPA MRI, even for lesions ≤2 cm. Moreover, this diagnostic algorithm allowed evaluating other lesions which could arise in a cirrhotic liver, such as early HCC and HGDN.

LI-RADS® ancillary features on CT and MRI

The Liver Imaging Reporting and Data System (LI-RADS) uses an algorithm to assign categories that reflect the probability of hepatocellular carcinoma (HCC), non-HCC malignancy, or benignity. Unlike other imaging algorithms, LI-RADS utilizes ancillary features (AFs) to refine the final category. AFs in LI-RADS v2017 are divided into those favoring malignancy in general, those favoring HCC specifically, and those favoring benignity. Additionally, LI-RADS v2017 provides new rules regarding application of AFs. The purpose of this review is to discuss ancillary features included in LI-RADS v2017, the rationale for their use, potential pitfalls encountered in their interpretation, and tips on their application.

Gadoxetic acid disodium-enhanced magnetic resonance imaging outperformed multidetector computed tomography in diagnosing small hepatocellular carcinoma: A meta-analysis

Early detection of small hepatocellular carcinoma (HCC) lesions can improve longterm patient survival. A systematic review and meta-analysis of the diagnostic performance of gadoxetic acid disodium (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) and multidetector computed tomography (MDCT) was performed in diagnosing small HCCs measuring up to 2 cm (≤2 cm). Two investigators searched multiple databases for studies in which the performances of either Gd-EOB-DTPA-enhanced MRI or MDCT were reported with sufficient data to construct 2 × 2 contingency tables for diagnosing HCCs up to 2 cm on a per-lesion or per-patient level. Diagnostic performances were quantitatively pooled by a bivariate random-effect model with further meta-regression and subgroup analyses. A total of 27 studies (14 on Gd-EOB-DTPA-enhanced MRI, 9 on MDCT, and 4 on both) were included, enrolling a total of 1735 patients on Gd-EOB-DTPA-enhanced MRI and 1781 patients on MDCT. Gd-EOB-DTPA-enhanced MRI demonstrated significantly higher overall sensitivity than did MDCT (0.96 versus 0.65; P < 0.01), without substantial loss of specificity (0.94 versus 0.98; P > 0.05). Area under the summary receiver operating characteristic curve was 0.97 with Gd-EOB-DTPA-enhanced MRI and 0.85 with MDCT. Regarding Gd-EOB-DTPA-enhanced MRI, sensitivity was significantly higher for studies from non-Asian countries than Asian countries (0.96 versus 0.93; P < 0.01), for retrospective studies than prospective studies (0.95 versus 0.91; P < 0.01), and for those with Gd-EOB-DTPA injection rate ≥ 1.5 mL/s than that of <1.5 mL/s (0.97 versus 0.90; P < 0.01). In conclusion, Gd-EOB-DTPA-enhanced MRI demonstrated higher sensitivity and overall diagnostic accuracy than MDCT, and thus should be the preferred imaging modality for diagnosing small HCCs measuring up to 2 cm. Liver Transplantation 23 1505-1518 2017 AASLD.

The uptake exploration of 68Ga-labeled NGR in well-differentiated hepatocellular carcinoma xenografts: Indication for the new clinical translational of a tracer based on NGR

