Gadoxetate Disodium-enhanced MRI Research Articles

Hepatoblastoma imaging with gadoxetate disodium-enhanced MRI—typical, atypical, pre- and post-treatment evaluation

Gadoxetate disodium (Gd-EOB-DTPA) is a hepatobiliary MRI contrast agent widely used in adults for characterization of liver tumors and increasingly used in children. Hepatoblastoma is the most common primary hepatic malignancy of childhood. In this review, we describe our experience with this agent both before and after initiating therapy in children with hepatoblastoma.

Is Gadoxetate Disodium–Enhanced MRI Useful for Detecting Local Recurrence of Hepatocellular Carcinoma After Radiofrequency Ablation Therapy?

The purpose of our study was to determine whether gadoxetate disodium-enhanced MRI improves the detection of locally recurrent hepatocellular carcinoma (HCC) after radiofrequency ablation therapy. Forty-two consecutive patients (26 men and 16 women; mean age, 70.9 years) who had undergone radiofrequency ablation therapy for HCC were examined by gadoxetate disodium-enhanced MRI. Three independent radiologists reviewed two sets of MR images separately. Set 1 contained unenhanced T1-weighted, T2-weighted, and contrast-enhanced extracellular phase images, and set 2 contained unenhanced T1-weighted, T2-weighted, and contrast-enhanced extracellular and hepatocyte phase images. Diagnostic accuracies were determined by receiver operating characteristic (ROC) curve analysis. Of the 61 ablated lesions included, 10 developed local recurrence and 51 did not. Sensitivity (60-80% and 70-80% for sets 1 and 2, respectively), specificity (90-98% and 92-100%), and accuracy (87-95% and 89-97%) were not improved by adding hepatocyte phase images. Rather, mean area under the ROC curve (AUC) significantly decreased from 0.94 for set 1 to 0.82 for set 2 (p = 0.046), and the AUC of the radiologist with the least experience significantly decreased from 0.91 to 0.75 (p = 0.037). For gadoxetate disodium-enhanced MRI, the detection of local recurrence of HCC after radiofrequency ablation therapy was not found to be improved by including hepatocyte phase images. Furthermore, detection may be further impaired when a less-experienced radiologist interprets the images.

Characteristics and Distinguishing Features of Hepatocellular Adenoma and Focal Nodular Hyperplasia on Gadoxetate Disodium–Enhanced MRI

The purpose of this study is to evaluate the performance of gadoxetate disodium-enhanced MRI in the characterization of focal nodular hyperplasia (FNH) and hepatocellular adenoma and to assess potential advantages of hepatocyte phase imaging in identifying features that distinguish FNH from hepatocellular adenoma. Gadoxetate disodium-enhanced MRI examinations of 12 patients with hepatocellular adenoma and 35 patients with FNH were retrospectively evaluated by three blinded readers. Diagnoses and confidence scores were recorded before and after disclosure of hepatocyte phase images. The data obtained were combined to create receiver operating characteristic curves, and the areas under the curves were compared. Imaging characteristics, including signal intensity, were recorded. Lesion-to-liver enhancement ratio was calculated for each contrast-enhanced phase. The readers' average receiver operating characteristic area was significantly higher after disclosure of hepatocyte phase images (p=0.024). FNHs were correctly diagnosed in 74.3-97.1% of cases before and 97.1-100% of cases after the disclosure of hepatocyte phase images; hepatocellular adenoma was correctly diagnosed in 83-100% and 91.7-100% of cases (p>0.05). The presence of a central scar in FNH and fat on hepatocellular adenoma were the only morphologic features that were statistically significantly different (p<0.05). FNH had greater average contrast-enhanced signal intensity and enhancement ratio in all phases (p<0.001). A hepatocyte phase enhancement ratio of less than 0.7 was 100% specific and 91.6% sensitive for hepatocellular adenoma, with accuracy of 97.1% for these data. Gadoxetate disodium-enhanced MRI had high accuracy in diagnosis of FNH and hepatocellular adenoma, and the hepatocyte phase improved their distinction. FNH enhances significantly more than hepatocellular adenoma. An enhancement ratio, particularly in the hepatocyte phase, can be potentially used as an additional distinguishing feature.

