Hepatobiliary Phase Magnetic Resonance Imaging Research Articles

Focal fatty sparing areas of the pediatric steatotic liver: pseudolesions on hepatobiliary phase magnetic resonance images.

Focal fatty sparing in liver can be detected as hyperintense pseudolesions on hepatobiliary phase magnetic resonance imaging (MRI). Distinguishing these pseudolesions from liver lesions may make diagnosis challenging. The aim of this study was to evaluate the imaging features of fatty sparing areas on liver MRI in pediatric patients who have been administered gadoxetate disodium. A total of 63 patients between January 2018 and June 2023 underwent gadoxetate disodium-enhanced liver MRI, and 9 (14%) patients with a focal fatty sparing were included in the study. The fat spared areas were evaluated qualitatively and quantitatively including signal intensity measurements and fat fraction calculations. The liver MRI examinations of 9 patients (5 boys, 4 girls; aged 8-18 years, median age: 14.4) using gadoxetate disodium were evaluated. Based on in-phase and opposed-phase sequences, 13 areas of focal fatty sparing were identified. The mean fat fraction of the liver and fat spared areas were 26.2% (range, 15-47) and 9% (range, 2-17), respectively. All fat spared areas were hyperintense in the hepatobiliary phase images. The mean relative enhancement ratios of the liver and fat spared areas were 0.78 (range, 0.35-1.6) and 1.11 (range, 0.45-1.9), respectively. Focal fatty sparing in liver in children was observed as hyperintense on hepatobiliary phase MRI, and it should not be identified as a focal liver lesion.

The value of periportal hyperintensity sign from gadobenate dimeglumine-enhanced hepatobiliary phase MRI for predicting clinical outcomes in patients with decompensated cirrhosis

ObjectivesTo determine the value of periportal hyperintensity sign from gadobenate dimeglumine (Gd-BOPTA)-enhanced hepatobiliary phase (HBP) magnetic resonance imaging (MRI) for predicting clinical outcomes in patients with decompensated cirrhosis.MethodsA total of 199 cirrhotic patients who underwent Gd-BOPTA-enhanced MRI were divided into control group (n = 56) and decompensated cirrhosis group (n = 143). The presence of periportal hyperintensity sign on HBP MRI was recorded. The Cox regression model was used to investigate the association between periportal hyperintensity sign and clinical outcomes.ResultsThere was a significant difference in the frequency of periportal hyperintensity sign on HBP between compensated and decompensated cirrhotic patients (p < 0.05). After a median follow-up of 29.0 months (range, 1.0–90.0 months), nine out of 143 patients (6.2%) with decompensated cirrhosis died. Periportal hyperintensity sign on HBP MRI was a significant risk factor for death (hazard ratio (HR) = 23.677; 95% confidence interval (CI) = 4.759–117.788; p = 0.0001), with an area under the curve (AUC) of 0.844 (95% CI = 0.774–0.899). Thirty patients (20.9%) developed further decompensation. Periportal hyperintensity sign on HBP MRI was also a significant risk factor for further decompensation (HR = 2.594; 95% CI = 1.140–5.903; p = 0.023).ConclusionsPeriportal hyperintensity sign from Gd-BOPTA-enhanced HBP MRI is valuable for predicting clinical outcomes in patients with decompensated cirrhosis.Critical relevance statementPeriportal hyperintensity sign from gadobenate dimeglumine-enhanced hepatobiliary phase magnetic resonance imaging is a new noninvasive method to predict clinical outcomes in patients with decompensated cirrhosis.Key points• There was a significant difference in the frequency of periportal hyperintensity sign on HBP between compensated and decompensated cirrhotic patients.• Periportal hyperintensity sign on the hepatobiliary phase was a significant risk factor for death in patients with decompensated cirrhosis.• Periportal hyperintensity sign on the hepatobiliary phase was a significant risk factor for further decompensation in patients with decompensated cirrhosis.Graphical

Beta-Catenin-Mutated Hepatocellular Adenomas at Hepatobiliary Phase MRI: A Systematic Review and Meta-Analysis.

