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Objective To accurately estimate liver PDFF from chemical shift-encoded (CSE) MRI using a deep learning (DL)-based Multi-Decoder Water-Fat separation Network (MDWF-Net), that operates over complex-valued CSE-MR images with only 3 echoes. Methods The proposed MDWF-Net and a U-Net model were independently trained using the first 3 echoes of MRI data from 134 subjects, acquired with conventional 6-echoes abdomen protocol at 1.5 T. Resulting models were then evaluated using unseen CSE-MR images obtained from 14 subjects that were acquired with a 3-echoes CSE-MR pulse sequence with a shorter duration compared to the standard protocol. Resulting PDFF maps were qualitatively assessed by two radiologists, and quantitatively assessed at two corresponding liver ROIs, using Bland Altman and regression analysis for mean values, and ANOVA testing for standard deviation (STD) (significance level: .05). A 6-echo graph cut was considered ground truth. Results Assessment of radiologists demonstrated that, unlike U-Net, MDWF-Net had a similar quality to the ground truth, despite it considered half of the information. Regarding PDFF mean values at ROIs, MDWF-Net showed a better agreement with ground truth (regression slope = 0.94, R2 = 0.97) than U-Net (regression slope = 0.86, R2 = 0.93). Moreover, ANOVA post hoc analysis of STDs showed a statistical difference between graph cuts and U-Net (p p = .53). Conclusion MDWF-Net showed a liver PDFF accuracy comparable to the reference graph cut method, using only 3 echoes and thus allowing a reduction in the acquisition times. Clinical relevance statement We have prospectively validated that the use of a multi-decoder convolutional neural network to estimate liver proton density fat fraction allows a significant reduction in MR scan time by reducing the number of echoes required by 50%. Key Points • Novel water-fat separation neural network allows for liver PDFF estimation by using multi-echo MR images with a reduced number of echoes. • Prospective single-center validation demonstrated that echo reduction leads to a significant shortening of the scan time, compared to standard 6-echo acquisition. • Qualitative and quantitative performance of the proposed method showed no significant differences in PDFF estimation with respect to the reference technique.

Radiotherapy (RT) is an essential part of breast cancer (BC) treatments. Unfortunately, heart exposure to radiation can also impair the long-term survival of patients. Our study aimed to quantify the oncological benefit and the cardiovascular (CV) risk associated with modern RT in a real-world cohort of BC patients. Our descriptive study enrolled BC patients who received adjuvant RT. Ten-year overall survival (OS) was estimated using Predict® version 2.1 (National Health Service, London, UK). The basal risk of CV events was estimated using the American Heart Association (ACC/AHA) CV score. Treatment volumes and mean cardiac doses were obtained from RT treatment plan records. The increased risk of CV events due to RT was estimated using a model proposed by Darby. The risk of acute myocardial infarction or stroke mortality was estimated using HeartScore® (European Society of Cardiology, Brussels, Belgium). A total of 256 BC patients were included in the study. The average age of patients was 57 years old (range: 25–91); 49.6% had left BC. The mean cardiac dose was 166 cGy (interquartile range (IQR) 94–273); the estimated hazard ratio (HR) for CV disease was HR 1.12 (confidence interval (CI) 1.04–1.24). The estimated baseline 10-year CV risk was 5.6% (0.2 to 51.2); CV risk increased by 0.9% (range 0.02–35.47%) after RT. The absolute risk of 10-year mortality from CV disease was 2.5% (0.1–9); RT was associated with an estimated 4.9% survival benefit (3.73–6.07) against BC death and a 0.23% (0.17–0.29) estimated increase in CV mortality. Modern RT decreased 10-year BC mortality by 4% but increased CV mortality by 0.2% in this cohort. Our findings encourage the implementation of personalized adjuvant RT treatments that balance risks and benefits to improve long-term BC patient survival.

We address the task of automatically generating a medical report from chest X-rays. Many authors have proposed deep learning models to solve this task, but they focus mainly on improving NLP metrics, such as BLEU and CIDEr, which are not suitable to measure clinical correctness in clinical reports. In this work, we propose CNN-TRG, a Template-based Report Generation model that detects a set of abnormalities and verbalizes them via fixed sentences, which is much simpler than other state-of-the-art NLG methods and achieves better results in medical correctness metrics.

Several deep learning architectures have been proposed over the last years to deal with the task of generating a written report given an imaging exam as input. Most works evaluate the generated reports using standard Natural Language Processing (NLP) metrics (e.g. BLEU, ROUGE), reporting significant progress. This article contrast this progress by comparing state of the art (SOTA) models against weak baselines. We show that simple and even naive approaches yield near SOTA performance on most traditional NLP metrics. We conclude that evaluation methods in this task should be further studied towards correctly measuring clinical accuracy, involving physicians to contribute to this end.

Every year physicians face an increasing demand of image-based diagnosis from patients, a problem that can be addressed with recent artificial intelligence methods. In this context, we survey works in the area of automatic report generation from medical images, with emphasis on methods using deep neural networks, with respect to: (1) Datasets, (2) Architecture Design, (3) Explainability and (4) Evaluation Metrics. Our survey identifies interesting developments, but also remaining challenges. Among them, the current evaluation of generated reports is especially weak, since it mostly relies on traditional Natural Language Processing (NLP) metrics, which do not accurately capture medical correctness., Accepted for publication in ACM CSUR

BACKGROUND: Multiparametric magnetic resonance imaging (mpMRI) combining different techniques such as MR elastography (MRE) has emerged as a noninvasive approach to diagnose and stage liver fibrosis with high accuracy allowing for anatomical and functional information. PURPOSE: To assess the diagnostic performance of mpMRI including qualitative and quantitative assessment of MRE, liver surface nodularity (LSN) measurement, hepatic enhancement ratios postgadoxetic acid, and serum markers (APRI, FIB-4) for the detection of liver fibrosis. STUDY TYPE: IRB-approved retrospective. SUBJECTS: Eighty-three adult patients. FIELD STRENGTH/SEQUENCE: 1.5T and 3.0T MR systems. MRE and T1 -weighted postgadoxetic acid sequences. ASSESSMENT: Two independent observers analyzed qualitative color-coded MRE maps on a scale of 0-3. Regions of interest were drawn to measure liver stiffness on MRE stiffness maps and on pre- and postcontrast T1 -weighted images to measure hepatic enhancement ratios. Software was used to generate LSN measurements. Histopathology was used as the reference standard for diagnosis of liver fibrosis in all patients. STATISTICAL TESTS: A multivariable logistic analysis was performed to identify independent predictors of liver fibrosis. Receiver operating characteristic (ROC) analysis evaluated the performance of each imaging technique for detection of fibrosis, in comparison with serum markers. RESULTS: Liver stiffness measured with MRE provided the strongest correlation with histopathologic fibrosis stage (r = 0.74, P < 0.001), and the highest diagnostic performance for detection of stages F2-F4, F3-F4, and F4 (areas under the curve [AUCs] of 0.87, 0.91, and 0.89, respectively, P < 0.001) compared to other methods. Qualitative assessment of MRE maps showed fair to good accuracy for detection of fibrosis (AUC range 0.76-0.84). Multivariable logistic analysis identified liver stiffness and FIB-4 as independent predictors of fibrosis with AUCs of 0.90 (F2-F4), 0.93 (F3-F4) and 0.92 (F4) when combined. DATA CONCLUSION: Liver stiffness measured with MRE showed the best performance for detection of liver fibrosis compared to LSN and gadoxetic acid uptake, with slight improvement when combined with FIB-4. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017.

