Hepatobiliary Phase MR Images Research Articles

Gd-EOB-DTPA enhanced MRI based radiomics combined with clinical variables in stratifying hepatic functional reserve in HBV infected patients.

To evaluate radiomics from Gd-EOB-DTPA enhanced MR combined with clinical variables for stratifying hepatic functional reserve in hepatitis B virus (HBV) patients. Our study included 279 chronic HBV patients divided 8:2 for training and test cohorts. Radiomics features were extracted from the hepatobiliary phase (HBP) MR images. Radiomics features were selected to construct a Rad-score which was combined with clinical parameters in two models differentiating hepatitis vs. Child-Pugh A and Child-Pugh A vs. B/C. Performances of these stratifying models were compared using area under curve (AUC). Rad-score alone discriminated hepatitis vs. Child-Pugh A with AUC = 0.890, 0.914 and Child-Pugh A vs. B/C with AUC = 0.862, 0.865 for the training and test cohorts, respectively. Model 1 [Rad-score + clinical parameters for hepatitis vs. Child-Pugh A] showed AUC = 0.978 for the test cohort, which was higher than ALBI [albumin-bilirubin] and MELD [model for end-stage liver disease], with AUCs of 0.716, 0.799, respectively (p < 0.001, < 0.001). Model 2 [Rad-score + clinical parameters for Child-Pugh A vs. B/C] showed AUC of 0.890 in the test cohort, which was similar to ALBI (AUC = 0.908, p = 0.760), and higher than MELD (AUC = 0.709, p = 0.018). Rad-score combined with clinical variables stratifies hepatic functional reserve in HBV patients.

Utility of Wavelet Denoising with Geometry Factor Weighting for Gadoxetic Acid-enhanced Hepatobiliary-phase MR Imaging.

The wavelet denoising with geometry factor weighting (g-denoising) method can reduce the image noise by adapting to spatially varying noise levels induced by parallel imaging. The aim of this study was to investigate the clinical applicability of g-denoising on hepatobiliary-phase (HBP) images with gadoxetic acid. We subjected 53 patients suspected of harboring hepatic neoplastic lesions to gadoxetic acid-enhanced HBP imaging with and without g-denoising (g+HBP and g-HBP). The matrix size was reduced for g+HBP images to avoid prolonging the scanning time. Two radiologists calculated the SNR, the portal vein-, and paraspinal muscle contrast-to-noise ratio (CNR) relative to the hepatic parenchyma (liver-to-portal vein- and liver-to-muscle CNR). Two other radiologists independently graded the sharpness of the liver edge, the visibility of intrahepatic vessels, the image noise, the homogeneity of liver parenchyma, and the overall image quality using a 5-point scale. Differences between g-HBP and g+HBP images were determined with the two-sided Wilcoxon signed-rank test. The liver-to-portal- and liver-to-muscle CNR and the SNR were significantly higher on g+HBP- than g-HBP images (P < 0.01), as was the qualitative score for the image noise, homogeneity of liver parenchyma, and overall image quality (P < 0.01). Although there were no significant differences in the scores for the sharpness of the liver edge or the score assigned for the visibility of intrahepatic vessels (P = 0.05, 0.43), with g+HBP the score was lower in three patients for the sharpness of the liver edge and in six patients for the visibility of intrahepatic vessels. At gadoxetic acid-enhanced HBP imaging, g-denoising yielded a better image quality than conventional HBP imaging although the anatomic details may be degraded.

Differentiation of focal nodular hyperplasia and hepatocellular adenoma using qualitative and quantitative imaging features and classification and regression tree analysis.