18F-FDG has low uptake and poor diagnostic efficiency in hepatocellular carcinoma (HCC), particularly in well-differentiated HCC. The NGR peptide selectively targets CD13, which is overexpressed in many types of tumor cells as well as neovasculature cells. In the present study, we aimed to evaluate the feasibility of utilizing 68Ga-NGR to image CD13-positive well-differentiated HCC xenografts. The in vitro cellular uptake, in vivo micro-PET/CT imaging and biodistribution studies of 68Ga-NGR and 18F-FDG were quantitatively compared in SMMC-7721-based well‑differentiated HCC xenografts. The human fibrosarcoma (HT-1080) and human colorectal adenocarcinoma (HT-29) xenografts were respectively used as positive and negative reference groups for CD13. The expression of CD13 was qualitatively verified by immunofluorescence staining and immunohistostaining studies. The expression levels of CD13 and glucose-6-phosphatase (G6Pase) were semi-quantitatively analyzed by western blotting. The in vitro SMMC-7721 cellular uptake of 68Ga‑NGR was significantly higher than that of 18F-FDG (1.23±0.11 vs. 0.515±0.14%; P<0.01). The in vivo micro-PET/CT imaging results revealed that the uptake of 68Ga-NGR in SMMC-7721-derived tumors was 2.17±0.21% ID/g (percentage of injected dose per gram of tissue), which was higher compared to that of 18F-FDG (0.73±0.26% ID/g; P<0.01); however, the tumor/liver ratio of 68Ga-NGR was 2-fold higher than that of 18F-FDG. We concluded that the uptake of 68Ga-NGR was significantly higher both in vitro and in vivo than 18F-FDG in the well‑differentiated HCC xenografts and therefore, it is promising for further clinical translation in well-differentiated HCC PET/CT diagnosis.

Image quality and diagnostic performance of free-breathing diffusion-weighted imaging for hepatocellular carcinoma

AIM

To retrospectively evaluate the diagnostic performance of free-breathing diffusion-weighted imaging (FB-DWI) with modified imaging parameter settings for detecting hepatocellular carcinomas (HCCs).

METHODS

Fifty-one patients at risk for HCC were scanned with both FB-DWI and respiratory-triggered DWI with the navigator echo respiratory-triggering technique (RT-DWI). Qualitatively, the sharpness of the liver contour, the image noise and the chemical shift artifacts on each DWI with b-values of 1000 s/mm² were independently evaluated by three radiologists using 4-point scoring. We compared the image quality scores of each observer between the two DWI methods, using the Wilcoxon signed-rank test. Quantitatively, we compared the signal-to-noise ratios (SNRs) of the liver parenchyma and lesion-to-nonlesion contrast-to-noise ratios (CNRs) after measuring the signal intensity on each DWI with a b-factor of 1000 s/mm². The average SNRs and CNRs between the two DWI methods were compared by the paired t-test. The detectability of HCC on each DWI was also analyzed by three radiologists. The detectability provided by the two DWI methods was compared using McNemar’s test.

RESULTS

For all observers, the averaged image quality scores of FB-DWI were: Sharpness of the liver contour [observer (Obs)-1, 3.08 ± 0.81; Obs-2, 2.98 ± 0.73; Obs-3, 3.54 ± 0.75], those of the distortion (Obs-1, 2.94 ± 0.50; Obs-2, 2.71 ± 0.70; Obs-3, 3.27 ± 0.53), and the chemical shift artifacts (Obs-1, 3.38 ± 0.60; Obs-2, 3.15 ± 1.07; Obs-3, 3.21 ± 0.85). The averaged image quality scores of RT-DWI were: Sharpness of the liver contour (Obs-1, 2.33 ± 0.65; Obs-2, 2.37 ± 0.74; Obs-3, 2.75 ± 0.81), distortion (Obs-1, 2.81 ± 0.56; Obs-2, 2.25 ± 0.74; Obs-3, 2.96 ± 0.71), and the chemical shift artifacts (Obs-1, 2.92 ± 0.59; Obs-2, 2.21 ± 0.85; Obs-3, 2.77 ± 1.08). All image quality scores of FB-DWI were significantly higher than those of RT-DWI (P < 0.05). The average SNR of the normal liver parenchyma by FB-DWI (11.0 ± 4.8) was not significantly different from that shown by RT-DWI (11.0 ± 5.0); nor were the lesion-to-nonlesion CNRs significantly different (FB-DWI, 21.4 ± 17.7; RT-DWI, 20.1 ± 15.1). For all three observers, the detectability of FB-DWI (Obs-1, 43.6%; Obs-2, 53.6%; and Obs-3, 45.0%) was significantly higher than that of RT-DWI (Obs-1, 29.1%; Obs-2, 43.6%; and Obs-3, 34.5%) (P < 0.05).

CONCLUSION

FB-DWI showed better image quality and higher detectability of HCC compared to RT-DWI, without significantly reducing the SNRs of the liver parenchyma and lesion-to-nonlesion CNRs.