Review the multiparametric MRI (mpMRI) findings of transition zone (TZ) prostate cancer (PCa) using T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and dynamic contrast-enhanced (DCE) MRI and to integrate mpMRI findings with clinical history, laboratory values, and histopathology. TZ prostate tumors are challenging to detect clinically and at MRI. mpMRI using the combination of sequences has the potential to improve accuracy of TZ cancer detection and staging.

The optimal palliative treatment for unresectable intrahepatic cholangiocarcinoma (ICC) remains controversial. While selective internal radiation therapy (SIRT) using yttrium-90 microspheres is a well-accepted treatment for hepatocellular carcinoma, data related to its use for locally advanced ICC remain relatively scarce. Twenty-nine patients (mean age 66 ± 11 years; 15 female) with unresectable biopsy-proven ICC treated with SIRT between June 2008 and April 2015 were retrospectively evaluated for post-treatment toxicity, overall survival, and imaging response using response evaluation criteria in solid tumors (RECIST) 1.1 criteria. RECIST 1.1 response was evaluable following 26 treatments [complete response (CR):0, partial response (PR):3; stable disease (SD):16, progression of disease (PD):7]. Objective response rate (CR+PR) was 12%. Disease control rate (CR+PR+SD) was 73%. Median time to progression was 5.6 [95% confidence interval (CI): 0-12.0] months. Median survival following SIRT was 9.1 (95% CI: 1.7-16.4) months. Post-treatment survival was prolonged in patients with absence of extrahepatic disease (p = 0.03) and correlated with RECIST 1.1 response (p = 0.02). Toxicities were limited to grade I severity and occurred following 27% of treatments. These findings support the safe, effective use of SIRT for unresectable ICC. Post-treatment survival is prolonged in patients with absence of extrahepatic disease at baseline. RECIST 1.1 response following SIRT for ICC is predictive of survival.

Purpose To quantify Tofts model (TM) and shutter-speed model (SSM) perfusion parameters in prostate cancer (PCa) and noncancerous peripheral zone (PZ) and to compare the diagnostic performance of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to Prostate Imaging and Reporting and Data System (PI-RADS) classification for the assessment of PCa aggressiveness. Materials and Methods Fifty PCa patients (mean age 60 years old) who underwent MRI at 3.0T followed by prostatectomy were included in this Institutional Review Board-approved retrospective study. DCE-MRI parameters (Ktrans, ve, kep [TM&SSM] and intracellular water molecule lifetime τi [SSM]) were determined in PCa and PZ. Differences in DCE-MRI parameters between PCa and PZ, and between models were assessed using Wilcoxon signed-rank tests. Receiver operating characteristic (ROC) analysis for differentiation between PCa and PZ was performed for individual and combined DCE-MRI parameters. Diagnostic performance of DCE-MRI parameters for identification of aggressive PCa (Gleason ≥8, grade group [GG] ≥3 or pathology stage pT3) was assessed using ROC analysis and compared with PI-RADSv2 scores. Results DCE-MRI parameters were significantly different between TM and SSM and between PZ and PCa (P 0.213). Conclusion SSM DCE-MRI did not increase the diagnostic performance of DCE-MRI for PCa characterization. PI-RADS outperformed both TM and SSM DCE-MRI for identification of aggressive cancer. Level of Evidence: 3 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:837–849

Purpose: To assess intra-observer, inter-observer and inter-modality (CT vs. MRI) reproducibility of liver surface nodularity (LSN) scores measured with software used for detection of liver fibrosis. Methods: This IRB-approved retrospective study included patients with both abdominal CT and MRI within 6 months of histopathologic sampling. Two independent observers used post-processing software to quantify LSN scores on axial non-contrast CT (NCT), axial contrast-enhanced CT (CECT), axial T2-weighted (T2W) HASTE, and axial and coronal post-gadoxetic acid T1-weighted (T1W) images obtained during the hepatobiliary phase (HBP). Ten slices were used to acquire the LSN scores. Intra-observer, inter-observer, and inter-modality (CT vs. MRI) reproducibility were assessed with intraclass correlation coefficient (ICC) and coefficients of variability (CV). Accuracy for detection of cirrhosis was evaluated for each technique. Results: 26 patients (M/F 19/7, mean age 57 years), including 7 with cirrhosis (26.9%), were assessed. Technical failure occurred with NCT (1/23, 4.3%) and T2 HASTE (8/28, 28.6%). Intra-observer reproducibility was excellent for NCT, CECT, axial and coronal T1W HBP [ICC â¥Â 0.92, CV â¤Â 8%]. Inter-observer reproducibility was also excellent for NCT and CECT (ICC â¥Â 0.95, CV â¤Â 7.3%) and for coronal T1W HBP (ICC = 0.84, CV = 5.6%). There was fair to moderate agreement between CT and MRI (ICC 0.20â0.44). There were significant differences in mean LSN scores between non-cirrhotic and cirrhotic patients with NCT (2.6 vs. 4.2, p = 0.04) and T1W HBP (3.7 vs. 4.6; p = 0.01) images, with AUCs of 0.81 and 0.82, respectively. Conclusions: LSN measurement is highly reproducible with NCT and post-contrast T1W HBP on MRI, with different results obtained between CT and MRI. Keywords: Liver surface nodularity, Fibrosis, Cirrhosis, CT, MRI