To assess qualitative and quantitative analysis of gadoxetate disodium-enhanced hepatobiliary phase MR imaging (MRI) and assess the performance of classification and regression tree analysis for the differentiation of focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA). This retrospective study was approved by our local ethics committee. One hundred seventy patients suspected of having FNH or HCA underwent gadoxetate disodium-enhanced MRI. The reference standard was either pathology or follow-up imaging. Two readers reviewed images to identify qualitative imaging features and measure signal intensity on unenhanced, dynamic, and hepatobiliary phase images. For quantitative analysis, contrast enhancement ratio (CER), lesion-to-liver contrast (LLC), signal intensity ratio (SIR), and relative signal enhancement ratio (RSER) were calculated. A classification and regression tree (CART) analysis was developed. Eighty-five patients met the inclusion criteria, with a total of 97 FNHs and 43 HCAs. For qualitative analysis, the T1 signal intensity on the hepatobiliary phase provided the highest overall classification performance (91.9% sensitivity, 90.1% specificity, and 90.9% accuracy). For quantitative analysis, RSER in the hepatobiliary phase with a threshold of 0.723 provided the highest classification performance (92.6% sensitivity and 89.4% specificity) to differentiate FNHs from HCAs. A CART model based on five qualitative imaging features provided an accuracy of 94.4% (95% confidence interval 90.0-98.9%). Gadoxetate disodium-enhanced hepatobiliary phase provides high diagnostic performance as demonstrated in quantitative and qualitative analysis in differentiation of FNH and HCA, supported by a CART decision model.

Gd-BOPTA-enhanced hepatobiliary phase MR imaging can predict the prognosis of patients with acute-on-chronic liver failure

To determine the value of gadobenate dimeglumine (Gd-BOPTA)-enhanced magnetic resonance imaging (MRI) from the hepatobiliary phase for predicting poor outcome in acute-on-chronic liver failure (ACLF) patients. In this single-center retrospective study, 74 patients diagnosed as ACLF who underwent Gd-BOPTA-enhanced hepatobiliary magnetic resonance imaging were collected. The quantitative liver-spleen contrast ratio (Q-LSC) and the relative enhancement ratio of the biliary system (REB) at the hepatobiliary phase were measured. Cox proportional hazards regression models were used to evaluate prognostic factors. The capacity of the Q-LSC and REB to predict the 90-day outcome was evaluated via receiver operating characteristic (ROC) curve. During the follow-up period, twenty-eight of 74 ACLF patients (38%) had a poor outcome. The Q-LSC and REB were significant predictive factors (hazard ratio [HR] = 0.03 [0.002-0.54], p < 0.05; HR = 0.07 [0.01-0.88], p < 0.05) for prognosis in patients with ACLF. Moreover, the areas under the ROC curves of Q-LSC and REB for predicting poor outcome in patients with ACLF were 0.81 and 0.80, respectively. The most appropriate cutoff values for the Q-LSC and REB were 1.09 and 0.57, respectively. The ACLF patients with the Q-LSC ≤ 1.09 or REB ≤ 0.57 had a low cumulative survival. Gd-BOPTA-enhanced hepatobiliary phase MR imaging can predict poor outcome in patients with acute-on-chronic liver failure. • The quantitative liver-spleen contrast ratio at the hepatobiliary phase was a significant predictive prognostic factor in patients with acute-on-chronic liver failure. • The relative enhancement ratio of the biliary system at the hepatobiliary phase was a significant prognostic factor in patients with acute-on-chronic liver failure. • Gadobenate dimeglumine contrast-enhanced MR imaging from the hepatobiliary phase can predict poor outcome in patients with acute-on-chronic liver failure.

Uptake of gadoxetic acid in hepatobiliary phase magnetic resonance imaging and transporter expression in hypovascular hepatocellular nodules

AimsTo evaluate the association between contrast patterns on gadoxetic acid-enhanced hepatobiliary phase (HBP) MR images and transporter expression in surgically resected hypovascular hepatocellular nodules including early hepatocellular carcinomas (HCCs). MethodsForty-two hypovascular hepatic nodules and 43 hypervascular HCCs as a control were included in this retrospective study. Contrast of the nodules on HBP images was graded as hypo-, iso-, or hyperintense. Histopathological assessment was performed in the context of multistep hepatocarcinogenesis. Immunohistochemical staining of organic anion transporter 1B3 (OATP1B3) and multidrug resistance protein 2 (MRP2) was performed. Cramer’s coefficient was used to determine the linear relationship between contrast grades and transporter expression, and the Cochran-Armitage trend test was used to determine the relationship between transporter expression and progression of multistep hepatocarcinogenesis. ResultsModerate linear relationships between contrast grades and OATP1B3 expression were observed for both hypo- and hypervascular nodules. OATP1B3 expression was negatively correlated with the progression of multistep hepatocarcinogenesis. MRP2 expression was not associated with the contrast grades or histopathological results. ConclusionOATP1B3 expression was associated with contrast grades of hepatocellular nodules observed in HBP image of gadoxetic acid-enhanced MRI in the hypovascular hepatocellular nodules and was negatively correlated with hepatocarcinogenesis.

