Gadolinium Ethoxybenzyl Diethylenetriamine Pentaacetic Acid Research Articles

Unenhanced fat fraction ratios obtained by MR and enhanced T2* values with liver-specific MR contrast agents for diagnosis of non-alcoholic steatohepatitis in rats

Non-invasive MR imaging is expected to be used for accurate diagnosis and quantification of non-alcoholic steatohepatitis (NASH), because NASH is a progressive fatty liver disease. New MR techniques, such as fat fraction ratio (FFR) and T2* value measurement, have attracted an increasing attention, because those techniques can measure quantitative parameters of fibrosis, fat and iron deposition in the liver. To investigate the potential of FFR and T2* value in NASH with pre-enhancement, gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) or super-paramagnetic iron oxide (SPIO)-enhanced MRI. Twenty-eight rats were divided equally into four groups (one control group and three NASH groups). All rats underwent unenhanced, Gd-EOB-DTPA, and SPIO-enhanced MRI. The T2* value of the liver was measured for each image sequence, and then changes in T2* values before and after each injection were analyzed using Dunnett's test. The reduction rate of T2* value before and 13 min after injection of Gd-EOB-DTPA or SPIO was analyzed using Mann-Whitney's U test. Moreover, FFR of the liver was measured before enhancement, and the relationship between fat fraction and the calculated fat area percentage on a pathological specimen was examined using Spearman's correlation test. On pre-enhancement, FFR and T2* value were 26.0% ± 12.0% and 21.5 ± 4.2 ms for all NASH groups, and 0.9% ± 0.5% and 30.8 ±-5.5 ms for control, respectively. Both FFR and T2* values were significantly different between the NASH and control groups. The reduction rate of T2* value was significantly lower in the NASH groups than in the control group on SPIO-enhanced MRI, though there was no significant difference on Gd-EOB-DTPA-enhanced MRI. FFR was correlated with the calculated fat area percentage for the pathological specimen. Pre-enhancement FFR, T2* value measurement and reduction rate of T2* value on SPIO-enhanced MRI may help estimate the progress of liver fat deposition and fibrosis in NASH.

Functional hepatobiliary MR imaging in children

Clinical application efforts for the hepatocyte-specific MRI contrast agent gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) have mainly been directed toward detection and characterization of various hepatic masses in the adult population. Here we report our initial experience with Gd-EOB-DTPA for evaluating congenital and acquired hepatobiliary pathologies in the pediatric population. Twenty-one consecutive children receiving Gd-EOB-DTPA for functional hepatobiliary evaluation at our institution were retrospectively identified with IRB approval. The use of Gd-EOB-DTPA was classified in each case as definite, potential, or no clinical utility, focusing on the clinical value gained beyond traditional noncontrast fluid-sensitive MR cholangiopancreatography (FS-MRCP) and other imaging modalities. Definite added value of Gd-EOB-DTPA was found in 12 patients, with potential value in 4 patients, and no value in 5 patients. Benefit was seen in cases of iatrogenic and non-iatrogenic biliary strictures, perihepatic fluid collections for biliary leak, hepatobiliary dysfunction in the absence of hyperbilirubinemia, and in the functional exclusion of cystic duct occlusion that can be seen in acute cholecystitis. This is the first reported series of children with Gd-EOB-DTPA and this early work suggests potential pediatric applications.

Estimation of liver function using T2* mapping on gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid enhanced magnetic resonance imaging

To investigate the usefulness of T2* mapping of liver on gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI for estimating liver function. 33 patients were classified into 3 groups as follows: normal liver function (NLF) (n = 7); mild liver damage (MLD) (n = 16) with Child-Pugh A; severe liver damage (SLD) (n = 10) with Child-Pugh B. T2*-weighted gradient-echo (T2*W-GRE) and T1-weighted gradient-echo (T1W-GRE) images were obtained before and after Gd-EOB-DTPA administration (3, 8, 13, and 18 min; 5, 10,15, and 20min; respectively). T2* mapping of liver was calculated from T2*W-GRE, then T2* values of liver and T2* reduction rates of T2* value between pre- and post-contrast enhancement were measured. The increase rates of liver-to-muscle signal intensity (LMS) ratio on T1W-GRE between pre- and post-contrast enhancement were calculated. T2* values on pre- and post-contrast showed no significant differences among three groups. Significant differences in T2* reduction rates were found among groups, and those of LCB were lower than those of other groups (NLF:MLD:SLD, 3.8:6.0:0.6% at 3 min, 8.2:10.3:1.0% at 8 min, 10.7:11.5:1.2% at 13 min, and 16.1:13.2:3.5% at 18 min, respectively) (P<0.05). Significant differences in increase rates of LMS ratio on T1W-GRE were identified (NLF:MLD:SLD, 1.53:1.46:1.35 at 5 min, 1.68:1.64:1.37 at 10 min, 1.79:1.76:1.44 at 15 min, and 1.89:1.78:1.49 at 20 min, respectively). T2* reduction rate and increase rate of LMS ratio on T1W-GRE may allow us estimation of liver function according to Child-Pugh score.

