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ObjectivesThe 9th International Forum for Liver Magnetic Resonance Imaging (MRI) was held in Singapore in September 2019, bringing together radiologists and allied specialists to discuss the latest developments in and formulate consensus statements for liver MRI, including the applications of gadoxetic acid-enhanced imaging.MethodsAs at previous Liver Forums, the meeting was held over 2 days. Presentations by the faculty on days 1 and 2 and breakout group discussions on day 1 were followed by delegate voting on consensus statements presented on day 2. Presentations and discussions centered on two main meeting themes relating to the use of gadoxetic acid-enhanced MRI in primary liver cancer and metastatic liver disease.Results and conclusionsGadoxetic acid-enhanced MRI offers the ability to monitor response to systemic therapy and to assist in pre-surgical/pre-interventional planning in liver metastases. In hepatocellular carcinoma, gadoxetic acid-enhanced MRI provides precise staging information for accurate treatment decision-making and follow-up post therapy. Gadoxetic acid-enhanced MRI also has potential, currently investigational, indications for the functional assessment of the liver and the biliary system. Additional voting sessions at the Liver Forum debated the role of multidisciplinary care in the management of patients with liver disease, evidence to support the use of abbreviated imaging protocols, and the importance of standardizing nomenclature in international guidelines in order to increase the sharing of scientific data and improve the communication between centers.Key points• Gadoxetic acid-enhanced MRI is the preferred imaging method for pre-surgical or pre-interventional planning for liver metastases after systemic therapy. • Gadoxetic acid-enhanced MRI provides accurate staging of HCC before and after treatment with locoregional/biologic therapies. • Abbreviated protocols for gadoxetic acid-enhanced MRI offer potential time and cost savings, but more evidence is necessary. The use of gadoxetic acid-enhanced MRI for the assessment of liver and biliary function is under active investigation.

Rationale and objectivesTo investigate whether transcatheter intraarterial perfusion (TRIP) magnetic resonance imaging (MRI) can differentiate reversible electroporation (RE) zones from irreversible electroporation (IRE) zones immediately after IRE procedure in the rabbit liver.Materials and methodsAll studies were approved by the institutional animal care and use committee and performed in accordance with institutional guidelines. A total of 13 healthy New Zealand White rabbits were used. After selective catheterization of the hepatic artery under X-ray fluoroscopy, we acquired TRIP-MRI at 20 minutes post-IRE using 3 mL of 5% intraarterial gadopentetate dimeglumine. Semi-quantitative (peak enhancement, PE; time to peak, TTP; wash-in slope, WIS; areas under the time-intensity curve, AUT, over 30, 60, 90, 120, 150, and 180 seconds after the initiation of enhancement) and quantitative (Ktrans, ve, and vp) TRIP-MRI parameters were calculated. The relationships between TRIP-MRI parameters and histological measurements and the differential ability of TRIP-MRI parameters was assessed.ResultsPE, AUT60, AUT90, AUT120, AUT150, AUT180, Ktrans, and ve were significantly higher in RE zones than in IRE zones (all P < 0.05), and AUC for these parameters ranged from 0.91(95% CI, 0.80, 1.00) to 0.99 (95% CI, 0.98, 1.00). There was no significant difference in AUC between any two parameters (Z, 0-1.47; P, 0.14-1.00). Hepatocyte apoptosis strongly correlated with PE, AUT60, AUT90, AUT120, AUT150, AUT180, Ktrans, and vp (the absolute value r, 0.6-0.7, all P < 0.0001).ConclusionAUT150 or AUT180 could be a potential imaging biomarker to differentiate RE from IRE zones, and TRIP-MRI permits to differentiate RE from IRE zones immediately after IRE procedure in the rabbit liver.

The efficacy of therapeutics for brain tumors is seriously hampered by multiple barriers to drug delivery, including severe destabilizing effects in the blood circulation, the blood-brain barrier/blood-brain tumor barrier (BBB/BBTB), and limited tumor uptake. Here, a sequential targeting in crosslinking (STICK) nanodelivery strategy is presented to circumvent these important physiological barriers to improve drug delivery to brain tumors. STICK nanoparticles (STICK-NPs) can sequentially target BBB/BBTB and brain tumor cells with surface maltobionic acid (MA) and 4-carboxyphenylboronic acid (CBA), respectively, and simultaneously enhance nanoparticle stability with pH-responsive crosslinkages formed by MA and CBA in situ. STICK-NPs exhibit prolonged circulation time (17-fold higher area under curve) than the free agent, allowing increased opportunities to transpass the BBB/BBTB via glucose-transporter-mediated transcytosis by MA. The tumor acidic environment then triggers the transformation of the STICK-NPs into smaller nanoparticles and reveals a secondary CBA targeting moiety for deep tumor penetration and enhanced uptake in tumor cells. STICK-NPs significantly inhibit tumor growth and prolong the survival time with limited toxicity in mice with aggressive and chemoresistant diffuse intrinsic pontine glioma. This formulation tackles multiple physiological barriers on-demand with a simple and smart STICK design. Therefore, these features allow STICK-NPs to unleash the potential of brain tumor therapeutics to improve their treatment efficacy.

Objective To investigate the value of T1 value before and after Gd-EOB-DTPA-enhanced MRI in evaluating the pathological grade of hepatocellular carcinoma (HCC). Methods A retrospective analysis was performed for the plain scan and Gd-EOB-DTPA-enhanced MRI images of 75 HCC patients (75 lesions in total) who were admitted to The Affiliated Hospital of Qingdao University from March 2019 to June 2020. According to Edmondson-Steiner grading, lesions were divided into low-grade group (grade Ⅰ-Ⅱ) and high-grade group (grade Ⅲ-Ⅳ). The T1 mapping technique was used to measure pre-enhanced T1 value (T1pre) and hepatobiliary-specific T1 value (T1-HBP), and the reduction in T1 value (△T1) and the reduction rate of T1 value (△T1%) were calculated. T1pre, T1-HBP, △T1, and △T1% were compared between the lesions with different pathological grades, and the correlation between each quantitative index and pathological grade was analyzed. The receiver operating characteristic (ROC) curve and the area under the ROC curve (AUC) were used to analyze the efficiency of each statistically significant index. Results There were significant differences in T1pre, T1-HBP, and △T1% between the low-grade group and the high-grade group (t=-3.725-2.551,P0.05). Correlation analysis showed that T1pre and T1-HBP were positively correlated with the pathological grade of HCC (r=0.293,0.472,P

Background/Aim. Since 2014 and the publication of the results of the first study on the accumulation of gadolinium contrast, we have witnessed a growing body of evidence on the deposition and retention of gadolinium in the brain after the use of gadolinium-based contrast agents (GBCAs). However, there is still no strong clinical evidence of the adverse effects of GBCAs on the brain parenchyma. The aim of the study was to determine the existence of gadolinium deposits in the brain of patients with relapsing-remitting multiple sclerosis after a ten-year follow-up period. During this period, the patients have regularly, each year, undergone magnetic resonance imaging (MRI) with the administration of gadolinium contrast (gadopentetate dimeglumine – Magnevist®) in order to follow the course of the disease. Methods. A cohort of 20 patients was formed for the purpose of this study. The ratio of the values of the signal intensity (SI) of different regions of the brain-to-cerebrospinal fluid (CSF) was com-pared for each patient on the initial MRI examination and the MRI examination ten years later. Results. Frontal cortex-to-CSF (p < 0.01), occipital cortex-to-CSF (p < 0.01), the white matter of the corona radiata-to-CSF (p < 0.01), parietal cortex-to-CSF (p < 0.05), thalamus-to-CSF (p = 0.051), putamen-to-CSF (p = 0.06), and anterior and posterior limb of the capsula interna-to-CSF (p = 0.062) SI ratios increased after multiple gadopentetate administrations. An increase in the absolute values of the T1- weighted (T1W) signal in three-quarters of patients was registered in the frontal and occipital cortex and cerebellar hemispheres. A slightly smaller increase in SI, but still greater than 55–65%, was registered in structures of the parietal cortex, putamen, cornu anterior and posterior of the capsula interna, corpus callosum (CC) splenium, pons, thalamus, nucleus caudatus, substantia nigra, CC genu, and temporal cortex. Conclusion. In the cohort of 20 patients, there was a statistically significant increase in SI in the pre-contrast T1W sequence in the following structures: frontal, parietal, and occipital cortex, as well as supratentorial white matter. This result speaks in favor of the existence of chronic accumulation of gadolinium contrast agent gadopentetate dimeglumine in brain structures.