Prediction of post-hepatectomy liver failure using gadoxetic acid-enhanced magnetic resonance imaging for hepatocellular carcinoma with portal vein invasion

PurposeAccurate prediction of post-hepatectomy liver failure (PHLF) is important in advanced hepatocellular carcinoma (HCC). We aimed to retrospectively evaluate the utility of gadoxetic acid-enhanced MRI for predicting PHLF in patients who underwent anatomic hepatectomy for HCC with portal vein invasion. MethodsForty-one patients (32 men, 9 women) were included. Hepatobiliary-phase MR images were acquired 20 min after injection of gadoxetic acid using a 3D fat-suppressed T1-weighted spoiled gradient-echo sequence. Liver-spleen ratio (LSR), remnant hepatocellular uptake index (rHUI), and HUI were calculated. The severity of PHLF was defined according to the International Study Group of Liver Surgery. Differences in LSR between the resected liver and the remnant liver, and HUI and rHUI/HUI between no/mild and severe PHLF were compared using the Wilcoxon signed-rank test and Wilcoxon rank-sum test, respectively. Univariate and multivariate logistic regression analyses were performed to identify predictors of severe PHLF. Areas under the receiver operating characteristic curves (AUCs) of rHUI and rHUI/HUI were calculated for predicting severe PHLF. ResultsNine patients developed severe PHLF. LSR of the remnant liver was significantly higher than that of the resected liver (P < 0.001). Severe PHLF demonstrated significantly lower rHUI (P < 0.001) and rHUI/HUI (P < 0.001) compared with no/mild PHLF. Multivariate logistic regression analysis showed that decreased rHUI (P = 0.012, AUC=0.885) and rHUI/HUI (P = 0.002, AUC=0.852) were independent predictors of severe PHLF. ConclusionGadoxetic acid-enhanced MRI can be a promising noninvasive examination for assessing global and regional liver function, allowing estimation of the functional liver remnant and accurate prediction of severe PHLF before hepatic resection.

Preoperative prediction of hepatocellular carcinoma with highly aggressive characteristics using quantitative parameters derived from hepatobiliary phase MR images.

To prospectively determine whether the quantitative imaging parameters derived from the hepatobiliary phase (HBP) can be used for the preoperative prediction of hepatocellular carcinoma (HCC) with highly aggressive characteristics. One hundred and three patients with surgical-proven HCC were included from July 2015 to June 2018. Two independent reviewers measured signal intensity (SI) of liver and tumor, and quantitative parameters, including relative tumor enhancement (RTE), tumor to liver contrast ratio (TLR), tumor enhancement index (TEI), and relative enhancement ratio (RER) were calculated. The aggressive characteristics of HCC were identified by using the Ki-67 labeling index (LI), and patients were classified into low aggressive (Ki-67 LI ≤10%) and high aggressive (Ki-67 LI >10%) groups. The difference of quantitative parameters between two groups was assessed, and the correlation between quantitative parameters and Ki-67 LI was explored. Receiver operating characteristic analyses was used to evaluate the predictive performance of quantitative parameters. The values of RTE, TLR, TEI, and RER, were significantly lower in the highly aggressive group than low aggressive group (P<0.05), and negative correlations were obtained between these quantitative parameters and Ki-67 LI (r ranges from -0.41 to -0.22, P<0.05). TLR demonstrated the highest predictive performance with the area under curve (AUC) of 0.83 [95% confidence interval (CI): 0.75-0.90], sensitivity of 89.0% and specificity of 63.3%, and subsequent with RER, TEI, and RTE with AUC of 0.78 (95% CI: 0.68-0.85), 0.74 (95% CI: 0.64-0.82) and 0.68 (95% CI: 0.58-0.77), respectively. Good inter-observer and intra-observer agreement were found in all parameters. TLR showed the highest predictive performance in highly aggressive HCC. Quantitative parameters based on HBP could preoperatively predict the aggressiveness of HCC.