To assess the value of qualitative and quantitative MRI radiomics features for noninvasive prediction of immuno-oncologic characteristics and outcomes of hepatocellular carcinoma (HCC).This retrospective, IRB-approved study included 48 patients with HCC (M/F 35/13, mean age 60y) who underwent hepatic resection or transplant within 4 months of abdominal MRI. Qualitative imaging traits, quantitative nontexture related and texture features were assessed in index lesions on contrast-enhanced T1-weighted and diffusion-weighted images. The association of imaging features with immunoprofiling and genomics features was assessed using binary logistic regression and correlation analyses. Binary logistic regression analysis was also employed to analyse the association of radiomics, histopathologic and genomics features with radiological early recurrence of HCC at 12 months.Qualitative (r = - 0.41-0.40, p 0.042) and quantitative (r = - 0.52-0.45, p 0.049) radiomics features correlated with immunohistochemical cell type markers for T-cells (CD3), macrophages (CD68) and endothelial cells (CD31). Radiomics features also correlated with expression of immunotherapy targets PD-L1 at protein level (r = 0.41-0.47, p 0.029) as well as PD1 and CTLA4 at mRNA expression level (r = - 0.48-0.47, p 0.037). Finally, radiomics features, including tumour size, showed significant diagnostic performance for assessment of early HCC recurrence (AUC 0.76-0.80, p 0.043), while immunoprofiling and genomic features did not (p = 0.098-0929).MRI radiomics features may serve as noninvasive predictors of HCC immuno-oncological characteristics and tumour recurrence and may aid in treatment stratification of HCC patients. These results need prospective validation.• MRI radiomics features showed significant associations with immunophenotyping and genomics characteristics of hepatocellular carcinoma. • Radiomics features, including tumour size, showed significant associations with early hepatocellular carcinoma recurrence after resection.

This multicenter study evaluated the effect of variations in arterial input function (AIF) determination on pharmacokinetic (PK) analysis of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) data using the shutter-speed model (SSM). Data acquired from eleven prostate cancer patients were shared among nine centers. Each center used a site-specific method to measure the individual AIF from each data set and submitted the results to the managing center. These AIFs, their reference tissue-adjusted variants, and a literature population-averaged AIF, were used by the managing center to perform SSM PK analysis to estimate Ktrans (volume transfer rate constant), ve (extravascular, extracellular volume fraction), kep (efflux rate constant), and τi (mean intracellular water lifetime). All other variables, including the definition of the tumor region of interest and precontrast T1 values, were kept the same to evaluate parameter variations caused by variations in only the AIF. Considerable PK parameter variations were observed with within-subject coefficient of variation (wCV) values of 0.58, 0.27, 0.42, and 0.24 for Ktrans, ve, kep, and τi, respectively, using the unadjusted AIFs. Use of the reference tissue-adjusted AIFs reduced variations in Ktrans and ve (wCV = 0.50 and 0.10, respectively), but had smaller effects on kep and τi (wCV = 0.39 and 0.22, respectively). kep is less sensitive to AIF variation than Ktrans, suggesting it may be a more robust imaging biomarker of prostate microvasculature. With low sensitivity to AIF uncertainty, the SSM-unique τi parameter may have advantages over the conventional PK parameters in a longitudinal study.

PURPOSE To assess the value of apparent diffusion coefficient (ADC) measured with diffusion-weighted imaging (DWI) and enhancement ratios (ER) measured with contrast-enhanced T1-weighted imaging (CE-T1WI) for the characterization of histopathologic tumor grade of neuroendocrine tumor liver metastases (NETLM). MATERIALS AND METHODS Twenty-two patients with pathology-proven NETLM and pretreatment 1.5 Tesla (T) and 3T MRI including DWI were included in this Institutional Review Board-approved retrospective study. ADC histogram parameters, including mean, minimum (min), skewness, and kurtosis as well as ER, were computed for all lesions. Tumor grading was based on the World Health Organization 2010 classification. Kruskal-Wallis and Mann-Whitney test were used to assess for differences in ADC and ER between different tumor grades. MRI parameters were correlated with pathologic findings using Spearman correlation test. Receiver operating characteristic analysis was performed to determine optimum thresholds for predicting tumor grade. RESULTS Forty-eight NETLM (mean size 3.5 cm) were analyzed with the following grade distribution: G1 (n = 25), G2 (n = 16), and G3 (n = 7). ADC-mean (×10-3 mm2 /s) of G3 tumors (0.87 ± 0.43) was significantly lower than that of G1 (1.47 ± 0.63) and G2 (1.27 ± 0.63; P = 0.042). A weak significant negative correlation was observed between ADC and tumor grade (ADC-mean: r = -0.33, P = 0.02; ADC-min: r = -0.37, P = 0.01) and Ki-67 (ADC-mean: r = -0.31, P = 0.03; ADC-min: r = -0.39, P = 0.007). AUROC, sensitivity and specificity of ADC-mean/ADC-min/ER (measured at the early arterial phase) for differentiation of G3 versus G1-G2 were 0.80/0.76/0.67, 100%/50%/70%, and 68.4%/84.2%/66.6%, respectively. CONCLUSION ADC is a promising marker for characterization of histopathologic grade of NETLM. These results should be confirmed in a prospective study. J. Magn. Reson. Imaging 2016;44:1432-1441.

Purpose To assess the correlation between intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) metrics in hepatocellular carcinoma (HCC) and liver parenchyma. Materials and Methods Twenty-five patients with HCC (M/F 23/2, mean age 58 years) underwent abdominal MRI at 1.5 or 3.0T, including IVIM-DWI (with 16 b-values) and DCE-MRI (3D FLASH sequence, mean temporal resolution of 2.3 sec). IVIM-DWI parameters (pseudodiffusion coefficient, D*, diffusion coefficient, D, and perfusion fraction, PF) were quantified in HCC lesions and liver parenchyma using a Bayesian fitting algorithm. DCE-MRI parameters (arterial flow, Fa, portal flow, Fp, total flow, Ft, mean transit time, MTT, distribution volume, DV, and arterial fraction, ART) were quantified using a dual-input single-compartment model. Correlations between IVIM-DWI and DCE-MRI parameters were assessed using a Spearman correlation test. Results Thirty-three HCC lesions (average size 5.0 ± 3.6 cm) were analyzed. D, D*, and PF were all significantly lower in HCC vs. liver (P