Beta-catenin-mutated hepatocellular adenomas (β-HCAs) can appear iso- to hyperintense at the hepatobiliary phase (HBP) at magnetic resonance imaging (MRI). Given the relatively lower prevalence of β-HCAs, prior studies had limited power to show statistically significant differences in the HBP signal intensity between different subtypes. To assess the diagnostic performance of HBP MRI to discriminate β-HCA from other subtypes. Systemic review and meta-analysis. Ten original studies were included, yielding 266 patients with 397 HCAs (9%, 36/397 β-HCAs and 91%, 361/397 non-β-HCAs). 1.5 T and 3.0 T, HBP. PubMed, Web of Science, and Embase databases were searched from January 1, 2000, to August 31, 2023, for all articles reporting HBP signal intensity in patients with histopathologically proven HCA subtypes. QUADAS-2 was used to assess risk of bias and concerns regarding applicability. Univariate random-effects model was used to calculate pooled estimates. Heterogeneity estimates were assessed with I2 heterogeneity index. Meta-regression (mixed-effect model) was used to test for differences in the prevalence of HBP signal between HCA groups. The threshold for statistical significance was set at P < 0.05. HBP iso- to hyperintensity was associated with β-HCAs (pooled prevalence was 72.3% in β-HCAs and 6.3% in non-β-HCAs). Pooled sensitivity and specificity were 72.3% (95% confidence interval 54.1-85.3) and 93.7% (93.8-97.7), respectively. Specificity had substantial heterogeneity with I2 of 83% due to one study, but not for sensitivity (I2 = 0). After excluding this study, pooled sensitivity and specificity were 77.4% (59.6-88.8) and 94.1% (88.9-96.9), with no substantial heterogeneity. One study had high risk of bias for patient selection and two studies were rated unclear for two domains. Iso- to hyperintensity at HBP MRI may help to distinguish β-HCA subtype from other HCAs with high specificity. However, there was heterogeneity in the pooled estimates. 3 TECHNICAL EFFICACY: Stage 2.

Assessing regional hepatic function changes after hypertrophy induction by radioembolisation: comparison of gadoxetic acid-enhanced MRI and 99mTc-mebrofenin hepatobiliary scintigraphy

BackgroundTo compare Gd-ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) and 99mTc-labelled mebrofenin hepatobiliary scintigraphy (HBS) as imaging-based liver function tests after unilateral radioembolisation (RE) in patients with primary or secondary liver malignancies.MethodsTwenty-three patients with primary or secondary liver malignancies who underwent Gd-EOB-DTPA-enhanced MRI within a prospective study (REVoluTion) were evaluated. REVoluTion was a prospective open-label, non-randomised, therapy-optimising study of patients undergoing right-sided or sequential RE for contralateral liver hypertrophy at a single centre in Germany. MRI and hepatobiliary scintigraphy were performed before RE (baseline) and 6 weeks after (follow-up). This exploratory subanalysis compared liver enhancement on hepatobiliary phase MRI normalised to the spleen (liver-to-spleen ratio (LSR)) and the muscle (liver-to-muscle ratio (LMR)) with mebrofenin uptake on HBS for the total liver (TL) and separately for the right (RLL) and left liver lobe (LLL).ResultsMebrofenin uptake at baseline and follow-up each correlated significantly with LSR and LMR on MRI for TL (≤ 0.013) and RLL (≤ 0.049). Regarding the LLL, mebrofenin uptake correlated significantly with LMR (baseline, p = 0.013; follow-up, p = 0.004), whereas with LSR, a borderline significant correlation was only seen at follow-up (p = 0.051; p = 0.046).ConclusionLSRs and LMR correlate with mebrofenin uptake in HBS. This study indicates that Gd-EOB-DTPA-enhanced MRI and 99mTc-labelled mebrofenin HBS may equally be used to assess an increase in contralateral liver lobe function after right-sided RE.Relevance statementMRI may be a convenient and reliable method for assessing the future liver remnant facilitating treatment planning and monitoring of patients after RE-induced hypertrophy induction.Key points• Both MRI and HBS can assess liver function after RE.• Liver enhancement on MRI correlates with mebrofenin uptake on HBS.• MRI might be a convenient alternative for estimating future liver remnants after hypertrophy induction.Graphical

Diagnosis of focal liver lesions with deep learning-based multi-channel analysis of hepatocyte-specific contrast-enhanced magnetic resonance imaging.