Estimation of Liver Function Using T1 Mapping on Gd-EOB-DTPA-Enhanced Magnetic Resonance Imaging

To investigate the ability of T1 mapping of liver on gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging for the estimation of liver function. Local institutional review board approved this study. Ninety-one patients (64 men, 27 women; mean age, 67.4 years) were classified into 4 groups as follows: normal liver function (NLF), n = 16; chronic hepatitis (CH), n = 38; liver cirrhosis with Child-Pugh A (LCA), n = 20; and liver cirrhosis with Child-Pugh B (LCB), n = 17. Look-Locker sequences (single slice multiphase imaging using gradient-echo sequence with inversion recovery pulse) were obtained before and at 3, 8, 13, and 18 minutes after Gd-EOB-DTPA administration. T1 mapping of liver parenchyma was calculated from the Look-Locker sequence. T1 relaxation time of liver and reduction rate of T1 relaxation time between pre- and postcontrast enhancement were measured. The Bonferroni t test was used for comparisons between the 4 groups. Precontrast T1 relaxation times were significantly longer for LCA and LCB than for NLF, and that of LCB was longer than that of chronic hepatitis (P < 0.05). Postcontrast T1 relaxation times were significantly longer for LCB than for other groups at all time points. Those of LCA were longer than those of NLF at all time points. Reduction rates were significantly lower for LCB than for the other groups at ≥8 minutes. Evaluation of hepatic uptake of Gd-EOB-DTPA using T1 mapping of liver parenchyma can help estimate liver function.

Quantitative analysis of liver function using superparamagnetic iron oxide- and Gd-EOB-DTPA-enhanced MRI: Comparison with Technetium-99m galactosyl serum albumin scintigraphy

To examine whether or not the parameters regarding the signal intensity of the liver parenchyma on superparamagnetic iron oxide (SPIO)- and gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI are correlated with the parameters of Technetium-99m galactosyl serum albumin ((99m)Tc-GSA) scintigraphy. This retrospective study consisted of 55 and 33 patients who underwent SPIO- and Gd-EOB-DTPA-enhanced MRI in addition to (99m)Tc-GSA scintigraphy, respectively. For each patient, we calculated Pre R2* and Pre R2, which are equivalent to R2* (=1/T2*) and R2 (=1/T2) values of the liver parenchyma; ΔR2* and ΔR2, which represent differences in R2* and R2 values of the liver parenchyma before and after administration of SPIO; and the increase rates of both the liver-to-spleen signal intensity ratio (LSR) and the liver-to-major psoas muscle signal intensity ratio (LMR) on the hepatobiliary phase compared with the precontrast image. For (99m)Tc-GSA scintigraphy, the receptor index LHL15 and the blood clearance index HH15 were recorded. Regression analysis showed a moderate correlation between Pre R2* and LHL15 (P<0.05). Mild to moderate correlations were also obtained between any combination of ΔR2* and ΔR2 on the one hand, and LHL15 and HH15 on the other (P<0.05). There were moderate correlations between any combination of increase rates of LSR and LMR on the one hand, and LHL15 and HH15 on the other (P<0.05-0.001). Pre R2*, ΔR2*, ΔR2 and the increase rates of LSR and LMR could be used as quantitative indicators of liver function.

Multiple hepatocellular adenomas in a patient with glycogen storage disease type I: various enhancement patterns in MRI with Gd-EOB-DTPA

The patient is a 20-year-old man with glycogen storage disease type I (GSD-type I). In his teens, multiple focal hepatic masses were detected on abdominal ultrasonography (US), which were diagnosed as multiple hepatocellular adenomas from the imaging. During follow-up, these masses had shown intermittent growth in size. In the evaluation of Gd-EOB-DTPA (gadolinium-ethoxybenzyl-diethylenetriamine penta-acetic acid) MR imaging, these masses showed various signal intensities from hypo- to hyperintense during the hepatocyte-specific phase. Intermittent growth and elevation of serum PIVKA-II levels indicate the potential for malignant transformation, so the patient underwent partial hepatectomy. The resected masses were all consistent with benign hepatocellular adenomas histopathologically.