Hypervascular hepatocellular carcinomas: detection with gadoxetate disodium-enhanced MR imaging and multiphasic multidetector CT

To retrospectively compare the accuracy of detection of hypervascular hepatocellular carcinoma (HCC) by multiphasic multidetector CT and by gadoxetate disodium-enhanced MR imaging. After ethical approval, we analysed a total of 73 hypervascular HCC lesions from 31 patients suspected of having HCC, who underwent both gadoxetate disodium-enhanced MR imaging and multiphasic multidetector CT. Five blinded observers independently reviewed CT images, as well as dynamic MR images alone and combined with hepatobiliary phase MR images. Diagnostic accuracy (Az values), sensitivities and positive predictive values were compared by using the Scheffe post hoc test. The mean Az value for dynamic and hepatobiliary phase MR combined (0.81) or dynamic MR images alone (0.78) was significantly higher than that for CT images (0.67, P < 0.001, 0.005, respectively). The mean sensitivity of the combined MR images (0.67) was significantly higher than that of dynamic MR alone (0.52, P < 0.05) or CT images (0.44, P < 0.05). The mean positive predictive values were 0.96, 0.95 and 0.94, for CT, dynamic MR alone and combined MR images, respectively. Compared with multiphasic multidetector CT, gadoxetate disodium-enhanced MR imaging combining dynamic and hepatobiliary phase images results in significantly improved sensitivity and diagnostic accuracy for detection of hypervascular HCC. Gadoxetate disodium is a new liver-specific MR imaging contrast agent. Gadoxetate disodium-enhanced MRI helps the assessment of patients with liver disease. It showed high diagnostic accuracy for the detection of hepatocellular carcinoma.

Gadoxetate Disodium–Enhanced Hepatobiliary Phase MRI of Hepatocellular Carcinoma: Correlation With Histological Characteristics

The purpose of this study was to assess whether gadoxetate disodium-enhanced hepatobiliary phase MRI could predict the histologic factors of hepatocellular carcinomas (HCCs). Fifty-three HCCs histopathologically proved by surgery in 51 patients were evaluated retrospectively. All patients underwent gadoxetate disodium-enhanced MRI before surgical resection. The differences in contrast enhancement ratio of the lesions and differences in contrast-to-noise ratio (CNR) among the histologic grades of HCC were compared by using the Kruskal-Wallis test. The Spearman method was used to determine the correlations among contrast enhancement ratio, CNR, cell density ratio, and positivity for anti-hepatocyte antibody, keratin 7, and keratin 19. Of 53 HCCs, 50 showed low signal intensity on hepatobiliary phase images, whereas three HCCs were hyperintense on hepatobiliary phase images compared with surrounding hepatic parenchyma. Although well-differentiated HCCs tended to show higher contrast enhancement, there was no statistical significance between contrast enhancement ratio of the tumors and histologic grade (p = 0.414). No significant difference was observed between CNR and histologic grade (p = 0.965). The contrast enhancement ratios of the tumors were significantly lower in the keratin 19-positive group than in the keratin 19-negative group (p = 0.015). There was no significant correlation among contrast enhancement ratio, anti-hepatocyte antibody positivity, cell density ratio, and keratin 7 positivity (p > 0.05). The contrast enhancement ratio and CNR of HCCs were not correlated with histologic grades. The contrast enhancement ratio was significantly lower in keratin 19-positive HCCs.

Hepatic enhancement during the hepatobiliary phase after gadoxetate disodium administration in patients with chronic liver disease: The role of laboratory factors

To identify factors influencing hepatobiliary phase (HBP) hepatic enhancement on gadoxetate disodium-enhanced MRI in patients with chronic liver disease (CLD). We retrospectively reviewed abdominal gadoxetate disodium-enhanced MRIs and medical records of patients with (n=97) and without (n=48) CLD. CLD subgroups were formed based on normal/abnormal components of liver function tests (LFTs). Hepatic enhancement coefficients (HEKs) were calculated on MRI, and compared with LFTs and Model for End-stage Liver Disease (MELD) scores. The mean HEK was significantly lower (P<0.0008) in the CLD than control group. The mean HEK was similar to controls in the subgroup with all normal LFTs (P=0.09) and subgroup with normal direct bilirubin (DB) (p=0.09), while it was significantly reduced (P<0.0001) in the subgroup with elevated DB. For all other LFT components, regardless of normal or abnormal values, there was a significant reduction in the mean HEKs versus controls (all P values<0.01). There was a highly negative correlation between the mean HEKs in CLD subgroups and number of abnormal LFTs (r=-0.93) and MELD scores (r=-0.89). HBP hepatic enhancement in CLD patients is similar to those with no CLD as long as direct bilirubin remains normal. Higher MELD scores and higher number of abnormal LFT components are associated with reduced hepatic enhancement.