BACKGROUNDThe nature of input data is an essential factor when training neural networks. Research concerning magnetic resonance imaging (MRI)-based diagnosis of liver tumors using deep learning has been rapidly advancing. Still, evidence to support the utilization of multi-dimensional and multi-parametric image data is lacking. Due to higher information content, three-dimensional input should presumably result in higher classification precision. Also, the differentiation between focal liver lesions (FLLs) can only be plausible with simultaneous analysis of multi-sequence MRI images. AIMTo compare diagnostic efficiency of two-dimensional (2D) and three-dimensional (3D)-densely connected convolutional neural networks (DenseNet) for FLLs on multi-sequence MRI.METHODSWe retrospectively collected T2-weighted, gadoxetate disodium-enhanced arterial phase, portal venous phase, and hepatobiliary phase MRI scans from patients with focal nodular hyperplasia (FNH), hepatocellular carcinomas (HCC) or liver metastases (MET). Our search identified 71 FNH, 69 HCC and 76 MET. After volume registration, the same three most representative axial slices from all sequences were combined into four-channel images to train the 2D-DenseNet264 network. Identical bounding boxes were selected on all scans and stacked into 4D volumes to train the 3D-DenseNet264 model. The test set consisted of 10-10-10 tumors. The performance of the models was compared using area under the receiver operating characteristic curve (AUROC), specificity, sensitivity, positive predictive values (PPV), negative predictive values (NPV), and f1 scores.RESULTSThe average AUC value of the 2D model (0.98) was slightly higher than that of the 3D model (0.94). Mean PPV, sensitivity, NPV, specificity and f1 scores (0.94, 0.93, 0.97, 0.97, and 0.93) of the 2D model were also superior to metrics of the 3D model (0.84, 0.83, 0.92, 0.92, and 0.83). The classification metrics of FNH were 0.91, 1.00, 1.00, 0.95, and 0.95 using the 2D and 0.90, 0.90, 0.95, 0.95, and 0.90 using the 3D models. The 2D and 3D networks' performance in the diagnosis of HCC were 1.00, 0.80, 0.91, 1.00, and 0.89 and 0.88, 0.70, 0.86, 0.95, and 0.78, respectively; while the evaluation of MET lesions resulted in 0.91, 1.00, 1.00, 0.95, and 0.95 and 0.75, 0.90, 0.94, 0.85, and 0.82 using the 2D and 3D networks, respectively.CONCLUSIONBoth 2D and 3D-DenseNets can differentiate FNH, HCC and MET with good accuracy when trained on hepatocyte-specific contrast-enhanced multi-sequence MRI volumes.

Assessment of the cut-off value of quantitative liver–portal vein contrast ratio in the hepatobiliary phase of liver MRI

To calculate the quantitative liver-portal vein contrast ratio (Q-LPC) cut-off value based on tumour detectability by using receiver operating characteristic (ROC) curves. Seventy-four patients with tumours (46 men and 28 women; age, 71±8.1 years), who underwent liver magnetic resonance imaging (MRI) using gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) were enrolled. Some patients were found to have multiple tumours. In total, 102 tumour images were evaluated for quantitative liver-spleen contrast ratio (Q-LSC) and Q-LPC 10 minutes after the administration of Gd-EOB-DTPA. Q-LPC and Q-LSC were compared to assess the cut-off values and usefulness. The ROC curve was evaluated using the method for continuously distributed test results, with a free scale of 50 mm. A score of ≥30 out of 50 points was considered good. Cut-off values of Q-LPC and Q-LSC were then calculated. The areas under the ROC curve (AUCs) were also examined and compared. The AUC-ROC for Q-LPC was 0.858 (95% confidence interval [CI], 0.783-0.933). The cut-off value was determined to be at 1.462. Sensitivity was 0.747, and specificity was 0.852 at the cut-off value. The AUC-ROC for Q-LSC was 0.710 (95% CI, 0.597-0.822). The cut-off value was at 1.543, the sensitivity was 0.560, and the specificity was 0.778 at the cut-off value. A significant difference was noted between the AUCs (p=0.0016). Q-LPC can be used for hepatobiliary phase MRI evaluation.

