Gadoxetic Acid-enhanced Liver Magnetic Resonance Imaging Research Articles

Added Value of Liver MRI in Patients Eligible for Surgical Resection or Ablation of Colorectal Liver Metastases Based on CT: A Systematic Review and Meta-Analysis

Background: Abdominal computed tomography (CT) is the standard imaging modality for detection and staging in patients with colorectal liver metastases (CRLM). Although liver magnetic resonance imaging (MRI) is superior to CT in detecting small lesions, guidelines are ambiguous regarding the added value of an additional liver MRI in the surgical workup of patients with CRLM. Therefore, this systematic review and meta-analysis aimed to evaluate the clinical added value of liver MRI in patients eligible for resection or ablation of CRLM based on CT. Methods: A systematic search was performed in the PubMed, Embase, and Cochrane Library databases through June 23, 2023. Studies investigating the impact of additional MRI on local treatment plan following CT in patients with CRLM were included. Risk of bias was assessed using the QUADAS-2 tool. The pooled weighted proportions for the primary outcome were calculated using random effect meta-analysis. Results: Overall, 11 studies with 1440 patients were included, of whom 468 patients (32.5%) were assessed for change in local treatment plan. Contrast-enhanced liver MRI was used in 10 studies, including gadoxetic acid in 9 studies. Liver MRI with diffusion-weighted imaging was used in 8 studies. Pooling of data found a 24.12% (95% confidence interval, 15.58%–32.65%) change in the local treatment plan based on the added findings of liver MRI following CT. Sensitivity analysis including 5 studies (268 patients) focusing on monophasic portal venous CT followed by gadoxetic acid-enhanced liver MRI with diffusion-weighted imaging showed a change of local treatment plan of 17.88% (95% confidence interval, 5.14%–30.62%). Conclusions: This systematic review and meta-analysis found that liver MRI changed the preinterventional local treatment plan in approximately one-fifth of patients eligible for surgical resection or ablation of CRLM based on CT. These findings suggest a clinically relevant added value of routine liver MRI in the preinterventional workup of CRLM, which should be confirmed by large prospective studies.

Application of a deep learning algorithm for three-dimensional T1-weighted gradient-echo imaging of gadoxetic acid-enhanced MRI in patients at a high risk of hepatocellular carcinoma.

To evaluate the efficacy of a vendor-specific deep learning reconstruction algorithm (DLRA) in enhancing image quality and focal lesion detection using three-dimensional T1-weighted gradient-echo images in gadoxetic acid-enhanced liver magnetic resonance imaging (MRI) in patients at a high risk of hepatocellular carcinoma. In this retrospective analysis, 83 high-risk patients with hepatocellular carcinoma underwent gadoxetic acid-enhanced liver MRI using a 3-T scanner. Triple arterial phase, high-resolution portal venous phase, and high-resolution hepatobiliary phase images were reconstructed using conventional reconstruction techniques and DLRA (AIRTM Recon DL; GE Healthcare) for subsequent comparison. Image quality and solid focal lesion detection were assessed by three abdominal radiologists and compared between conventional and DL methods. Focal liver lesion detection was evaluated using figures of merit (FOMs) from a jackknife alternative free-response receiver operating characteristic analysis on a per-lesion basis. DLRA-reconstructed images exhibited significantly improved overall image quality, image contrast, lesion conspicuity, vessel conspicuity, and liver edge sharpness and reduced subjective image noise, ringing artifacts, and motion artifacts compared to conventionally reconstructed images (all P < 0.05). Although there was no significant difference in the FOMs of non-cystic focal liver lesions between the conventional and DL methods, DLRA-reconstructed images showed notably higher pooled sensitivity than conventionally reconstructed images (P < 0.05) in all phases and higher detection rates for viable post-treatment HCCs in the arterial and hepatobiliary phases (all P < 0.05). Implementing DLRA can enhance the image quality in 3D T1-weighted gradient-echo sequences of gadoxetic acid-enhanced liver MRI examinations, leading to improved detection of viable post-treatment HCCs.

Suboptimal hepatobiliary phase image in gadoxetic acid-enhanced liver MRI for the evaluation of the HCC: Predictive factors.