Purpose: To evaluate the prognostic impact of dynamic gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd‐EOB‐DTPA)‐enhanced magnetic resonance imaging (MRI) in patients with hepatocellular carcinoma (HCC). Methods: We retrospectively reviewed the data of 206 patients with HCC who underwent preoperative Gd‐EOB‐DTPA‐enhanced MRI and hepatectomy and quantitatively evaluated the signal intensity ratio of the tumor to the surrounding liver tissue in the portal phase (SIRPP). We verified the survival rates and assessed the prognostic factors associated with overall survival (OS) and recurrence‐free survival (RFS) using SIRPP. Results: Multivariate analysis revealed that the independent predictive factors for poorly‐differentiated HCC were α‐fetoprotein > 20 ng/mL (hazard ratio [HR]: 3.1909, 95% confidence interval [CI]: 1.3464–7.5622, p =.0084) and SIRPP ≤ 0.85 (HR: 3.7155, 95% CI: 1.521–9.076, p =.004). The 5‐year OS and RFS rates in the high and low SIRPP groups were 83.2 and 52.1%, respectively (p <.0001) and 49.7 and 18.5%, respectively (p =.0003). Multivariate analysis revealed that SIRPP ≤ 0.68 was an independent prognostic factor related to OS (HR: 4.4537, 95% CI: 1.6581–11.9626, p =.003). Conclusion: The SIRPP of preoperative Gd‐EOB‐DTPA‐enhanced MRI might predict the histological differentiation and prognosis of HCC. [ABSTRACT FROM AUTHOR]

Objectives: We aimed to develop and evaluate a modified Liver Imaging Reporting and Data System (LI-RADS) version 2018 using significant ancillary features for diagnosing hepatocellular carcinoma (HCC) < 1.0 cm on gadoxetate disodium–enhanced magnetic resonance imaging (MRI). Methods: Patients who underwent preoperative gadoxetate disodium–enhanced MRI for focal solid nodules < 2.0 cm within 1 month of MRI between January 2016 and December 2020 were retrospectively analyzed. Major and ancillary features were compared between HCCs of < 1.0 cm and 1.0–1.9 cm using the chi-square test. Significant ancillary features associated with HCC < 1.0 cm were determined by univariable and multivariable logistic regression analysis. The sensitivity and specificity of LR-5 were compared between LI-RADS v2018 and our modified LI-RADS (applying the significant ancillary feature) using generalized estimating equations. Results: Of 796 included nodules, 248 were < 1.0 cm and 548 were 1.0–1.9 cm. HCC < 1.0 cm less frequently showed an enhancing capsule (7.1% vs. 31.1%, p <.001) and threshold growth (0% vs. 8.3%, p =.007) than HCC of 1.0−1.9 cm. Restricted diffusion was the only ancillary feature significant for diagnosing HCC < 1.0 cm (adjusted odds ratio = 11.50, p <.001). In the diagnosis of HCC, our modified LI-RADS using restricted diffusion had significantly higher sensitivity than LI-RADS v2018 (61.8% vs. 53.5%, p <.001), with similar specificity (97.3% vs. 97.8%, p =.157). Conclusion: Restricted diffusion was the only significant independent ancillary feature for diagnosing HCC < 1.0 cm. Our modified LI-RADS using restricted diffusion can improve the sensitivity for HCC < 1.0 cm. Key Points: • The imaging features of hepatocellular carcinoma (HCC) < 1.0 cm differed from those of HCC of 1.0–1.9 cm. • Restricted diffusion was the only significant independent ancillary feature for HCC < 1.0 cm. • Modified Liver Imaging Reporting and Data System (LI-RADS) with the addition of restricted diffusion can improve the sensitivity for HCC < 1.0 cm. [ABSTRACT FROM AUTHOR]

Purpose: Hepatobiliary phase (HBP) hypointense nodules without arterial phase hyperenhancement (APHE) on gadoxetic acid-enhanced MRI (GA-MRI) may be nonmalignant cirrhosis-associated nodules or hepatocellular carcinomas (HCCs). We aimed to characterize HBP hypointense nodules without APHE on GA-MRI by performing contrast-enhanced ultrasound using perfluorobutane (PFB-CEUS). Methods: In this prospective, single-center study, participants at high-risk of HCC having HBP hypointense nodules without APHE at GA-MRI were enrolled. All participants underwent PFB-CEUS; if APHE and late, mild washout or washout in the Kupffer phase were present, the diagnosis of HCC was established according to the v2022 Korean guidelines. The reference standard consisted of histopathology or imaging. The sensitivity, specificity, and positive/negative predictive values of PFB-CEUS for detecting HCC were calculated. Associations between clinical/imaging features and the diagnosis of HCC were evaluated with logistic regression analyses. Results: In total, 67 participants (age, 67.0 years ± 8.4; 56 men) with 67 HBP hypointense nodules without APHE (median size, 1.5 cm [range, 1.0–3.0 cm]) were included. The prevalence of HCC was 11.9% (8/67). The sensitivity, specificity, and positive and negative predictive values of PFB-CEUS for detecting HCC were 12.5%(1/8), 96.6%(57/59), 33.3%(1/3) and 89.1%(57/64), respectively. Mild-moderate T2 hyperintensity on GA-MRI (odds ratio, 5.756; P = 0.042) and washout in the Kupffer phase on PFB-CEUS (odds ratio, 5.828; P = 0.048) were independently associated with HCC. Conclusion: Among HBP hypointense nodules without APHE, PFB-CEUS was specific for detecting HCC, which had a low prevalence. Mild-moderate T2 hyperintensity on GA-MRI and washout in the Kupffer phase on PFB-CEUS may be useful to detect HCC in those nodules. [ABSTRACT FROM AUTHOR]

Gadopentetic acid is a common contrast agent for enhanced magnetic resonance imaging. Adverse reactions due to gadolinium-based contrast agents are rare and easily overlooked by medical staff. A patient developed a rash as the first symptom and quickly developed a severe allergic reaction after receiving gadopentetic acid. A 74-year-old female patient was admitted on January 11, 2022, for femur magnetic resonance imaging. At 12:05 pm , a routine intravenous rapid injection of gadopentetic acid (15 ml) was given. Two minutes after administration, the patient developed skin itching. No obvious rash was found, but a 10 mg intravenous injection of dexamethasone was given. After 1 minute, skin pruritus had not improved significantly, saliva secretion had increased significantly, and a general discomfort appeared. At 12:10 pm , outside the scanning room, the patient suddenly became unconscious; 1 mg of EPINEPHrine was injected intramuscularly, and oxygen was given through a mask. Heart rate, blood pressure, and oxygen saturation steadily dropped. The patient was transferred to the intensive care unit. After EPINEPHrine, norepinephrine, terlipressin, and dexamethasone treatments, the vital signs eventually stabilized. The patient was judged to have had a grade III severe allergic reaction according to the first aid guidelines for severe allergic reactions in China. The patient was discharged from the hospital on the morning of January 14. This case stresses the importance of being equipped with the medicines, items, supplies, and equipment needed for emergency treatments in all departments where contrast agents are used. Patients with apparently mild adverse reactions to contrast agents should not be overlooked. [ABSTRACT FROM AUTHOR]

PurposeTo develop and evaluate the performance of a fully-automated convolutional neural network (CNN)-based algorithm to evaluate hepatobiliary phase (HBP) adequacy of gadoxetate disodium (EOB)-enhanced MRI. Secondarily, we explored the potential of the proposed CNN algorithm to reduce examination length by applying it to EOB-MRI examinations.MethodsWe retrospectively identified EOB-enhanced MRI-HBP series from examinations performed 2011-2018 (internal and external datasets). Our algorithm, comprising a liver segmentation and classification CNN, produces an adequacy score. Two abdominal radiologists independently classified series as adequate or suboptimal. The consensus determination of HBP adequacy was used as ground truth for CNN model training and validation. Reader agreement was evaluated with Cohen's kappa. Performance of the algorithm was assessed by receiver operating characteristics (ROC) analysis and computation of the area under the ROC curve (AUC). Potential examination duration reduction was evaluated descriptively.Results1408 HBP series from 484 patients were included. Reader kappa agreement was 0.67 (internal dataset) and 0.80 (external dataset). AUCs were 0.97 (0.96-0.99) for internal and 0.95 (0.92-96) for external and were not significantly different from each other (p = 0.24). 48 % (50/105) examinations could have been shorter by applying the algorithm.ConclusionA proposed CNN-based algorithm achieves higher than 95 % AUC for classifying HBP images as adequate versus suboptimal. The application of this algorithm could potentially shorten examination time and aid radiologists in recognizing technically suboptimal images, avoiding diagnostic pitfalls.