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.

Gadoxetic acid-based hepatobiliary MRI in hepatocellular carcinoma.

Background & AimsSORAMIC is a prospective phase II randomised controlled trial in hepatocellular carcinoma (HCC). It consists of 3 parts: a diagnostic study and 2 therapeutic studies with either curative ablation or palliative Yttrium-90 radioembolisation combined with sorafenib. We report the diagnostic cohort study aimed to determine the accuracy of gadoxetic acid-enhanced magnetic resonance imaging (MRI), including hepatobiliary phase (HBP) imaging features compared with contrast-enhanced computed tomography (CT). The primary objective was the accuracy of treatment decisions stratifying patients for curative or palliative (non-ablation) treatment.MethodsPatients with clinically suspected HCC underwent gadoxetic acid-enhanced MRI (HBP MRI, including dynamic MRI) and contrast-enhanced CT. Blinded read of the image data was performed by 2 reader groups (radiologists, R1 and R2). A truth panel with access to all clinical data and follow-up imaging served as reference. Imaging criteria for curative ablation were defined as up to 4 lesions <5 cm and absence of macrovascular invasion. The primary endpoint was non-inferiority of HBP MRI vs. CT in a first step and superiority in a second step.ResultsThe intent-to-treat population comprised 538 patients. Treatment decisions matched the truth panel assessment in 83.3% and 81.2% for HBP MRI (R1 and R2), and 73.4% and 70.8% for CT. Non-inferiority and superiority (second step) of HBP MRI vs. CT were demonstrated (odds ratio 1.14 [1.09–1.19]). HBP MRI identified patients with >4 lesions significantly more frequently than CT.ConclusionsIn HCC, HBP MRI provided a more accurate decision than CT for a curative vs. palliative treatment strategy.Lay summaryPatients with hepatocellular carcinoma are allocated to curative or palliative treatment according to the stage of their disease. Hepatobiliary imaging using gadoxetic acid-enhanced MRI is more accurate than CT for treatment decision-making.

Detection of Hepatocellular Carcinoma in Contrast-Enhanced Magnetic Resonance Imaging Using Deep Learning Classifier: A Multi-Center Retrospective Study

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors and a leading cause of cancer-related death worldwide. We propose a fully automated deep learning model to detect HCC using hepatobiliary phase magnetic resonance images from 549 patients who underwent surgical resection. Our model used a fine-tuned convolutional neural network and achieved 87% sensitivity and 93% specificity for the detection of HCCs with an external validation data set (54 patients). We also confirmed whether the lesion detected by our deep learning model is a true lesion using a class activation map.

Personalized 3D-Printed Transparent Liver Model Using the Hepatobiliary Phase MRI: Usefulness in the Lesion-by-Lesion Imaging-Pathologic Matching of Focal Liver Lesions-Preliminary Results.

The aim of this study was to investigate the usefulness of a personalized, 3-dimensional (3D)-printed, transparent liver model with focal liver lesions (FLLs) for lesion-by-lesion imaging-pathologic matching. This preliminary, prospective study was approved by our institutional review board, and written informed consent was obtained. Twenty patients (male-to-female ratio, 13:7; mean age, 56 years) with multiple FLLs, including at least one presumed malignant, or an indeterminate lesion 10 mm or less on the preoperative gadoxetic acid-enhanced magnetic resonance imaging (MRI), were included. After digital segmentation of hepatobiliary phase MRI, a transparent, 3D-printed liver model with colored anatomical structures and FLLs was produced. During the gross examination of the liver specimen, the per-lesion detection rates were compared between those without (routine protocol) and those with the aid of the 3D-printed liver model. Among 98 MRI-detected FLLs (11.5 ± 12.5 mm), the per-lesion detection rate on gross examination using the 3D-printed liver model was 99.0% (97/98), which was significantly higher than that obtained on routine examination (82.7% [81/98]; P < 0.001). In the subgroup analysis, according to the tumor size, 23.9% (16/67) of FLLs 10 mm or less were additionally detected using the liver model, whereas none were additionally detected in greater than 10 mm. The additionally detected 16 FLLs in 12 patients included histologic diagnoses of viable metastases, pathologic complete response of metastases, hepatocellular carcinomas, focal nodular hyperplasia-like nodules, and hemangiomas. A personalized, 3D-printed liver model with FLLs may improve the lesion-by-lesion imaging-pathologic matching for small FLLs, thus leading to accurate pathologic tumor staging and obtaining a reliable reference for imaging-detected FLLs.