To determine the relevant laboratory values for hepatobiliary phase (HBP) imaging and predictive factors for suboptimal HBP images on gadoxetic acid-enhanced liver magnetic resonance imaging (MRI) for the evaluation of hepatocellular carcinoma (HCC) in patients with chronic liver disease (CLD). This study included 307 patients with CLD who underwent gadoxetic acid-enhanced liver MRI for HCC evaluation. The liver-portal vein contrast ratio and liver-spleen contrast ratio were calculated from the measurements of the HBP images. In this study, a suboptimal HBP image was defined as the presence of a bright portal vein or a liver-spleen contrast ratio of <1.5. Correlation, comparison, and receiver operating characteristic analyses were performed between the measured parameters on the HBP images and hepatic and renal function tests. The estimated glomerular filtration rate did not correlate with any measured or calculated values on the HBP images. On receiver operating characteristic analysis, the optimal cutoff value for the bright portal vein was an albumin level of 4.05 g/dL (area under the curve, 0.971; sensitivity, 65%; specificity, 82%). The optimal cutoff value of the suboptimal HBP image was a serum direct bilirubin level of 0.83 mg/dL (area under the curve, 0.830; sensitivity, 69%; specificity, 84%). On gadoxetic acid-enhanced MRI for the evaluation of HCC in patients with CLD, suboptimal HBP images were most strongly correlated with serum direct bilirubin levels. Renal function was not associated with suboptimal HBP imaging. Although the sensitivity is low, suboptimal HBP images can be predicted before gadoxetic acid-enhanced liver MRI can be performed.

Utility of combined gadoxetic acid and ferumoxytol-enhanced liver MRI for preoperative detection of colorectal cancer liver metastases: a pilot study.

Colorectal cancer (CRC) is the second-leading cause of cancer-related death worldwide and resection of CRC metastases confined to the liver is the treatment of choice when feasible. Ferumoxytol is an off-label contrast agent that opacifies vasculature and may be helpful in distinguishing metastases from small hemangiomas and blood vessels on gadoxetic acid-enhanced magnetic resonance imaging (MRI). To compare the diagnostic accuracy of MRI using a standard gadoxetic acid protocol and a combined gadoxetic acid/ferumoxytol protocol in patients with suspected colorectal hepatic metastases. In this institutional review board-approved, single-institution, retrospective study, eight patients underwent gadoxetic acid-enhanced liver MRI, supplemented with additional T1-weighted ferumoxytol enhanced sequences. Two radiologists in consensus identified all metastases using all available sequences, which served as the reference standard. Two different radiologists reviewed each exam twice, once using the standard protocol and once with additional ferumoxytol sequences. The detection rate was estimated as the predicted probability of a metastasis along with the 95% confidence interval (CI) using hierarchical logistic regression models. A total of 49 metastases were identified. The mean diameter was 10 mm, measured in greatest axial dimension (median=7 mm; range=2-70 mm). Readers 1 and 2 had detection rates of 69.6% (95% CI = 48.2-85.0) and 53.1% (95% CI = 35.2-70.3) for gadoxetic acid alone and 98.0% (95% CI = 86.3-99.7) and 83.5% (95% CI = 59.3-94.7) for combined protocol. In this preliminary investigation, adding ferumoxytol-enhanced sequences to gadoxetic acid liver MRI protocol increased the detection rate of CRC hepatic metastases and may aid in preoperative decision making.

Gadoxetic acid-enhanced MRI-derived functional liver imaging score (FLIS) and spleen diameter predict outcomes in ACLD.

Functional liver imaging score (FLIS) - derived from gadoxetic acid-enhanced MRI - correlates with liver function and independently predicts liver-related mortality in patients with chronic liver disease (CLD), while splenic craniocaudal diameter (SCCD) is a marker of portal hypertension. The aim of this study was to investigate the accuracy of a combination of FLIS and SCCD for predicting hepatic decompensation, acute-on-chronic liver failure (ACLF), and mortality in patients with advanced CLD (ACLD). We included 397 patients with CLD who underwent gadoxetic acid-enhanced liver MRI. The FLIS was calculated by summing the points (0-2) of 3 hepatobiliary-phase features: hepatic enhancement, biliary excretion, and portal vein signal intensity. Patients were stratified into 3 groups according to liver fibrosis severity and presence/history of hepatic decompensation: non-ACLD, compensated ACLD (cACLD), and decompensated ACLD (dACLD). SCCD showed excellent intra- and inter-reader agreement. Importantly, SCCD was an independent risk factor for hepatic decompensation in patients with cACLD (per cm; adjusted hazard ratio [aHR] 1.13; 95% CI 1.04-1.23; p= 0.004). Patients with cACLD and a FLIS of 0-3 points and/or a SCCD of >13cm were at increased risk of hepatic decompensation (aHR 3.07; 95% CI 1.43-6.59; p= 0.004). In patients with dACLD, a FLIS of 0-3 was independently associated with an increased risk of ACLF (aHR 2.81; 95% CI 1.16-6.84; p= 0.02), even after adjusting for other prognostic factors. Finally, a FLIS and SCCD-based algorithm was independently predictive of transplant-free mortality and stratified the probability of transplant-free survival (TFS) in ACLD (p <0.001): FLIS 4-6 and SCCD ≤13cm (5-year TFS of 84%) vs. FLIS 4-6 and SCCD >13cm (5-year TFS of 70%) vs. FLIS 0-3 (5-year TFS of 24%). The FLIS and SCCD are simple imaging markers that provide complementary information for risk stratification in patients with compensated and decompensated ACLD. Magnetic resonance imaging (MRI) can be used to assess the state of the liver. Previously the functional liver imaging score, which is based on MRI criteria, was developed as a measure of liver function and to predict the risk of liver-related complications or death. By combining this score with a measurement of spleen diameter, also using MRI, we generated an algorithm that could predict the risk of adverse liver-related outcomes in patients with advanced chronic liver disease.