Purpose. To compare multiparametric (mp)FDG-PET/MRI metrics between hepatocellular carcinoma (HCC) and liver parenchyma and to assess the correlation between mpMRI and FDG-PET standard uptake values (SUVs) in liver parenchyma and HCC. Methods. This prospective, institutional review board-approved study enrolled 15 patients (M/F 12/3; mean age 61 y) with HCC. mpMRI including blood-oxygen-level-dependent (BOLD) MRI, intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI), and dynamic contrast-enhanced-(DCE-) MRI was performed simultaneously with 18F-FDG-PET on a 3T PET/MRI hybrid system. Quantitative BOLD, IVIM and DCE-MRI parameters (Tofts model (TM) and shutter-speed model (SSM)), and PET parameters (SUVmean and SUVmax) were quantified and compared between HCC lesions and liver parenchyma using Wilcoxon signed-rank tests. SUV ratios between HCCs and liver were also calculated (SUVmean T/L and SUVmax T/L). Diagnostic performance of (combined) mp-PET/MRI parameters for characterization of HCC was assessed using ROC analysis. Spearman correlations between PET and mpMRI parameters in HCC tumors and liver parenchyma were evaluated. Results. 21 HCC lesions (mean size 4.0 ± 2.4 cm; range 2–13 cm) were analyzed. HCCs exhibited significantly higher arterial fraction (from DCE-MRI) and lower R2∗ pre-O2 and post-O2 (from BOLD-MRI) versus liver parenchyma (P<0.032). The highest diagnostic performance for differentiation between HCC and liver parenchyma was achieved for combined ART SSM and R2∗ post-O2 (AUC = 0.91). SUVmax showed reasonable performance for differentiation of HCC versus liver (AUC = 0.75). In HCC, DCE-MRI parameters Ktrans (TM and SSM) and ve TM exhibited significant negative correlations with SUVmax T/L (r ranges from −0.624 to −0.566; FDR-adjusted P<0.050). Conclusions. Despite the observed reasonable diagnostic performance of FDG-PET SUVmax for HCC detection and several significant correlations between FDG-PET SUV and DCE-MRI parameters, FDG-PET did not provide clear additional value for HCC characterization compared to mpMRI in this pilot study.

To assess the diagnostic value of a 3D dual-flip-angle (DFA) T1 mapping technique with whole liver coverage before and after gadoxetic acid injection for assessment of cirrhosis and liver function, compared to blood tests (APRI: aspartate aminotransferase-to-platelet ratio index).A total of 133 patients who underwent gadoxetic acid-enhanced liver MRI including a 3D FLASH DFA-T1 mapping sequence before and 20min post-contrast (hepatobiliary phase, HBP) were included in this retrospective IRB approved study. T1 values (msec) were measured on pre-contrast and during HBP in liver parenchyma, ΔT1 (%) was calculated as [(T1 pre-T1 post)/T1 pre]×100. T1 and ΔT1 values were compared between cirrhotic and non-cirrhotic patients and between patients stratified using Child-Pugh and Model for End-Stage Liver Disease (MELD) scores using Mann-Whitney U test. Diagnostic performance of T1 mapping parameters vs. APRI for diagnosing cirrhosis and for assessing degree of liver dysfunction was evaluated using ROC analysis.Fifty non-cirrhotic and 83 cirrhotic patients [Child-Pugh A (n=41), B (n=31) and C (n=11)] were included. There was no significant difference in pre-contrast T1 values between cirrhotic and non-cirrhotic patients. T1-HBP and ΔT1 values were significantly different in patients with cirrhosis (p0.0001) and higher MELD scores (17) (p=0.003). ΔT1 showed significant strong correlations with Child-Pugh and MELD scores (r=-0.7, p0.0001; r=-0.56, p0.001 respectively). Similar AUCs (p=0.9) for detection of liver cirrhosis were observed for T1 HBP (0.83), ΔT1 (0.86) and APRI (0.85); however APRI showed limited sensitivity (≤55%) in comparison with ΔT1 (74.7%) and T1 HBP (80.7%).3D DFA-T1 mapping sequence used before and after gadoxetic acid injection is useful for the diagnosis of cirrhosis and for the assessment of liver function.

Purpose To assess interplatform reproducibility of liver stiffness (LS) and spleen stiffness (SS) measured with magnetic resonance elastography (MRE) based on a 2D gradient echo (GRE) sequence. Materials and Methods This prospective Health Insurance Portability and Accountability Act (HIPAA)-compliant and Institutional Review Board (IRB)-approved study involved 12 subjects (five healthy volunteers and seven patients with liver disease). A multislice 2D-GRE-based MRE sequence was performed using two systems from different vendors (3.0T GE and 1.5T Siemens) on the same day. Two independent observers measured LS and SS on confidence maps. Bland–Altman analysis (with coefficient of reproducibility, CR), coefficient of variability (CV), and intraclass correlation (ICC) were used to analyze interplatform, intra- and interobserver variability. Human data were validated using a gelatin-based phantom. Results There was excellent reproducibility of phantom stiffness measurement (CV 4.4%). Mean LS values were 3.44–3.48 kPa and 3.62–3.63 kPa, and mean SS values were 7.54–7.91 kPa and 8.40–8.85 kPa at 3.0T and 1.5T for observers 1 and 2, respectively. The mean CVs between platforms were 9.2%–11.5% and 13.1%–14.4% for LS and SS, respectively, for observers 1 and 2. There was excellent interplatform reproducibility (ICC >0.88 and CR 0.99, CV 0.97, CV and CR

Purpose To quantify baseline relaxation rates R2* and R1 in the abdomen, their changes after respiratory challenges, and their reproducibility in healthy volunteers and patients with hepatocellular carcinoma (HCC) at 1.5T and 3.0T. Materials and Methods R2* measurements were acquired in the liver in 8 volunteers and 27 patients with 34 HCCs using multiecho T2* at baseline and after respiratory challenges with 100% oxygen (O2) and carbogen (CB = 95%O2/5%CO2). R1 was measured at 1.5T in one volunteer and 21 patients with 23 HCCs. Test–retest coefficient of variation (CV) was assessed in 10 subjects. Intra- and interobserver variability of R2* and R1 measurements was assessed in 12 and 10 patients, respectively. Parameters for HCC, liver, and muscle were compared between baseline and after gas challenges. Results We observed that R2* and R1 imaging of HCCs with O2 and CB is feasible and reproducible (test–retest CV R2* 0.88/R1>0.7 and CV R2*