Hepatic Hemangiomas: Evaluation of Enhancement Patterns at Dynamic MRI With Gadoxetate Disodium

The aim of this retrospective study was to assess the enhancement patterns of hepatic hemangiomas on gadoxetate disodium. A total of 22 patients with 32 hepatic hemangiomas (23 typical type and nine high-flow type) in normal liver underwent gadoxetate disodium-enhanced MRI. Contrast-enhanced images were obtained before and after contrast injection, including arterial phase, portal phase, equilibrium phase, and three hepatobiliary phases (10, 15 and 20 minutes). Signal-to-phantom ratios of hemangiomas and the portal vein as well as lesion-to-liver contrast-to-phantom ratios were assessed. Mean signal-to-phantom ratios of all 32 hemangiomas showed the highest value on the arterial phase and subsequently decreased over time (p = 0.029 to p < 0.001). Mean lesion-to-liver contrast-to-phantom ratios of all 32 hemangiomas showed a positive value during the arterial phase and increasingly negative values at later time points (p = 0.001 to p < 0.001). The enhancement pattern of hemangiomas was equal to that of the portal vein at all time points. There was no significant difference in signal-to-phantom ratio between typical hemangiomas and high-flow hemangiomas at any time point. Most hepatic hemangiomas showed hypointensity relative to surrounding liver parenchyma during the equilibrium phase and the hepatobiliary phase. In addition, hepatic hemangiomas showed a signal intensity matching the portal vein at all phases, a finding we believe may be characteristic for hepatic hemangiomas on gadoxetate disodium-enhanced MR images.

Gadoxetate Disodium–Enhanced Hepatic MRI: Dose-Dependent Contrast Dynamics of Hepatic Parenchyma and Portal Vein

The purpose of this study was to investigate the relative enhancement characteristics of the hepatic parenchyma and portal vein during gadoxetate disodium-enhanced abdominal MRI and to assess whether contrast between the portal vein and the hepatic parenchyma can be improved with higher doses of gadoxetate disodium. A total of 102 patients (61 women, 41 men) underwent gadoxetate disodium-enhanced abdominal MRI. They received a weight-independent dose of 10 mL of gadoxetate disodium, corresponding to a dose spectrum of 0.02-0.06 mmol/kg body weight. The patients were assigned to one of three dose groups: recommended dose (0.02-0.03 mmol/kg), intermediate dose (0.03-0.045 mmol/kg), or high dose (0.045-0.06 mmol/kg). The signal-to-noise ratios for the portal vein, liver, and the portal vein-to-liver contrast-to-noise ratio were calculated for three consecutive arterial phases, one portal venous phase, and four delayed imaging phases. The delayed phase images of the liver showed statistically significant dose dependency and greater enhancement in the intermediate- and high-dose groups (p < 0.01). Analogously, the portal vein also exhibited greater enhancement in the two higher-dose groups, but the difference was not statistically significant (p > 0.05). Regarding portal vein-to-liver contrast, all three groups had a dose-independent fast parallel increase from baseline toward maximum contrast followed by a steady decline in contrast with no statistically significant differences between dose groups (p > 0.05). Portal vein-to-liver contrast during gadoxetate disodium-enhanced hepatic MRI cannot be improved within a dose spectrum of 0.025-0.06 mmol/kg body weight.

Hepatic Hemangioma and Metastasis: Differentiation With Gadoxetate Disodium–Enhanced 3-T MRI

The purpose of this study was to evaluate the gadoxetate disodium-enhanced MRI findings of hepatic hemangioma and to investigate the diagnostic performance in differentiating hepatic hemangioma and metastasis. Images of 32 hepatic hemangiomas in 25 patients and of 29 hepatic metastatic lesions in 20 patients were retrospectively reviewed. Two independent readers interpreted hepatobiliary phase images alone, dynamic extracellular phase images alone, and combined hepatobiliary and dynamic extracellular phase images. MRI findings and performance with respect to the differential diagnosis of hemangioma and metastasis were assessed. During the hepatic arterial phase, 11 of the 32 hemangiomas (34%) exhibited early total enhancement, and nine (28%) exhibited peripheral nodular enhancement. A bright dot sign or minimal peripheral enhancement during the late dynamic phase was observed for a small number of lesions (6% and 28%, respectively). Twenty-three of the 29 metastatic lesions (79%) exhibited ring enhancement during the hepatic arterial phase. Twenty-nine hemangiomas (91%) and all of the metastatic lesions exhibited homogeneous or heterogeneous hypointensity during the hepatobiliary phase. The sensitivity, specificity, and area under the receiver operating characteristic curve for the detection of hemangioma were 76%, 81%, and 0.87 for the hepatobiliary phase alone; 97%, 88%, and 0.97 for the dynamic extracellular phase alone; and 97%, 88%, and 0.98 for the combination. Five nodules smaller than 1 cm (four hemangiomas, one metastatic lesion) that exhibited no enhancement during the arterial phase and minimal enhancement during the late dynamic phase were not differentiated. Gadoxetate disodium-enhanced MRI was found useful for differentiating hepatic hemangiomas and metastatic lesions, especially during the dynamic extracellular phase. Only a limited number of lesions smaller than 1 cm in diameter, which exhibited minimal enhancement on late dynamic phase images, were difficult to diagnose.