Performance of gadoxetic acid-enhanced MRI for detecting hepatocellular carcinoma in recipients of living-related-liver-transplantation: comparison with dynamic multidetector row computed tomography and angiography-assisted computed tomography

Prospective evaluation of Gadoxetate-enhanced magnetic resonance imaging and computed tomography for hepatocellular carcinoma detection and transplant eligibility assessment with explant histopathology correlation

BACKGROUND

We aimed to prospectively compare the diagnostic performance of gadoxetic acid-enhanced MRI (EOB-MRI) and contrast-enhanced Computed Tomography (CECT) for hepatocellular carcinoma (HCC) detection and liver transplant (LT) eligibility assessment in cirrhotic patients with explant histopathology correlation.

METHODS

In this prospective, single-institution ethics-approved study, 101 cirrhotic patients were enrolled consecutively from the pre-LT clinic with written informed consent. Patients underwent CECT and EOB-MRI alternately every 3 months until LT or study exclusion. Two blinded radiologists independently scored hepatic lesions on CECT and EOB-MRI utilizing the liver imaging reporting and data system (LI-RADS) version 2018. Liver explant histopathology was the reference standard. Pre-LT eligibility accuracies with EOB-MRI and CECT as per Milan criteria (MC) were assessed in reference to post-LT explant histopathology. Lesion-level and patient-level statistical analyses were performed.

RESULTS

Sixty patients (49 men; age 33-72 years) underwent LT successfully. One hundred four non-treated HCC and 42 viable HCC in previously treated HCC were identified at explant histopathology. For LR-4/5 category lesions, EOB-MRI had a higher pooled sensitivity (86.7% versus 75.3%, p <  0.001) but lower specificity (84.6% versus 100%, p <  0.001) compared to CECT. EOB-MRI had a sensitivity twice that of CECT (65.9% versus 32.2%, p <  0.001) when all HCC identified at explant histopathology were included in the analysis instead of imaging visible lesions only. Disregarding the hepatobiliary phase resulted in a significant drop in EOB-MRI performance (86.7 to 72.8%, p <  0.001). EOB-MRI had significantly lower pooled sensitivity and specificity versus CECT in the LR5 category with lesion size < 2 cm (50% versus 79%, p = 0.002 and 88.9% versus 100%, p = 0.002). EOB-MRI had higher sensitivity (84.8% versus 75%, p <  0.037) compared to CECT for detecting < 2 cm viable HCC in treated lesions. Accuracies of LT eligibility assessment were comparable between EOB-MRI (90-91.7%, p = 0.156) and CECT (90-95%, p = 0.158).

CONCLUSION

EOB-MRI had superior sensitivity for HCC detection; however, with lower specificity compared to CECT in LR4/5 category lesions while it was inferior to CECT in the LR5 category under 2 cm. The accuracy for LT eligibility assessment based on MC was not significantly different between EOB-MRI and CECT.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03342677 , Registered: November 17, 2017.

Optimal imaging criteria and modality to determine Milan criteria for the prediction of post-transplant HCC recurrence after locoregional treatment

OBJECTIVES

We aimed to investigate the optimal radiologic method to determine Milan criteria (MC) for the prediction of recurrence in patients who underwent locoregional treatment (LRT) for hepatocellular carcinoma (HCC) and subsequent liver transplantation (LT).

METHODS

This retrospective study included 121 HCC patients who underwent LRT and had both liver dynamic CT and MRI. They were classified with MC using four cross combinations of two imaging modalities (CT and MRI) and two diagnostic criteria (modified Response Evaluation Criteria in Solid Tumors [mRECIST] and Liver Imaging Reporting and Data System treatment response algorithm [LI-RADS TRA]). Competing risk regression was performed to analyze the time to recurrence after LT. The predictive abilities of the four methods for recurrence were evaluated using the time-dependent area under the curve (AUC).

RESULTS

Competing risk regression analyses found that beyond MC determined by MRI with mRECIST was independently associated with recurrence (hazard ratio, 6.926; p = 0.001). With mRECIST, MRI showed significantly higher AUCs than CT at 3 years and 5 years after LT (0.597 vs. 0.756, p = 0.012 at 3 years; and 0.588 vs. 0.733, p = 0.024 at 5 years). Using the pathologic reference standard, MRI with LI-RADS TRA showed higher sensitivity (61.5%) than CT with LI-RADS TRA (30.8%, p < 0.001) or MRI with mRECIST (38.5%, p < 0.001).

CONCLUSIONS

MRI with mRECIST was the optimal radiologic method to determine MC for the prediction of post-LT recurrence in HCC patients with prior LRT.