Gadolinium Ethoxybenzyl Diethylenetriamine Pentaacetic Acid-Enhanced Magnetic Resonance Imaging Findings of Borderline Lesions at High Risk for Progression to Hypervascular Classic Hepatocellular Carcinoma

The objectives of the study were to assess the imaging features of hypovascular borderline lesions containing hypervascular foci on gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) and to evaluate the ability of Gd-EOB-DTPA-enhanced MRI to diagnose high-risk borderline lesions possibly consistent with early hepatocellular carcinoma (HCC). Institutional review board approval was obtained for this retrospective analysis of imaging findings, and informed consent was obtained from 217 consecutive patients undergoing Gd-EOB-DTPA-enhanced MRI and angiography-assisted computed tomography (CT) for examination of hepatocellular nodular lesions in cirrhotic livers. There were 73 nodules showing hypervascular foci in borderline lesions identified by angiography-assisted CT. Signal intensity patterns of the nodules were evaluated on hepatobiliary-phase Gd-EOB-DTPA-enhanced T1-weighted MRI obtained 20 minutes after intravenous injection of contrast media. Among 73 high-risk borderline lesions, 59 were hypointense (81%), and 14 were isointense (19%), compared with background liver parenchyma. There were 27 untreated lesions followed by CT and/or MRI. Almost half of these nodules transformed into hypervascular HCC, regardless of signal intensities seen on hepatobiliary-phase Gd-EOB-DTPA-enhanced MRI. Although many high-risk borderline HCC lesions are hypointense on hepatobiliary-phase Gd-EOB-DTPA-enhanced MRI, some high-risk borderline lesions are isointense and transform at the same rate into hypervascular HCC.

Effect of change in transporter expression on gadolinium‐ethoxybenzyl‐diethylenetriamine pentaacetic acid‐enhanced magnetic resonance imaging during hepatocarcinogenesis in rats

To analyze the difference in signal intensity on gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) among various hepatocellular nodules during hepatocarcinogenesis as correlated with the expressions of the transporters of Gd-EOB-DTPA. We received institutional animal review board approval prior to the commencement of all studies. Forty rats were divided into three groups. The rats in the tumor groups received N-nitrosomorpholine solution (n = 16), and rats in the cirrhosis group (thioacetamide [TAA] group) received thioacetamide solution (n = 12). As a control, the remaining 12 rats were fed normal water. Each group was divided into two sub-groups: Group 1 for Gd-EOB-DTPA-enhanced MRI (0.025 mmol Gd/kg, n =7) and Group 2 for reverse transcription-polymerase chain reaction to compare transporter (oatp1 and mrp2) expressions (n = 5 for control and TAA groups, n = 9 for tumor groups). Signal enhancement of tumors decreased according to the progress of hepatocarcinogenesis. Although the relative enhancement of each tumor group was significantly lower than that of the control group (P < 0.01), and there was no significant difference between TAA, hyperplastic nodules (HPN), and HCC(well) groups. The relative enhancement of the HCC(mod) group was significantly lower than the other groups (P < 0.01). The oatp1 expression of HPN tended to be higher than those of HCC(well) and HCC(mod). The mrp2 expression of TAA was significantly higher than those of HCC(well), HCC(mod), HPN and control (P < 0.01). The mrp2 expression of HPN tended to be higher than those of HCC(well ) and HCC(mod). It was suggested that the signal enhancement on Gd-EOB-DTPA-enhanced MRI would correlate with the transporter expression in various hepatocellular nodules during hepatocarcinogenesis.