ObjectivesTo examine inter- and intra-observer agreement for four simple hepatobiliary phase (HBP)-based scores on gadoxetic acid (GA)-enhanced MRI and their correlation with liver function in patients with mixed chronic liver disease (CLD).MethodsThis single-center, retrospective study included 287 patients (62% male, 38% female, mean age 53.5 ± 13.7 years) with mixed CLD (20.9% hepatitis C, 19.2% alcoholic liver disease, 8% hepatitis B) who underwent GA-enhanced MRI of the liver for clinical care between 2010 and 2015. Relative liver enhancement (RLE), contrast uptake index (CUI), hepatic uptake index (HUI), and liver-to-spleen contrast index (LSI) were calculated by two radiologists independently using unenhanced and GA-enhanced HPB (obtained 20 min after GA administration) images; 50 patients selected at random were reviewed twice by one reader to assess intra-observer reliability. Agreement was assessed by intraclass correlation coefficient (ICC). The albumin-bilirubin (ALBI) score, the model of end-stage liver disease (MELD), and the Child-Turcotte-Pugh (CTP) score were calculated as standards of reference for hepatic function.ResultsIntra-observer ICCs ranged from 0.814 (0.668-0.896) for CUI to 0.969 (0.945-0.983) for RLE. Inter-observer ICCs ranged from 0.777 (0.605-0.874) for HUI to 0.979 (0.963-0.988) for RLE. All HBP-based scores correlated significantly (all p

PurposeTo describe a single-center preliminary experience with gadoxetate disodium-enhanced abbreviated MRI for hepatocellular carcinoma (HCC) screening and surveillance in patients with cirrhosis or chronic hepatitis B virus (cHBV).Materials and methodsThis was a retrospective study of consecutive patients aged 18 years and older with cirrhosis or cHBV who underwent at least one gadoxetate-enhanced abbreviated MRI examination for HCC surveillance from 2014 through 2016. Examinations were interpreted prospectively by one of six abdominal radiologists for clinical care. Clinical, imaging, and other data were extracted from electronic medical records. Diagnostic adequacy was assessed in all patients. Diagnostic accuracy was assessed in the subset of patients who could be classified as having HCC or not having HCC on the basis of a composite reference standard.ResultsIn this study, 330 patients (93% with cirrhosis; 45% women; mean age, 59 years) underwent gadoxetate-enhanced abbreviated MRI. In the 330 patients, 311 (94.2%) baseline gadoxetate-enhanced abbreviated MRI examinations were diagnostically adequate. Of 141 (43%) of the 330 patients, 91.4% (129 of 141) could be classified as not having HCC and 8.6% (12 of 141) could be classified as having HCC. Baseline gadoxetate-enhanced abbreviated MRI had 0.92 sensitivity (95% confidence interval [CI]: 0.62, 1.00) and 0.91 specificity (95% CI: 0.84, 0.95) for detection of HCC. Of the 330 patients who underwent baseline gadoxetate-enhanced abbreviated MRI, 187 (57%) were lost to follow-up.ConclusionGadoxetate-enhanced abbreviated MRI is feasible clinically, has a high diagnostic adequacy rate, and, on the basis of our preliminary experience, accurately depicts HCC in high-risk patients. Strategies to enhance follow-up compliance are needed.© RSNA, 2019Keywords: Abdomen/GI, Cirrhosis, Liver, MR-Imaging, Oncology, ScreeningSupplemental material is available for this article.

PurposeCardiac native-T1 times have correlated to extracellular volume fraction in patients with confirmed fibrosis. However, whether other factors that can occur either alongside or independently of fibrosis including increased intracellular water volume, altered magnetization transfer (MT), or glycation of hemoglobin, lengthen T1 times in the absence of fibrosis remains unclear. The current study examined whether native-T1 times are elevated in hypertrophic diabetics with elevated hemoglobin A1C (HbA1c) without diffuse fibrosis.MethodsNative-T1 times were quantified in 27 diabetic and 10 healthy adults using a modified Look-Locker imaging (MOLLI) sequence at 1.5 T. The MT ratio (MTR) was quantified using dual flip angle cine balanced steady-state free precession. Gadolinium (0.2 mmol/kg Gd-DTPA) was administered as a bolus and post-contrast T1-times were quantified after 15 min. Means were compared using a two-tailed student's t-test, while correlations were assessed using Pearson's correlations.ResultsWhile left ventricular volumes, ejection fraction, and cardiac output were similar between groups, left ventricular mass and mass-to-volume ratio (MVR) were significantly higher in diabetic adults. Mean ECV (0.25 ± 0.02 Healthy vs. 0.25 ± 0.03 Diabetic, P = 0.47) and MTR (125 ± 16% Healthy vs. 125 ± 9% Diabetic, P = 0.97) were similar, however native-T1 times were significantly higher in diabetics (1016 ± 21 ms Healthy vs. 1056 ± 31 ms Diabetic, P = 0.00051). Global native-T1 times correlated with MVR (ρ = 0.43, P = 0.008) and plasma HbA1c levels (ρ = 0.43, P = 0.0088) but not ECV (ρ = 0.06, P = 0.73). Septal native-T1 times correlated with septal wall thickness (ρ = 0.50, P = 0.001).ConclusionIn diabetic adults with normal ECV values, elevated native-T1 times may reflect increased intracellular water volume and changes secondary to increased hemoglobin glycation.

Use of gadoxetate disodium, a hepatobiliary gadolinium-based agent, in patients with chronic parenchymal liver disease offers the advantage of improved sensitivity for detecting hepatocellular carcinoma (HCC). Imaging features of liver observations on gadoxetate-enhanced MRI may also serve as biomarkers of recurrence-free and overall survival following definitive treatment of HCC. A number of technical and interpretative pitfalls specific to gadoxetate exist, however, and needs to be recognized when protocoling and interpreting MRI exams with this agent. This article reviews the advantages and pitfalls of gadoxetate use in patients at risk for HCC, and the potential impact on Liver Imaging Reporting and Data System (LI-RADS) imaging feature assessment and categorization. Level of Evidence: 5 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2019;49:1236-1252.

Objectives: To evaluate the recall rate and performance of free-breathing T1W dynamic imaging in patients who underwent gadoxetic acid–enhanced liver MRI. Methods: We retrospectively reviewed patients who underwent free-breathing dynamic T1WI liver MRI using Cartesian (XD-VIBE) or self-gated radial (SG-GRASP) sequences at two institutions. Four radiologists independently reviewed the overall image quality, streak, and motion artifacts for precontrast, arterial, and portal venous phases on a 4-point scale. Hepatic observations were annotated and assessed according to LI-RADS v2018. Results: In total, 360 patients were included (XD-VIBE [n = 253], SG-GRASP [n = 107]). The overall image quality of free-breathing T1WI was 3.4 ± 0.4, 3.2 ± 0.4, and 3.5 ± 0.4 for precontrast, arterial, and portal venous phases, respectively. The actual recall rate was 0.6% (2/360). The SG-GRASP group showed fewer motion artifacts and more streak artifacts than the XD-VIBE group in all phases (p < 0.001 for all). The overall image quality was not significantly different between the two sequences in arterial (3.2 ± 0.4 in both, p = 0.607) and portal venous phases (3.5 ± 0.4 in XD-VIBE, 3.4 ± 0.4 in SG-GRASP, p = 0.214). Two sequences did not show significant differences in the lesion detection rate (figure of merit, FOM: 0.67 vs. 0.68, p = 0.876) or diagnostic performance for hepatocellular carcinoma (FOM: 0.55 vs. 0.62, p = 0.105). Conclusions: Both XD-VIBE and SG-GRASP provided sufficient image quality for patients at risk of developing motion artifacts, without significant differences in image quality or the lesion detection rate between sequences. Key Points: • The overall image quality of free-breathing T1-weighted images using Cartesian or radial sequences was 3.4 ± 0.4, 3.2 ± 0.4, and 3.5 ± 0.4 for precontrast, arterial, and portal venous phases, respectively. • Only 0.3% (1/360) had undiagnostic exams and the actual recall rate was 0.6% (2/360) in patients who underwent free-breathing dynamic T1WI. • The overall lesion detection rate was 0.67 without a significant difference between Cartesian and radial sequences (figure of merit: 0.67 vs. 0.68, respectively, p = 0.876). [ABSTRACT FROM AUTHOR]

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Post-laparoscopic cholecystectomy bile duct injuries, especially involving Luschka’s duct, are concerning. Biliary tree anomalies and the efficacy of intravenous administration of Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) in detecting bile leakage are reported based on a case. Teaching Point: Hepatobiliary-specific MRI-contrast agents prove valuable for noninvasive assessment of bile leakage after cholecystectomy.