KEY POINTS

• MRI with modified RECIST (mRECIST) is the optimal preoperative method to determine Milan criteria for the prediction of post-transplant HCC recurrence in patients with prior locoregional treatment. • With mRECIST, MRI was better than CT for the prediction of post-transplant recurrence.

Gadoxetate-Enhanced MRI as a Diagnostic Tool in the Management of Hepatocellular Carcinoma: Report from a 2020 Asia-Pacific Multidisciplinary Expert Meeting

Gadoxetate magnetic resonance imaging (MRI) is widely used in clinical practice for liver imaging. For optimal use, we must understand both its advantages and limitations. This article is the outcome of an online advisory board meeting and subsequent discussions by a multidisciplinary group of experts on liver diseases across the Asia-Pacific region, first held on September 28, 2020. Here, we review the technical considerations for the use of gadoxetate, its current role in the management of patients with hepatocellular carcinoma (HCC), and its relevance in consensus guidelines for HCC imaging diagnosis. In the latter part of this review, we examine recent evidence evaluating the impact of gadoxetate on clinical outcomes on a continuum from diagnosis to treatment decision-making and follow-up. In conclusion, we outline the potential future roles of gadoxetate MRI based on an evolving understanding of the clinical utility of this contrast agent in the management of patients at risk of, or with, HCC.

Computed tomography for the diagnosis of hepatocellular carcinoma in adults with chronic liver disease

BACKGROUND

Hepatocellular carcinoma occurs mostly in people with chronic liver disease and ranks sixth in terms of global incidence of cancer, and fourth in terms of cancer deaths. In clinical practice, computed tomography (CT) is used as a second-line diagnostic imaging modality to confirm the presence of focal liver lesions suspected as hepatocellular carcinoma on prior diagnostic test such as abdominal ultrasound or alpha-foetoprotein, or both, either in surveillance programmes or in clinical settings. According to current guidelines, a single contrast-enhanced imaging study CT or magnetic resonance imaging (MRI) showing typical hallmarks of hepatocellular carcinoma in people with cirrhosis is valid to diagnose hepatocellular carcinoma. However, a significant number of hepatocellular carcinomas do not show typical hallmarks on imaging modalities, and hepatocellular carcinoma is, therefore, missed. There is no clear evidence of the benefit of surveillance programmes in terms of overall survival: the conflicting results can be a consequence of inaccurate detection, ineffective treatment, or both. Assessing the diagnostic accuracy of CT may clarify whether the absence of benefit could be related to underdiagnosis. Furthermore, an assessment of the accuracy of CT in people with chronic liver disease, who are not included in surveillance programmes is needed for either ruling out or diagnosing hepatocellular carcinoma.

OBJECTIVES

Primary: to assess the diagnostic accuracy of multidetector, multiphasic contrast-enhanced CT for the diagnosis of hepatocellular carcinoma of any size and at any stage in adults with chronic liver disease, either in a surveillance programme or in a clinical setting. Secondary: to assess the diagnostic accuracy of CT for the diagnosis of resectable hepatocellular carcinoma in adults with chronic liver disease.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Trials Register, Cochrane Hepato-Biliary Diagnostic-Test-Accuracy Studies Register, the Cochrane Library, MEDLINE, Embase, LILACS, Science Citation Index Expanded, and Conference Proceedings Citation Index - Science until 4 May 2021. We applied no language or document-type restrictions.

SELECTION CRITERIA

Studies assessing the diagnostic accuracy of CT for the diagnosis of hepatocellular carcinoma in adults with chronic liver disease, with cross-sectional designs, using one of the acceptable reference standards, such as pathology of the explanted liver and histology of resected or biopsied focal liver lesion with at least a six-month follow-up.

DATA COLLECTION AND ANALYSIS

At least two review authors independently screened studies, extracted data, and assessed the risk of bias and applicability concerns, using the QUADAS-2 checklist. We presented the results of sensitivity and specificity, using paired forest plots, and tabulated the results. We used a hierarchical meta-analysis model where appropriate. We presented uncertainty of the accuracy estimates using 95% confidence intervals (CIs). We double-checked all data extractions and analyses.

