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Objective: To test the hypothesis that there is a measureable upward motion of the diaphragm during prolonged breath-holds that could have a detrimental effect on image quality in liver MRI and to identify factor that potentially influence the magnitude of this motion. Methods: 15 healthy volunteers underwent MRI examination using prolonged breath-holds in the maximum inspiratory position and a moderate inspiratory position. Coronal T1 weighted three-dimensional gradient echo sequences of the entire thorax were acquired every 6 s during breath-holding allowing the calculation of total lung volume and the measurement of the absolute position of the dome of the liver. The potential impact of subject’s gender, body mass index, and total lung capacity on the change in lung volume/diaphragmatic motion was assessed using random coefficient regression. Results: All volunteers demonstrated a slow reduction of the total lung volume during prolonged breath-holding up to 123 ml. There was a measurable associated upward shift of the diaphragm, measuring up to 5.6 mm after 24 s. There was a positive correlation with female gender (p = 0.037) and total lung volume (p = 0.005) and a negative association with BMI (p = 0.012) for the maximum inspiratory position only. Conclusion: There is a measureable reduction of lung volumes with consecutive upward shift of the diaphragm during prolonged breath-holding which likely contributes to motion artifacts in liver MRI. Advances in knowledge: There is a measureable gas exchange-related reduction of lung volumes with consecutive upward shift of the diaphragm during prolonged breath-holding which likely contributes to motion artifacts in liver MRI. Correcting for this predictable upward shift has potential to improve image quality. The magnitude of this effect does not seem to be related to gender, BMI or total lung capacity if a moderate inspiratory position is used.

To demonstrate the feasibility of combined delayed-phase gadoxetic acid (GA) and gadobenate dimeglumine (GD) enhanced liver MRI for improved detection of liver metastases, and to optimize contrast agent dose, timing, and flip angle (FA). Fourteen healthy volunteers underwent liver MRI at 3.0T at two visits during which they received two consecutive injections: 1. GA (Visit 1 = 0.025 mmol/kg; Visit 2 = 0.05 mmol/kg) and 2. GD (both visits = 0.1 mmol/kg) 20 min after GA administration. Two sub-studies were performed: Experiment-1 Eight subjects underwent multi-phase breath-held 3D-fat-saturated T1-weighted spoiled gradient echo (SGRE) imaging to determine the optimal imaging window for the combined GA + GD protocol to create a homogeneously hyperintense liver and vasculature (“plain-white-liver”) with maximum contrast to muscle which served as a surrogate for metastatic lesions in both experiments. Experiment-2 Six subjects underwent breath-held 3D-fat-saturated T1-weighted SGRE imaging at three different FA to determine the optimal FA for best image contrast. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were evaluated. Experiment-1 The combined GA + GD protocol created a homogeneously hyperintense liver and vasculature with maximum CNR liver/muscle at approximately 60–120 s after automatic GD-bolus detection. Experiment-2 Flip angles between 25° and 35° at a dose of 0.025 mmol/kg GA provided the best combination that minimized liver/vasculature CNR, while maximizing liver/muscle CNR. CNR performance to achieve a “plain-white-liver” was superior with 0.025 mmol/kg GA compared to 0.05 mmol/kg. Combined GA + GD enhanced T1-weighted MRI is feasible to achieve a homogeneously “plain-white-liver”. Future studies need to confirm that this protocol can improve sensitivity of liver lesion detection in patients with metastatic liver disease.

Due to significant improvements in morbidity and mortality, surgery with curative intent is now the standard of care for patients with colorectal liver metastases who are surgical candidates. As a result, highly accurate preoperative per-lesion diagnosis is crucial. However, in some instances, this remains limited with standard techniques, including magnetic resonance imaging (MRI) with conventional contrast agents. Delayed retention of contrast of fibrotic liver metastases on MRI with extracellular contrast agents may mimic the late retention of contrast in hemangiomas and represent a diagnostic pitfall that limits diagnosis. Early preliminary work suggests that this imaging pitfall may not be seen on MRI with intravascular contrast agents (e.g., gadofosveset). This case report describes a surgical patient with colorectal liver metastases where gadofosveset-enhanced liver MRI was helpful in determining patient management.

One of the key strategies to improve the prognosis of HCC, beside prevention, is to diagnose the tumor in early stages, when the patient is asymptomatic and the liver function is preserved, because in this clinical situation effective therapies with survival benefit can be applied. Imaging techniques are a key tool in the surveillance and diagnosis of HCC. Screening should be based in US every 6 months and non-invasive diagnostic criteria of HCC based on imaging findings on dynamic-MR and/or dynamic-CT have been validated and thus, accepted in clinical guidelines. The typical vascular pattern depicted by HCC on CT and or MRI consists on arterial enhancement, stronger than the surrounding liver (wash-in), and hypodensity or hyposignal intensity compared to the surrounding liver (wash-out) in the venous phase. This has a sensitivity of around 60% with a 96–100% specificity. Major improvements on liver imaging have been introduced in the latest years, adding functional information that can be quantified: the use of hepatobiliary contrast media for liver MRI, the inclusion of diffusion-weighted sequences in the standard protocols for liver MRI studies and new radiotracers for positron-emission tomography (PET). However, all them are still a matter of research prior to be incorporated in evidence based clinical decision making. This review summarizes the current knowledge about imaging techniques for the early diagnosis and staging of HCC, and it discusses the most relevant open questions.