Objective:To investigate the prognostic value of the magnetic resonance imaging in Bell’s palsy patients.Methods:Patients who were diagnosed and treated with Bell’s palsy between October 2013 and March 2016 retrospectively selected. House–Brackmann grades, pre- and post-treatment pure tone audiograms, stapedial reflexes were analyzed and magnetic resonance imaging (MRI) scans with gadolinium-based contrast agents were evaluated. Contrast-enhanced segments of the facial nerve were determined. MRI findings were compared statistically with pre- and post-treatment grade, recurrence rate of Bell’s palsy, MRI scanning timing, presence of stapes reflexes and posttreatment recovery data.Results:No significant correlation was observed between pretreatment House–Brackmann grades and enhancement (p>0.05). Similarly, there was no significant correlation between clinical recovery and enhancement (p>0.05). Also, no significant correlation was observed between MRI scanning time, the recurrence rate of Bell’s palsy and MRI findings (p>0.05). None of the MRIs showed neoplastic contrast enhancement.Conclusion:The routine use of the contrast-enhanced temporal MRI is not recommended in the diagnosis and monitoring of Bell’s palsy patients, because the contrast enhancement pattern of the facial nerve has no effect on the prognosis of Bell’s palsy. MRI should be used in cases that do not heal despite treatment, for the differential diagnosis of facial nerve tumors and in patients who are candidates for surgical decompression.

Abstract Background Studying dynamic processes in living organisms with MRI is one of the most promising research areas. The use of paramagnetic compounds as contrast agents (CA), has proven key to such studies, but so far, the lack of appropriate techniques limits the application of CA-technologies in experimental plant biology. The presented proof-of-principle aims to support method and knowledge transfer from medical research to plant science. Results In this study, we designed and tested a new approach for plant Dynamic Contrast Enhanced Magnetic Resonance Imaging (pDCE-MRI). The new approach has been applied in situ to a cereal crop (Hordeum vulgare). The pDCE-MRI allows non-invasive investigation of CA allocation within plant tissues. In our experiments, gadolinium-DTPA, the most commonly used contrast agent in medical MRI, was employed. By acquiring dynamic T1-maps, a new approach visualizes an alteration of a tissue-specific MRI parameter T1 (longitudinal relaxation time) in response to the CA. Both, the measurement of local CA concentration and the monitoring of translocation in low velocity ranges (cm/h) was possible using this CA-enhanced method. Conclusions A novel pDCE-MRI method is presented for non-invasive investigation of paramagnetic CA allocation in living plants. The temporal resolution of the T1-mapping has been significantly improved to enable the dynamic in vivo analysis of transport processes at low-velocity ranges, which are common in plants. The newly developed procedure allows to identify vascular regions and to estimate their involvement in CA allocation. Therefore, the presented technique opens a perspective for further development of CA-aided MRI experiments in plant biology.

ObjectivesTo determine whether repeated administration of the macrocyclic gadolinium-based contrast agent (GBCA) gadobutrol in children is associated with T1-weighted hyperintensity within the dentate nucleus, an imaging surrogate for gadolinium deposition.MethodsWith institutional review board approval, we identified a cohort of eight patients aged 18 years or younger who underwent at least four gadobutrol-enhanced magnetic resonance imaging (MRI) examinations of the brain from 2013 to 2017. For comparison, we identified a cohort of 19 patients who underwent at least four gadopentetate dimeglumine-enhanced MRI examinations. For each examination, both dentate nuclei were contoured on unenhanced images; the mean dentate-to-pons signal intensity (DN-P SI) ratio was calculated. DN-P SI ratios from the first and last MRI exams were compared using Wilcoxon signed ranks tests and linear regression analyses.ResultsIn the gadobutrol cohort, there was no significant change in the mean DN-P SI ratio from the first to the last scan (1.02 vs 1.02, p = 1.00). In the gadopentetate dimeglumine cohort, there was a significant increase in the mean DN-P SI ratio from the first to the last scan (1.05 vs 1.13, p = 0.003). After controlling for potentially confounding variables, the change in DN-P SI ratio from the first to the last scan was significantly lower for patients in the gadobutrol group than in the gadopentetate dimeglumine group (β = -0.08, p = 0.04).ConclusionsRepeated administration of the macrocyclic GBCA gadobutrol in children was not associated with T1-weighted dentate hyperintensity, while the repeated administration of the linear GBCA gadopentetate dimeglumine was associated with T1-weighted dentate hyperintensity, presumably due to gadolinium deposition.Key points• Gadolinium-based contrast agents are routinely used in magnetic resonance imaging. • Repeated administration of the macrocyclic agent gadobutrol in children was not associated with T1-weighted dentate hyperintensity.

Level of evidence5 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2018;47:1169-1171.

Background Non-invasive monitoring of autologous vein graft (VG) bypass grafts is largely limited to detecting late luminal narrowing. Although magnetic resonance imaging (MRI) delineates vein graft intima, media, and adventitia, which may detect early failure, the scan time required to achieve sufficient resolution is at present impractical. Purpose To study VG visualization enhancement in vivo and delineate whether a covalently attached MRI contrast agent would enable quicker longitudinal imaging of the VG wall. Material and Methods Sixteen 12-week-old male C57BL/6J mice underwent carotid interposition vein grafting. The inferior vena cava of nine donor mice was treated with a gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA)-based contrast agent, with control VGs labeled with a vehicle. T1-weighted (T1W) MRI was performed serially at postoperative weeks 1, 4, 12, and 20. A portion of animals was sacrificed for histopathology following each imaging time point. Results MRI signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were significantly higher for treated VGs in the first three time points (1.73 × higher SNR, P = 0.0006, and 5.83 × higher CNR at the first time point, P = 0.0006). However, MRI signal enhancement decreased consistently in the study period, to 1.29 × higher SNR and 2.64 × higher CNR, by the final time point. There were no apparent differences in graft morphometric analyses in Masson's trichrome-stained sections. Conclusion A MRI contrast agent that binds covalently to the VG wall provides significant increase in T1W MRI signal with no observed adverse effects in a mouse model. Further optimization of the contrast agent to enhance its durability is required.

PURPOSE:Gadoxetate-disodium (Gd-EOB-DTPA)-enhanced 3D T1- weighted (T1w) MR cholangiography (MRC) is an efficient method to evaluate biliary anatomy due to T1 shortening of excreted contrast in the bile. A method that exploits both T1 shortening and T2* effects may produce even greater bile duct conspicuity. The aim of our study is to determine feasibility and compare the diagnostic performance of two-dimensional (2D) T1w multi-echo (ME) spoiled gradient-recalled-echo (SPGR) derived R2* maps against T1w MRC for bile duct visualization in living liver donor candidates. MATERIALS AND METHODS:Ten potential living liver donor candidates underwent pretransplant 3T MRI and were included in our study. Following injection of Gd-EOBDTPA and a 20-min delay, 3D T1w MRC and 2D T1w ME SPGR images were acquired. 2D R2* maps were generated inline by the scanner assuming exponential decay. The 3D T1w MRC and 2D R2* maps were retrospectively and independently reviewed in two separate sessions by three radiologists. Visualization of eight bile duct segments was scored using a 4-point ordinal scale. The scores were compared using mixed effects regression model. RESULTS:Imaging was tolerated by all donors and R2* maps were successfully generated in all cases. Visualization scores of 2D R2* maps were significantly higher than 3D T1w MRC for right anterior (p = 0.003) and posterior (p = 0.0001), segment 2 (p

Dynamic gadoxetic acid-enhanced magnetic resonance imaging (MRI) allows the investigation of liver function through the observation of the perfusion and uptake of contrast agent in the parenchyma. Voxel-by-voxel quantification of the contrast uptake rate (k1 ) from dynamic gadoxetic acid-enhanced MRI through the standard dual-input, two-compartment model could be susceptible to overfitting of variance in the data. The aim of this study was to develop a linearized, but more robust, model. To evaluate the estimated k1 values using this linearized analysis, high-temporal-resolution gadoxetic acid-enhanced MRI scans were obtained in 13 examinations, and k1 maps were created using both models. Comparison of liver k1 values estimated from the two methods produced a median correlation coefficient of 0.91 across the 12 scans that could be used. Temporally sparse clinical MRI data with gadoxetic acid uptake were also employed to create k1 maps of 27 examinations using the linearized model. Of 20 scans, the created k1 maps were compared with overall liver function as measured by indocyanine green (ICG) retention, and yielded a correlation coefficient of 0.72. In the 27 k1 maps created via the linearized model, the mean liver k1 value was 3.93 ± 1.79 mL/100 mL/min, consistent with previous studies. The results indicate that the linearized model provides a simple and robust method for the assessment of the rate of contrast uptake that can be applied to both high-temporal-resolution dynamic contrast-enhanced MRI and typical clinical multiphase MRI data, and that correlates well with the results of both two-compartment analysis and independent whole liver function measurements.