Assessing Liver Function by T1 Maps on Gd-EOB-DTPA-Enhanced MRI for up to 50 Min in Rat Models of Liver Fibrosis: A Longer Hepatobiliary Time Period may Help

Objectives To investigate whether a longer time period of gadolinium ethoxybenzyl diethylenetriaminepen-taacetic acid (Gd-EOB-DTPA)-enhanced T1 mapping scanning, as well as dynamic contrast-enhanced (DCE) and multiple hepatobiliary phase magnetic resonance imaging (MRI) have the potential to provide information about liver function in rats with liver fibrosis. Methods Forty rats were divided into the carbon tetrachloride-induced hepatic injury groups [carbon tetrachloride for four (n=14), eight (n=8), or twelve (n=8) weeks] and the control group (n=10). Gd-EOB-DTPA-enhanced MRI was performed including T1-mapping (delayed to 50 min), DCE, and multiple hepatobiliary phases. Indocyanine green retention rate at 15 min (ICG-R15) was determined. Parameters such as T1 reduction rate (ΔT1), elimination half-life of ΔT1 (TΔT1 1/2), relative enhancement (RE), time to maximum RE (Tmax), and perfusion parameters were calculated. Pearson correlation analysis was used for correlation analysis between ICG-R15 and each MRI indices. Results ΔT1 at 30, 40, and 50 min showed significant positive correlations with ICG-R15 ( r=0.784, 0.653, 0.757, P=0.007, 0.041, 0.030). TΔT1 1/2 showed a significant positive correlation with ICG-R15 (r=0.685, P=0.029). Tmaxshowed a significant positive correlation with ICG-R15 (r=0.532, P=0.019). Conclusions ΔT1 in the late hepatobiliary phase and T ΔT1 1/2 exhibited moderate correlations with liver function. The longer time period of Gd-EOB-DTPA-enhanced T1 mapping scanning, as well as DCE and multiple hepatobiliary phases, may be of some value for estimating liver function in rats with liver fibrosis.

Emerging Role of Hepatobiliary Magnetic Resonance Contrast Media and Contrast-Enhanced Ultrasound for Noninvasive Diagnosis of Hepatocellular Carcinoma: Emphasis on Recent Updates in Major Guidelines.

Hepatocellular carcinoma (HCC) can be noninvasively diagnosed on the basis of its characteristic imaging findings of arterial phase enhancement and portal/delayed “washout” on computed tomography (CT) and magnetic resonance imaging (MRI) in cirrhotic patients. However, different specific diagnostic criteria have been proposed by several countries and major academic societies. In 2018, major guideline updates were proposed by the Association for the Study of Liver Diseases, European Association for the Study of the Liver (EASL), Korean Liver Cancer Association and National Cancer Center (KLCA-NCC) of Korea. In addition to dynamic CT and MRI using extracellular contrast media, these new guidelines now include magnetic resonance imaging (MRI) using hepatobiliary contrast media as the first-line diagnostic test, while the KLCA-NCC and EASL guidelines also include contrast-enhanced ultrasound (CEUS) as the second-line diagnostic test. Therefore, hepatobiliary MR contrast media and CEUS will be increasingly used for the noninvasive diagnosis and staging of HCC. In this review, we discuss the emerging role of hepatobiliary phase MRI and CEUS for the diagnosis of HCC and also review the changes in the HCC diagnostic criteria in major guidelines, including the KLCA-NCC practice guidelines version 2018. In addition, we aimed to pay particular attention to some remaining issues in the noninvasive diagnosis of HCC.