Deep Learning-Based Automatic Detection and Grading of Motion-Related Artifacts on Gadoxetic Acid-Enhanced Liver MRI.

The aim of this study was to develop and validate a deep learning-based algorithm (DLA) for automatic detection and grading of motion-related artifacts on arterial phase liver magnetic resonance imaging (MRI). Multistep DLA for detection and grading of motion-related artifacts, based on the modified ResNet-101 and U-net, were trained using 336 arterial phase images of gadoxetic acid-enhanced liver MRI examinations obtained in 2017 (training dataset; mean age, 68.6 years [range, 18-95]; 254 men). Motion-related artifacts were evaluated in 4 different MRI slices using a 3-tier grading system. In the validation dataset, 313 images from the same institution obtained in 2018 (internal validation dataset; mean age, 67.2 years [range, 21-87]; 228 men) and 329 from 3 different institutions (external validation dataset; mean age, 64.0 years [range, 23-90]; 214 men) were included, and the per-slice and per-examination performances for the detection of motion-related artifacts were evaluated. The per-slice sensitivity and specificity of the DLA for detecting grade 3 motion-related artifacts were 91.5% (97/106) and 96.8% (1134/1172) in the internal validation dataset and 93.3% (265/284) and 91.6% (948/1035) in the external validation dataset. The per-examination sensitivity and specificity were 92.0% (23/25) and 99.7% (287/288) in the internal validation dataset and 90.0% (72/80) and 96.0% (239/249) in the external validation dataset, respectively. The processing time of the DLA for automatic grading of motion-related artifacts was from 4.11 to 4.22 seconds per MRI examination. The DLA enabled automatic and instant detection and grading of motion-related artifacts on arterial phase gadoxetic acid-enhanced liver MRI.

Outcomes of patients presenting with elevated tumor marker levels but negative gadoxetic acid-enhanced liver MRI after a complete response to hepatocellular carcinoma treatment.

PurposeHepatocellular carcinoma (HCC) patients usually achieve a complete response after treatment. This study was aimed to assess the clinical outcome of HCC patients who had achieved a complete response but later presented with elevated tumor marker levels without an identifiable recurrent tumor on gadoxetic acid-enhanced magnetic resonance imaging (MRI).MethodsWe retrospectively reviewed the clinical outcome of 58 HCC treated patients who had achieved a complete response but later was referred to our institution’s multidisciplinary tumor board for a clinically suspected hidden HCC recurrence based on elevated tumor marker levels but negative gadoxetic acid-enhanced MRI. The imaging studies, tumor markers, and clinical information were reviewed. The total follow-up period was at least 15 months after the initial negative gadoxetic acid-enhanced MRI.ResultsFollow-up imaging studies detected an HCC lesion in 89.7% (n = 52/58) of the patients within the study period, and approximately half of the tumors (46.2%, n = 24/52) developed within 3 months. The most frequent site of recurrence was the liver (86.5%; n = 45/52), but extra-hepatic metastasis was also common (19.2%; n = 10/52). In 5.8% (n = 3/52), HCC reoccurred in the combined form of intra-hepatic and extra-hepatic recurrence. Extra-hepatic metastasis alone occurred in 13.5% (n = 7/52) of patients.ConclusionsHCC frequently recurred within a short interval in patients who achieved a complete response to treatment in the presence of increased tumor marker levels, even if gadoxetic acid-enhanced MRI was negative. Under such circumstances, we suggest a short-term follow-up including, but not limited to, gadoxetic acid-enhanced MRI along with systemic evaluation.

Gadoxetic acid-enhanced MRI for differentiating hepatic sclerosing hemangioma from malignant tumor