Diagnostic Accuracy of Split-Bolus Single-Phase Contrast-Enhanced Cone-Beam CT for the Detection of Liver Tumors before Transarterial Chemoembolization

PurposeTo evaluate detectability of hepatocellular carcinoma (HCC) using split-bolus cone-beam CT in intraindividual comparison between cone-beam CT and contrast-enhanced MR imaging. Materials and MethodsIn a retrospective, single-center study, 28 patients with 85 HCC tumors were treated with transarterial chemoembolization between May 2015 and June 2016. All patients underwent arterial and hepatobiliary phase (HBP) MR imaging within 1 month before transarterial chemoembolization. Cone-beam CT images were acquired using a split-bolus contrast injection with 2 contrast injections and 1 cone-beam CT acquisition. Statistical analyses included Friedman 2-way analysis, Kendall coefficient of concordance, and Wilcoxon test. Tumor detectability was scored using a 5-point system (1 = best; 5 = worst) by 2 independent readers resulting in 170 evaluated tumors. Quantitative analysis included signal-to-noise and contrast-to-noise ratio and contrast measurements. P values < .05 were considered significant. ResultsBetter tumor detection was provided with split-bolus cone-beam CT (2.91/2.73) and HBP MR imaging (2.93/2.21) compared with arterial MR imaging (3.72/3.05; P < .001) without statistical difference between cone-beam CT and HBP MR imaging in terms of detectability (P = .154) and sensitivity for hypervascularized tumors. More tumors were identified on cone-beam CT (n = 121/170) than on arterial MR imaging (n = 94/170). Average contrast-to-noise ratio values of arterial and HBP MR imaging were higher than for cone-beam CT (7.79, 8.58, 4.43), whereas contrast values were higher for cone-beam CT than for MR imaging (0.11, 0.13, 0.97). ConclusionsSplit-bolus cone-beam CT showed excellent detectability of HCC. Sensitivity is comparable to HBP MR imaging and better than arterial phase MR imaging.

Evaluation of hypointense liver lesions during hepatobiliary phase MR imaging in normal and cirrhotic livers: is increasing flip angle reliable?

Gd-EOB-DTPA is a newly developed liver specific magnetic resonance contrast agent, which is widely used for focal liver lesion (FLL) detection and liver function evaluation. However, it has been demonstrated that hepatocytes uptake of Gd-EOB-DTPA obviously decreased in cirrhotic liver, and cirrhotic liver parenchyma may show reduced enhancement in hepatobiliary phase, which would result in decreased liver-to-lesion contrast (LLC) and liver to lesion signal intensity ratio (LLSIR). Therefore, it is important to improve the image quality in cirrhotic liver, as it may alter therapeutic strategy. In this paper, we have shown adjustments of the flip angle (FA) provides a simple step to achieve better image quality for evaluation of FLLs, especially to those patients with severe liver cirrhosis. On the basis of our quantitative analysis, both of the LLC and the LLSIR with high FA protocol were always higher than those of low FA protocol. Additionally, on high FA images, more FLLs were detected, peritumoral invasion was found, boundary of the tumor was more remarkably, and better visualization of bile duct was observed. In conclusion, for the patient with severe liver cirrhosis, increasing FA can obviously improve the image quality, which is helpful for FLLs depiction.

Focal Nodular Hyperplasia and Hepatocellular Adenoma: Accuracy of Gadoxetic Acid-enhanced MR Imaging--A Systematic Review.

To perform a systematic review to evaluate the diagnostic accuracy of hepatobiliary (HPB) phase gadoxetic acid-enhanced MR imaging of the liver in the diagnosis of focal nodular hyperplasia (FNH) versus hepatocellular adenoma (HCA) and to identify the rate of (a) reported HCAs that are iso- or hyperintense to liver and (b) reported FNHs that are hypointense to liver on HPB phase MR images. The institutional review board granted a waiver for this study type, and multiple databases were searched for studies in which researchers distinguished between FNH and HCA with gadoxetic acid-enhanced MR imaging. Studies to evaluate diagnostic accuracy were included; case reports and series were included to analyze the rate of iso- or hyperintense HCAs on HPB phase MR images. Risk of bias was assessed by using the Quality Assessment Tool for Diagnostic Accuracy Studies-2. Sensitivity and specificity were plotted with a forest plot; pooling was not performed because a small number of heterogeneous studies were included. Rate of iso- or hyperintense HCA on HPB phase gadoxetic acid-enhanced MR images was evaluated. Six studies (309 patients; 164 with HCA, 233 with FNH) were included for diagnostic accuracy assessment. Twelve case series (129 patients; 81 with HCA, 70 with FNH) were included (studies with insufficient 2 × 2 table data for diagnostic accuracy assessment). Sensitivity was high (range, 0.91-1.00; lower margin of the 95% confidence interval: 0.77). Specificity was high (range, 0.87-1.00; lower margin of the 95% confidence interval: 0.54). Specificity was lowest among studies in which molecular subtyping of HCA was performed. Rate of iso-or hyperintensity of HCA on HPB phase MR images was variable (range, 0%-67%) and occurred more frequently in the inflammatory subtype. High risk of bias was identified in the domains of patient selection and reference standard. The reported diagnostic accuracy of HPB phase gadoxetic acid-enhanced MR imaging in the diagnosis of HCA versus FNH is high; however, studies are few, heterogeneous, and at high risk for bias, indicating that diagnostic accuracy may be overestimated.