MAIN RESULTS

We included 21 studies, with a total of 3101 participants. We judged all studies to be at high risk of bias in at least one domain because most studies used different reference standards, often inappropriate to exclude the presence of the target condition, and the time-interval between the index test and the reference standard was rarely defined. Regarding applicability in the patient selection domain, we judged 14% (3/21) of studies to be at low concern and 86% (18/21) of studies to be at high concern owing to characteristics of the participants who were on waiting lists for orthotopic liver transplantation. CT for hepatocellular carcinoma of any size and stage: sensitivity 77.5% (95% CI 70.9% to 82.9%) and specificity 91.3% (95% CI 86.5% to 94.5%) (21 studies, 3101 participants; low-certainty evidence). CT for resectable hepatocellular carcinoma: sensitivity 71.4% (95% CI 60.3% to 80.4%) and specificity 92.0% (95% CI 86.3% to 95.5%) (10 studies, 1854 participants; low-certainty evidence). In the three studies at low concern for applicability (861 participants), we found sensitivity 76.9% (95% CI 50.8% to 91.5%) and specificity 89.2% (95% CI 57.0% to 98.1%). The observed heterogeneity in the results remains mostly unexplained. The sensitivity analyses, which included only studies with clearly prespecified positivity criteria and only studies in which the reference standard results were interpreted without knowledge of the results of the index test, showed no variation in the results.

AUTHORS' CONCLUSIONS

In the clinical pathway for the diagnosis of hepatocellular carcinoma in adults with chronic liver disease, CT has roles as a confirmatory test for hepatocellular carcinoma lesions, and for staging assessment. We found that using CT in detecting hepatocellular carcinoma of any size and stage, 22.5% of people with hepatocellular carcinoma would be missed, and 8.7% of people without hepatocellular carcinoma would be unnecessarily treated. For resectable hepatocellular carcinoma, we found that 28.6% of people with resectable hepatocellular carcinoma would improperly not be resected, while 8% of people without hepatocellular carcinoma would undergo inappropriate surgery. The uncertainty resulting from the high risk of bias in the included studies and concerns regarding their applicability limit our ability to confidently draw conclusions based on our results.

Comparison of LI-RADS with other non-invasive liver MRI criteria and radiological opinion for diagnosing hepatocellular carcinoma in cirrhotic livers using gadoxetic acid with histopathological explant correlation

AIM

To establish the diagnostic accuracy of the Liver Imaging Reporting and Data System (LI-RADS) for hepatocellular carcinoma (HCC) and compare its performance to that of international criteria from European Assofor the Study of the Liver (EASL), Japan Society of Hepatology (JSH), Asian Pacific Association for the Study of the Liver (APASL), and Organ Procurement and Transplantation Network (OPTN), and to the reporting radiologist's overall opinion regarding the probability of a nodule being a HCC by correlating with a histological diagnosis from whole liver explants.

MATERIALS AND METHODS

The present single-centre, retrospective review selected participants based on the following criteria: adults (≥18 years) listed for liver transplantation in 2014/2015, with liver cirrhosis at the time of magnetic resonance imaging (MRI) with hepatocyte specific contrast agent, and at least one liver lesion ≥10 mm on MRI with histology from subsequent liver explant for comparison. Each lesion was assessed against international criteria and given a "radiologist opinion" score of 1-5 (1 = definitely benign, 5 = definitely HCC).

RESULTS

Total 268 patient records were reviewed, with 105 eligible lesions identified from 47 patients. Median lesion size was 15.5 mm (range 10-68 mm). Sensitivity (%), specificity (%), and positive predictive value (PPV; %) for LI-RADS LR5 was 45, 89, and 89, for LI-RADS LR4+5 + TIV was 61, 80, and 86, for EASL was 44, 86 and 86, for JSH/APASL was 64, 81, and 87, for OPTN was 36, 90, and 88, and for "radiologist impression" of probably or definitely HCC was 79, 79, and 88 respectively.

CONCLUSIONS

MRI has moderate sensitivity and good specificity for the diagnosis of HCC with considerable variation depending on criteria used. OPTN criteria have the best specificity, but low sensitivity. "Radiologist opinion" gives highest overall accuracy with increases in sensitivity and reduction in specificity when compared to the imaging criteria.

Diagnostic performance of Liver Imaging Reporting and Data System treatment response algorithm: a systematic review and meta-analysis

OBJECTIVE

To systematically determine the accuracy of Liver Imaging Reporting and Data System treatment response (LR-TR) algorithm for diagnosing the viability of hepatocellular carcinoma (HCC) treated with locoregional therapy (LRT).

METHODS

Original studies reporting the diagnostic accuracy of LR-TR algorithm on dynamic contrast-enhanced computed tomography or magnetic resonance imaging (MRI) were identified in MEDLINE and EMBASE up to June 1, 2020. The meta-analytic summary sensitivity and specificity of LR-TR algorithm were calculated using a bivariate random-effects model. Subgroup analyses and meta-regression analysis were performed to explore study heterogeneity.