BackgroundTo investigate the imaging features of gadoxetic acid-enhanced magnetic resonance imaging (MRI) to differentiate hepatic sclerosing hemangioma from malignant tumors. MethodsThis retrospective case-control study included 18 patients with sclerosing hemangioma and 54 patients with common hepatic malignant tumor, including hepatocellular carcinoma, metastatic adenocarcinoma, and cholangiocarcinoma, who were examined using gadoxetic acid-enhanced liver MRI from January 2008 to June 2019. Imaging features including signal intensity, tumor margins, enhancement pattern, and presence or absence of diffusion restriction were analyzed. Significant MRI features for predicting sclerosing hemangioma were identified using multivariable logistic regression analysis. Diagnostic performances of each imaging feature and combinations of significant imaging features were summarized. ResultsIn the multivariable analysis, irregular margins (odds ratio [OR], 10.12; 95 % confidence interval [CI], 1.27−80.94; p = 0.029), centripetal or internal nodular enhancement in the transitional phase (OR, 13.58; 95 % CI, 1.48−124.82; p = 0.021), and absence of diffusion restriction (OR, 39.20; 95 % CI, 4.82−318.49; p = 0.001) were significant imaging features for the diagnosis of sclerosing hemangioma. Presence of at least two significant imaging features had a sensitivity, specificity, and accuracy of 88.9 %, 96.3 %, and 94.4 %, respectively, for diagnosing sclerosing hemangioma. ConclusionCombinations of two or more of the significant imaging features (irregular margins, centripetal or internal nodular enhancement in the transitional phase, and absence of diffusion restriction) were effective for differentiating hepatic sclerosing hemangioma from malignant tumors using gadoxetic acid-enhanced MRI.

Effects of gadoxetic acid on image quality of arterial multiphase magnetic resonance imaging of liver: comparison study with gadoteric acid-enhanced MRI.

To compare the effects of gadoxetic acid and gadoteric acid on the image quality of single-breath-hold, triple (first, second, and third) arterial hepatic magnetic resonance imaging (MRI). Two hundred and eleven patients were divided into two groups according to the contrast materials used (gadoxetic acid, 108 patients and gadoteric acid, 103 patients). All 3.0-T MR examinations included triple arterial phase acquisition using the 4D enhanced T1-weighted high-resolution isotropic volume examination (eTHRIVE) keyhole technique. The image qualities of the pre-contrast and triple arterial phases were assessed in terms of image artifacts, sharpness of the intrahepatic vessel and liver edge, and overall image quality with a 5-point scale for qualitative analysis. The image quality of gadoxetic acid-enhanced liver MRI in the triple arterial phases was significantly degraded compared with that of gadoteric acid-enhanced liver MRI, although better image scores were observed in the pre-contrastimages in the gadoxetic acid group (P < 0.001). The overall image quality gradually improved from the first to the third arterial phases in both groups (P < 0.003). Intravenous gadoxetic acid could have a detrimental effect on image quality of triple arterial phase MRI with the 4D eTHRIVE Keyhole technique. The third arterial phase images had the best image qualities; thus, they could be used as key scans.

Whole-body MRI added to gadoxetic acid-enhanced liver MRI for detection of extrahepatic disease in patients considered eligible for hepatic resection and/or local ablation of colorectal cancer liver metastases.

Background Fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) can detect extrahepatic disease before local treatment of colorectal liver metastases. Purpose To investigate if whole-body magnetic resonance imaging (MRI) added to gadoxetic acid liver MRI could replace FDG-PET/CT for detection of extrahepatic disease in patients with colorectal liver metastases eligible for hepatic local treatment. Material and Methods This health-research-ethics-committee-approved prospective consecutive diagnostic accuracy study with written informed consent analyzed 79 cases included between 29 June 2015 and 7 February 2017. Whole-body MRI covering the thorax, abdomen, and pelvis and FDG-PET/CT including contrast-enhanced CT was performed 0–3 days before local treatment of liver metastases. Whole-body MR images were read independently by two readers. FDG-PET/CT images were read independently by two pairs of readers. Histopathology and follow-up imaging were used as reference standard. Sensitivities and specificities were calculated and compared including noninferiority analysis. Results Seventy-five malignant lesions and 419 benign lesions were confirmed. Sensitivities of both PET/CT reader pairs 1 and 2 (56.7 and 67.9%) and MRI reader 2 (63.0%) were significantly higher than that of MRI reader 1 (42.7) (P&lt;0.04). Specificities of both PET/CT reader pairs 1 and 2 (92.5 and 92.4%) and MRI reader 1 (91.1%) were significantly higher than that of MRI reader 2 (86.3%) ( P &lt; 0.02). Sensitivity of MRI reader 2 was non-inferior compared to PET/CT reader pair 1. Specificities of both MRI readers were non-inferior to both PET/CT reader pairs. Conclusion For detection of extrahepatic disease in patients with colorectal liver metastases, whole-body MRI was non-inferior to FDG-PET/CT for some reader combinations. However, reader-independent non-inferiority could not be demonstrated.

Experimental studies on artifacts and tumor enhancement on gadoxetic acid-enhanced arterial phase liver MRI in a rabbit VX2 tumor model.