Patients with hemochromatosis require regular surveillance of liver and cardiac iron concentration with liver and cardiac MRI. However, cardiac MRI includes a part of the liver in the field of view. The purpose of this retrospective and prospective study is to determine if liver T2* measured on cardiac MRI may be used as a surrogate for T2* obtained on standard liver MRI. Liver iron concentrations were measured on cardiac and liver MRI in 21 patients. Although statistically significant, the difference may be clinically insignificant as the same patients merited chelation therapy when relying on either the cardiac or liver MRI.

Purpose: The aim of this project is to investigate the usefulness of the absolute liver lesion ADC value and ratio of Apparent diffusion coefficient (ADC) values of a liver lesion and liver parenchyma to discriminate between a benign and malignant lesion.Methods: Liver MRI scans performed between January 2009 and June 2015 were retrospectively analysed. Scans were performed on either a 1.5 T or 3 T MRI unit. The type of liver lesion (benign or malignant) was determined by its radiological appearance, histology result and clinical management. Lesions with undetermined diagnosis or MRI studies degraded by artifacts were excluded. Liver cysts were also excluded from the analysis. ADC value of a lesion and liver parenchyma was measured and ADCratio was calculated. The values were analysed using independent samples t-testResults:Data set contained 39 benign lesions and 36 malignant lesions. Mean ADC value for benign lesions was 1678, and the mean value for malignant lesions was 1097 with a statistically significant difference of p 1.5 were benign. ADCratio of 1.1 was identified statistically as the best available cut-off value for differentiating benign from malignant lesions, with sensitivity of 82%, specificity of 86% and an overall accuracy of 92%.Conclusion:Our dataset indicates that lesion to background liver ADCratio is superior in discriminating between benign and malignant focal lesions compared to absolute ADC values of the hepatic lesions. Keywords: Magnetic resonance imaging (MRI), Liver lesion, Benign, Malignant, Apparent diffusion coefficient (ADC), Apparent diffusion coefficient ratio. (ADCratio)

PURPOSE: In this study, we compare an abbreviated screening MRI protocol (aMRI), utilizing only dynamic contrast-enhanced images, to a conventional liver MRI (cMRI) for the characterization of observations in at-risk patients. MATERIALS & METHODS: 164 consecutive HCC screening MRIs were retrospectively analyzed. Two sets of deidentified image sets were created: one with all acquired sequences including T2- and diffusion-weighted sequences (cMRI), and one with only T1-weighted precontrast and dynamic post-contrast images utilizing an extracellular gadolinium contrast agent (aMRI). Three readers assigned a LI-RADS score based on the lesion with the highest LI-RADS category using the aMRI and cMRI data sets during separate reads. RESULTS: There was no change between the aMRI and cMRI LI-RADS categorization in 93%, 96% and 96% of cases for readers 1, 2 and 3 respectively. In the majority of the discrepant cases, the score increased from LI-RADS 3 to LI-RADS 4 due to the presence of ancillary features on T2 and DWI. Kappa values for interobserver variability demonstrated fair to moderate LI-RADS agreement among the 3 readers. CONCLUSION: There was strong agreement between the abbreviated T1-only MRI protocol and a full liver MRI, with only 5% of cases changing LI-RADS categorization due to the inclusion of T2 and DWI. The estimated time to run this abbreviated MRI is approximately 7–10 minutes, possibly allowing for a more cost-effective screening MRI than our cMRIs.

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

Liver MR is a well-established modality with multiparametric capabilities. However, to take advantage of its full capacity, it is mandatory to master the technique and optimize imaging protocols, apply advanced imaging concepts and understand the use of different contrast media. Physiologic artefacts although inherent to upper abdominal studies can be minimized using triggering techniques and new strategies for motion control. For standardization, the liver MR protocol should include motion-resistant T2-w sequences, in-op phase GRE T1 and T2-w fast spin echo sequences with fat suppression. Diffusion-weighted imaging (DWI) is mandatory, especially for detection of sub-centimetre metastases. Contrast-enhanced MR is the cornerstone of liver MR, especially for lesion characterization. Although extracellular agents are the most extensively used contrast agents, hepatobiliary contrast media can provide an extra-layer of functional diagnostic information adding to the diagnostic value of liver MR. The use of high field strength (3T) increases SNR but is more challenging especially concerning artefact control. Quantitative MR belongs to the new and evolving field of radiomics where the use of emerging biomarkers such as perfusion or DWI can derive new information regarding disease detection, prognostication and evaluation of tumour response. This information can overcome some of the limitations of current tests, especially when using vascular disruptive agents for oncologic treatment assessment. MR is, today, a robust, mature, multiparametric imaging modality where clinical applications have greatly expanded from morphology to advanced imaging. This new concept should be acknowledged by all those involved in producing high quality, high-end liver MR studies. info:eu-repo/semantics/publishedVersion