Imaging features of subcentimeter hypointense nodules on gadoxetic acid-enhanced hepatobiliary phase MR imaging that progress to hypervascular hepatocellular carcinoma in patients with chronic liver disease.

With the advent of 3-T magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI), many subcentimeter hepatic nodules have been frequently detected in patients with chronic liver disease, and the prediction of subcentimeter nodules that progress to hypervascular hepatocellular carcinoma (HCC) is important. To reveal the imaging features of subcentimeter hypointense nodules on gadoxetic acid-enhanced hepatobiliary phase MR images in patients with chronic liver disease that may be related with progression to hypervascular HCC. This study included 109 patients with 135 subcentimeter hypointense nodules (103 hepatocellular carcinomas [HCCs] and 32 benign nodules) on gadoxetic acid-enhanced hepatobiliary phase. For each subcentimeter nodule, the following imaging features were analyzed: (i) hyperintensity on T2-weighted (T2W) image or DWI; (ii) arterial hypervascularization; and (iii) hypointensity on a portal or late phase. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of those imaging features for predicting subcentimeter nodules that progressed to hypervascular HCC were evaluated. Volume doubling time (VDT) of subcentimeter nodules that progressed to hypervascular HCC was compared to that of growing benign nodules. Arterial hypervascularization with washout yielded the highest specificity (90.6%) and PPV (95.4%) for prediction of subcentimeter nodules that progressed to hypervascular HCC. Combining hyperintensity on T2W image or DWI and arterial hypervascularization with washout did not raise the specificity (90.6%) for prediction of subcentimeter nodules that progressed to hypervascular HCC. Mean VDT (112.2 ± 106.3 days) of subcentimeter nodules that progressed to hypervascular HCC during follow-up was significantly shorter than those of benign subcentimeter nodules (1258 ± 766.5 days, P < 0.001). Arterial hypervascularization with washout in subcentimeter hypointense nodules on gadoxetic acid-enhanced hepatobiliary phase in patients with chronic liver disease is strongly related with progression to hypervascular HCC.

Appearance of hepatocellular carcinoma on gadoxetic acid-enhanced hepato-biliary phase MR imaging: a systematic review.

To perform a systematic review of the contrast behaviour of HCC on Gd-EOB-DTPA hepato-biliary phase MRI. This review was completed in accordance with the recommendations outlined in the preferred reporting items for systematic reviews statement. In all reports, qualitative analysis of signal intensity (SI) of HCC on hepato-biliary phase was performed: the relative SI of HCC. When available, a quantitative analysis of tumour enhancement was evaluated. A total of 106 studies were retrieved, of which 41 met the inclusion criteria. The total number of patients was 2550, with 3132 HCC. MRI showed 3110 HCC (22 non-detected). 2692/3110 (87 %) HCC were hypointense on Gd-EOB-DTPA-enhanced hepatocyte-phase MRI, 134 (4 %) isointense; 106 (3 %) hyperintense and 178 (6 %) iso-hyperintense. In 26 articles, 1653 HCCs were classified as follows: 519 well-differentiated, 883 moderately differentiated, 251 poorly differentiated. Among well-differentiated HCC, 445 (86 %) were hypointense, 12 isointense (2 %), 9 hyperintense (2 %), 53 iso/hyperintense (10 %). Among moderately differentiated HCC, 774 (88 %) were hypointense, 8 isointense (1 %), 27 hyperintense (3 %), 74 iso/hyperintense (8 %). Among poorly differentiated HCCs, 245 (98 %) were hypointense, one isointense, one hyperintense and four iso-hyperintense (2 %). We found a Chi-square (χ (2)) equivalent to 25,082 (p < 0.001). The percentage of lesions iso/hyper/iso-hyper is the same when considering well-differentiated and moderately differentiated HCC; when considering poorly differentiated HCC, the percentage of lesions iso/hyper/iso-hyper is significantly lower. Conversely, the percentage of lesions hypointense is significantly more represented in poorly differentiated HCC compared to well-differentiated and moderately differentiated HCC.