An Imaging Biomarker for Assessing Hepatic Function in Patients With Primary Sclerosing Cholangitis

We aimed to evaluate the potential of hepatobiliary phase magnetic resonance imaging (MRI) as parameter for assessment of hepatocellular function in patients with primary sclerosing cholangitis (PSC). We collected data from 111 patients (83 male, 28 female; median, 44 years old), from March 2012 through March 2016, with a confirmed diagnosis of PSC who underwent MRI evaluation before and after injection (hepatobiliary phase) of a hepatocyte-specific contrast agent (gadoxetate disodium). Signal intensities were measured in each liver segment. Mean relative enhancement values were calculated and correlated with findings from liver functions tests, prognostic scoring systems (model for end-stage liver disease [MELD] score; Mayo risk score; Amsterdam-Oxford-PSC score), abnormalities detected by endoscopic retrograde cholangiopancreatography (using the Amsterdam cholangiographic classification system), andclinical endpoints (liver transplantation, cholangiocarcinoma, liver-related death). Ourprimary aim was to associate relative enhancement values with liver function and patient outcomes. Most patients had moderate-stage disease and had intermediate levels of risk (median MELD score, 8 and median Mayo score, 0.27). Clinical endpoints were reached by 21 patients (6developed cholangiocarcinoma, 8 underwent liver transplantation, and 7 patients died). The highest levels of correlations were observed for relative enhancement 20 min after contrast injection and level of alkaline phosphatase (r= -0.636), bilirubin (r= -0.646), albumin (r= 0.538); as well as international normalized ratio (r= 0.456); MELD score (r=-0.587); Mayo risk score (r= -0.535), and Amsterdam-Oxford model score (r= -0.595) (P < .0001). Relative enhancement correlated with all clinical endpoints (all P < .05). A cutoff relative enhancement value of 0.65 identified patients with a clinical endpoint with 73.9% sensitivity 92.9% specificity (area under the receiver operating characteristic curve, 0.901; likelihood ratio, 10.34; P < .0001). In an analysis of 111 patients with PSC, we found MRI-measured relative enhancement, using a hepatocyte-specific contrast agent, to identify patients with clinical outcomes with 73.9% sensitivity 92.9% specificity. Long-term, multicenter studies are needed to further evaluate this marker of PSC progression.

Fusion imaging with contrast-enhanced ultrasonography for evaluating the early therapeutic efficacy of radiofrequency ablation for small hypervascular hepatocellular carcinomas with iso-echoic or unclear margins on conventional ultrasonography.

We evaluated the efficacy of fusion imaging combining contrast-enhanced ultrasonography (CEUS) images and arterial phase contrast-enhanced CT (CECT) or hepatobiliary phase magnetic resonance imaging with gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (EOB-MRI) images for the early evaluation of the effectiveness of radiofrequency ablation (RFA) for small hypervascular hepatocellular carcinoma (HCC) with iso-echoic or unclear margins on conventional US. Forty HCCs (22 iso-echoic and 18 unclear margin lesions) with mean diameters of 13.7mm were treated using RFA under the guidance of fusion imaging with CEUS. The adequacy of RFA was evaluated using fusion imaging with CEUS 1day after RFA. CECT or EOB-MRI was performed 1month after RFA. We reviewed the images obtained using both modalities. When the 1-month CECT or EOB-MRI scans were used as the reference standard, the sensitivity, specificity, and accuracy of the 1-day fusion imaging for the diagnosis of the adequate ablation of these HCCs were 97, 100, and 98%, respectively; the kappa value for the agreement between the findings using the two modalities was 0.655. Fusion imaging with CEUS appears to be a useful method for the early evaluation of the efficacy of RFA for the treatment of HCCs with iso-echoic or unclear margins on conventional US.

Liver Fibrosis: Deep Convolutional Neural Network for Staging by Using Gadoxetic Acid-enhanced Hepatobiliary Phase MR Images.