AimTo evaluate the diagnostic per-lesion performance of a simulated gadoxetate disodium-enhanced abbreviated MRI (AMRI) in cirrhotic and chronic hepatitis B (CHB) patients for hepatocellular carcinoma (HCC) screening.Materials and methodsSeventy-nine consecutive patients at risk for HCC due to cirrhosis and/or CHB were included in this retrospective study. For each patient, the first gadoxetate disodium-enhanced MRI between 2008 through 2014 was analysed. Two independent readers read an anonymised abbreviated image set comprising axial T1-weighted (W) images with fat saturation in the hepatobiliary phase, 20 minutes or more after gadoxetate injection, and axial T2W single-shot fast spin echo images. Each observation >10 mm was scored as negative or suspicious for HCC. Inter-reader agreement was assessed. A composite reference standard was used to determine the per-lesion diagnostic performance for each reader.ResultsInter-reader agreement was substantial (κ = 0.75). The final reference standard showed 27 HCCs in 13 patients (median 21 mm, range 11-100 mm). The two readers each correctly scored 23 as suspicious for HCC (sensitivity = 85.2%), scored a total of 27 and 32 observations as suspicious for HCC (positive predictive value [PPV] = 85.2% and 71.9%), and scored 83 and 78 observations or complete examinations as negative for HCC (negative predictive value [NPV] = 95.2% and 94.9%).ConclusionsThe AMRI protocol provides higher per-lesion sensitivity and NPV than reported values for ultrasound, the current recommended technique for screening, and similar per-lesion sensitivity and PPV to reported values for complete dynamic contrast-enhanced MRI.

Objective: This study aims to evaluate the value of Kupffer phase imaging with Sonazoid-Contrast-Enhanced Ultrasound (CEUS) in differentiating atypical Hepatocellular Carcinoma (HCC) from Focal Nodular Hyperplasia (FNH), compared to the efficacy of Gadodiamide-Enhanced Magnetic Resonance Imaging (CEMRI)., Methods: We retrospectively reviewed a total of 56 focal liver lesions, comprising 36 atypical HCC and 20 FNH lesions, which were examined pre-operatively using both CEUS and CEMRI. Features were extracted from the images obtained from both modalities. The diagnostic performance of these features was evaluated using the Area Under the Receiver Operating Characteristic Curve (AUC)., Results: In the multivariate analysis, HBsAg-positive status (OR = 8.395, p = 0.021) and hypo-enhancement in the Kupffer phase (OR = 5.276, p = 0.042) were identified as independent predictors of atypical HCC. The specificity and sensitivity of HBsAg-positive for diagnosing atypical HCC are 65.0 % and 91.7 %, respectively. The specificity and sensitivity of hypo-enhancement in the Kupffer phase for diagnosing atypical HCC are 95.0 % and 63.9 %, respectively. Significantly, by integrating CEUS diagnostic characteristics to distinguish atypical HCC from FNH, we attained a specificity of 100.0 %, a sensitivity of 63.9 %, and a diagnostic accuracy of 76.8 %. Similarly, the combination of CEMRI diagnostic features resulted in a specificity of 100.0 %, a sensitivity of 47.2 %, and an overall diagnostic accuracy of 66.1 %. CEUS's diagnostic accuracy is superior to CEMRI and this difference is statistically significant (P < 0.05)., Conclusion: Sonazoid-CEUS demonstrates significant clinical potential and is a viable tool for the differential diagnosis of atypical HCC and FNH., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025. Published by Elsevier B.V.)

Objectives: To evaluate the accuracy of combined imaging and blood test indices related to liver fibrosis (LF) compared to magnetic resonance elastography (MRE) for estimating severe LF (F3-4) in preoperative patients., Methods: This retrospective study included patients who underwent MRE, gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI, and dynamic CT before liver resection. Liver stiffness measurement (LSM) using MRE, liver-to-spleen signal intensity ratio (LSR) using Gd-EOB-DTPA-enhanced MRI, and spleen volume normalized to body surface area (SV/BSA) using CT volumetry were measured. Laboratory parameters, including levels of type IV collagen 7S and hyaluronic acid, were also measured. Logistic regression and receiver operating characteristic analyses were performed to identify parameters that could estimate severe LF more accurately than LSM alone., Results: A total of 81 patients (mean age, 67 years ± 9.9 [SD]; 58 men) were enrolled. Multivariable logistic regression analysis indicated that LSR (odds ratio [OR]: 0.14, 95% confidence interval [CI]: 0.05-0.37, p < 0.001), SV/BSA (OR: 1.25, 95% CI: 1.02-1.52, p = 0.03) and type IV collagen 7S (OR: 1.84, 95% CI: 1.12-3.00, p = 0.02) were associated with severe LF. Receiver operating characteristic analysis showed that for estimating severe LF, the area under the curve was significantly larger for the combination of LSR, SV/BSA, and type IV collagen 7S than for LSM alone (0.95 vs 0.85, p = 0.04)., Conclusion: The combined evaluation of LSR, SV/BSA, and type IV collagen 7S obtained by clinically common preoperative examinations was more accurate than MRE alone for estimating severe LF in preoperative patients., Key Points: Question What indicators among the imaging and blood tests commonly performed preoperatively can provide a more accurate estimate of severe LF compared to MRE? Findings The combination of LSR, SV/BSA, and type IV collagen 7S was more accurate than an LSM alone for estimating severe LF. Clinical relevance A combination of commonly performed non-invasive preoperative tests provides a more accurate estimation of severe LF than MR elastography, an examination with relatively limited., Competing Interests: Compliance with ethical standards. Guarantor: The scientific guarantor of this publication is Masahiro Okada. Conflict of interest: The authors of this manuscript declare no relationships with any companies whose products or services may be related to the subject matter of the article. Statistics and biometry: No complex statistical methods were necessary for this paper. Informed consent: Written informed consent was waived by the Institutional Review Board. Ethical approval: Institutional Review Board approval was obtained. Study subjects or cohorts overlap: Some study subjects or cohorts have been previously reported. This study included shared patients with three previous studies with different aims: (1) 64 patients in a study aimed to propose a predictive model for post-operative complications [28]; (2) 66 in a study investigating the association between LSM and postoperative outcomes [29]; and (3) 42 in a study for investigating the predictive ability of LSM for recurrence for HCC [30]. Methodology: Retrospective Observational study Performed at one institution, (© 2024. The Author(s), under exclusive licence to European Society of Radiology.)