RESULTS

We found six studies reporting the accuracy of LR-TR viable category (601 observations in 453 patients). The meta-analytic pooled sensitivity and specificity of LR-TR viable category were 63% (95% confidence interval [CI], 39-81%; I² = 88%) and 96% (95% CI, 91-99%; I² = 76%), respectively. The meta-analytic pooled sensitivity and specificity of LR-TR viable or equivocal category combined were 71% (95% CI, 55-84%; I² = 89%) and 87% (95% CI, 73-94% I² = 80%), respectively. Studies which used only MRI showed a trend towards higher sensitivity (71% [95% CI, 46-88%]) with a comparable specificity (95% [95% CI, 86-99%]) of LR-TR viable category compared to the whole group. The type of reference standard and study design were significantly associated with study heterogeneity (p ≤ 0.01).

CONCLUSIONS

The LR-TR viable category had high specificity but suboptimal sensitivity for diagnosing the viability of HCC after LRT. Substantial study heterogeneity was noted, and it was significantly associated with the type of reference standard and study design.

KEY POINTS

• The meta-analytic pooled sensitivity and specificity of LR-TR viable category were 63% (95% CI, 39-81%) and 96% (95% CI, 91-99%), respectively. • The meta-analytic pooled sensitivity and specificity of LR-TR viable or equivocal category combined were 71% (95% CI, 55-84%) and 87% (95% CI, 73-94%), respectively. • The type of reference standard and study design were the factors significantly influencing study heterogeneity (p ≤ 0.01).

Surgical Indications for Hepatocellular Carcinoma with Non-hypervascular Hypointense Nodules Detected by Gd-EOB-DTPA-Enhanced MRI

BACKGROUND

The surgical indication for non-hypervascular hypointense nodules (NHVN) detected incidentally on gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (Gd-EOB-MRI) for classical hepatocellular carcinoma (HCC) is unknown. Our aim is to clarify the long-term outcomes in patients with this finding.

METHODS

We reviewed the cases of 290 HCC patients, including 66 patients with NHVN, who underwent Gd-EOB-MRI prior to hepatectomy, between October 2008 and December 2017 at our center. We divided the patients into three groups: a no-NHVN group, a treated NHVN group, and an untreated NHVN group.

RESULTS

There was no significant difference in (RFS) or overall survival (OS) between the no-NHVN and untreated NHVN groups (p = 0.103 and 0.103, respectively). There was no significant difference between these two groups after propensity score matching. Multivariate analyses showed that microscopic intrahepatic metastases and the size of the main classical HCC, the target tumor, were independent prognostic factors of overall survival, but the presence of non-hypervascular hypointense nodules was not. There was no significant difference in RFS or OS between the treated NHVN and untreated NHVN groups (p = 0.158 and 0.109, respectively).

CONCLUSIONS

Non-hypervascular hypointense nodules detected incidentally on Gd-EOB-MRI associated with targeted hypervascular HCC did not reflect prognosis of HCC after hepatectomy. Surgical procedures for classical enhancing HCC may be performed even if non-hypervascular hypointense nodules adjacent to the targeted HCC cannot be removed completely.

Hyperintensity at fat spared area in steatotic liver on the hepatobiliary phase MRI

PURPOSE

We aimed to investigate the reasons for hyperintensity at fat spared area in steatotic liver at hepatobiliary phase (HBP) on gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) enhanced liver magnetic resonance imaging.

METHODS

Twenty-two patients with focal fat spared area demonstrating hyperintensity on HBP images were included. A region of interest was placed on in- and opposed-phase images at fat spared area and liver to measure the fat. The measurement was also performed on precontrast T1-weighted and HBP images. The signal intensities of spleen, kidney, muscle, intervertebral disc, and spinal cord were also recorded.

RESULTS

The mean fat fraction of liver and fat spared area was 24.86% (8%-46%) and 8.41% (1%-34%), respectively (P < 0.001). There was a significant positive correlation between liver parenchyma fat fraction and delta fat fraction (r=0.74, P < 0.001). The mean signal intensity values of fat spared areas were higher compared with liver on precontrast T1-weighted and HBP images (P < 0.001). The mean relative enhancement ratio of liver and fat spared areas were 0.98 (0.05-1.90) and 1.15 (0.22-2.03), respectively (P < 0.001). However, in 6 patients, the relative enhancement ratio of liver and fat spared areas were almost equal. The uptake of Gd-EOB at fat spared area was not correlated with the degree of steatosis (r = -0.01, P = 0.95).

CONCLUSION

Fat spared area in steatotic liver appears hyperintense on HBP images due to increased relative enhancement ratio and/or baseline hyperintensity on precontrast images.