Comparison of three different injection methods for arterial phase of Gd-EOB-DTPA enhanced MR imaging of the liver

To compare three different injection methods for optimizing hepatic arterial phase of gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) enhanced MR imaging. Arterial phase images were obtained after the injection of contrast agent at a rate of 3 mL/s with diluted Gd-EOB-DTPA (dilution method) in 27 patients, 3 mL/s with undiluted Gd-EOB-DTPA (3 mL method) in 26 patients and 1 mL/s with undiluted Gd-EOB-DTPA (1 mL method) in 28 patients. In the quantitative evaluation, signal-to-phantom ratios (SPR) of the liver parenchyma, pancreas, renal cortex, portal vein and aorta were evaluated. In the qualitative evaluation, the seven items for image quality of hepatic arterial phase were assessed, and the total score of all items in each subject was calculated. The score of enhancement of abdominal aorta and total score of seven items in 1 mL method were significantly higher than those in 3 mL method. The SPR of the liver parenchyma in 3 mL method was significantly higher than that in 1 mL method, suggesting substantial hepatic inflow from portal venous return. For the optimal arterial phase imaging, injection rate of 1 mL/s with undiluted Gd-EOB-DTPA is convenient and preferable, compared with other two methods, based on our qualitative analysis.

The Possibility of Differentiation between Nonalcoholic Steatohepatitis and Fatty Liver in Rabbits on Gd-EOB-DTPA-enhanced Open-type MRI Scans

We used rabbits to investigate the possibility of differentiating between nonalcoholic steatohepatitis (NASH) and fatty liver (FL) on scans acquired by open-type‒ and gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)‒enhanced magnetic resonance imaging (MRI). We divided 15 adult rabbits into three equal groups; they received standard (control group), high-fat (FL) content (FL group), or choline-deficient chow (NASH group). With the animals under general anesthesia we acquired scans on an open 0.3-Tesla MRI system. Signal intensity (SI) was measured before and after contrast administration and defined as SI-pre and SI-post, respectively. Relative SI enhancement (Sr) was calculated using the equation: Sr = (average of three SI-post- minus average of three SI values in no-signal fields)/(average of three SI-pre- minus average of three SI values in no-signal fields) × 100. Maximum Sr (Srmax), the time (in seconds) required to reach Srmax (Tmax), and the difference between Srmax and Sr at 30 minutes (Sr(30m)R) were analyzed. Srmax was significantly higher in the NASH rabbits than the other two groups (P < .05). In rabbits, the Srmax value made it possible to differentiate NASH from normal and fatty liver.

Segmental liver hyperintensity in malignant biliary obstruction on diffusion weighted MRI: associated MRI findings and relationship with serum alanine aminotransferase levels

Segmental liver hyperintensity can be observed in malignant biliary obstruction on diffusion weighted MRI (DW-MRI). We describe MRI findings associated with this sign and evaluate whether DW-MRI segmental hyperintensity has any relationship with serum alanine aminotransferase (ALT) levels. The DW-MRI T(1) weighted, T(2) weighted and gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced T(1) weighted images obtained in 21 patients with hepatic malignancy, who demonstrated biliary obstruction and segmental hyperintensity on DW-MRI (b=0-750 s mm(-2)), were retrospectively reviewed by 2 readers blinded to clinical results. DW-MRI hyperintense liver segments were recorded as hypointense, isointense or hyperintense relative to normal liver on T(1)/T(2) weighted imaging. It was also noted whether contrast enhancement was similar to that observed in normal liver or diminished in the hepatocellular phase. The mean apparent diffusion coefficient (ADC) value (×10(-3) s mm(-2)) of DW-MRI hyperintense segments, normal liver and tumour were compared using Student's t-test. The frequency of MRI findings was corroborated with serum ALT levels, which reflect hepatocyte injury. DW-MRI hyperintense segments frequently showed T(1) hyperintensity (10/21), T(2) hyperintensity (19/21) and/or diminished contrast enhancement (15/21). Tumours showed significantly lower mean ADC values than liver (1.23 ± 0.08 vs 1.43 ± 0.05; p=0.013). Segments showing concomitant T(1) hyperintensity had lower mean ADC values than liver (1.30 ± 0.05 vs 1.43 ± 0.05; p=0.023). The patients (8/10) with concomitant T(1) and DW-MRI segmental hyperintensity showed elevated ALT levels (p=0.030, Fisher's exact test). Concomitantly high T(1) weighted and DW-MRI signal in liver segments was associated with lower ADC values and abnormal liver function tests, which could reflect underlying cellular swelling and damage.