Purpose To investigate the performance of a deep convolutional neural network (DCNN) model in the staging of liver fibrosis using gadoxetic acid-enhanced hepatobiliary phase magnetic resonance (MR) imaging. Materials and Methods This retrospective study included patients for whom input data (hepatobiliary phase MR images, static magnetic field of the imaging unit, and hepatitis B and C virus testing results available, either positive or negative) and reference standard data (liver fibrosis stage evaluated from biopsy or surgical specimens obtained within 6 months of the MR examinations) were available were assigned to the training (534 patients) or the test (100 patients) group. For the training group (54, 53, 81, 113, and 233 patients with fibrosis stages F0, F1, F2, F3, and F4, respectively; mean patient age, 67.4 ± 9.7 years; 388 men and 146 women), MR images with three different section levels were augmented 90-fold (rotated, parallel-shifted, brightness-changed and contrast-changed images were generated; a total of 144 180 images). Supervised training was performed by using the DCNN model to minimize the difference between the output data (fibrosis score obtained through deep learning [FDL score]) and liver fibrosis stage. The performance of the DCNN model was evaluated in the test group (10, 10, 15, 20, and 45 patients with fibrosis stages F0, F1, F2, F3, and F4, respectively; mean patient age, 66.8 years ± 10.7; 71 male patients and 29 female patients) with receiver operating characteristic (ROC) analyses. Results The FDL score was correlated significantly with fibrosis stage (Spearman rank correlation coefficient: 0.63; P < .001). Fibrosis stages F4, F3, and F2 were diagnosed with areas under the ROC curve of 0.84, 0.84, and 0.85, respectively. Conclusion The DCNN model exhibited a high diagnostic performance in the staging of liver fibrosis. © RSNA, 2017 Online supplemental material is available for this article.

Rapid Cartesian versus radial acquisition: comparison of two sequences for hepatobiliary phase MRI at 3 tesla in patients with impaired breath-hold capabilities

BackgroundHepatocyte-specific gadolinium based contrast agents (HSCA) provide substantial information for the classification of liver lesions in magnetic resonance imaging (MRI). However, breathing artifacts which reduce image quality and diagnostic confidence of hepatobiliary phase acquisitions are regularly observed in clinical routine. The aim of this study was to evaluate two approaches to reduce breathing artifacts for hepatobiliary phase imaging.MethodsTwenty minutes after administration of a HSCA (gadoxetic acid), a T1-weighted VIBE sequence with radial k-space sampling (radialVIBE, 180 s acquisition time in free breathing) and a highly accelerated Cartesian VIBE with Dixon fat separation (CD-VIBE, CAIPIRINHA acceleration with r = 2 × 2, breath-hold 8–10 s) were acquired in 35 patients (12 female, 57 ± 13 years), who showed breath-holding difficulties in early phases of the examinations. Image quality (image sharpness, noise, artifacts, homogeneity of fat saturation, bile duct delineation and overall image quality) as well as conspicuity and liver-to-lesion signal intensity (SI) ratios of focal liver lesions were assessed for both radial- and CD-VIBE.ResultsOverall image quality was rated good to excellent for both sequences, while CD-VIBE was preferred in most cases. Though radialVIBE received better results regarding image noise and artifacts, both sequences were rated equally regarding bile duct delineation and sharpness. Focal liver lesion (n = 42) conspicuity was rated significantly better and SI-ratios were significantly higher on CD-VIBE (2.45 ± 1.44 vs. 1.61 ± 0.70 in radialVIBE, p = 0.0001). In three patients, CD-VIBE was rated non-diagnostic due to severe breathing artifacts, while radialVIBE was diagnostic in those patients.ConclusionBoth highly accelerated Cartesian as well as radial acquisition techniques provide good to excellent image quality in hepatobiliary phase MRI. In comparison, CD-VIBE offered better overall image quality and liver lesion conspicuity. However, radialVIBE was a valuable alternative in patients unable to sustain even short breath-hold intervals. Further studies including lager patient cohorts are desirable to allow a transfer of these results to a general patient population.

Magnetic Resonance Elastography and Other Magnetic Resonance Imaging Techniques in Chronic Liver Disease: Current Status and Future Directions.