Histogram Analysis of Hepatobiliary Phase MR Imaging as a Quantitative Value for Liver Cirrhosis: Preliminary Observations

PurposeTo investigate whether histogram analysis of the hepatobiliary phase on gadoxetate enhanced-MRI could be used as a quantitative index for determination of liver cirrhosis.Materials and MethodsA total of 63 patients [26 in a normal liver function (NLF) group and 37 in a cirrhotic group] underwent gadoxetate-enhanced MRI, and hepatobiliary phase images were obtained at 20 minutes after contrast injection. The signal intensity of the hepatic parenchyma was measured at four different regions of interest (ROI) of the liver, avoiding vessels and bile ducts. Standard deviation (SD), coefficient of variation (CV), and corrected CV were calculated on the histograms at the ROIs. The distributions of CVs calculated from the ROI histogram were examined and statistical analysis was carried out.ResultsThe CV value was 0.041±0.009 (mean CV±SD) in the NLF group, while that of cirrhotic group was 0.071±0.020. There were statistically significant differences in the CVs and corrected CV values between the NLF and cirrhotic groups (p<0.001). The most accurate cut-off value among CVs for distinguishing normal from cirrhotic group was 0.052 (sensitivity 83.8% and specificity 88.5%). There was no statistically significant differences in SD between NLF and cirrhotic groups (p=0.307).ConclusionThe CV of histograms of the hepatobiliary phase on gadoxetate-enhanced MRI may be useful as a quantitative value for determining the presence of liver cirrhosis.

Erratum to "Histogram Analysis of Hepatobiliary Phase MR Imaging as a Quantitative Value for Liver Cirrhosis: Preliminary Observations" by Choi JY, et al. (Yonsei Med J 2014;55:651-9.)

Erratum to "Histogram Analysis of Hepatobiliary Phase MR Imaging as a Quantitative Value for Liver Cirrhosis: Preliminary Observations" by Choi JY, et al. (Yonsei Med J 2014;55:651-9.)

Added value of Gd-EOB-DTPA-enhanced Hepatobiliary phase MR imaging in evaluation of focal solid hepatic lesions

BackgroundCorrect characterization of focal solid hepatic lesions has always been a challenge and is of great diagnostic and therapeutic relevance. The purpose of this study was to determine the added value of hepatobiliary phase images in Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) for differentiating focal solid hepatic lesions.MethodsIn this retrospective trial 84 consecutive patients underwent Gd-EOB-DTPA-enhanced MR examinations. MRI was conducted for 64 patients with malignant focal hepatic lesions (34 hepatocellular carcinoma (HCC), 30 metastases) and for 20 patients with benign hepatic lesions (14 focal nodular hyperplasia (FNH), 3 adenoma, 3 hemangioma). Five radiologists independently reviewed three sets of MR images by means of a 5-point confidence scale from score 1 (definitely benign) to score 5 (definitely malignant): set 1: unenhanced images; set 2: unenhanced and Gd-EOB-DTPA-enhanced dynamic images; set 3: hepatobiliary phase images in addition to set 2. Accuracy was assessed by the alternative free-response receiver operating characteristic curve (Az) and the index of diagnostic performance was calculated.ResultsDiagnostic accuracy was significantly improved by the addition of Gd-EOB-DTPA-enhanced dynamic images: Az in set 1 was 0.708 and 0.833 in set 2 (P = 0.0002). The addition of hepatobiliary phase images increased the Az value to 0.941 in set 3 (set 3 vs set 2, P < 0.0001; set 3 vs set 1, P < 0.0001). The index of diagnostic performance was lowest in set 1 (45%), improved in set 2 (71%), and highest in set 3 (94%).ConclusionsHepatobiliary phase images obtained after Gd-EOB-DTPA-enhanced dynamic MRI improve the differentiation of focal solid hepatic lesions.