A case of Budd-Chiari syndrome: Gd-EOB-DTPA-enhanced MR findings

Budd-Chiari syndrome (BCS) is a rare disorder caused by the obstruction of hepatic venous outflow, leading to sinusoidal congestion, ischemic injury to liver cells and portal hypertension. Long-term survival largely depends on whether hepatocellular carcinoma occurs. A recently available liver-specific contrast medium, gadolinium-ethoxybenzyl-diethylenetriamine penta-acetic acid (Gd-EOB-DTPA), reportedly has high diagnostic capability for detection of malignant liver tumors. However, there has been no report of the sue of Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) for BCS. We present a case of chronic BCS who underwent both gadopentetate dimeglumine (Gd-DTPA) and Gd-EOB-DTPA-enhanced MRI. Hepatic congestion and edema were seen as slightly hypointense areas on Gd-EOB-DTPA-enhanced hepatobiliary-phase images, although these areas were observed as slightly hyperintense on previously obtained Gd-DTPA-enhanced delayed-phase image. Reduced uptake of Gd-EOB-DTPA by hepatocytes in the region of congestion or edema may account for this difference, which should be recognized in image interpretations.

Focal Nodular Hyperplasia-Like Nodule with Reduced Expression of Organic Anion Transporter 1B3 in Alcoholic Liver Cirrhosis

We report a patient with alcoholic liver cirrhosis who had a 15 mm focal nodular hyperplasia (FNH)-like nodule in the liver. This FNH-like nodule was diagnosed as hepatocellular carcinoma (HCC) mainly based on hypervascularity during the hepatic arterial phase, washout pattern during the equilibrium phase and low signal intensity during the hepatobiliary phase in gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI; it was surgically resected. Its histology exhibited hepatocyte hyperplasia, fibrous septa containing unpaired small arteries accompanied by reactive bile ductules, remarkable iron deposits and sinusoidal capillarization, and was compatible with the diagnosis of an FNH-like nodule. When we analyzed the images of the present nodule retrospectively, low signal intensity on in-phase and isosignal intensity on opposed-phase T1-weighted MRI may have reflected iron deposits in the FNH-like nodule. In addition, a low signal intensity on T2-weighted MRI and no detection in diffusion-weighted MRI may help in distinguishing FNH-like nodules from HCC, since these image findings are inconsistent with typical HCC. Immunohistochemical analysis revealed a markedly reduced expression of organic anion transporter (OATP) 1B3 in this nodule, which implied decreased Gd-EOB-DTPA uptake by hepatocytes and accounted for the low signal intensity during the hepatobiliary phase on Gd-EOB-DTPA-enhanced MRI. To the best of our knowledge this is the first report in which an FNH-like nodule was assessed for OATP1B3 expression.

Gd-EOB-DTPA-enhanced MR Imaging Findings of Hepatocellular Adenoma: Correlation with Pathological Findings

We report a case of a 28-year-old woman with hepatocellular adenoma and correlate findings of pathology and magnetic resonance (MR) imaging with gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) enhancement. In the hepatobiliary phase, the peripheral region of the tumor that corresponded with proliferating hepatocytes with steatosis showed slight hypointensity compared with the surrounding liver parenchyma, and the central region of the tumor that corresponded with cellular areas showed isointensity.

Gd-EOB-DTPA-Enhanced Magnetic Resonance Imaging Findings of Nondiffuse Fatty Change of the Liver

To evaluate the difference in enhancement effects between the area of fatty change and the area of nonfatty change in patients with nondiffuse fatty change of the liver at gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance (MR) imaging. Thirteen patients with nondiffuse fatty change of the liver underwent Gd-EOB-DTPA-enhanced MR imaging including dynamic study using a 1.5-T MR unit. Dynamic contrast-enhanced (DCE) MR images were obtained at pre, arterial phase (25 seconds), portal phase (70 seconds), equilibrium phase (3 minutes), and hepatobiliary phase (10, 15, 20 minutes). The percentage differences of signal enhancement ratio were calculated from signal intensity measurement of the liver in each phase of DCE study and were compared between the area of fatty change and the area of nonfatty change in all phases. In the all phases on DCE study, there were no significant differences in the signal enhancement ratio between the area of fatty change (27.7% ± 14.8%, 58.2% ± 14.7%, 62.7% ± 10.6%, 80.4% ± 15.2%, 84.9% ± 16.2%, 88.0% ± 14.3%) and the area of nonfatty change (29.9% ± 16.6%, 54.9% ± 13.3%, 63.0% ± 8.8%, 75.7% ± 12.6%, 80.3% ± 15.7%, 86.4% ± 14.5%) (P = 0.613). Although our results are limited by the small number of patients, our results showed that the presence of fatty change of the liver did not affect the hepatic contrast enhancement effects of Gd-EOB-DTPA in all phases on dynamic study. This indicates that Gd-EOB-DTPA may be a reliable marker to identify areas of nondiffuse fatty change of the liver.