Optimal Combination of Features on Gadoxetate Disodium-enhanced MR Imaging for Non-invasive Differential Diagnosis of Hepatocellular Carcinoma: The JAMP-HCC Study

Purpose:

To determine the optimal combination of gadoxetate disodium-enhanced magnetic resonance imaging (MRI) findings for the diagnosis of hepatocellular carcinoma (HCC) and to compare its diagnostic ability to that of dynamic computed tomography (CT) in patients with chronic liver disease.

Methods:

This multi-institutional study consisted of two parts: Study 1, a retrospective study to determine the optimal combination of gadoxetate disodium-enhanced MRI findings (decision tree and logistic model) to distinguish HCC (n = 199) from benign (n = 81) or other malignant lesions (n = 95) (375 nodules in 269 patients) and Study 2, a prospective study to compare the diagnostic ability of gadoxetate disodium-enhanced MRI to distinguish HCC (n = 73) from benign (n = 15) or other malignant lesions (n = 12) with that of dynamic CT (100 nodules in 83 patients). Two radiologists independently evaluated the imaging findings (Study 1 and 2) and made a practical diagnosis (Study 2).

Results:

In Study 1, rim or whole enhancement on arterial phase images, signal intensities on T₂-weighted/diffusion-weighted/portal venous/transitional/hepatobiliary phase images, and signal drop on opposed-phase images were independently useful for differential diagnosis. In Study 2, the accuracy, sensitivity, negative predictive value, and negative likelihood ratio of the CT decision tree (reader 2) were higher than those of MRI Model 2 (P = 0.015–0.033). There were no other significant differences in diagnostic ability (P = 0.059–1.000) and radiologist-made practical diagnosis (P = 0.059–1.000) between gadoxetate disodium-enhanced MRI and CT.

Conclusion:

We identified the optimal combination of gadoxetate disodium-enhanced MRI findings for HCC diagnosis. However, its diagnostic ability was not superior to that of dynamic CT.

Use of Gadoxetic Acid-enhanced Liver MRI and Mortality in More than 30 000 Patients with Hepatocellular Carcinoma: A Nationwide Analysis

Background The impact on survival of gadoxetic acid-enhanced MRI in addition to multiphase contrast material-enhanced CT for initial staging in patients with hepatocellular carcinoma (HCC) is unknown. Purpose To compare all-cause mortality in patients with HCC who underwent CT only, CT plus non-gadoxetic acid-enhanced MRI, or CT plus gadoxetic acid-enhanced MRI as part of their initial diagnostic work-up. Materials and Methods The authors performed a nationwide retrospective cohort study of patients diagnosed with HCC in South Korea between January 2008 and December 2010. Follow-up extended through December 2014. The primary outcome was all-cause mortality. Cox proportional hazards regression model with adjustment of confounding factors was used to estimate hazard ratios (HRs) for all-cause mortality. Results Among 30 023 patients with HCC (mean age ± standard deviation, 58.5 years ± 10.7, 23 978 men), the proportions of patients in whom HCC was diagnosed using CT only, CT plus non-gadoxetic acid-enhanced MRI, and CT plus gadoxetic acid-enhanced MRI were 56.1%, 12.9%, and 31.0%, respectively. In adjusted analysis using CT only as the reference category, the HR for mortality for CT plus gadoxetic acid-enhanced MRI was 0.64 (95% confidence interval [CI]: 0.62, 0.67; P < .001), and the HR for CT plus non-gadoxetic acid-enhanced MRI was 0.71 (95% CI: 0.68, 0.75; P < .001). Use of CT plus gadoxetic acid-enhanced MRI was associated with lower mortality compared with CT plus non-gadoxetic acid-enhanced MRI (adjusted HR, 0.90; 95% CI: 0.85, 0.95; P < .001), but this survival advantage was restricted to patients with localized disease. Conclusion In patients with hepatocellular carcinoma, additional use of contrast-enhanced MRI was associated with lower mortality. Furthermore, CT plus gadoxetic acid-enhanced MRI was associated with better survival than CT plus non-gadoxetic acid-enhanced MRI but only in patients with localized disease. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Kim in this issue.

Evaluation of treatment response in hepatocellular carcinoma in the explanted liver with Liver Imaging Reporting and Data System version 2017

OBJECTIVE

To investigate the performance of Liver Imaging Reporting and Data System (LI-RADS) v2017 treatment response algorithm for predicting hepatocellular carcinoma (HCC) viability after locoregional therapy (LRT) using the liver explant as reference.