Purpose: To determine to what extent colorectal liver metastases (CRLM) display typical imaging characteristics on gadoxetic acid-enhanced magnetic resonance imaging (MRI) and what changes after chemotherapy., Methods: We retrospectively identified 258 patients with a gadoxetic acid-enhanced MRI between 2015 and 2021 and pathologically proven non-mucinous adenocarcinoma CRLM. 722 unique CRLMs were analyzed: 378 CRLM in only the chemotherapy-naïve analysis; 217 in post-chemotherapy analysis; and 127 CRLM were analyzed both pre- and post-chemotherapy. The following six characteristics were defined as typical; "hypovascular", "unenhanced T1-weighted (UE-T1W) hypointensity", "arterial rim enhancement", "non-enhancing during hepatobiliary phase", "T2-weighted (T2W) mild hyperintensity", and "diffusion restriction"., Results: All six typical characteristics were found in 249/505 chemotherapy-naïve CRLM (49 %) and 87/344 post-chemotherapy CRLM (25 %). The occurrence of some typical characteristics decreased post-chemotherapy: UE-T1W hypointensity 485/505 (96 %) versus 311/336 (93 %), arterial rim enhancement 291/498 (58 %) versus 154/301 (51 %), T2W mild hyperintensity 478/505 (95 %) versus 269/338 (79 %), and diffusion restriction 435/497 (87 %) versus 200/306 (65 %). Almost all metastases showed a hypovascular appearance, both in the chemotherapy-naïve (495/504, 98 %) and post-chemotherapy group (330/331, 100 %). Additionally, all CRLM appeared non-enhancing compared to the liver in the hepatobiliary phase (100 %)., Conclusion: Most CRLM show various combinations of at least five typical characteristics on gadoxetic acid-enhanced MRI. Arterial rim enhancement is the least prevalent characteristic both in chemotherapy-naïve and post-chemotherapy patients. Post-chemotherapy the occurrence of typical MRI characteristics decreases, especially mild T2W hyperintensity and the presence of diffusion restriction., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests, or personal relationships, that could have appeared to influence the work reported in this paper., (Copyright © 2025 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Hepatocellular carcinoma (HCC) has a poor prognosis, often characterized by microvascular invasion (MVI). Radiomics and habitat imaging offer potential for preoperative MVI assessment., Purpose: To identify MVI in HCC by habitat imaging, tumor radiomic analysis, and peritumor habitat-derived radiomic analysis., Study Type: Retrospective., Subjects: Three hundred eighteen patients (53 ± 11.42 years old; male = 276) with pathologically confirmed HCC (training:testing = 224:94)., Field Strength/sequence: 1.5 T, T2WI (spin echo), and precontrast and dynamic T1WI using three-dimensional gradient echo sequence., Assessment: Clinical model, habitat model, single sequence radiomic models, the peritumor habitat-derived radiomic model, and the combined models were constructed for evaluating MVI. Follow-up clinical data were obtained by a review of medical records or telephone interviews., Statistical Tests: Univariable and multivariable logistic regression, receiver operating characteristic (ROC) curve, calibration, decision curve, Delong test, K-M curves, log rank test. A P-value less than 0.05 (two sides) was considered to indicate statistical significance., Results: Habitat imaging revealed a positive correlation between the number of subregions and MVI probability. The Radiomic-Pre model demonstrated AUCs of 0.815 (95% CI: 0.752-0.878) and 0.708 (95% CI: 0.599-0.817) for detecting MVI in the training and testing cohorts, respectively. Similarly, the AUCs for MVI detection using Radiomic-HBP were 0.790 (95% CI: 0.724-0.855) for the training cohort and 0.712 (95% CI: 0.604-0.820) for the test cohort. Combination models exhibited improved performance, with the Radiomics + Habitat + Dilation + Habitat 2 + Clinical Model (Model 7) achieving the higher AUC than Model 1-4 and 6 (0.825 vs. 0.688, 0.726, 0.785, 0.757, 0.804, P = 0.013, 0.048, 0.035, 0.041, 0.039, respectively) in the testing cohort. High-risk patients (cutoff value >0.11) identified by this model showed shorter recurrence-free survival., Data Conclusion: The combined model including tumor size, habitat imaging, radiomic analysis exhibited the best performance in predicting MVI, while also assessing prognostic risk., Evidence Level: 3 TECHNICAL EFFICACY: Stage 2., (© 2024 International Society for Magnetic Resonance in Medicine.)

In Gd-EOB-DTPA-enhanced MRI, cardiac pulsation artifacts in the left lobe often hinder diagnosis, the image quality need to improve. This study aimed to reduce cardiac pulsation artifacts in Gd-EOB-DTPA-enhanced three-dimensional (3D) T1-weighted turbo-field echo (3D-T1TFE) using compressed sensitivity encoding (CS).For phantom evaluation, the cardiac phantom was manually operated using a metronome-synchronized apparatus, comprising a bag-valve mask, a breathing circuit, and a Jackson-Rees system. Transverse images of a liver phantom were acquired using enhanced T1 high-resolution isotropic volumetric excitation with CS (CS-eTHRIVE) and sensitivity encoding (S-eTHRIVE). For evaluation, images obtained during cardiac phantom operation were subtracted from those obtained when the phantom was stationary. Standard deviation (SD) of the difference images was used as the evaluation metric, and assessments were conducted based on changes in heart rate and TFE factor. For clinical image evaluation, artifacts in hepatobiliary phase images acquired 15 min after Gd-EOB-DTPA injection in the order of S-eTHRIVE and CS-eTHRIVE were visually evaluated at four levels. In heart-rate evaluation (40, 60, and 80 beats/min), CS-eTHRIVE revealed significantly lower SD values compared to S-eTHRIVE across all heart rates (P < 0.01), with no significant differences between heart rates. For TFE factor evaluation, CS-eTHRIVE with a factor of 35 exhibited the lowest SD, which was significantly different from all other groups (P < 0.01). In clinical image evaluation, CS-eTHRIVE achieved higher visual scores (mean ± SD: 3.72 ± 0.46) compared with S-eTHRIVE (2.72 ± 0.98, P < 0.01).CS reduced pulsation artifacts in Gd-EOB-DTPA-enhanced 3D-T1TFE., Competing Interests: Declarations. Conflict of interest: All authors declare that they have no competing interests. Ethical approval: This cross-section study was approved by the ethics committee of Otsu City Hospital (June 29, 2022, approval number, 85). Informed consent: Opt-out consent was performed., (© 2024. The Author(s), under exclusive licence to Japanese Society of Radiological Technology and Japan Society of Medical Physics.)

Background: Gadobenate and gadoxetate are hepatobiliary magnetic resonance imaging (MRI) contrast agents. We intraindividually compared these two agents for the characterization of focal liver lesions (FLLs)., Methods: A total of 140 adult subjects were randomized to undergo two 3-T MRI exams separated by 7-14 days, one with 0.05 mmol/kg gadobenate and one with 0.025 mmol/kg gadoxetate. For both exams, we acquired the same unenhanced T1-weighted, T2-weighted, and diffusion-weighted sequences, followed by contrast-enhanced T1-weighted sequences during the dynamic and hepatobiliary phases (HBP) (at 20 min for gadoxetate, at 120 min for gadobenate). Three experienced unaffiliated readers independently evaluated each exam in blinded, randomized order for lesion nature (benign/malignant) and specific lesion diagnosis. McNemar test, Wald tests. paired t-tests and κ statistics were used., Results: A total of 208 FLLs (108 malignant and 100 benign) were confirmed at final diagnosis. Sensitivity and specificity for malignant/benign differentiation ranged from 91.6% to 99.1% and from 87.5% to 90.5% for gadobenate, and from 86.0% to 91.6% and from 79.7% to 83.6% for gadoxetate. Significantly (p ≤ 0.025) higher values for gadobenate were determined for all diagnostic performance parameters except for sensitivity and negative predictive value for one reader. Significantly (p < 0.001) greater accuracy and confidence for specific lesion diagnosis was achieved with gadobenate for two of three blinded readers. Interreader agreement for malignant/benign differentiation was better with gadobenate (κ = 0.91 versus κ = 0.72)., Conclusion: Gadobenate was superior to gadoxetate for the differentiation and diagnosis of malignant and benign FLLs for two of three readers. Further confirmatory studies that include a wider representation of different types of FLLs are warranted., Relevance Statement: Better diagnostic performance and greater confidence in the characterization of FLLs with gadobenate might improve patient management decisions and timings, and potentially lead to better patient outcomes., Key Points: Better diagnostic performance for the differentiation of FLLs was achieved with gadobenate for two of three readers. Reader confidence for lesion diagnosis was greater with gadobenate. Superior dynamic phase imaging with gadobenate was crucial for accurate lesion diagnosis., Competing Interests: Declarations. Ethics approval and consent to participate: The study was approved by the local Ethics Committee of the Third Affiliated Hospital of Sun Yat-Sen University (approval number: GH0255, dated: 25/10/2019) and all patients provided written informed consent to take part. Consent for publication: Not applicable. Competing interests: The authors declare that they have no competing interests., (© 2025. The Author(s).)

Objective: To investigate the accuracy of magnetic resonance imaging (MRI) in classifying sonographically indeterminate ovarian and adnexal masses., Materials and Methods: This was a retrospective cross-sectional study of the unenhanced pelvic MRI scans of 243 patients with a collective total of 336 adnexal and ovarian masses., Results: Unenhanced MRI showed a sensitivity of 97.7%, a specificity of 86.4%, and an accuracy of 93.8%. The area under the ROC curve was 0.944 (95% CI: 0.913-0.974)., Conclusion: Our results show that an unenhanced MRI protocol can be used to classify adnexal masses, especially in clinical settings in which the intravenous administration of gadolinium-based contrast is not safe and should be avoided.