Gd-EOB-DTPA Enhanced Micro-MR Imaging of Hepatic Tumors in H- ras 12V Transgenic Mice

The aims of this study were to evaluate the morphologic characteristics and growth pattern of hepatic tumors in H-ras 12V transgenic (TG) mice using a micro-magnetic resonance (MR) system and to assess the usefulness of gadolinium ethoxybenzyl diethylenetriamine penta-acetic acid (Gd-EOB-DTPA) enhancement for the detection of hepatic tumors in these mice. Hepatocellular carcinoma lines were established to allow insertion of the H-ras 12V transgene under the control of the albumin enhancer/promoter. Seven H-ras 12V TG mice and four wild-type mice were included in this study. The mice underwent various MR imaging examinations, including T1-weighted imaging (repetition time, 300 ms; echo time, 11 ms), Gd-EOB-DTPA-enhanced T1-weighted imaging (dose, 0.025 mmol/kg), and T2-weighted imaging (repetition time, 3500 ms; echo time, 36 ms), with a 4.7-T MR scanner, at 4, 6, 8, and 9 months of age. All mice were euthanized after the final MR imaging procedure, except for one TG mouse and two wild-type mice that were euthanized after MR imaging procedures at 4 months of age. For imaging analysis, the tumor characteristics in each MR sequence, including tumor size, number, and signal intensity (SI), were recorded, and the contrast-to-noise ratio and contrast enhancement ratio were calculated to quantify the SI of the tumor. The MR images were correlated with the findings of histopathologic examinations. No tumors were detected in the four wild-type mice. In the six TG mice, a total of 67 tumors were found in histopathologic specimens obtained at 9 months of age. Of the 67 tumors, 62 were detected on Gd-EOB-DTPA-enhanced T1-weighted images with fat saturation. The majority of hepatic tumors showed high SI on T1-weighted images without fat saturation. The SI diminished on T1-weighted images with fat saturation. The tumor contrast-to-noise ratio for Gd-EOB-DTPA-enhanced T1-weighted imaging was significantly better than that for the other sequences. The tumors were histopathologically confirmed as hepatocellular adenomas (n = 32) and well-differentiated hepatocellular carcinomas (n = 35). Micro-MR imaging can reveal the characteristics of hepatic tumors in a live murine model. Gd-EOB-DTPA-enhanced T1-weighted imaging is helpful in the detection of hepatic tumors in H-ras 12V TG mice.

Assessment of liver function in primary biliary cirrhosis using Gd-EOB-DTPA-enhanced liver MRI

ObjectivesGd-EOB-DTPA (gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid) is a gadolinium-based hepatocyte-specific contrast agent for magnetic resonance imaging (MRI). The aim of this study was to determine whether the hepatic uptake and excretion of Gd-EOB-DTPA differ between patients with primary biliary cirrhosis (PBC) and healthy controls, and whether differences could be quantified. MethodsGd-EOB-DTPA-enhanced liver MRI was performed in 20 healthy volunteers and 12 patients with PBC. The uptake of Gd-EOB-DTPA was assessed using traditional semi-quantitative parameters (Cmax, Tmax and T1/2), as well as model-free parameters derived after deconvolutional analysis (hepatic extraction fraction [HEF], input-relative blood flow [irBF] and mean transit time [MTT]). In each individual, all parameters were calculated for each liver segment and the median of the segmental values was used to define a global liver median (GLM). ResultsAlthough the PBC patients had relatively mild disease according to their Model for End-stage Liver Disease (MELD), Child–Pugh and Mayo risk scores, they had significantly lower HEF and shorter MTT values compared with the healthy controls. These differences significantly increased with increasing MELD and Child–Pugh scores. ConclusionsDynamic hepatocyte-specific contrast-enhanced MRI (DHCE-MRI) has a potential role as an imaging-based liver function test. The high spatial resolution of MRI enables hepatic function to be assessed on segmental and sub-segmental levels.