Purpose To assess the diagnostic value of MRI using dual-echo (2PD) and triple-echo (3PD) chemical shift imaging for liver fat quantification against multi-echo T2 corrected MR spectroscopy (MRS) used as the reference standard, and examine the effect of T2* imaging on accuracy of MRI for fat quantification. Materials and methods Patients who underwent 1.5 T liver MRI that incorporated 2PD, 3PD, multi-echo T2* and MRS were included in this IRB approved prospective study. Regions of interest were placed in the liver to measure fat fraction (FF) with 2PD and 3PD and compared with MRS-FF. A random subset of 25 patients with a wide range of MRS-FF was analyzed with an advanced FF calculation method, to prove concordance with the 3PD. The statistical analysis included correlation stratified according to T2*, Bland-Altman analysis, and calculation of diagnostic accuracy for detection of MRS-FF > 6.25%. Results 220 MRI studies were identified in 217 patients (mean BMI 28.0 ± 5.6). 57/217 (26.2%) patients demonstrated liver steatosis (MRS-FF > 6.25%). Bland-Altman analysis revealed strong agreement between 3PD and MRS (mean ± 1.96 SD: −0.5% ± 4.6%) and weaker agreement between 2PD and MRS (4.7% ± 16.0%). Sensitivity of 3PD for diagnosing FF> 6.25% was higher than that of 2PD. 3PD-FF showed minor discrepancies (coefficient of variation

To develop a highly accelerated phase-contrast cardiac-gated volume flow measurement (four-dimensional [4D] flow) magnetic resonance (MR) imaging technique based on spiral sampling and dynamic compressed sensing and to compare this technique with established phase-contrast imaging techniques for the quantification of blood flow in abdominal vessels.This single-center prospective study was compliant with HIPAA and approved by the institutional review board. Ten subjects (nine men, one woman; mean age, 51 years; age range, 30-70 years) were enrolled. Seven patients had liver disease. Written informed consent was obtained from all participants. Two 4D flow acquisitions were performed in each subject, one with use of Cartesian sampling with respiratory tracking and the other with use of spiral sampling and a breath hold. Cartesian two-dimensional (2D) cine phase-contrast images were also acquired in the portal vein. Two observers independently assessed vessel conspicuity on phase-contrast three-dimensional angiograms. Quantitative flow parameters were measured by two independent observers in major abdominal vessels. Intertechnique concordance was quantified by using Bland-Altman and logistic regression analyses.There was moderate to substantial agreement in vessel conspicuity between 4D flow acquisitions in arteries and veins (κ = 0.71 and 0.61, respectively, for observer 1; κ = 0.71 and 0.44 for observer 2), whereas more artifacts were observed with spiral 4D flow (κ = 0.30 and 0.20). Quantitative measurements in abdominal vessels showed good equivalence between spiral and Cartesian 4D flow techniques (lower bound of the 95% confidence interval: 63%, 77%, 60%, and 64% for flow, area, average velocity, and peak velocity, respectively). For portal venous flow, spiral 4D flow was in better agreement with 2D cine phase-contrast flow (95% limits of agreement: -8.8 and 9.3 mL/sec, respectively) than was Cartesian 4D flow (95% limits of agreement: -10.6 and 14.6 mL/sec).The combination of highly efficient spiral sampling with dynamic compressed sensing results in major acceleration for 4D flow MR imaging, which allows comprehensive assessment of abdominal vessel hemodynamics in a single breath hold.

OBJECTIVE. The objective of our study was to evaluate the performance of a high-spatial-resolution 2D phase-contrast (PC) MRI technique accelerated with compressed sensing for portal vein (PV) and hepatic artery (HA) flow quantification in comparison with a standard PC MRI sequence. SUBJECTS AND METHODS. In this prospective study, two PC MRI sequences were compared, one with parallel imaging acceleration and low spatial resolution (generalized autocalibrating partial parallel acquisition [GRAPPA]) and one with compressed sensing acceleration and high spatial resolution (sparse). Seventy-six patients were assessed, including 37 patients with cirrhosis. Two observers evaluated PC image quality. Quantitative analyses yielded a mean velocity, flow, and vessel area for the PV and HA and an arterial fraction. The PC techniques were compared using the paired Wilcoxon test and Bland-Altman statistics. The sensitivity of the flow parameters to the severity of cirrhosis was also assessed. RESULTS. Vessel delineation was significantly improved using the PC sparse sequence (p < 0.034). For both in vitro and in vivo measurements, PC sparse yielded lower estimates for vessel area and flow, and larger differences between PC GRAPPA and PC sparse were observed in the HA. PV velocity and flow were significantly lower in patients with cirrhosis on both PC sparse (p < 0.001 and p = 0.042, respectively) and PC GRAPPA (p < 0.001 and p = 0.005, respectively). PV velocity correlated negatively with Child-Pugh class (r = -0.50, p < 0.001), whereas the arterial fraction measured with PC sparse was higher in patients with Child-Pugh class B or C disease than in those with Child-Pugh class A disease, with a trend toward significance (p = 0.055). CONCLUSION. A high-spatial-resolution highly accelerated compressed sensing technique (PC sparse) allows total hepatic blood flow measurements obtained in 1 breath-hold, provides improved delineation of the hepatic vessels compared with a standard PC MRI sequence (GRAPPA), and can potentially be used for the noninvasive assessment of liver cirrhosis.

Purpose To compare intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) of the liver between 1.5T and 3.0T in terms of parameter quantification and inter-platform reproducibility. Materials and methods In this IRB approved prospective study, 19 subjects (17 patients with chronic liver disease and 2 healthy volunteers) underwent two repeat scans at 1.5T and 3.0T. Each scan included IVIM DWI using 16 b values from 0 to 800s/mm 2 . A single observer measured IVIM parameters for each platform and estimated signal to noise ratio (eSNR) at b 0, 200, 400 and 800s/mm 2 . Wilcoxon paired tests were used to compare liver eSNR and IVIM parameters. Inter-platform reproducibility was assessed by calculating within-subject coefficient of variation (CV) and Bland–Altman limits of agreement. An ice water phantom was used to test ADC variability between the two MRI systems. Results The mean invitro difference in ADC between the two platforms was 6.8%. eSNR was significantly higher at 3.0T for all selected b values ( p =0.006–0.020), except for b 0 ( p =0.239). Liver IVIM parameters were significantly different between 1.5T and 3.0T ( p =0.005–0.044), except for ADC ( p =0.748). The inter-platform reproducibility of true diffusion coefficient ( D ) and ADC were good, with mean CV of 10.9% and 11.1%, respectively. Perfusion fraction (PF) and pseudodiffusion coefficient ( D *) showed more limited inter-platform reproducibility (mean CV of 22.6% for PF and 46.9% for D *). Conclusion Liver D and ADC values showed good reproducibility between 1.5T and 3.0T platforms; while there was more variability in PF, and large variability in D * parameters between the two platforms. These findings may have implications for drug trials assessing the role of IVIM DWI in tumor response and liver fibrosis.