Background Rapid injection of gadoxetic acid is reported to produce more frequent artifacts and lower vascular enhancement on arterial phase liver magnetic resonance imaging (MRI). However, its effect on tumor enhancement and the mechanism of the artifacts remain unclear. Purpose To evaluate the effect of rapid injection of gadoxetic acid on artifacts and tumor enhancement during arterial phase liver MRI, and on arterial blood gases (ABGs) which may explain the cause of the artifacts. Material and Methods ABG analysis was performed in 13 free-breathing rabbits after rapid injection (1 mL/s; injection time = 0.6-0.8 s) of gadoxetic acid (0.025 mmol/kg). Dynamic liver MRI was performed in six anesthetized rabbits with VX2 tumors under a ventilation stoppage after rapid and slow injection (0.25 mL/s; injection time = 2.4-3.2 s) of gadoxetic acid. Artifacts and signal enhancement on arterial phase imaging were compared with those obtained after rapid injection of gadopentetic acid (Gd-DTPA, 0.1 mmol/kg) using a Friedman test or Kruskal-Wallis test. Results ABG analysis did not find any significant changes. Artifacts were not related to injection protocols ( P = 0.95). Aortic enhancement with slow injection of gadoxetic acid was significantly higher than that with rapid injection ( P < 0.05), and was comparable to that with Gd-DTPA injection. Tumor enhancement obtained with gadoxetic acid was not significantly different between rapid and slow injection, and was significantly lower than that with Gd-DTPA injection ( P < 0.05). Conclusion Rapid injection of gadoxetic acid did not affect ABGs and may not be the cause of the artifacts. It lowered vascular enhancement but not arterial tumor enhancement.

Diagnostic Performance of Gadoxetic Acid–enhanced Liver MR Imaging versus Multidetector CT in the Detection of Dysplastic Nodules and Early Hepatocellular Carcinoma

Purpose To compare the diagnostic performance of gadoxetic acid-enhanced liver magnetic resonance (MR) imaging with that of contrast material-enhanced multidetector computed tomography (CT) in the detection of borderline hepatocellular nodules in patients with liver cirrhosis and to determine the Liver Imaging Reporting and Data System (LI-RADS) categories of these detected nodules. Materials and Methods The institutional review board approved this retrospective study and waived the informed consent requirement. Sixty-eight patients with pathologically proven dysplastic nodules (DNs) (low-grade DNs, n = 20; high-grade DNs, n = 17), early hepatocellular carcinomas (HCCs) (n = 42), or progressed HCCs (n = 33) underwent gadoxetic acid-enhanced MR imaging and multidetector CT. An additional 57 patients without any DNs or HCCs in the explanted livers were included as control subjects. Three radiologists independently graded the presence of liver nodules on a five-point confidence scale and assigned LI-RADS categories by using imaging findings. Jackknife alternative free-response receiver operating characteristics (JAFROC) software was used to compare the diagnostic accuracy of each modality in lesion detection. Results Reader-averaged figures of merit estimated with JAFROC software to detect hepatocellular nodules were 0.774 for multidetector CT and 0.842 for MR imaging (P = .002). Readers had significantly higher detection sensitivity for early HCCs with MR imaging than with multidetector CT (78.6% vs 52.4% [P = .001], 71.4% vs 50.0% [P = .011], and 73.8% vs 50.0% [P = .001], respectively). A high proportion of overall detected early HCCs at multidetector CT (59.4%) and MR imaging (72.3%) were categorized as LI-RADS category 4. Most early HCCs (76.2%) and high-grade DNs (82.4%) demonstrated hypointensity on hepatobiliary phase images. In total, 30 more LI-RADS category 4 early HCCs were identified with MR imaging than with multidetector CT across all readers. Conclusion Gadoxetic acid-enhanced MR imaging performed significantly better in the detection of high-risk borderline nodules, especially early HCCs, than did multidetector CT. © RSNA, 2017 Online supplemental material is available for this article.

T2* Mapping from Multi-Echo Dixon Sequence on Gadoxetic Acid-Enhanced Magnetic Resonance Imaging for the Hepatic Fat Quantification: Can It Be Used for Hepatic Function Assessment?

ObjectiveTo evaluate the diagnostic value of T2* mapping using 3D multi-echo Dixon gradient echo acquisition on gadoxetic acid-enhanced liver magnetic resonance imaging (MRI) as a tool to evaluate hepatic function.Materials and MethodsThis retrospective study was approved by the IRB and the requirement of informed consent was waived. 242 patients who underwent liver MRIs, including 3D multi-echo Dixon fast gradient-recalled echo (GRE) sequence at 3T, before and after administration of gadoxetic acid, were included. Based on clinico-laboratory manifestation, the patients were classified as having normal liver function (NLF, n = 50), mild liver damage (MLD, n = 143), or severe liver damage (SLD, n = 30). The 3D multi-echo Dixon GRE sequence was obtained before, and 10 minutes after, gadoxetic acid administration. Pre- and post-contrast T2* values, as well as T2* reduction rates, were measured from T2* maps, and compared among the three groups.ResultsThere was a significant difference in T2* reduction rates between the NLF and SLD groups (−0.2 ± 4.9% vs. 5.0 ± 6.9%, p = 0.002), and between the MLD and SLD groups (3.2 ± 6.0% vs. 5.0 ± 6.9%, p = 0.003). However, there was no significant difference in both the pre- and post-contrast T2* values among different liver function groups (p = 0.735 and 0.131, respectively). A receiver operating characteristic (ROC) curve analysis showed that the area under the ROC curve for using T2* reduction rates to differentiate the SLD group from the NLF group was 0.74 (95% confidence interval: 0.63–0.83).ConclusionIncorporation of T2* mapping using 3D multi-echo Dixon GRE sequence in gadoxetic acid-enhanced liver MRI protocol may provide supplemental information for liver function deterioration in patients with SLD.