Purpose To evaluate the feasibility of a self-gated free-breathing volume-interpolated breath-hold examination (VIBE) sequence using compressed sensing (CS) for contrast-enhanced multiphase liver MRI. Materials and Methods We identified 23 patients who underwent multiphase gadobutrol-enhanced liver magnetic resonance imaging (MRI) using 1) a prototype free-breathing VIBE sequence with respiratory self-gating and CS (VIBECS), and 2) a standard breath-hold VIBE (VIBESTD) on the same 1.5T scanner at two timepoints. VIBECS was continuously acquired for 128 seconds and a time-series of 16 timepoints was jointly reconstructed from the dataset. The unenhanced, arterial, portal-venous, and venous timepoints with the best image quality were selected and compared to the corresponding VIBESTD series serving as reference. Image quality was assessed qualitatively (image quality, sharpness, lesion conspicuity, vessel contrast, noise, motion/other artifacts; two readers independently; 5-point Likert scale; 5 = excellent) and quantitatively (vessel contrast [VC], coefficient-of-variation [CV]) Statistics were performed using Wilcoxon-sign-rank (ordinal) and paired t-test (continuous variables). Results Image quality and lesion conspicuity revealed no significant differences between the sequences (P ≥ 0.3). VIBESTD showed a tendency to higher motion artifacts (P ≥ 0.07). Image sharpness significantly increased in VIBECS as compared to VIBESTD (P ≤ 0.03). Arterial phase vessel contrast appeared significantly lower in VIBECS than in VIBESTD (P = 0.04). VIBECS showed reconstruction artifacts not present in VIBESTD (P = 0.001). Image noise was significantly lower in VIBECS than in VIBESTD (P ≤ 0.004). Arterial phase VC was significantly lower in VIBECS than in VIBESTD (P = 0.01). CV revealed no differences between sequences (P = 0.7). Conclusion VIBECS is feasible for continuous free-breathing contrast-enhanced multiphase liver MRI, providing similar image quality and lesion conspicuity as VIBESTD. Level of Evidence: 3 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;47:459–467.

Purpose To develop and test a deep learning approach named Convolutional Neural Network (CNN) for automated screening of T2-weighted (T2WI) liver acquisitions for nondiagnostic images, and compare this automated approach to evaluation by two radiologists. Materials and Methods We evaluated 522 liver magnetic resonance imaging (MRI) exams performed at 1.5T and 3T at our institution between November 2014 and May 2016 for CNN training and validation. The CNN consisted of an input layer, convolutional layer, fully connected layer, and output layer. 351 T2WI were anonymized for training. Each case was annotated with a label of being diagnostic or nondiagnostic for detecting lesions and assessing liver morphology. Another independently collected 171 cases were sequestered for a blind test. These 171 T2WI were assessed independently by two radiologists and annotated as being diagnostic or nondiagnostic. These 171 T2WI were presented to the CNN algorithm and image quality (IQ) output of the algorithm was compared to that of two radiologists. Results There was concordance in IQ label between Reader 1 and CNN in 79% of cases and between Reader 2 and CNN in 73%. The sensitivity and the specificity of the CNN algorithm in identifying nondiagnostic IQ was 67% and 81% with respect to Reader 1 and 47% and 80% with respect to Reader 2. The negative predictive value of the algorithm for identifying nondiagnostic IQ was 94% and 86% (relative to Readers 1 and 2). Conclusion We demonstrate a CNN algorithm that yields a high negative predictive value when screening for nondiagnostic T2WI of the liver. Level of Evidence: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017.

Background To investigate the agreement between Kupffer phase of Sonazoid contrast-enhanced sonography (CEUS) and hepatobiliary phase of gadoxetic acid–enhanced MRI in the evaluation of focal liver lesions (FLLs). Methods One hundred fifty-four FLLs in 154 patients who underwent both Sonazoid CEUS and gadoxetic acid–enhanced liver MRI were included in this retrospective study. FLL visibility on the Kupffer-phase images was graded as one (invisible or isoenhancing), two (vaguely visible or vaguely hypoenhancing), or three (clearly visible or clearly hypoenhancing), and that on the hepatobiliary-phase images of MRI was graded as one (invisible or hyper/isointense), two (vaguely visible or weakly hypointense), or three (clearly visible or strongly hypointense). Pairwise comparison of lesion visibility between the two modalities was performed, and intermodality agreement was assessed. Results. On Kupffer-phase CEUS, 31 (20.1%) lesions were invisible, 17 (11.1%) were vaguely visible, and 106 (68.9%) were clearly visible. On the hepatobiliary-phase MRI, 9 (5.9%) lesions were invisible, 45 (29.2%) were vaguely visible, and 100 (64.9%) were clearly visible. Overall, lesion visibility scores were not significantly different between the two modalities (p = 0.121), but the visibility was significantly better on MRI in smaller lesions. Twenty-eight lesions (18.2%) showed discrepancy in the visibility on CEUS and MRI, and most of the cases (89.7%) were lesions that were invisible on CEUS but visible on MRI. Conclusions. The overall visibility of FLLs was comparable between the Kupffer phase of Sonazoid-CEUS and the hepatobiliary-phase images of gadoxetic acid–enhanced MRI, with a discrepancy between the two modalities in 18% of the cases. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound, 2017