To correlate qualitative and quantitative diffusion weighted imaging (DWI) characteristics of intrahepatic cholangiocarcinoma (ICC) with histopathologic tumour grade and fibrosis content. Fifty-one patients (21M/30F; mean age 61y) with ICC and MRI including DWI were included in this IRB-approved multicentre retrospective study. Qualitative tumour features were assessed. Tumour apparent diffusion coefficient (ADC) mean, minimum, and normalized (nADCliver) values were computed. Tumour grade [well(G1), moderately(G2), or poorly differentiated(G3)] and tumour fibrosis content [minimal(1), moderate(2), or abundant(3)] were categorized pathologically. Imaging findings and ADC values were compared with pathologic measures. Utility of ADC values for predicting tumour grade was assessed using ROC analysis. 51 ICCs (mean size 6.5±1.1 cm) were assessed. 33/51(64%) of ICCs demonstrated diffuse hyperintensity and 15/51(29%) demonstrated target appearance on DWI. Infiltrative morphology (p=0.02) and tumour size (p=0.04) were associated with G3. ADCmean and nADCmean of G3 (1.32±0.47x10-3 mm2/sec and 0.97±0.95) were lower than G1+G2 (1.57±0.39x10-3 mm2/sec and 1.24±0.49; p=0.03 and p=0.04). ADCmean and nADCmean were inversely correlated with tumour grade (p

Multiparametric magnetic resonance imaging (mpMRI) combining different techniques such as MR elastography (MRE) has emerged as a noninvasive approach to diagnose and stage liver fibrosis with high accuracy allowing for anatomical and functional information.To assess the diagnostic performance of mpMRI including qualitative and quantitative assessment of MRE, liver surface nodularity (LSN) measurement, hepatic enhancement ratios postgadoxetic acid, and serum markers (APRI, FIB-4) for the detection of liver fibrosis.IRB-approved retrospective.Eighty-three adult patients.1.5T and 3.0T MR systems. MRE and TTwo independent observers analyzed qualitative color-coded MRE maps on a scale of 0-3. Regions of interest were drawn to measure liver stiffness on MRE stiffness maps and on pre- and postcontrast TA multivariable logistic analysis was performed to identify independent predictors of liver fibrosis. Receiver operating characteristic (ROC) analysis evaluated the performance of each imaging technique for detection of fibrosis, in comparison with serum markers.Liver stiffness measured with MRE provided the strongest correlation with histopathologic fibrosis stage (r = 0.74, P0.001), and the highest diagnostic performance for detection of stages F2-F4, F3-F4, and F4 (areas under the curve [AUCs] of 0.87, 0.91, and 0.89, respectively, P0.001) compared to other methods. Qualitative assessment of MRE maps showed fair to good accuracy for detection of fibrosis (AUC range 0.76-0.84). Multivariable logistic analysis identified liver stiffness and FIB-4 as independent predictors of fibrosis with AUCs of 0.90 (F2-F4), 0.93 (F3-F4) and 0.92 (F4) when combined.Liver stiffness measured with MRE showed the best performance for detection of liver fibrosis compared to LSN and gadoxetic acid uptake, with slight improvement when combined with FIB-4.3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:1552-1561.

This study evaluates the performance of various magnetic resonance imaging (MRI) response criteria for the prediction of complete pathologic necrosis (CPN) of hepatocellular carcinoma (HCC) post locoregional therapy (LRT) using explant pathology as a reference.We included 61 patients (male/female 46/15; mean age 60years) who underwent liver transplantation after LRT with transarterial chemoembolization plus radiofrequency or microwave ablation (n=56), orA total of 97HCCs (mean size 2.3±1.3cm) including 28 with CPN were evaluated. There was excellent inter-reader agreement (ICC 0.77-0.86, all methods). EASL, mRECIST, percentage of necrosis and qualitative DWI were all significant (p0.001) predictors of CPN, while RECIST and ADC were not. EASL, mRECIST and percentage of necrosis performed similarly (area under the curves [AUCs] 0.810-0.815) while the performance of qualitative DWI was lower (AUC 0.622). Image subtraction demonstrated the strongest correlation (r=0.71-0.72, p0.0001) with pathologic degree of tumor necrosis.EASL/mRECIST criteria and image subtraction have excellent diagnostic performance for predicting CPN in HCC treated with LRT, with image subtraction correlating best with pathologic degree of tumor necrosis. Thus, MR image subtraction is recommended for assessing HCC response to LRT.The assessment of hepatocellular carcinoma (HCC) tumor necrosis after locoregional therapy is essential for additional treatment planning and estimation of outcome. In this study, we assessed the performance of various magnetic resonance imaging (MRI) response criteria (RECIST, mRECIST, EASL, percentage of necrosis on subtraction images, and diffusion-weighted imaging) for the prediction of complete pathologic necrosis of HCC post locoregional therapy on liver explant. Patients who underwent liver transplantation after locoregional therapy were included in this retrospective study. All patients underwent routine liver MRI within 90days of liver transplantation. EASL/mRECIST criteria and image subtraction had excellent diagnostic performance for predicting complete pathologic necrosis in treated HCC, with image subtraction correlating best with pathologic degree of tumor necrosis.