Combined hepatocellular-cholangiocarcinoma: Gadoxetic acid-enhanced MRI findings correlated with pathologic features and prognosis.

To evaluate gadoxetic acid-enhanced magnetic resonance imaging (MRI) findings of combined hepatocellular cholangiocarcinoma (cHCC-CC) with special emphasis on correlation of MRI findings with histopathologic tumor characteristics and survival outcomes after curative surgery. Our Institutional Review Board approved this study, with a waiver of informed consent. For 82 patients (64 men, 18 women; mean age, 54.0 years; age range, 30-81) with surgically confirmed cHCC-CCs, we evaluated clinical features, histologic findings, and tumor morphologic and enhancement features on gadoxetic acid-enhanced liver MRI at 1.5T (n = 67) or 3.0T (n = 15). Imaging features of cHCC-CCs were correlated with pathologic findings according to the 2010 World Health Organization classification system. Tumors were categorized as hypervascular or nonhypervascular based on arterial phase enhancement and were compared with respect to overall and recurrence-free survival after curative-intent surgery. Of the 82 lesions, 48 showing global arterial phase enhancement were categorized as the hypervascular group, while 34 lesions demonstrating rim, peripheral, or isoenhancement were categorized as the nonhypervascular group. There was no significant difference in MRI findings between pathologic tumor types (classical type versus stem cell feature type, P = 0.324-1.0). Compared with the nonhypervascular group, the hypervascular group had a larger HCC component (P = 0.014), smaller CC component (P = 0.001), and lesser amount of fibrotic stroma (P = 0.006) on pathologic analysis and was an independent factor associated with better overall survival after surgical resection (P = 0.033). Gadoxetic acid-enhanced MRI findings of cHCC-CCs were diverse, reflecting heterogeneous histologic features. The hypervascular group on MRI is associated with a larger HCC component, smaller CC component, less fibrotic stroma, and better overall survival after curative surgery than the nonhypervascular group. 4 J. MAGN. RESON. IMAGING 2017;46:267-280.

Disappearing or residual tiny (≤5mm) colorectal liver metastases after chemotherapy on gadoxetic acid-enhanced liver MRI and diffusion-weighted imaging: Is local treatment required?

To evaluate the clinical course of disappearing colorectal liver metastases (DLM) or residual tiny (≤5mm) colorectal liver metastases (RTCLM) on gadoxetic acid-enhanced magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) in patients who had colorectal liver metastases (CLM) and received chemotherapy. Among 137 patients who received chemotherapy for CLM and underwent gadoxetic acid-enhanced MRI and DWI between 2010 and 2012, 43 patients with 168 DLMs and 48 RTCLMs were included. The cumulative in situ recurrence rate of DLM and progression rate of RTCLM and their predictive factors were evaluated. A total of 150 DLMs and 26 RTCLMs were followed up without additional treatment. At 1 and 2years, respectively, the cumulative in situ recurrence rates for DLM were 10.9% and 15.7% and the cumulative progression rates for RTCLM were 27.2% and 33.2%. The in situ recurrence rate at 2years was 4.9% for the DLM group that did not show reticular hypointensity of liver parenchyma on hepatobiliary phase. DLM on gadoxetic acid-enhanced liver MRI and DWI indicates a high possibility of clinical complete response, especially in patients without chemotherapy-induced sinusoidal obstruction syndrome. Thirty-three percent of RTCLMs showed progression at 2years. • DLMs on gadoxetic acid-enhanced MRI and DWI showed low recurrence rates. • If there is sinusoidal obstruction syndrome, evaluation of DLM needs special care. • The progression rate for residual tiny CLMs was 33.2% at 2years.

Quantitative Liver Function Analysis: Volumetric T1 Mapping with Fast Multisection B1 Inhomogeneity Correction in Hepatocyte-specific Contrast-enhanced Liver MR Imaging.