Purpose Varying frequencies (5 – 18 %) of contrast-related transient severe motion (TSM) imaging artifacts during gadoxetate disodium-enhanced arterial phase liver MRI have been reported. Since previous reports originated from the United States and Japan, we aimed to determine the frequency of TSM at a German institution and to correlate it with potential risk factors and previously published results. Materials and Methods Two age- and sex-matched groups were retrospectively selected (gadoxetate disodium n = 89; gadobenate dimeglumine n = 89) from dynamic contrast-enhanced MRI examinations in a single center. Respiratory motion-related artifacts in non-enhanced and dynamic phases were assessed independently by two readers blinded to contrast agents on a 4-point scale. Scores of ≥ 3 were considered as severe motion artifacts. Severe motion artifacts in arterial phases were considered as TSM if scores in all other phases were Results For gadoxetate disodium, the mean score for respiratory motion artifacts was significantly higher in the arterial phase (2.2 ± 0.9) compared to all other phases (1.6 ± 0.7) (p 0.05). Conclusion We revealed a high frequency of TSM after injection of gadoxetate disodium at a German institution, substantiating the importance of a diagnosis-limiting phenomenon that so far has only been reported from the United States and Japan. In accordance with previous studies, we did not identify associated risk factors for TSM. Key Points: Citation Format

Liver cancer is one of the leading causes of cancer-related mortality worldwide. Magnetic resonance imaging (MRI) is a non-invasive imaging technique that is often used by radiologists for diagnosis and surgical planning. Analysis of a large amount of liver MRI data for each patient limits the radiologist's efficiency and may lead to misdiagnoses. The redundant MRI data, especially from dynamic contrast enhanced (DCE) sequences, is also a bottleneck in transmitting the images via the internet or PACS for remote consultancy in a reasonable amount of time. This study included 25 patients (aged between 20 and 70 years) with liver cysts (seven cases), hemangiomas (eight cases), or hepatic cell carcinomas (10 cases). DCE T1WI MRI was performed for all the patients. The diagnosis reference included typical MRI findings and post-surgery pathology. The methods were as follows: (i) MRI sequence pre-processing based on large vessels variation level set method to remove non-liver parts from MRI images; (ii) human visual model features (luminance, motion, and contour) extraction and fusion; (iii) anomaly-based MRI ranking; and (iv) methods assessment with the 25 patients' DCE MRI data. The prioritization methods applied to the DCE images could automatically assimilate and determine the content of the medical images, identifying the liver cysts, hemangiomas, and carcinomas. The average uniformity between radiologists and prioritization with the proposed method was 0.805, 0.838, and 0.818 for cysts, hemangiomas, and carcinomas, respectively, which indicates that the proposed method is an efficient method for liver DCE image prioritization.

MRI-based corrected T1 (cT1) is a non-invasive method to grade the severity of steatohepatitis and liver fibrosis. We aimed to identify genetic variants influencing liver cT1 and use genetics to understand mechanisms underlying liver fibroinflammatory disease and its link with other metabolic traits and diseases.First, we performed a genome-wide association study (GWAS) in 14,440 Europeans, with liver cT1 measures, from the UK Biobank. Second, we explored the effects of the cT1 variants on liver blood tests, and a range of metabolic traits and diseases. Third, we used Mendelian randomisation to test the causal effects of 24 predominantly metabolic traits on liver cT1 measures.We identified 6 independent genetic variants associated with liver cT1 that reached the GWAS significance threshold (p 5×10The association between 2 metal ion transporters and cT1 indicates an important new mechanism in steatohepatitis. Future studies are needed to determine whether interventions targeting the identified transporters might prevent liver disease in at-risk individuals.We estimated levels of liver inflammation and scarring based on magnetic resonance imaging of 14,440 UK Biobank participants. We performed a genetic study and identified variations in 6 genes associated with levels of liver inflammation and scarring. Participants with variations in 4 of these genes also had higher levels of markers of liver cell injury in blood samples, further validating their role in liver health. Two identified genes are involved in the transport of metal ions in our body. Further investigation of these variations may lead to better detection, assessment, and/or treatment of liver inflammation and scarring.