Background and AimsRecently, smooth muscle hypertrophy has been suggested to be a contributor to small bowel lesions secondary to Crohn’s disease [CD], in addition to inflammation and fibrosis. Here, we assess the value of magnetic resonance imaging [MRI] for the characterisation of histopathological tissue composition of small bowel CD, including inflammation, fibrosis, and smooth muscle hypertrophy.MethodsA total of 35 consecutive patients [male/female 17/18, mean age 33 years] with ileal CD, who underwent small bowel resection and a preoperative contrast-enhanced MRI examination within 1 month before surgery, were retrospectively included. Image assessment included qualitative [pattern/degree of enhancement, presence of ulcerations/fistulas/abscesses] and quantitative parameters [wall thickness on T2/T1-weighted images [WI], enhancement ratios, apparent diffusion coefficient [ADC], Clermont and Magnetic Resonance Index of Activity [MaRIA] scores). MRI parameters were compared with histopathological findings including active inflammation, collagen deposition, and muscle hypertrophy using chi square/Fisher or Mann-Whitney tests and univariate/multivariate logistic/linear regression analyses.ResultsForty ileal segments were analysed in 35 patients. Layered pattern at early-post-contrast phase was more prevalent (odds ratio [OR] = 8; p = 0.008), ADC was significantly lower [OR = 0.005; p = 0.022], and MaRIA score was significantly higher [OR = 1.125; p = 0.022] in inflammation grades 2–3 compared with grade 1. Wall thickness on T2WI was significantly increased [OR = 1.688; p = 0.043], and fistulas [OR = 14.5; p = 0.017] were more prevalent in segments with disproportionately increased muscle hypertrophy versus those with disproportionately increased fibrosis. MaRIA/Clermont scores, wall thickness on T1WI and T2WI, and ADC were all significantly correlated with degree of muscular hypertrophy.ConclusionsMRI predicts the degree of inflammation, and can distinguish prominent muscle hypertrophy from prominent fibrosis in ileal CD with reasonable accuracy (area under receiver operating characteristic curve [AUROC] > 0.7).

The aim of the study was to correlate tumor stiffness (TS) measured with MR elastography (MRE) with degree of tumor enhancement and necrosis on contrast-enhanced T1-weighted imaging (CE-T1WI) in hepatocellular carcinomas (HCC) treated with Yttrium-90 radioembolization (RE) or transarterial chemoembolization plus radiofrequency ablation (TACE/RFA). This retrospective study was IRB-approved and the requirement for informed consent was waived. 52 patients (M/F 38/14, mean age 67 years) with HCC who underwent RE (n = 22) or TACE/RFA (n = 30) and 11 controls (M/F 6/5, mean age 64 years) with newly diagnosed untreated HCC were included. The MRI protocol included a 2D MRE sequence. TS and LS (liver stiffness) were measured on stiffness maps. Degree of tumor necrosis was assessed on subtraction images by two observers, and tumor enhancement ratios (ER) were calculated on CE-T1WI by one observer. 63 HCCs (mean size 3.2 ± 1.6 cm) were evaluated. TS was significantly lower in treated vs. untreated tumors (3.9 ± 1.8 vs. 6.9 ± 3.4 kPa, p = 0.006) and also compared to LS (5.3 ± 2.2 kPa, p = 0.002). There were significant correlations between TS and each of enhancement ratios (r = 0.514, p = 0.0001), and percentage of necrosis (r = −0.540, p = 0.0001). The observed correlations were stronger in patients treated with RE (TS vs. ER, r = 0.636, TS vs. necrosis, r = −0.711, both p = 0.0001). Percentage of necrosis and T1-signal in native T1WI were significant independent predictors of TS (p = 0.0001 and 0.001, respectively). TS measured with MRE shows a significant correlation with tumor enhancement and necrosis, especially in HCCs treated with RE.

Objective To assess whether horizontal vs vertical bolster orientation affects kidney position during prone percutaneous nephrolithotomy as this could impact the need for supracostal access and therefore the likelihood of pleural injury. Materials and Methods In a prospective trial, 10 subjects with 20 renal units underwent magnetic resonance imaging in prone position with standard cylindrical bolsters oriented vertically and then horizontally. Vertical bolsters were placed along the lateral aspect of the chest. Horizontal bolsters were placed at the xiphoid and symphysis pubis. The position of the kidney relative to the pleura was assessed by measuring distances from the kidney upper pole to diaphragm, to the top of the first lumbar vertebra, and inferior-most rib. Nephrostomy tract length and tract proximity to adjacent organs were also measured. Results Right and left kidney-to-diaphragm distance significantly increased with horizontal vs vertical bolsters by 3.44 cm and 1.86 cm, respectively ( P = .02, P = .01). Right kidney-to-rib distance significantly increased by 2.4 cm ( P = .025); left kidney-to-rib distance increased by 0.5 cm ( P = .123). Right kidney-to-vertebral distance significantly increased by 2.16 cm ( P = .007); left kidney-to-vertebral distance increased by 0.9 cm ( P = .059). There was no significant difference in maximum access angle, overall tract length, or colon position between horizontal and vertical bolsters. Conclusion Orienting bolsters horizontally results in caudal kidney displacement without affecting access angle, overall tract length, or colon position. In comparison with vertical orientation, this may improve safety of percutaneous nephrolithotomy by decreasing the need for supracostal access and increasing the safety of supracostal access when required.

Purpose: The purpose of this study was to evaluate the diagnostic performance of a “simulated” abbreviated MRI (AMRI) protocol using diffusion-weighted imaging (DWI) and T1-weighted (T1w) imaging obtained at the hepatobiliary phase (HBP) post gadoxetic acid injection alone and in combination, compared to dynamic contrast-enhanced (CE)-T1w imaging for the detection of hepatocellular carcinoma (HCC). Methods: This was an IRB approved HIPAA compliant retrospective single institution study including patients with liver disease who underwent gadoxetic acid-enhanced MRI for HCC diagnosis. Three independent observers assessed 2 sets of images (full CE-set and AMRI including DWI+T1w-HBP). Diagnostic performance of T1w-HBP and DWI alone and in combination was compared to that of CE-set. All imaging sets included unenhanced T1w and T2w sequences. A preliminary analysis was performed to assess cost savings of AMRI protocol compared to a full MRI study. Results: 174 patients including 62 with 80 HCCs were assessed. Equivalent per-patient sensitivity and negative predictive value (NPV) were observed for DWI (85.5% and 92.2%, pooled data) and T1w-HBP (89.8% and 94.2%) (P = 0.1–0.7), while these were significantly lower for the full AMRI protocol (DWI+T1w-HBP, 80.6% and 80%, P = 0.02) when compared to CE-set (90.3% and 94.9%). Higher specificity and positive predictive value were observed for CE-set vs. AMRI (P = 0.02). The estimated cost reduction of AMRI versus full MRI ranged between 30.7 and 49.0%. Conclusion: AMRI using DWI and T1w-HBP has a clinically acceptable sensitivity and NPV for HCC detection. This could serve as the basis for a future study assessing AMRI for HCC screening and surveillance. © 2016, Springer Science+Business Media New York.