Purpose To determine whether B1 inhomogeneity-corrected volumetric T1 maps of gadoxetic acid-enhanced liver magnetic resonance (MR) imaging are able to demonstrate global liver function and functional heterogeneity in patients with cirrhosis and to investigate their relationship with the development of hepatic insufficiency and decompensation. Materials and Methods This institutional review board-approved retrospective study with waiver of informed consent included 234 consecutive patients who underwent gadoxetic acid-enhanced liver MR imaging, including B1 inhomogeneity-corrected volumetric T1 mapping. For all patients, T1 relaxation times of the liver and liver volumes were measured on T1 maps. Liver T1 and functional liver volume-to-weight ratio (liver volume divided by liver T1 and the patient's weight) were compared between Child-Pugh class A and class B cirrhosis. Associations between serum markers, MR parameters, hepatic insufficiency, and decompensation were investigated by using Cox proportional hazards analysis. Results Patients with Child-Pugh class B disease showed significantly longer liver T1 (548.2 msec ± 257.7 vs 372.2 msec ± 77.5, P < .0001) and lower kurtosis of liver T1 (29.1 ± 39.6 vs 43.9 ± 64.9, P = .016) than patients with Child-Pugh class A disease. Prolonged liver T1 (≥462 msec) (hazard ratio [HR], 5.9; 95% confidence interval [CI]: 1.1, 62.8) and an albumin level of less than 3.5 g/dL (HR, 20.7; 95% CI: 3.9, 221.9) were independently associated with the development of hepatic insufficiency. Functional liver volume-to-weight ratio was associated with the development of hepatic decompensation in patients with Child-Pugh class A disease (HR, 0.03; 95% CI: 0.004, 0.23). Conclusion B1 inhomogeneity-corrected volumetric T1 mapping provided information on global liver function and demonstrated functional heterogeneity. In addition, prolonged liver T1 (≥462 msec) was associated with the development of hepatic insufficiency, and functional liver volume-to-weight ratio was negatively related with the development of decompensation in compensated cirrhosis. © RSNA, 2016 Online supplemental material is available for this article.

Diffusion-weighted and hepatobiliary phase gadoxetic acid-enhanced quantitative MR imaging for identification of complete pathologic response in colorectal liver metastases after preoperative chemotherapy.

To evaluate the diagnostic performance of diffusion-weighted imaging (DWI) and gadoxetic acid-enhanced magnetic resonance imaging (MRI) to differentiate colorectal liver metastasis (CRLM) with complete pathologic response from those with incomplete response in patients treated with preoperative chemotherapy. Gadoxetic acid-enhanced liver MRI and DWI were performed after completion of preoperative chemotherapy in patients with CRLM scheduled for liver resection. Metastases were classified as those with complete pathologic response (CR-CRLM) or incomplete response (IR-CRLM) according to postsurgical histopathology. Quantitative analysis was performed on non-contrast-enhanced images and hepatobiliary phase images following gadoxetic acid administration. Apparent diffusion coefficient values (ADC), normalized relative enhancement (NRE), and relative signal intensity difference (RSID) along with their diagnostic measures for detection of CR-CRLM were calculated for all lesions. In 23 patients, 10 CR-CRLM and 35 IR-CRLM (mean diameter, 21.2 mm) were evaluated. In CR-CRLM, ADC was significantly higher after exclusion of the outliers (p = 0.030); and RSID was significantly lower (p = 0.008). Combined indices range of ADC = 1.25-1.9 × 10(-3) mm(2)/s, NRE = 0-35% and RSID <120 had 60% sensitivity and 100% specificity for detection of CR-CRLM. DWI and gadoxetic acid-enhanced MRI appear promising for the detection of CRLM with complete response to preoperative chemotherapy. This could have significant implications for liver resection planning after preoperative chemotherapy.

Quantitative assessment of hepatic function: modified look-locker inversion recovery (MOLLI) sequence for T1 mapping on Gd-EOB-DTPA-enhanced liver MR imaging

To determine whether multislice T1 mapping of the liver using a modified look-locker inversion recovery (MOLLI) sequence on gadoxetic acid-enhanced magnetic resonance imaging (MRI) can be used as a quantitative tool to estimate liver function and predict the presence of oesophageal or gastric varices. Phantoms filled with gadoxetic acid were scanned three times using MOLLI sequence to test repeatability. Patients with chronic liver disease or liver cirrhosis who underwent gadoxetic acid-enhanced liver MRI including MOLLI sequence at 3T were included (n = 343). Pre- and postcontrast T1 relaxation times of the liver (T1liver), changes between pre- and postcontrast T1liver (ΔT1liver), and adjusted postcontrast T1liver (postcontrast T1liver-T1spleen/T1spleen) were compared among Child-Pugh classes. In 62 patients who underwent endoscopy, all T1 parameters and spleen sizes were correlated with varices. Phantom study showed excellent repeatability of MOLLI sequence. As Child-Pugh scores increased, pre- and postcontrast T1liver were significantly prolonged (P < 0.001), and ΔT1liver and adjusted postcontrast T1liver decreased (P < 0.001). Adjusted postcontrast T1liver and spleen size were independently associated with varices (R (2) = 0.29, P < 0.001). T1 mapping of the liver using MOLLI sequence on gadoxetic acid-enhanced MRI demonstrated potential in quantitatively estimating liver function, and adjusted postcontrast T1liver was significantly associated with varices. • T1 mapping using MOLLI sequence can be achieved within a breath-hold. • T1liver measured by MOLLI sequence provided excellent short-term repeatability. • Precontrast and postcontrast T1liver were significantly prolonged as Child-Pugh scores increased. • Adjusted postcontrast T1liver and spleen size were independently associated with varices.