New advances in liver magnetic resonance imaging (MRI) may enable diagnosis of unseen pathologies by conventional techniques. Normal T1 (550-620 ms for 1.5 T and 700-850 ms for 3 T), T2, T2* (20 ms), T1rho (40-50 ms) mapping, proton density fat fraction (PDFF) (≤5%) and stiffness (2-3kPa) values can enable differentiation of a normal liver from chronic liver and diffuse diseases. Gd-EOB-DTPA can enable assessment of liver function by using postcontrast hepatobiliary phase or T1 reduction rate (normally above 60%). T1 mapping can be important for the assessment of fibrosis, amyloidosis and copper overload. T1rho mapping is promising for the assessment of liver collagen deposition. PDFF can allow objective treatment assessment in NAFLD and NASH patients. T2 and T2* are used for iron overload determination. MR fingerprinting may enable single slice acquisition and easy implementation of multiparametric MRI and follow-up of patients. Areas covered: T1, T2, T2*, PDFF and stiffness, diffusion weighted imaging, intravoxel incoherent motion imaging (ADC, D, D* and f values) and function analysis are reviewed. Expert commentary: Multiparametric MRI can enable biopsyless diagnosis and more objective staging of diffuse liver disease, cirrhosis and predisposing diseases. A comprehensive approach is needed to understand and overcome the effects of iron, fat, fibrosis, edema, inflammation and copper on MR relaxometry values in diffuse liver disease.

Rapid injection of gadoxetic acid has been shown not to increase tumor enhancement in arterial phase liver MRI for unknown reasons. This study aimed to investigate the effect of injection durations on peak contrast concentration in tumors and to correlate it with signal enhancement in gadoxetic acid-enhanced arterial phase MRI.Gadoxetic acid-enhanced arterial phase MRI was obtained using a bolus-tracking technique with injection durations of 1, 3, and 6s in six rabbits with VX2 liver tumors. The peak concentration of gadoxetic acid in the aorta and tumor was estimated by iopromide-enhanced time-resolved CT using the same injection volume and durations with those for MRI. Signal enhancement on MRI and peak enhancement on CT were compared and correlated.There was no significant difference in MR signal enhancement of tumors among the 3 injection durations (p = 0.87). In CT, shorter injection durations significantly increased peak contrast concentration in the aorta (p0.01) but produced equivalent peak contrast concentration in tumors (p = 0.24). The longer injections resulted in the stronger correlation between peak contrast concentration in CT and MR signal enhancement in tumors (r = 0.31, 0.43, and 0.86 with 1s-, 3s-, and 6s-injection, respectively) with a statistical significance only found with 6s-injection (p = 0.03).Estimation of contrast concentration by CT demonstrated that shorter injections did not increase peak contrast concentration in tumors despite increased peak concentration in the aorta. Furthermore, tumor signal enhancement in gadoxetic acid-enhanced arterial phase MRI was less correlated with the peak contrast concentration with shorter injections.

There is discrepancy in the literature regarding the optimal dose of gadobenate for liver MRI. We evaluated the quality of liver MRIs performed in the same individual using two dosages.With ethics approval, this retrospective study evaluated sixty patients who underwent liver MRIs between July 2015 and May 2017 (low dose, 0.06 mmol/kg) and May 2017 and September 2018 (standard dose, 0.10 mmol/kg). Regions of interest were drawn over the aorta, portal veins, and liver on unenhanced and post-contrast phases; relative enhancement values were compared (paired t-tests). Two blinded radiologists graded the arterial and portal venous sequences of each MRI from 1 to 4 (1 = suboptimal, 2 = adequate, 3 = good, 4 = excellent); grades were compared overall and in cirrhotic and non-cirrhotic subgroups (Wilcoxon signed-rank test). Radiologists graded each MRI pair from 1 to 5 (1 = substantially inferior, 2 = slightly inferior, 3 = equivalent, 4 = slightly improved, 5 = substantially improved). Inter-reader agreement was assessed (kappa statistic).Relative enhancement increased significantly with the standard dose for all structures on all phases (p 0.05). For both radiologists and both post-contrast phases, individual grades of the low- and standard-dose MRIs were similar, including the cirrhotic and non-cirrhotic subgroups (p 0.05). Compared to the low-dose MRIs, the number of standard-dose MRIs graded 1-5 were 9, 31, 97, 88, and 11 for all patients, and 6, 13, 26, 45, and 6 in cirrhotics. Inter-observer agreement was fair-moderate (Κ range 0.23-0.45).Although the standard dose of gadobenate yields greater relative enhancement, there is overall little improvement in subjective imaging quality. A trend towards better image quality is observed in cirrhotics.