Tumour heterogeneity poses a significant challenge for treatment stratification. The goals of this study were to quantify heterogeneity in hepatocellular carcinoma (HCC) using multiparametric magnetic resonance imaging (mpMRI), and to report preliminary data correlating quantitative MRI parameters with advanced histopathology and gene expression in a patient subset. Thirty-two HCC patients with 39 HCC lesions underwent mpMRI including diffusion-weighted imaging (DWI), blood-oxygenation-level-dependent (BOLD), tissue-oxygenation-level-dependent (TOLD) and dynamic contrast-enhanced (DCE)-MRI. Histogram characteristics [central tendency (mean, median) and heterogeneity (standard deviation, kurtosis, skewness) MRI parameters] in HCC and liver parenchyma were compared using Wilcoxon signed-rank tests. Histogram data was correlated between MRI methods in all patients and with histopathology and gene expression in 14 patients. HCCs exhibited significantly higher intra-tissue heterogeneity vs. liver with all MRI methods (P GLUL, pharmacological target FGFR4, stemness markers EPCAM and KRT19 and immune checkpoint PDCD1. Histogram analysis combining central tendency and heterogeneity mpMRI features is promising for non-invasive HCC characterization on the imaging, histologic and genomics levels.

To compare MR elastography (MRE) using a single and a dual driver excitation for the quantification of hepatic and splenic stiffness (HS and SS), and to investigate the performance of HS and SS measured with single or dual driver excitation for the detection of liver cirrhosis in subjects with liver disease.This prospective HIPAA compliant and IRB approved study involved 49 subjects who underwent MRE at 3.0T, comparing three different acquisition methods (single driver on the liver, single driver on the spleen and dual driver acoustic excitation). A Mann-Whitney test was used to assess changes in stiffness values. Bland-Altman analysis was used to compare single and dual driver configurations for each organ. Performance for detection of liver cirrhosis was assessed using ROC analysis. Pearson correlation was used to estimate the dependence of HS and SS on spleen size.There were 40 noncirrhotic and 9 cirrhotic patients. There was good agreement between stiffness values measured with a single or a dual driver (Bland-Altman limits of agreement -14.3 % to 18.9 % and -18.1 % to 29.7 %, CV 6.4 % and 9.4 %, for HS and SS. respectively). HS and SS were higher in subjects with liver cirrhosis (p0.001), with excellent detection performance (AUROC range 0.87-0.93). SS correlated strongly with spleen size (r = 0.69, p0.001), while HS showed weak correlation (r = 0.38, p = 0.006).Using a dual acoustic driver configuration, hepatic and splenic stiffness can be simultaneously estimated with good concordance with single driver measurement.

Purpose To evaluate short-term test–retest and interobserver reproducibility of IVIM (intravoxel incoherent motion) diffusion parameters and ADC (apparent diffusion coefficient) of hepatocellular carcinoma (HCC) and liver parenchyma at 3.0T. Materials and Methods In this prospective Institutional Review Board (IRB)-approved study, 11 patients were scanned twice using a free-breathing single-shot echo-planar-imaging, diffusion-weighted imaging (DWI) sequence using 4 b values (b = 0, 50, 500, 1000 s/mm2) and IVIM DWI using 16 b values (0–800 s/mm2) at 3.0T. IVIM parameters (D: true diffusion coefficient, D*: pseudodiffusion coefficient, PF: perfusion fraction) and ADC (using 4 b and 16 b) were calculated. Short-term test–retest and interobserver reproducibility of IVIM parameters and ADC were assessed by measuring correlation coefficient, coefficient of variation (CV), and Bland–Altman limits of agreements (BA-LA). Results Fifteen HCCs were assessed in 10 patients. Reproducibility of IVIM metrics in HCC was poor for D* and PF (mean CV 60.6% and 37.3%, BA-LA: −161.6% to 135.3% and −66.2% to 101.0%, for D* and PF, respectively), good for D and ADC (CV 19.7% and

To quantify Tofts model (TM) and shutter-speed model (SSM) perfusion parameters in prostate cancer (PCa) and noncancerous peripheral zone (PZ) and to compare the diagnostic performance of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to Prostate Imaging and Reporting and Data System (PI-RADS) classification for the assessment of PCa aggressiveness.Fifty PCa patients (mean age 60 years old) who underwent MRI at 3.0T followed by prostatectomy were included in this Institutional Review Board-approved retrospective study. DCE-MRI parameters (KDCE-MRI parameters were significantly different between TM and SSM and between PZ and PCa (P0.037). Diagnostic performances of TM and SSM for differentiation of PCa from PZ were similar (highest AUC TM: KSSM DCE-MRI did not increase the diagnostic performance of DCE-MRI for PCa characterization. PI-RADS outperformed both TM and SSM DCE-MRI for identification of aggressive cancer.3 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:837-849.

OBJECTIVE The aim of this study was to compare 2-dimensional (2D) gradient recalled echo (GRE) and 2D spin echo echoplanar imaging (SE-EPI) magnetic resonance elastography (MRE) sequences of the liver in terms of image quality and quantitative liver stiffness (LS) measurement. MATERIALS AND METHODS This prospective study involved 50 consecutive subjects (male/female, 33/17; mean age, 58 years) who underwent liver magnetic resonance imaging at 3.0 T including 2 MRE sequences, 2D GRE, and 2D SE-EPI (acquisition time 56 vs 16 seconds, respectively). Image quality scores were assessed by 2 independent observers based on wave propagation and organ coverage on the confidence map (range, 0-15). A third observer measured LS on stiffness maps (in kilopascal). Mean LS values, regions of interest size (based on confidence map), and image quality scores between SE-EPI and GRE-MRE were compared using paired nonparametric Wilcoxon test. Reproducibility of LS values between the 2 sequences was assessed using intraclass coefficient correlation, coefficient of variation, and Bland-Altman limits of agreement. T2* effect on image quality was assessed using partial Spearman correlation. RESULTS There were 4 cases of failure with GRE-MRE and none with SE-EPI-MRE. Image quality scores and region of interest size were significantly higher using SE-EPI-MRE versus GRE-MRE (P < 0.0001 for both measurements and observers). Liver stiffness measurements were not significantly different between the 2 sequences (3.75 ± 1.87 kPa vs 3.55 ± 1.51 kPa, P = 0.062), were significantly correlated (intraclass coefficient correlation, 0.909), and had excellent reproducibility (coefficient of variation, 10.2%; bias, 0.023; Bland-Altman limits of agreement, -1.19; 1.66 kPa). Image quality scores using GRE-MRE were significantly correlated with T2* while there was no correlation for SE-EPI-MRE. CONCLUSIONS Our data suggest that SE-EPI-MRE may be a better alternative to GRE-MRE. The diagnostic performance of SE-EPI-MRE for detection of liver fibrosis needs to be assessed in a future study.