Background Prediction of high-risk pathologic features such as microvascular invasion (MVI), poorly differentiated pathologic grade (poor PG), and satellite nodules (SNs) has significant clinical value, as these features are associated with early recurrence and metastasis in hepatocellular carcinoma (HCC). Purpose To develop and validate a preoperative scoring model using gadoxetic acid-enhanced MRI features for noninvasive prediction of HCC high-risk pathologic features and early recurrence. Materials and Methods This retrospective study included consecutive patients with HCC who underwent preoperative gadoxetic acid-enhanced MRI at three centers (one training dataset and two external validation datasets) between January 2014 and January 2021. The preoperative imaging characteristics of each patient were evaluated via multivariable logistic regression, using surgical specimen pathologic evaluation as the reference standard, for prediction of MVI, poor PG, and SNs. In the training dataset, eight intratumoral features, three peritumoral features, and three laboratory indicators were initially evaluated. A scoring model was developed based on the results of the logistic regression, with the following imaging features demonstrating significant independent association with high-risk pathologic features: diameter greater than 4.0 cm, irregular morphology, intratumoral arteries, peritumoral enhancement in the arterial phase, and low peritumoral signal intensity. The resulting score, called the Image score (I-score), to predict early recurrence of HCC in patients was further validated in an outcome dataset. Results A total of 366 patients (median age, 57 years [IQR, 49-64 years]; 314 men, 52 women) from the three centers were included in the training dataset ( n = 150), two external validation datasets ( n = 73 and 56), and outcome dataset ( n = 87). The area under the receiver operating characteristic curve (AUC) of the I-score for predicting high-risk pathologic features was 0.93 (95% CI: 0.88, 0.97) in the training dataset and 0.86 (95% CI: 0.76, 0.93) and 0.84 (95% CI: 0.72, 0.92) in the two external datasets. In the outcome dataset, the I-score was an independent predictor of early recurrence (hazard ratio, 5.2 [95% CI: 1.9, 14.2]; P = .002). A combined model including the I-score and two other predictors demonstrated superior prognostic performance (C index, 0.84 [95% CI: 0.74, 0.91]). Conclusion The developed scoring model based on gadoxetic acid-enhanced MRI enabled noninvasive preoperative prediction of HCC high-risk pathologic features and early recurrence. © RSNA, 2025 Supplemental material is available for this article.

Aim: To investigate the value of the LR-5, which is based on hepatobiliary phase (HBP) hypointensity, for small hepatocellular carcinoma (sHCC) using LI-RADS v2018 criteria., Materials and Methods: From January 2015 to December 2021 in institution 1, and from January 2019 to February 2022 in institution 2, 239 patients at high risk for hepatocellular carcinoma (HCC) underwent contrast-enhanced MRI. Two radiologists independently evaluated the imaging features and classified them according to LI-RADS v2018 criteria, calculating the diagnostic performance of LR-5 based on consensus data. LI-RADS-m1: HBP hypointensity was used as an additional major feature along with the LI-RADS v2018. LI-RADS-m2: HBP hypointensity replaced nonperipheral "washout" in the portal venous phase. The definition of LR-DN was nodules pathologically diagnosed as high-grade dysplastic nodules (HGDN) were recategorized as LR-DN. The diagnostic performance of LR-5 was recalculated. The diagnostic performance of the LR-5 was compared using McNemar's test., Results: Using LI-RADS v2018, LI-RADS-m1, and LI-RADS-m2 criteria for LR-5, the sensitivities were 82.67%, 86.22%, and 88.44%, the specificities were 82.00%, 66.00%, and 54.00%, and the accuracies were 82.55%, 82.55%, and 82.18%, respectively. After the addition of the LR-DN, the sensitivities of LR-5 in the above diagnostic model remained unchanged, with accuracies of 84.36%, 87.27%, and 88.36% and specificities of 92.00%, 92.00%, and 88.00%, respectively., Conclusions: HBP hypointensity may improve the sensitivity of LR-5. We attempted to propose the LR-DN, HBP hypointensity may be used as a complement to washout as an additional major feature without significantly decreasing specificity., Competing Interests: Conflict of interest The authors of this manuscript declare no relationships with any companies whose products or services may be related to the subject matter of the article., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Aim: Various magnetic resonance imaging (MRI) sequences can be utilized to visualize human meningeal lymphatic vessels (MLVs) for investigating the associations between MLVs and central nervous system (CNS) disorders. This study aimed to compare the quality of contrast-enhanced 3D-T2WI and 3D-T2-fluid-attenuated inversion recovery (FLAIR) MRI sequences to display human MLVs., Materials and Methods: Sixty-two patients (27 males, 35 females; mean age 55.8 ± 14.9 years) underwent 3D-T2WI and 3D-T2-FLAIR scan in combination with Gd-DTPA injection to show MLVs., Results: (1) The positivity rates of the 3D-T2WI sequence were 98.4%, 29.0%, and 46.8%, around the dural sinus, middle meningeal artery, and ethmoid sinus, respectively. The positivity rates of the 3D-T2-FLAIR sequence were 100%, 48.4%, and 66.1%, respectively. The positivity rate was significantly higher with the 3D-T2-FLAIR sequence compared with the 3D-T2WI sequence for the middle meningeal artery and ethmoid sinus regions (p < 0.05). (2) In patients with brain lesions and intracranial space-occupying lesions, the positivity rate was significantly higher with the 3D-T2-FLAIR sequence compared with the 3D-T2WI sequence for the middle meningeal artery and ethmoid sinus regions (p < 0.05). (3) The mean cross-sectional areas of MLVs around the dural sinus, middle meningeal artery, and ethmoid sinus were all higher using the 3D-T2-FLAIR sequence compared with the 3D-T2WI sequence at all three sites (p < 0.01). (4) The signal intensity was significantly higher using the 3D-T2-FLAIR sequence compared with the 3D-T2WI sequence around the dural sinus and ethmoid sinus (p < 0.001)., Conclusion: The 3D-T2-FLAIR sequence contrast-enhanced scan showed superior visualization of MLVs compared with the 3D-T2WI sequence., (Copyright © 2024 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.)

Purpose: Vessels encapsulating tumor clusters (VETC) was implicated in the unfavourable prognosis of hepatocellular carcinoma (HCC). While potentially valuable for noninvasive evaluation, the proposed imaging criteria of VETC require external validation. This study aimed to evaluate the performance and prognostic value of these imaging criteria via CT and gadoxetic acid-enhanced MRI., Methods: Retrospectively, we gathered study included 191 patients with a single HCC who underwent preoperative CT and gadoxetic acid-enhanced MRI at three tertiary care centers between January 2017 and May 2021. The performance of previously reported radiological feature-based criteria of VETC, including the SN (size and necrosis) score, the VETC nomogram, and Fan's model, were evaluated using the area under the curve (AUC) and compared using the DeLong method. Imaging estimated VETC stratification was assessed for its association with early recurrence., Results: Ninety-four patients (49.2%) were pathologically identified as VETC-positive HCC. No significant differences were found between CT and gadoxetic acid-enhanced MRI regarding the performance of the criteria (allP> 0.05). However, the VETC nomogram, which incorporates tumor size, necrosis, and enhancement pattern, outperformed the SN score and Fan's model (AUC: 0.825 vs. 0.716 and 0.588 at CT; 0.841 vs. 0.721 and 0.621 at gadoxetic acid-enhanced MRI, bothP< 0.001). Stratification using the VETC nomogram, validated on both CT and gadoxetic acid-enhanced MRI, was associated with early recurrence (P< 0.05)., Conclusion: This study confirmed that the radiological feature-based criteria of VETC in HCC are applicable to both CT and gadoxetic acid-enhanced MRI, with the VETC nomogram showing strong discriminatory power in identifying VETC-positive HCC and predicting early recurrence., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier B.V. All rights reserved.)