Diagnosis of hepatocellular carcinoma: An update on international guidelines

Imaging is essential for the successful management of patients with or at risk of developing hepatocellular carcinoma (HCC). If ultrasound remains the key screening modality, computed tomography and magnetic resonance imaging (MRI) can play a major role in the characterization and noninvasive diagnosis of nodules in patients at risk of developing HCC. Each technique has succeeded in adapting to the wide histological spectrum of focal liver lesions. In this review, we discuss recent advancements in imaging techniques and evaluation - notably diffusion-weighted imaging, contrast-enhanced ultrasound, and liver-specific MRI contrast agents - as well as their addition to international guidelines and reporting systems such as the Liver imaging reporting and data system (LI-RADS).

Standard-b-Value Versus Low-b-Value Diffusion-Weighted Imaging in Hepatic Lesion Discrimination: A Meta-analysis

OBJECTIVE

We sought to determine the comparative diagnostic performance of standard-b-value (500-1000s/mm) versus low-b-value (≤500 s/mm) diffusion-weighted imaging (DWI) in the discrimination of hepatic lesions.

METHODS

A total of 1775 hepatic malignant lesions and 1120 benign hepatic lesions from 21 studies were included.

RESULTS

(1) The global sensitivity was 0.86 (95% confidence interval [CI], 0.847-0.879), the specificity was 0.82 (95% CI, 0.797-0.842), the positive likelihood ratio (PLR) was 6.234 (95% CI, 4.260-9.123), the negative likelihood ratio (NLR) was 0.175 (95% CI, 0.135-0.227), and diagnostic odds ratio (DOR) was 42.836 (95% CI, 24.134-76.031). The area under the curve (AUC) and Q* index were 0.93 and 0.87. Publication bias was not present (P > 0.05). (2)The sensitivity of a subgroup meta-analysis of standard-b-value DWI was 0.858 (95% CI, 0.835-0.880), the specificity was 0.836 (95% CI, 0.807-0.863), the PLR was 6.527 (95% CI, 3.857-11.046), the NLR was 0.168 (95% CI, 0.123-0.239), and the DOR was 49.716 (95% CI, 22.897-107.98). The AUC and Q* index were 0.941 and 0.88. (3)The sensitivity of a subgroup meta-analysis of low-b-value DWI was 0.87 (95% CI, 0.84-0.89), the specificity was 0.80 (95% CI, 0.76-0.83), the PLR was 6.22 (95% CI, 3.29-11.76), the NLR was 0.19 (95% CI, 0.12-0.29), and the DOR was 37.14 (95% CI, 14.80-93.18). The AUC and Q* index were 0.922 and 0.86.

CONCLUSIONS

Hepatic DWI is useful in differentiating between malignant and benign hepatic lesions. Standard-b-value DWI displayed an overall superior diagnostic accuracy over low-b-value DWI. Further trials needed to determine whether increasing b values beyond 1000 s/mm affects the diagnostic accuracy of hepatic lesion discrimination.

Respiratory Motion-Resolved Compressed Sensing Reconstruction of Free-Breathing Radial Acquisition for Dynamic Liver Magnetic Resonance Imaging

OBJECTIVE

This study aimed to demonstrate feasibility of free-breathing radial acquisition with respiratory motion-resolved compressed sensing reconstruction [extra-dimensional golden-angle radial sparse parallel imaging (XD-GRASP)] for multiphase dynamic gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced liver imaging, and to compare image quality to compressed sensing reconstruction with respiratory motion-averaging (GRASP) and prior conventional breath-held Cartesian-sampled data sets [BH volume interpolated breath-hold examination (VIBE)] in same patients.