METHODS

One hundred fourteen patients with 206 HCCs who underwent liver transplantation (LT) after LRT for HCCs were included in this retrospective study. Two radiologists independently evaluated tumor viability using the LI-RADS and modified RECIST (mRECIST) with CT and MRI, respectively. The sensitivity and specificity of arterial phase hyperenhancement (APHE) and LR-TR viable criteria (any of three findings: APHE, washout, and enhancement pattern similar to pretreatment imaging) were compared using logistic regression. Receiver operating characteristics (ROC) analysis was used to compare the diagnostic performance between LI-RADS and mRECIST and between CT and MRI.

RESULTS

The sensitivity and specificity for diagnosing viable tumor were not significantly different between APHE alone and LR-TR viable criteria on CT (p = 0.054 and p = 0.317) and MRI (p = 0.093 and p = 0.603). On CT, the area under the ROC curve (AUC) of LI-RADS was significantly higher than that of mRECIST (0.733 vs. 0.657, p < 0.001). On MRI, there was no significant difference in AUCs between LI-RADS and mRECIST (0.802 vs. 0.791, p = 0.500). Intra-individual comparison of CT and MRI showed comparable AUCs using LI-RADS (0.783 vs. 0.795, p = 0.776).

CONCLUSIONS

LI-RADS v2017 treatment response algorithm showed better diagnostic performance than mRECIST on CT. With LI-RADS, CT and MRI were comparable to diagnose tumor viability of HCC after LRT.

KEY POINTS

• Using Liver Imaging Reporting and Data System (LI-RADS) v2017 treatment response algorithm, the viability of hepatocellular carcinoma (HCC) after locoregional therapy (LRT) can be accurately diagnosed. • LI-RADS v2017 treatment response algorithm is superior to modified Response Evaluation Criteria in Solid Tumors for evaluating HCC viability using CT. • Either CT or MRI can be performed to assess tumor viability after LRT using LI-RADS v2017 treatment response algorithm.

Accuracy of Computed Tomography in the Assessment of Milan Criteria in Liver Transplantation for Hepatocellular Carcinoma

BACKGROUND

Despite worldwide debate on optimal selection of patients with hepatocellular carcinoma (HCC) for liver transplantation, the Milan criteria remain the benchmark for comparisons. Moreover, morphologic tumor features are universally considered important in pretransplant patient evaluation. The aim of this study was to establish the diagnostic accuracy of multiphasic computed tomography (CT) in assessing HCC burden before liver transplantation with special reference to Milan criteria fulfillment.

METHODS

This retrospective study was based on a data from 27 HCC patients after liver transplantation with available CT performed within 30 days pretransplant. CT results were compared with explant pathology with respect to Milan criteria fulfillment, tumor number, and diameter of the largest tumor.

RESULTS

Out of 19 patients within the Milan criteria on CT, 3 fell beyond the criteria on explant pathology with a gross underestimation rate of 15.8%. Out of 8 patients beyond the Milan criteria on CT, 3 were within the criteria on explant pathology with a gross overestimation rate of 37.5%. Regarding tumor number, CT was accurate only in 14 patients (51.9%), while overestimation and underestimation occurred in 5 (18.5%) and 8 (29.6%) patients, respectively. Overestimation and underestimation of largest tumor size by at least 1 cm occurred in 4 (14.8%) and 7 (25.9%) patients, respectively.

DISCUSSION

Multiphasic CT is associated with a remarkable risk of both under- and overestimation of HCC burden before transplantation. Transplant eligibility should not be solely based on CT results.

Diagnostic performance of contrast-enhanced multidetector computed tomography and gadoxetic acid disodium-enhanced magnetic resonance imaging in detecting hepatocellular carcinoma: direct comparison and a meta-analysis

The purpose of this study was to directly (head-to-head) compare the per-lesion diagnostic performance of contrast-enhanced computed tomography (CT) (also referred to as CT hereafter) and gadoxetic acid disodium (Gd-EOB-DTPA)-enhanced magnetic resonance (MR) imaging (also referred to as MRI hereafter) for the detection of hepatocellular carcinoma (HCC). Studies reporting direct per-lesion comparison data of contrast-enhanced multidetector CT and Gd-EOB-DTPA-enhanced MR imaging that were published between January 2000 and January 2015 were analyzed. The data of each study were extracted. Systematic review, paired meta-analysis, and subgroup analysis were performed. Twelve studies including 627 patients and 793 HCC lesions were analyzed. The sensitivity estimates of MRI and CT were, respectively, 0.86 (95% CI 0.76–0.93) and 0.70 (95% CI 0.58–0.80), with significant difference (P < 0.05). The sensitivity estimates were both 0.94 (95% CI 0.92–0.96) (Chi-square 4.84, degrees of freedom = 1, P > 0.05). In all subgroups, Gd-EOB-DTPA-enhanced MR imaging was more sensitive than multidetector CT for the detection of HCC, and specificity estimates of both tests maintained at a similarly high level in all conditions: sensitivity estimates of both tests were reduced in studies where patients were diagnosed with HCC solely by liver explant or in those where HCC lesions were small (≤2 cm, especially when ≤1 cm). But in all situations, sensitivities of MRI were higher than those of CT with or without significance. Gd-EOB-DTPA-enhanced MR imaging showed better per-lesion diagnostic performance than multidetector CT for the diagnosis of HCC in patients with cirrhosis and in small hepatic lesions.