Detecting hepatocellular carcinoma in gadoxetic-acid-enhanced hepatobiliary-phase MR imaging at 3T: comparing high and low flip angle

We evaluated the diagnostic performance of fat-suppressed 3D T1-weighted gradient-echo magnetic resonance imaging (MRI) sequences for the hepatobiliary phase of gadoxetic-acid-enhanced liver MRI between low and high flip angle (FA) at 3T. Forty-six patients with 62 HCCs were enrolled in this retrospective study from among 267 consecutive patients who underwent 3T MRI with low and high FA (10° and 25°) sequences at the hepatobiliary phase. A radiologist measured signal intensities and standard deviations (SD) of lesion, liver, and spleen and calculated signal-to-noise ratio, liver-spleen contrast, and liver-lesion contrast. Two reviewers assessed both image sequences using a five-point rating scale focusing on detecting hypointense lesions. The high FA sequence showed significantly higher liver-spleen and liver-lesion contrast compared with those of low FA (p<0.05, p<0.05, respectively). Per-lesion sensitivities of high FA were higher than those of low FA (p<0.05, p<0.05, respectively), and per-person sensitivities were elevated on high FA (p<0.05 in a reviewer). There were statistically significant differences for detecting HCCs larger than 1cm (p<0.05, p<0.05, respectively). Increasing FA in T1-weighted hepatobiliary-phase liver MRI may help in detecting HCC at 3T.

Biologic Factors Affecting HCC Conspicuity in Hepatobiliary Phase Imaging With Liver-Specific Contrast Agents

The purpose of this study was to evaluate factors influencing hepatic enhancement and the conspicuity of hepatocellular carcinoma (HCC) on gadobenate dimeglu-mine- and gadoxetate disodium-enhanced hepatobiliary phase MR images. Patients with chronic liver disease who underwent liver MRI with gadobenate dimeglumine (n = 93) or gadoxetate disodium (n = 92) were included in this study. The degree of hepatic enhancement on 1-hour and 3-hour delayed phase gadobenate dimeglumine-enhanced and 20-minute delayed phase gadoxetate disodium-enhanced hepatobiliary phase images were evaluated with quantitative and visual indexes. The conspicuity of 40 HCCs in the gadobenate dimeglumine group and 38 HCCs in the gadoxetate disodium group were graded on a 5-point scale. Correlation between hepatic enhancement indexes and clinical factors (age, body weight, serum bilirubin concentration, model for end-stage liver disease score, Child-Pugh class, and renal function stage) and association between the conspicuity of HCCs and clinical factors, lesion diameter, and hepatic enhancement indexes were evaluated. In the gadobenate dimeglumine group, the visual index of hepatic enhancement independently correlated with Child-Pugh class on both 1- and 3-hour delayed images (p < 0.001) and with renal function stage only on 3-hour delayed images (p ≤ 0.031). In the gadoxetate disodium group, both quantitative and visual indexes of hepatic enhancement independently correlated with Child-Pugh class (p ≤ 0.019). The conspicuity of HCCs independently correlated with Child-Pugh class and lesion diameter on 3-hour delayed gadobenate dimeglumine-enhanced images (p ≤ 0.031) and on gadoxetate disodium-enhanced images (p = 0.033) and significantly correlated with the visual index of hepatic enhancement on both gadobenate dimeglumine- and gadoxetate disodium-enhanced images (p ≤ 0.001). Liver enhancement and conspicuity of HCC are significantly affected by Child-Pugh class on both gadobenate dimeglumine- and gadoxetate disodium-enhanced hepatobiliary phase MR images.

Focal nodular hyperplasia: characterisation at gadoxetic acid-enhanced MRI and diffusion-weighted MRI