SUBJECTS AND METHODS

In this Health Insurance Portability and Accountability Act-compliant prospective study, 16 subjects underwent free-breathing continuous radial acquisition during Gd-EOB-DTPA injection and had prior BH-VIBE available. Acquired data were reconstructed using motion-averaging GRASP approach in which consecutive 84 spokes were grouped in each contrast-enhanced phase for a temporal resolution of approximately 14 seconds. Additionally, respiratory motion-resolved reconstruction was performed from the same k-space data by sorting each contrast-enhanced phase into multiple respiratory motion states using compressed sensing algorithm named XD-GRASP, which exploits sparsity along both the contrast-enhancement and respiratory-state dimensions.Contrast-enhanced dynamic multiphase XD-GRASP, GRASP, and BH-VIBE images were anonymized, pooled together in a random order, and presented to 2 board-certified radiologists for independent evaluation of image quality, with higher score indicating more optimal examination.

RESULTS

The XD-GRASP reconstructions had significantly (all P < 0.05) higher overall image quality scores compared to GRASP for early arterial (reader 1: 4.3 ± 0.6 vs 3.31 ± 0.6; reader 2: 3.81 ± 0.8 vs 3.38 ± 0.9) and late arterial (reader 1: 4.5 ± 0.6 vs 3.63 ± 0.6; reader 2: 3.56 ± 0.5 vs 2.88 ± 0.7) phases of enhancement for both readers. The XD-GRASP also had higher overall image quality score in portal venous phase, which was significant for reader 1 (4.44 ± 0.5 vs 3.75 ± 0.8; P = 0.002). In addition, the XD-GRASP had higher overall image quality score compared to BH-VIBE for early (reader 1: 4.3 ± 0.6 vs 3.88 ± 0.6; reader 2: 3.81 ± 0.8 vs 3.50 ± 1.0) and late (reader 1: 4.5 ± 0.6 vs 3.44 ± 0.6; reader 2: 3.56 ± 0.5 vs 2.94 ± 0.9) arterial phases.

CONCLUSION

Free-breathing motion-resolved XD-GRASP reconstructions provide diagnostic high-quality multiphase images in patients undergoing Gd-EOB-DTPA-enhanced liver examination.

Is there an added value of a hepatobiliary phase with gadoxetate disodium following conventional MRI with an extracellular gadolinium agent in a single imaging session for detection of primary hepatic malignancies?

PURPOSE

To determine added value of hepatobiliary phase (HBP) using gadoxetate disodium compared to MRI with extracellular gadolinium-based contrast agent (GBCA) for detection of primary hepatic malignancies in a single imaging session.

MATERIALS AND METHODS

IRB approved this HIPAA compliant retrospective study. Within 90 days of resection or liver transplant, thirty patients underwent MRI with extracellular GBCA followed by separate injection of gadoxetate for HBP. Two sets of images were reviewed: Set #1-unenhanced and enhanced images with an extracellular GBCA and set #2-with addition of HBP. Data were analyzed in two groups, cases with hepatocellular carcinoma (HCC) only and cases with either HCC and/or cholangiocarcinoma. Observer diagnostic accuracy (Az), sensitivity, and specificity were calculated.

RESULTS

14/30 subjects had HCC (46%, CI 28-66%), 2/30 (2%, CI 1-22%) cholangiocarcinoma, and 14/30 (46%, CI 28-66%) no malignancy. There was no significant change in A z value with addition of gadoxetate in the detection of HCC (range 0.84-0.97 set #1 and 0.85-0.97 set #2, p > 0.05). Sensitivity and specificity showed no significant differences (p > 0.05) between the image sets for all readers. When stratified by lesion size, there was no significant difference in accuracy, sensitivity, or specificity for any reader (p > 0.05).

CONCLUSION

When compared to extracellular GBCA, gadoxetate HBP imaging does not result in a significant difference in accuracy or sensitivity in diagnosis of HCC or cholangiocarcinoma and may result in a decrease in specificity.

Diagnostic criteria for hepatocellular carcinoma ⩽3 cm with hepatocyte-specific contrast-enhanced magnetic resonance imaging

BACKGROUND & AIMS

Current diagnostic imaging criteria for hepatocellular carcinoma (HCC) are dedicated to imaging with nonspecific extracellular contrast agents. This study aimed to evaluate diagnostic criteria for HCC ⩽3 cm on magnetic resonance imaging (MRI) with a hepatocyte-specific contrast agent through an inception cohort study.