Background Imaging is an essential tool in the management of patients with Colorectal cancer (CRC) by helping evaluate number and sites of metastases, determine resectability, assess response to treatment, detect drug toxicities and recurrences. Although multidetector computed tomography (MDCT) is the first tool used for staging and patient’s surveillance, magnetic resonance imaging (MRI) is the most reliable imaging modality that allows to assess liver metastases. Our purpose is to compare the diagnostic performance of gadoxetic acid-(Gd-EOB) enhanced liver MRI and contrast-enhanced MDCT in the detection of liver metastasis from colorectal cancer (mCRC). Methods One hundred and twenty-eight patients with pathologically proven mCRC (512 liver metastases) underwent Gd-EOB MRI and MDCT imaging. An additional 46 patients without mCRC were included as control subjects. Three radiologists independently graded the presence of liver nodules on a five-point confidence scale. Sensitivity and specificity for the detection of metastases were calculated. Weighted к values were used to evaluate inter-reader agreement of the confidence scale regarding the presence of the lesion. Results MRI detected 489 liver metastases and MDCT 384. In terms of per-lesion sensitivity in the detection of liver metastasis, all three readers had higher diagnostic sensitivity with Gd-EOB MRI than with MDCT (95.5% vs. 72% reader 1; 90% vs. 72% reader 2; 96% vs. 75% reader 3). Each reader showed a statistical significant difference (p

Patients with liver metastases of uveal melanoma (LMUM) die from their metastatic evolution within 2 years. We established a nomogram to choose a treatment adapted to life expectancy. From 2002 to 2013, we reviewed 224 patients with LMUM selected by liver MRI. A nomogram was developed based on a Cox model. The predictive performance of the model was assessed according to the C-statistic, Kaplan&ndash, Meier curve, and calibration plots. The median follow-up was 49.2 months (range, 0.6&ndash, 70.9). The survival rates at 6, 12, and 24 months were 0.88 (0.95 CI [0.84&ndash, 0.93]), 0.68 (0.95 CI [0.62&ndash, 0.75]), and 0.26 (0.95 CI [0.21&ndash, 0.33]), respectively. The four factors selected for the nomogram with a worse prognosis were: A disease-free interval between the UM and LMUM groups of less than 6 months (HR = 3.39, 0.95 CI [1.90&ndash, 6.05]), more than 10 LMUM (HR = 3.95, 0.95 CI [1.97&ndash, 4.43]), a maximum LMUM of more than 1200 mm2 (HR = 2.47, 0.95 CI [1.53&ndash, 3.98]), and a lactate dehydrogenase (LDH) value greater than 1.5 (HR = 3.72, 0.95 CI [2.30&ndash, 6.00]). The model achieved relatively good discrimination and calibration (C-statistic 0.71). This nomogram could be useful for decision-making and risk stratification for therapeutic options.

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) (PConclusion 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.

Acquired over a breath hold, multi-echo Dixon (mDixon) magnetic resonance imaging (MRI) of the liver can be used to quantify proton density fat fraction (PDFF) and iron-related signal decay. However, young, obese, and co-morbid patients may have limited breath holding capacity and could benefit from a motion-robust mDixon acquisition. The purpose of this study was to compare hepatic PDFF and R2* values between navigator-gated and breath-held mDixon MRI acquisition techniques in children and young adults with suspected liver disease. This retrospective study was institutional review board-approved with a waiver of informed consent. Patients who underwent liver MRI with breath-held and navigator-gated mDixon sequences between January 2017 and July 2018 were included. One reviewer, blinded to sequence, measured PDFF and R2* on four images from each sequence. Another blinded reviewer graded respiratory motion (5-point Likert scale). Pearson correlation (r), Lin’s concordance coefficients (rc), and Bland–Altman analyses were used to assess agreement between techniques. Frequency of clinically limiting motion (score ≥ 3) was compared with Fisher’s exact test. Forty-two patients were included (15 female, 27 male; mean age: 15.7 ± 4.6 years). Mean PDFF and R2* were 16.6 ± 13.1% and 29.3 ± 4.7 s−1 (breath-held) versus 17.0 ± 13.2% and 29.6 ± 5.2 s−1 (navigator-gated). PDFF agreed almost perfectly between sequences (rc = 0.997, 95% CI 0.994–0.998; mean bias: 0.3%; 95% limits of agreement: − 2.4 to +1.7%), while R2* values correlated very strongly but with poor agreement (r = 0.837, rc = 0.832, 95% CI 0.716–0.910). Navigator-gated images exhibited significantly higher frequency of clinically limiting respiratory motion (88% vs. 48%, p = 0.0001). Despite greater respiratory motion artifact, a free-breathing navigator-gated mDixon sequence produces PDFF values with almost perfect agreement to a breath-held sequence.

Purpose: To investigate the frequency, influence of arterial phase timing and risk factors for TSM artifacts in arterial phase of gadoxetate-enhanced MRI of the liver. Materials and Methods: Between 2013-2016, gadoxetate-enhanced liver MRI of 354 patients (196 men, 158 women, mean age 60.8±14.2 years) were retrospectively enrolled. Sixty-nine patients received follow-up. Arterial phase images were evaluated regarding motion artifacts on a four-point scale (0 = no motion artifacts, 1 = minor artifacts, 2 = distinct artifacts, 3 = severe artifacts/non-diagnostic). Occurrence and artifact grading were correlated with arterial phase timing (early, true and late arterial phase), previous TSM and selected risk factors such as patients’ demographics, behaviors and laboratory data. Results: TSM artifacts occurred in 48.6% (172/354) of the patients. 25.7% (91/354) had distinct (18.4%) or severe (7.3%) image artifacts. Significantly higher incidence of TSM was detected in the true arterial phase (58.8%) compared to early (51.6%) or late arterial phase (42.1%) (p=0.031). Severe artifacts were mainly seen in the true arterial phase (42.3%). Occurrence of TSM was correlated with BMI (p=0.001). Longitudinal analysis showed significant association between TSM at baseline and follow-up (p=0.041). Conclusion: Severity of TSM in gadoxetic-enhanced MRI is influenced by arterial phase timing, more common in the true arterial phase compared to early or late arterial phases, and is associated with BMI and prior TSM occurrence.