The aim of this study was to assess the enhancement patterns of hepatic focal nodular hyperplasia (FNH) on gadoxetic acid-enhanced MRI and diffusion-weighted (DW) MRI. This retrospective study had institutional review board approval. Gadoxetic acid-enhanced and DW MR images were evaluated in 23 patients with 30 FNHs (26 histologically proven and 4 radiologically diagnosed). The lesion enhancement patterns of the hepatobiliary phase images were classified as heterogeneous or homogeneous signal intensity (SI), and as dominantly high/iso or low SI compared with those of adjacent liver parenchyma. Heterogeneous (any) SI lesions and homogeneous low SI lesions were categorised into the fibrosis group, whereas homogeneous high/iso SI lesions were categorised into the non-fibrosis group. Additionally, lesion SI on T2 weighted images, DW images and apparent diffusion coefficient (ADC) values were compared between the two groups. The lesions showed heterogeneous high/iso SI (n=16), heterogeneous low SI (n=5), homogeneous high/iso SI (n=7) or homogeneous low SI (n=2) at the hepatobiliary phase MR images. The fibrosis group lesions were more likely to show high SI on DW images and T2 weighted images compared with those in the non-fibrosis group (p<0.05). ADC values tended to be lower in the fibrosis group than those in the non-fibrosis group without significance. FNH showed variable enhancement patterns on hepatobiliary phase images during gadoxetic acid-enhanced MRI. SI on DW and T2 weighted images differed according to the fibrosis component contained in the lesion. FNH shows a wide spectrum of imaging findings on gadoxetic acid-enhanced MRI and DW MRI.

Relationship between severity of liver dysfunction and the relative ratio of liver to aortic enhancement (RE) on MRI using hepatocyte‐specific contrast

To evaluate differences in liver enhancement among patients with low and high morbidity risks and to determine the relationship between severity of liver dysfunction and the relative ratio of liver to aortic enhancement (RE) on MRI using hepatocyte-specific contrast. A total of 126 patients underwent magnetic resonance imaging (MRI) and blood serum testing including serology, bilirubin, international normalized ratio, and creatinine tests. Radiologists analyzed a region of interest in the liver and aorta on precontrast and 10- and 20-minute delayed hepatobiliary phase MR images. Liver enhancement after 10 (LE10min ) and 20 minutes (LE20min ) were compared between the low- and high-risk groups by independent t-test. Regression analysis was used to assess the relationship between the Model for Endstage Liver Disease (MELD) score and RE. All 126 patients were classified into either the low-risk group (MELD <8; n = 85) or high-risk group (MELD ≥8; n = 41). The mean LE10min and LE20min were significantly higher in the low-risk group (471.61; 95% confidence interval [CI]: 449.79-493.43 and 510.69; 95% CI: 486.51-534.87, respectively) than in the high-risk group (401.6776; 95% CI: 364.75-438.61 and 413.81; 95% CI: 370.91-456.70). There was a moderate inverse correlation between MELD score and the relative ratio of liver enhancement (RLE) (r = -0.5442; 95% CI: -0.6480 to -0.4207; P<0.01), but a high positive correlation between MELD score and RE (r = 0.7470; 95% CI: 0.6665-0.8102; P < 0.01). Although liver enhancement was significantly greater in low-risk patients compared to high-risk patients, RE may be a better predictor of liver function than RLE.

Three-dimensional magnetic resonance imaging for stringent diagnosis of advanced fibrosis associated with nonalcoholic steatohepatitis.

The definitive diagnosis of nonalcoholic steatohepatitis (NASH) is currently based on histopathological assessment. This study aimed to elucidate the utility of a novel noninvasive method, three-dimensional magnetic resonance imaging (3D-MRI), for diagnosing advanced fibrosis in patients with NASH, using histopathological diagnosis as the reference standard. This retrospective study included 30 consecutive patients who had been diagnosed with NASH by histopathology and had undergone 3D-MRI before biopsy. 3D-MRI provided a three-dimensional reconstruction of the liver from contrast-enhanced hepatobiliary phase MR images. In the present study, histopathological advanced fibrosis was defined as stage 3 and 4 NASH. Advanced fibrosis, diagnosed by 3D-MRI, was considered to be diffuse irregularity of the entire surface of the liver. The diagnostic features of 3D-MRI and the noninvasive evaluation systems (APRI, FIB-4 index, and BARD score) for identifying advanced and nonadvanced fibrosis of NASH were determined and compared. Nine (30%) of the 30 study patients were diagnosed histopathologically with advanced fibrosis, and 11 (37%) of 30 patients were diagnosed with advanced fibrosis using 3D-MRI. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 3D-MRI for diagnosing advanced fibrosis were 100, 90, 82, and 100%, respectively. The sensitivities of APRI, the FIB-4 index, and BARD score ranged from 78 to 89%, the specificities from 71 to 90%, the PPVs from 54 to 78%, and the NPVs from 88 to 94%. Compared with the common noninvasive methods for diagnosing advanced fibrosis associated with NASH, 3D-MRI was more accurate.