METHODS

Of 291 patients with chronic liver disease and new nodules of 1-3 cm in diameter at surveillance ultrasonography, 295 solid nodules (194 HCCs, 98 benign nodules, and three other malignancies) in 198 patients with a confirmed final diagnosis or ⩾24 months follow-up were evaluated on gadoxetic acid-enhanced MRI. Through univariate and multivariate logistic regression analyses, various diagnostic criteria were developed by combining significant MRI findings for diagnosing HCC. The diagnostic performance of each criterion was compared with that of the European Association for the Study of the Liver (EASL) criteria.

RESULTS

Four MRI findings (arterial-phase hyperintensity, transitional-phase hypointensity, hepatobiliary-phase hypointensity, and rim enhancement) were independently significant for diagnosis of HCC ⩽3 cm. For whole nodules, EASL criteria showed the best performance for diagnosing HCC (sensitivity, 83.5%; specificity, 81.2%). For nodules ⩽2 cm in diameter, a new criterion (arterial-phase hyperintensity and hepatobiliary-phase hypointensity) showed a significantly higher sensitivity than that of the EASL criteria (83.0% vs. 74.5%, p=0.008), without a significantly different specificity (76.7% vs. 81.1%, p=0.125).

CONCLUSIONS

EASL criteria exhibit the best diagnostic performance for HCC ⩽3 cm on hepatocyte-specific contrast-enhanced MRI. A newly identified criterion (arterial-phase hyperintensity and hepatobiliary-phase hypointensity) may increase the diagnostic sensitivity of small (⩽2 cm) HCC.

Proposal of a new diagnostic algorithm for hepatocellular carcinoma based on the Japanese guidelines but adapted to the Western world for patients under surveillance for chronic liver disease

To date, despite many scientific evidences, the guidelines of the principal hepatological societies, such as the American Association for the Study of Liver Diseases, the European Association for the Study of the Liver, and the Asian Pacific Association for the Study of the Liver, do not recognize the diagnostic superiority of magnetic resonance imaging (MRI) over computed tomography in the diagnosis of hepatocellular carcinoma (HCC) and, for the most part, do not contemplate the use of hepatospecific contrast media, such as gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (EOB). The aim of this paper was to analyze the recent results of EOB-MRI in the study of chronic liver disease and the differences between the American Association for the Study of Liver Diseases and the Japan Society of Hepatology guidelines, of which the latter represents the most consolidated experience on EOB-MRI use for HCC diagnosis. Finally, a new diagnostic algorithm for HCC in patients under surveillance for chronic liver disease was formulated, which contemplates the use of EOB. This new diagnostic algorithm is based on the Japan Society of Hepatology algorithm but goes beyond it by adapting it to the Western world, taking into account both the difference between the two and the latest results concerning the diagnosis of HCC. This new diagnostic algorithm for HCC is proposed in order to provide useful diagnostic tools to all those Western countries where the use of EOB (more expensive than extracellular contrast media) is widespread but in which common strategies to manage the nodules that this new contrast agent allows identifying have not been available to date.

Focal liver lesions: Practical magnetic resonance imaging approach

With the widespread of cross-sectional imaging, a growth of incidentally detected focal liver lesions (FLL) has been observed. A reliable detection and characterization of FLL is critical for optimal patient management. Maximizing accuracy of imaging in the context of FLL is paramount in avoiding unnecessary biopsies, which may result in post-procedural complications. A tremendous development of new imaging techniques has taken place during these last years. Nowadays, Magnetic resonance imaging (MRI) plays a key role in management of liver lesions, using a radiation-free technique and a safe contrast agent profile. MRI plays a key role in the non-invasive correct characterization of FLL. MRI is capable of providing comprehensive and highly accurate diagnostic information, with the additional advantage of lack of harmful ionizing radiation. These properties make MRI the mainstay for the noninvasive evaluation of focal liver lesions. In this paper we review the state-of-the-art MRI liver protocol, briefly discussing different sequence types, the unique characteristics of imaging non-cooperative patients and discuss the role of hepatocyte-specific contrast agents. A review of the imaging features of the most common benign and malignant FLL is presented, supplemented by a schematic representation of a simplistic practical approach on MRI.