Radiofrequency ablation of hepatocellular carcinoma: The feasibility of magnetic resonance imaging with gadolinium ethoxybenzyl diethylene triamine pentaacetic acid for evaluating the ablative margin

The aim of this study was to evaluate the feasibility of gadolinium ethoxybenzyl diethylene triamine pentaacetic acid (Gd-EOB-DTPA) in magnetic resonance imaging (MRI) to assess the ablative margin of radiofrequency (RF) ablation to hepatocellular carcinoma (HCC). RF ablation was performed in the livers of six pigs after the i.v. administration of Gd-EOB-DTPA 20 min before ablation. Three pigs were killed 2 h after administration (group A), and the other pigs were killed 7 days after ablation (group B). Thereafter, correlation between pathological findings and MRI was investigated. Moreover, the Gd concentrations were examined in ablated and non-ablated regions. An initial clinical evaluation was conducted for 28 HCC nodules. Percutaneous RF ablation was performed 20 min after administration, and T(1)-weighted images were taken 2, 24 and 72 h post-treatment. On T(1)-weighted images of the porcine liver, the RF ablated lesions showed hyperintense regions with hypointense rims, which histopathologically corresponded to sinusoidal congestion. The Gd concentrations in ablated regions in group A were significantly higher than those in non-ablated regions, while the concentrations in both regions in group B fell to nearly undetectable levels. In 27 of the 28 HCC nodules, the treated area consisted of a hypointense region, indicative of the tumor, and a surrounding hyperintense rim 2 h after ablation. Subsequently, a thin hypointense region was observed in the outermost layer 24 and 72 h after ablation. Administration of Gd-EOB-DTPA in conjunction with RF ablation of HCC may be feasible for the assessment of an accurate ablative margin.

Gd-EOB-DTPA enhanced MR imaging: Evaluation of biliary and renal excretion in normal and cirrhotic livers

The purpose of this study was to assess the difference in the activity of biliary and renal excretion between normal and cirrhotic livers on contrast-enhanced MR imaging obtained with gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA). A total of 78 patients with cirrhotic liver (n=44) and with normal liver (n=34) underwent multi-phase Gd-EOB-DTPA enhanced MR imaging (arterial, portal, equilibrium, and three hepatobiliary phases (10, 15 and 20 min HP), respectively), and these contrast-enhanced images were qualitatively and quantitatively evaluated for the differences of the biliary and renal excretion between normal and cirrhotic livers. The timing of biliary excretion of contrast agents in the cirrhotic liver was significantly slower than that in the normal liver (P<0.001). The degree of contrast enhancement in the common bile duct in the normal liver was significantly better than that in the cirrhotic liver (P=0.003). Contrast agents were demonstrated in the duodenum at 20 min HP in 8/44 (18%) cirrhotic liver while they were seen in 15/34 (44%) normal liver (P=0.013). The enhancement effects of renal medulla and portal vein at 20 min HP in the cirrhotic liver were significantly higher than those of normal liver (P=0.043 and P<0.001, respectively). Biliary excretion of Gd-EOB-DPTA was impaired in cirrhotic livers in comparison with normal livers while renal excretion of Gd-EOB-DPTA was increased.

Paradoxical high signal intensity of hepatocellular carcinoma in the hepatobiliary phase of Gd-EOB-DTPA enhanced MRI: initial experience

PurposeTo describe the paradoxical high signal intensity of hepatocellular carcinoma (HCC) in the hepatobiliary phase on gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI). Materials and MethodsA database search was performed to identify cases of HCC that showed unusual prolonged enhancement in the hepatobiliary phase of Gd-EOB-DTPA MRI. All patients received 3.0-T liver MRI including precontrast T1-weighted images, T2-weighted images and a post Gd-EOB-DTPA-enhanced dynamic study. The signal intensity of HCC was measured at pre-enhanced, arterial, portal, delayed and hepatobiliary phase using regions of interest. Radiologic and pathologic correlation was performed for the paradoxically prolonged enhancing portion of HCC in the hepatobiliary phase. ResultsFour patients (all male, age range 44–70; mean 57.5 years) were included in this study. All patients showed HCC lesions that were low signal intensity (SI) on T1-WI, high SI on T2-WI, enhanced in arterial phase, and washed-out in delayed phase. All cases showed paradoxically high SI in hepatobiliary phase, which was unusual for HCC. Pathologically, they were all diagnosed as well-differentiated HCC with prominent cytoplasm and a bile secreting appearance. ConclusionHCC may demonstrate the prolonged high signal intensity at the hepatobiliary phase on Gd-EOB-DTPA enhanced MRI. These HCCs tended to be highly differentiated and to have prominent bile secretion.