Gadoxetic acid-enhanced MRI for the characterization of hepatocellular carcinoma: A systematic review and meta-analysis

PURPOSE

To establish the relative diagnostic accuracy of gadoxetic acid-enhanced magnetic resonance imaging (GA-MRI) compared with contrast-enhanced computed tomography (CE-CT), dynamic MRI (D-MRI), gadopentetic acid-enhanced MRI (GP-MRI), or gadobenic acid-enhanced MRI (GB-MRI) in the characterization of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

PubMed, EMBASE, the Cochrane Library, and the University of York CRD databases were searched to February 29 2016 for any studies that compared the diagnostic accuracy of GA-MRI to CE-CT, D-MRI, GP-MRI, or GB-MRI in patients with known or suspected HCC. Diagnostic accuracy outcomes (true positive, true negative, false positive, false negative) were extracted and analyzed using the bivariate model of Reitsma et al (2005).

RESULTS

In studies comparing GA-MRI to CE-CT in patients with any-sized lesions, estimated sensitivities were 0.881 (95% confidence interval [CI] = 0.766, 0.944) and 0.713 (95% CI = 0.577, 0.819) respectively. Estimated specificities were 0.926 (95% CI = 0.829, 0.97) and 0.918 (95% CI = 0.829, 0.963), respectively. This difference was not statistically significant. In studies including patients with small lesions GA-MRI was superior to CE-CT, with estimated sensitivities of 0.919 (95% CI = 0.834, 0.962) and 0.637 (95% CI = 0.565, 0.704 and estimated specificities of 0.936 (95% CI = 0.882, 0.966) and 0.971 (95% CI = 0.937, 0.987), respectively. In studies comparing GA-MRI to D-MRI in patients with any-sized lesions estimated sensitivities were 0.907 (95% CI = 0.870, 0.934) and 0.820 (95% CI = 0.776, 0.857); estimated specificities were 0.929 (95% CI = 0.877, 0.961) and 0.934 (95% CI = 0.881, 0.964).

CONCLUSION

GA-MRI has superior diagnostic ability to CE-CT in patients with small lesions. In patients with any-sized lesions there is no evidence that GA-MRI is superior to either CE-CT to D-MRI.

LEVEL OF EVIDENCE

3 J. Magn. Reson. Imaging 2017;45:281-290.

Imaging Techniques for the Diagnosis of Hepatocellular Carcinoma: A Systematic Review and Meta-analysis

BACKGROUND

Several imaging modalities are available for diagnosis of hepatocellular carcinoma (HCC).

PURPOSE

To evaluate the test performance of imaging modalities for HCC.

DATA SOURCES

MEDLINE (1998 to December 2014), the Cochrane Library Database, Scopus, and reference lists.

STUDY SELECTION

Studies on test performance of ultrasonography, computed tomography (CT), or magnetic resonance imaging (MRI).

DATA EXTRACTION

One investigator abstracted data, and a second investigator confirmed them; 2 investigators independently assessed study quality and strength of evidence.

DATA SYNTHESIS

Few studies have evaluated imaging for HCC in surveillance settings. In nonsurveillance settings, sensitivity for detection of HCC lesions was lower for ultrasonography without contrast than for CT or MRI (pooled difference based on direct comparisons, 0.11 to 0.22), and MRI was associated with higher sensitivity than CT (pooled difference, 0.09 [95% CI, 0.07 to 12]). For evaluation of focal liver lesions, there were no clear differences in sensitivity among ultrasonography with contrast, CT, and MRI. Specificity was generally 0.85 or higher across imaging modalities, but this item was not reported in many studies. Factors associated with lower sensitivity included use of an explanted liver reference standard, and smaller or more well-differentiated HCC lesions. For MRI, sensitivity was slightly higher for hepatic-specific than nonspecific contrast agents.