Recent advances in the noninvasive imaging of chronic liver disease have led to improvements in diagnosis, particularly with magnetic resonance imaging (MRI). A comprehensive evaluation of the liver may be performed with the quantification of the degree of hepatic steatosis, liver iron concentration, and liver fibrosis. In addition, MRI of the liver may be used to identify complications of cirrhosis, including portal hypertension, ascites, and the development of hepatocellular carcinoma. In this review article, we discuss the state of the art techniques in liver MRI, namely, magnetic resonance elastography, hepatobiliary phase MRI, and liver fat and iron quantification MRI. The use of these advanced techniques in the management of chronic liver diseases, including non-alcoholic fatty liver disease, will be elaborated.

Cholangiocarcinoma: Diagnosis and Pre-operative Evaluation

Cholangiocarcinoma is a primary malignancy of the biliary tree that comprises various anatomic and histologic subtypes. The purpose of this manuscript is to review the various imaging manifestations of cholangiocarcinoma in order to aid clinical radiologists in the diagnosis and classification of the complex malignancy, and to aid clinical colleagues in facilitating proper clinical management. Various imaging modalities may aid in the proper diagnosis and staging of cholangiocarcinoma. Recent studies have advocated the use of hepatobiliary phase magnetic resonance imaging following gadoxetic acid administration in order to improve lesion conspicuity and detection of satellite nodules and intrahepatic metastases. Accurate recognition and classification of cholangiocarcinoma is essential for proper patient management. A thorough understanding of the different anatomic classifications, morphological patterns, and the mode of metastatic spread of cholangiocarcinoma is essential for radiologists involved in the interpretation of abdominal imaging studies.

Hepatobiliary Tumors: Update on Diagnosis and Management.

Tumors of the liver and biliary tree, mainly hepatocellular carcinoma and cholangiocarcinoma, are the second leading cause of cancer related death worldwide and the sixth leading cause of cancer related death among men in developed countries. Recent developments in biomarkers and imaging modalities have enhanced early detection and accurate diagnosis of these highly fatal malignancies. These advances include serological testing, micro-ribonucleic acids, fluorescence in situ hybridization, contrast-enhanced ultrasound, and hepatobiliary-phase magnetic resonance imaging. In addition, there have been major developments in the surgical and nonsurgical management of these tumors, including expansion of the liver transplantation criteria, new locoregional treatments, and molecularly targeted therapies. In this article, we review various types of hepatobiliary tumors and discuss new developments in their diagnosis and management.

Differentiation of focal nodular hyperplasia from hepatocellular adenoma: Role of the quantitative analysis of gadobenate dimeglumine-enhanced hepatobiliary phase MRI.

To determine the value of quantitative analysis of the hepatobiliary phase (HBP) in gadobenate dimeglumine (Gd-BOPTA)-enhanced magnetic resonance imaging (MRI) to differentiate focal nodular hyperplasia (FNH) from hepatocellular adenoma (HCA). Thirty-eight patients bearing 67 lesions (40 FNH; 27 HCA) were retrospectively included in this Institutional Review Board-approved study. The same volumetric interpolated breath-hold examination (VIBE) T1 -weighted sequences were performed before and after contrast injection on a 1.5T MRI, with HBP images acquired with a mean delay of 80 minutes (range 60-120 min). After a visual assessment of lesions enhancement (qualitative HBP analysis), the HBP signal intensity ratio (SIR) and the lesion-to-liver contrast enhancement ratio (LLCER) were calculated for each lesion by two observers (Mann-Whitney test). The sensitivities, specificities (receiver operating characteristic [ROC] curve analysis) and interobserver correlation (intraclass coefficient, ICC) of quantitative HBP analysis were determined. All FNH and 44.4% of HCA appeared hyper- or isointense relative to the adjacent liver on qualitative HBP analysis. The mean SIR (P < 0.01) and LLCER (P < 0.0001) of FNH were significantly higher than that of HCA. The area under the ROC curve for the differentiation of FNH from HCA with LLCER was 0.98 for both observers. With a cutoff value of -0.3%-observer 1 with highest experience- LLCER assessment provided respective sensitivity and specificity values of 100% and 96.2% for the differentiation of FNH from HCA. The ICC was 0.7 for SIR measurements and 0.8 for LLCER measurements. Quantitative LLCER assessment allows an accurate differentiation of FNH from HCA, even in hyper- or isointense HCA on HBP images.