Der Einsatz von Kontrastmitteln in der MRT verbessert den Nachweis und die Charakterisierung fokaler Leberlasionen signifikant. Der vorliegende Beitrag fokussiert auf das hepatozytenspezifische Kontrastmittel Gd-EOB-DTPA, das seit 2004 in Deutschland fur die Leberbildgebung verfugbar ist. Zunachst werden dabei die pharmakokinetischen und -dynamischen Eigenschaften dieses Kontrastmittels dargelegt und ein optimiertes Untersuchungsprotokoll fur den Workflow im klinischen Alltag prasentiert. Dann wird das Erscheinungsbild der haufigsten fokalen Leberlasionen im Einzelnen dargestellt, wobei die Unterschiede zur Bildgebung mit einem extrazellularen Kontrastmittel berucksichtigt und die wichtigsten Differenzialdiagnosen diskutiert werden.

BACKGROUND/AIMS To assess the usefulness of magnetization-tagged magnetic resonance imaging (MRI) in quantifying cardiac-induced liver motion and deformation in order to predict liver fibrosis. METHODS This retrospective study included 85 patients who underwent liver MRI including magnetization-tagged sequences from April 2010 to August 2010. Tagged images were acquired in three coronal and three sagittal planes encompassing both the liver and heart. A Gabor filter bank was used to measure the maximum value of displacement (MaxDisp) and the maximum and minimum values of principal strains (MaxP1 and MinP2, respectively). Patients were divided into three groups (no fibrosis, mild-to-moderate fibrosis, and significant fibrosis) based on their aspartate-aminotransferase-to-platelet ratio index (APRI) score. Group comparisons were made using ANOVA tests. RESULTS The patients were divided into three groups according to APRI scores: no fibrosis (≤ 0.5; n=41), moderate fibrosis (0.5-1.5; n=23), and significant fibrosis (>1.5; n=21). The values of MaxDisp were 2.9 ± 0.9 (mean ± SD), 2.3 ± 0.7, and 2.1 ± 0.6 in the no fibrosis, moderate fibrosis, and significant fibrosis groups, respectively (P

To investigate whether a trained group of technicians using a modified breathing command during gadoxetate-enhanced liver MRI reduces respiratory motion artefacts compared to non-trained technicians using a traditional breathing command. The gadoxetate-enhanced liver MR images of 30 patients acquired using the traditional breathing command and the subsequent 30 patients after training the technicians to use a modified breathing command were analyzed. A subgroup of patients (n = 8) underwent scans both by trained and untrained technicians. Images obtained using the traditional and modified breathing command were compared for the presence of breathing artefacts [respiratory artefact-based image quality scores from 1 (best) to 5 (non-diagnostic)]. There was a highly significant improvement in the arterial phase image quality scores in patients using the modified breathing command compared to the traditional one (P

Objective The objective of this study is to evaluate if intensified pre-scan patient preparation (IPPP) that comprises custom-made educational material on dynamic phase imaging and supervised pre-imaging breath-hold training in addition to standard informative conversation with verbal explanation of breath-hold commands (standard pre-scan patient preparation-SPPP) might reduce the incidence of gadoxetate disodium (Gd-EOB-DTPA)-related transient severe respiratory motion (TSM) and severity of respiratory motion (RM) during dynamic phase liver MRI. Material and methods In this bi-institutional study 100 and 110 patients who received Gd-EOB-DTPA for dynamic phase liver MRI were allocated to either IPPP or SPPP at site A and B. The control group comprised 202 patients who received gadoterate meglumine (Gd-DOTA) of which each 101 patients were allocated to IPPP or SPPP at site B. RM artefacts were scored retrospectively in dynamic phase images (1: none- 5: extensive) by five and two blinded readers at site A and B, respectively, and in the hepatobiliary phase of the Gd-EOB-DTPA-enhanced scans by two blinded readers at either site. Results The incidence of TSM was 15% at site A and 22.7% at site B (p = 0.157). IPPP did not reduce the incidence of TSM in comparison to SPPP: 16.7% vs. 21.6% (p = 0.366). This finding was consistent at site A: 12% vs. 18% (p = 0.401) and site B: 20.6% vs. 25% (p = 0.590). The TSM incidence in patients with IPPP and SPPP did not differ significantly between both sites (p = 0.227; p = 0.390). IPPP did not significantly mitigate RM in comparison to SPPP in any of the Gd-EOB-DTPA-enhanced dynamic phases and the hepatobiliary phase in patients without TSM (all p≥0.072). In the Gd-DOTA control group on the other hand, IPPP significantly mitigated RM in all dynamic phases in comparison to SPPP (all p≤0.031). Conclusions We conclude that Gd-EOB-DTPA-related TSM cannot be mitigated by education and training and that Gd-EOB-DTPA-related breath-hold difficulty does not only affect the subgroup of patients with TSM or exclusively the arterial phase as previously proposed.