Role of gadoxetic acid-enhanced magnetic resonance imaging in the preoperative evaluation of small hepatic lesions in patients with colorectal cancer.

The initial abdominal computed tomography (CT) scans of patients with colorectal cancer (CRC) sometimes reveal equivocal hepatic lesions. In this study, we evaluated the outcomes of equivocal hepatic lesions found by abdominal CT and the diagnostic accuracy of subsequent liver magnetic resonance imaging (MRI). We evaluated data of patients who underwent CRC resection between January 1, 2009 and December 31, 2009. Equivocal hepatic lesions of <1 cm in size on preoperative staging CT scans were included in this study. Gadoxetic acid-enhanced liver MRI was subsequently performed in all patients. Hepatic lesions that grew during the follow-up period (≥ 3 years) were considered potential metastases. Overall, 121 equivocal hepatic lesions were detected on preoperative staging CT in 65 out of 494 patients (13.2 %) who underwent colorectal surgery. Based on subsequent MRI, 11 lesions were classified as definitive metastatic lesions and 100 were classified as definitive benign lesions, including simple cysts or hemangiomas. Findings in the other 10 lesions were still inconclusive even after examining CT and MRI. Of the 11 lesions that were classified as metastatic by MRI and were resected, 10 were pathologically confirmed as metastases and one lesion was a pathologically benign nodule. All 100 benign lesions were stable on follow-up imaging and were classified as benign. Of the 10 equivocal lesions, 6 increased in size during the follow up, suggesting they were early metastases, while 4 were stable. The sensitivity and specificity for detecting liver metastases by gadoxetic acid-enhanced MRI of small equivocal hepatic lesions found by CT were 100 % (16/16) and 95.2 % (100/105), respectively, if MRI was equivocal or indicated definite metastasis. The negative predictive value was 100 % (100/100). Gadoxetic acid-enhanced MRI is a useful diagnostic tool for assessing equivocal hepatic lesions on preoperative CT of CRC patients that allows increased diagnostic accuracy and detection of additional colorectal liver metastasis lesions.

Fat-suppressed, three-dimensional T1-weighted imaging using high-acceleration parallel acquisition and a dual-echo Dixon technique for gadoxetic acid-enhanced liver MRI at 3 T.

Parallel imaging (PI) techniques are used for overcoming lower spatial and time resolution for magnetic resonance imaging (MRI). There is clinical need to overcome inevitable noise by decreased voxel size and signal-to-noise issue by using high-acceleration factor (AF). To determine whether the combination of a modified Dixon three-dimensional (3D) T1-weighted (T1W) gradient echo technique (mDixon-3D-GRE) and high-acceleration ([HA], AF = 5) PI can provide breath-hold (BH) T1W imaging with better image quality than conventional fat-suppressed 3D-T1W-GRE (SPAIR-3D-GRE) for Gd-EOB-DTPA-enhanced liver MR. This retrospective study was approved by our institutional review board and informed consent was waived. There were 138 patients who underwent Gd-EOB-DTPA-enhanced liver MR at 3 T using either standard SPAIR-3D-GRE sequences with an AF of 2.6 (n = 68, Standard group) or mDixon-3D-GRE with an AF of 5 (n = 70, HA group). In the HA group, hepatobiliary phase was obtained three times using HA-mDixon-3D-GRE (AF = 5), HA-SPAIR-3D-GRE (AF = 5), and standard-SPAIR-3D-GRE (AF = 2.6). Image noise, quality, and anatomic depiction of dynamic phase were compared between standard and HA groups, and those of hepatobiliary phase were compared among the three image sets in HA group. As for dynamic imaging, the HA-mDixon-3D-GRE images showed better anatomic details and overall image quality than standard-SPAIR-3D-GRE sequence (arterial phase: 3.56 ± 0.63 vs. 2.66 ± 0.69, P < 0.001). In the intra-individual comparison, HA-mDixon-3D-GRE provided better orang depiction and overall image quality than standard-SPAIR-3D-GRE (3.99 ± 0.75 vs. 3.0 ± 0.72, P < 0.001) and better fat suppression and significantly less noise than HA-SPAIR-3D-GRE (4.76 ± 0.43 vs. 3.71 ± 0.54, P < 0.001). The combined use of mDixon-3D-GRE sequence and high-acceleration PI provided better quality BH-T1W imaging compared with conventional SPAIR-3D-GRE for Gd-EOB-DTPA-enhanced liver MRI.