LIMITATIONS

Only English-language articles were included, there was statistical heterogeneity in pooled analyses, and costs were not assessed. Most studies were conducted in Asia and had methodological limitations.

CONCLUSION

CT and MRI are associated with higher sensitivity than ultrasonography without contrast for detection of HCC; sensitivity was higher for MRI than CT. For evaluation of focal liver lesions, the sensitivities of ultrasonography with contrast, CT, and MRI for HCC are similar.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality. (

PROSPERO

CRD42014007016).

Perfusion computed tomography for detection of hepatocellular carcinoma in patients with liver cirrhosis

PURPOSE

To evaluate the diagnostic performance of dynamic perfusion CT (P-CT) for detection of hepatocellular carcinoma (HCC) in the cirrhotic liver.

MATERIALS AND METHODS

Twenty-six cirrhotic patients (19 men, aged 69 ± 10 years) with suspicion of HCC prospectively underwent P-CT of the liver using the 4D spiral-mode (100/80 kV; 150/175mAs/rot) of a dual-source system. Two readers assessed: (1) arterial liver-perfusion (ALP), portal-venous liver-perfusion (PLP) and hepatic perfusion-index (HPI) maps alone; and (2) side-by-side with maximum-intensity-projections of arterial time-points (art-MIP) for detection of HCC using histopathology and imaging follow-up as standard of reference. Another reader quantitatively assessed perfusion maps of detected lesions.

RESULTS

A total of 48 HCCs in 21/26 (81%) patients with a mean size of 20 ± 10 mm were detected by histopathology (9/48, 19%) or imaging follow-up (39/48, 81%). Detection rates (Reader1/Reader2) of HPI maps and side-by-side analysis of HPI combined with arterial MIP were 92/88% and 98/96%, respectively. Positive-predictive values were 63/63% and 68/71%, respectively. A cut-off value of ≥85% HPI and ≥99% HPI yielded a sensitivity and specificity of 100%, respectively, for detection of HCC.

CONCLUSION

P-CT shows a high sensitivity for detection of HCC in the cirrhotic liver. Quantitative assessment has the potential to reduce false-positive findings improving the specificity of HCC diagnosis.

KEY POINTS

• Visual analysis of perfusion maps shows good sensitivity for detection of HCC. • Additional assessment of anatomical arterial MIPs further improves detection rates of HCC. • Quantitative perfusion analysis has the potential to reduce false-positive findings. • In cirrhotic livers, a hepatic-perfusion-index ≥ 9 9% might be specific for HCC.

Surveillance and diagnostic algorithm for hepatocellular carcinoma proposed by the Liver Cancer Study Group of Japan: 2014 update

Surveillance and diagnostic algorithms for hepatocellular carcinoma (HCC) have already been described in guidelines published by the American Association for the Study of Liver Diseases (AASLD), the European Association for the Study of the Liver and the European Organisation for Research and Treatment of Cancer (EASL-EORTC), and the Japan Society of Hepatology (JSH), but the content of these algorithms differs slightly. The JSH algorithm mainly differs from the other two algorithms in that it is highly sophisticated and considers the functional imaging techniques of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced MRI (EOB-MRI) and Sonazoid contrast-enhanced ultrasound (CEUS) to be very important diagnostic modalities. In contrast, the AASLD and EASL-EORTC algorithms are less advanced and suggest that a diagnosis be made based solely on hemodynamic findings using dynamic CT/MRI and biopsy findings. A consensus meeting regarding the JSH surveillance and diagnostic algorithm was held at the 50th Liver Cancer Study Group of Japan Congress, and a 2014 update of the algorithm was completed. The new algorithm reaffirms the very important role of EOB-MRI and Sonazoid CEUS in the surveillance and diagnosis of liver cancer and is more sophisticated than those currently used in the United States and Europe. This is now an optimized algorithm that can be used to diagnose early-stage to classical HCC easily and highly accurately.

JSH Consensus-Based Clinical Practice Guidelines for the Management of Hepatocellular Carcinoma: 2014 Update by the Liver Cancer Study Group of Japan

The Clinical Practice Guidelines for the Management of Hepatocellular Carcinoma proposed by the Japan Society of Hepatology was updated in June 2014 at a consensus meeting of the Liver Cancer Study Group of Japan. Three important items have been updated: the surveillance and diagnostic algorithm, the treatment algorithm, and the definition of transarterial chemoembolization (TACE) failure/refractoriness. The most important update to the diagnostic algorithm is the inclusion of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging as a first line surveillance/diagnostic tool. Another significant update concerns removal of the term "lipiodol" from the definition of TACE failure/refractoriness.