Introduction Liver MRI has been used in cases where ultrasound or computed tomography findings are equivocal. Diffusion-weighted imaging (DWI) established an important role in clinical use in the liver. DWI can potentially add useful information to conventional imaging. Objective The aim was to assess the role of DWI in the detection and characterization of hepatic focal lesions and its value to differentiate benign from malignant masses. Patients and methods The study included 40 patients, 19 women and 21 men, their ages ranged from 20 to 63 years. All patients underwent detailed MRI study of the abdomen. Diffusion study was performed with tridirectional diffusion gradients using b values 0, 500, and 1000 s/mm2 to increase the sensitivity. Apparent diffusion coefficient (ADC) maps and values were calculated for all lesions. Results In all, 20 patients were diagnosed to have benign lesions and 20 patients were diagnosed to have malignant lesions. Hemangiomas and cysts showed facilitated diffusion while adenomas show restricted diffusion pattern mimicking malignant focal lesions. On the other hand, all malignant lesions showed restricted diffusion evidenced by increased signal on increasing the b values and low signal on ADC maps. Mostly benign lesions show higher ADC values than malignant lesions. Conclusion Diffusion-weighted MRI sequence with quantitative ADC measurements should be used as an additional sequence to supplement conventional MRI protocol studies for proper characterization of focal hepatic lesions putting into consideration an overlap range.

Ultrasound evaluation of the liver volume can be useful for clinicians to aid in objective quantitative assessment of the liver size For some organs for example thyroid gland testicles ovaries in diagnostic radiology the volume is the most objective criterion for estimation its size Today CT and MRI imaging modalities use an objective techniques for volume calculation of the liver MRI and CT based liver volumetry are regarded as gold standard for evaluation of the liver volume ndash Nevertheless currently the ultrasonic linear measurements being used clinically as an indicator of overall liver size Up to date in clinical sonography the ultrasound report contains only the linear measurements of the liver Surely this fact significantly reduces the diagnostic value of the clinical estimation of the liver size

SUMMARY The current algorithm for the imaging diagnosis of hepatocellular carcinoma accurately detects large, progressed tumors displaying the classical imaging features of arterial hyperenhancement with ‘washout’ and/or ‘capsule’ appearance. Liver MRI with the relatively newer hepatobiliary agent, gadoxetate disodium, provides information on hepatocellular function in addition to vascularity, facilitates detection of small progressed tumors, as well as early/vaguely nodular tumors, and shows promise for characterizing hepatocellular carcinoma biology. Prediction of tumor grade, presence of biliary and stem cell markers, microvascular invasion, future hypervascularization and post-treatment recurrence have all been studied with gadoxetate disodium-enhanced MRI with encouraging results. Incorporation of gadoxetate disodium-enhanced MRI into standard diagnostic and management algorithms will likely unfold in the future.

Background Liver magnetic resonance imaging (MRI) provides reliable diagnostic performance for detecting liver metastasis but is costly and time-consuming. Purpose To compare the diagnostic performance of non-contrast liver MRI to whole MRI using gadoxetic acid for detecting liver metastasis in patients with colorectal cancer (CRC). Material and Methods We included 175 patients with histologically confirmed 401 liver metastases and 73 benign liver lesions. A non-contrast MRI (T1-weighted, T2-weighted, and diffusion-weighted images) with or without multidetector computed tomography (MDCT) and a whole MRI (gadoxetic acid-enhanced and non-contrast MRI) were analyzed independently by two observers to detect liver metastasis using receiver operating characteristic analysis. Results We found no significant differences in Az value (range = 0.914–0.997), sensitivity (range = 95.2–99.6%), specificity (range = 77.3–100%), or positive (range = 92.9–100%) or negative predictive value (range = 87.5–95.7%) between the non-contrast MRI with or without MDCT and the whole MRI for both observers for all lesions as well as lesions ≤1.0 cm and lesions >1.0 cm in size ( P = 0.203–1.000). Combined MDCT and non-contrast MRI led to similar numbers of false-positive diagnosis to the whole MRI (eight for Observers 1 and 4 vs. 3 for Observer 2). Conclusion Non-contrast liver MRI may serve as an alternative to gadoxetic acid-enhanced MRI for detecting and characterizing liver metastasis from CRC, at least in patients with relatively high risk of liver metastasis who underwent MDCT. Non-contrast liver MRI could be beneficial especially for patients with lesions that are already documented as benign but require additional follow-up MRIs.