Objective: Differentiating hepatic epithelioid hemangioendothelioma (EHE) and angiosarcoma (AS), the two most common vascular tumors in the liver, is important due to disparities in their prognosis and treatment. We aimed to compare clinical and MRI features of the two tumors., Methods: This retrospective study included patients with pathologically-confirmed AS or EHE who underwent MRI using gadoxetate disodium between 2008 and 2023. Two radiologists independently reviewed MR images. Wilcoxon rank sum and Fisher's exact tests were used to compare clinical and imaging features. Overall survival was compared using restricted mean survival time at 3 years., Results: 32 patients with AS (18 women [56.3%]; median age, 68 years) and 38 with EHE (24 women [63.2%]; 51 years) were included. Patients with AS were generally older (81.3% ≥ 60 years; P < 0.001), had more frequent laboratory abnormalities (P ≤ 0.018), and poorer overall survival (11.2 vs. 31.8 months; P < 0.001) than those with EHE. On MRI, a large dominant mass accompanied by smaller nodules (14/32, 43.8%), often with ill-defined margins (15/32, 46.9%) was prevalent in AS; compared with nodules of similar sizes (24/38, 63.2%; P = 0.015) with well-defined margin (30/38, 78.9%; P = 0.002) in EHE. Cirrhotic appearance of the liver was more frequent in AS (62.5%, P < 0.001), along with decreased parenchymal enhancement on hepatobiliary phase (31.3%, P < 0.001) and ascites (37.5%, P = 0.010). AS frequently presented with avid enhancement of bizarrely-shaped foci, with a centrifugal enhancement pattern. In comparison, targetoid appearance was characteristic of EHE (78.9% on T2-weighted, 54.1% on diffusion-weighted, 65.8% on multiphase images) (P ≤ 0.002), with enhancement degree typically lower than that of the aorta. On hepatobiliary phase, all the AS exhibited hypointensity, while 39.5% of EHE showed targetoid appearance (P < 0.001)., Conclusion: Patients aged ≥ 60 years presenting with laboratory abnormalities, typically with a large dominant mass accompanied by smaller nodules, exhibiting avid, bizarre, and centrifugal enhancement-particularly in the cirrhotic-appearing liver-suggests the likelihood of AS over EHE., Competing Interests: Declarations. Competing interests: The authors declare no competing interests. Ethical approval: This single-center retrospective study was approved by the Institutional Review Board. The requirement for obtaining informed consent was waived owing to the retrospective nature of the data analysis., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objectives: To explore whether T1 mapping parameters and the functional liver imaging score (FLIS) based on Gd-EOB-DTPA MRI could evaluate liver regeneration after hepatectomy for HCC patient., Methods: This retrospective study finally included 60 HCC patients (48 men and 12 women, with a median age of 53 years). T1 relaxation time of liver before gadoxetic acid injection (T1 pre ) and during the hepatobiliary phase (T1 HBP ), reduction rate (Δ%) and FLIS were calculated, their correlations with liver fibrosis stage, hepatic steatosis, and liver regeneration, quantified as regeneration index (RI), were assessed by Kendall's tau-b correlation test or Spearman's correlation test. Multivariate linear regression analyses were used to explore the indicator of RI., Results: T1 pre , T1 HBP , Δ%, and FLIS manifested significant correlation with fibrosis stage (r = 0.434, P =0.001; r = 0.546, P < 0.001; r = -0.356, P =0.005; r = -0.653, P < 0.001, respectively). T1 pre showed significant correction with steatosis grade (r = 0.415, P =0.001). Fibrosis stage and steatosis grade were associated with RI (r = -0.436, P <0.001; r = -0.338, P =0.008). Accordingly, T1 pre , T1 HBP and FLIS were the significant predictors ( P <0.05) of RI in multivariate analysis. Similarly, in the patients undergoing minor hepatectomy (n=35), T1 HBP , Δ% and FLIS were related to RI ( P <0.05) in multivariate analysis. Nevertheless, in the patients undergoing major hepatectomy (n=25), no T1 mapping parameter and FLIS was the independent predictor of RI., Conclusions: T1 mapping parameters and FLIS were the potential noninvasive indicators of liver regeneration, except for HCC patients undergoing major hepatectomy., Clinical Relevance Statement: The value of T1 mapping and FLIS with Gd-EOB-DTPA MRI for accurate preoperative evaluation of liver regeneration is critical to prevent liver failure and improve prognosis of HCC patients., Competing Interests: Author LN was employed by the company GE Healthcare. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2025 Li, Zhang, Yao, Gao, Nie, Tang, Song and Wei.)

Background: Hepatocellular carcinoma (HCC) heterogeneity impacts prognosis, and imaging is a potential indicator., Purpose: To characterize HCC image subtypes in MRI and correlate subtypes with recurrence., Study Type: Retrospective., Population: A total of 440 patients (training cohort = 213, internal test cohort = 140, external test cohort = 87) from three centers., Field Strength/sequence: 1.5-T/3.0-T, fast/turbo spin-echo T 2 -weighted, spin-echo echo-planar diffusion-weighted, contrast-enhanced three-dimensional gradient-recalled-echo T 1 -weighted with extracellular agents (Gd-DTPA, Gd-DTPA-BMA, and Gd-BOPTA)., Assessment: Three-dimensional volume-of-interest of HCC was contoured on portal venous phase, then coregistered with precontrast and late arterial phases. Subtypes were identified using non-negative matrix factorization by analyzing radiomics features from volume-of-interests, and correlated with recurrence. Clinical (demographic and laboratory data), pathological, and radiologic features were compared across subtypes. Among clinical, radiologic features and subtypes, variables with variance inflation factor above 10 were excluded. Variables (P < 0.10) in univariate Cox regression were included in stepwise multivariate analysis. Three recurrence estimation models were built: clinical-radiologic model, subtype model, hybrid model integrating clinical-radiologic characteristics, and subtypes., Statistical Tests: Mann-Whitney U test, Kruskal-Wallis H test, chi-square test, Fisher's exact test, Kaplan-Meier curves, log-rank test, concordance index (C-index). Significance level: P < 0.05., Results: Two subtypes were identified across three cohorts (subtype 1:subtype 2 of 86:127, 60:80, and 36:51, respectively). Subtype 1 showed higher microvascular invasion (MVI)-positive rates (53%-57% vs. 26%-31%), and worse recurrence-free survival. Hazard ratio (HR) for the subtype is 6.10 in subtype model. Clinical-radiologic model included alpha-fetoprotein (HR: 3.01), macrovascular invasion (HR: 2.32), nonsmooth tumor margin (HR: 1.81), rim enhancement (HR: 3.13), and intratumoral artery (HR: 2.21). Hybrid model included alpha-fetoprotein (HR: 2.70), nonsmooth tumor margin (HR: 1.51), rim enhancement (HR: 3.25), and subtypes (HR: 5.34). Subtype model was comparable to clinical-radiologic model (C-index: 0.71-0.73 vs. 0.71-0.73), but hybrid model outperformed both (C-index: 0.77-0.79)., Conclusion: MRI radiomics-based clustering identified two HCC subtypes with distinct MVI status and recurrence-free survival. Hybrid model showed superior capability to estimate recurrence., Level of Evidence: 3 TECHNICAL EFFICACY STAGE: 2., (© 2024 International Society for Magnetic Resonance in Medicine.)

Rationale and Objectives: To investigate the diagnostic performance of water-specific T1 mapping for staging liver fibrosis in a non-alcoholic fatty liver disease (NAFLD) rabbit model, in comparison to Modified Look-Locker Inversion recovery (MOLLI) T1 mapping., Materials and Methods: 60 rabbits were randomly divided into the control group (12 rabbits) and NAFLD model groups (eight rabbits per subgroup) corresponding to different durations of high-fat high cholesterol diet feeding. All rabbits underwent MRI examination including MOLLI T1 mapping and 3D multi-echo variable flip angle (VFAME- GRE) sequences were acquired before and 20 min after the administration of Gd- EOB-DTPA. Histological assessments were performed to evaluate steatosis, inflammation, ballooning, and fibrosis. Statistical analysis included the intraclass correlation coefficient, analysis of variance, spearman correlation, multiple linear regression, and receiver operating characteristic curve., Results: A moderate correlation was observed between conventional native T1 and MRI-PDFF (r = -0.513, P < 0.001), as well as between conventional native T1 and liver steatosis grades (r = -0.319, P = 0.016). However, no significant correlation was found between the native wT1 and PDFF (r = 0.137, P = 0.314), or between the native wT1 and steatosis grades (r = 0.106, P = 0.435). In the multiple regression analysis, liver fibrosis, and hepatocellular ballooning were identified as independent factors influencing native wT1 in this study (R2 =0.545, P < 0.05), while steatosis was independently associated with conventional native T1 (R2 =0.321, P < 0.05). The AUC values for native T1, native wT1, HBP T1, and HBP wT1 were 0.549(0.410-0.682), 0.811(0.684-0.903), 0.775(0.644-0.876), and 0.752(0.619-0.858) for F1 or higher, 0.581(0.441-0.711), 0.828(0.704-0.916), 0.832(0.708-0.919), and 0.854(0.734-0.934) for F2 or higher, respectively., Conclusion: The native wT1 may provide a more reliable assessment of early liver fibrosis in the context of NAFLD compared to conventional native T1., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Fubi Hu reports financial support was provided by the Health Commission of Sichuan Province. Chao Zou reports financial support was provided by National Natural Science Foundation of China. Fubi Hu reports financial support was provided by Sichuan Medical Association. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)

Background: Proliferative hepatocellular carcinoma (HCC), aggressive with poor prognosis, and lacks reliable MRI diagnosis., Purpose: To develop a diagnostic model for proliferative HCC using liver imaging reporting and data system (LI-RADS) and assess its prognostic value., Study Type: Retrospective., Population: 241 HCC patients underwent hepatectomy (90 proliferative HCCs: 151 nonproliferative HCCs), divided into the training (N = 167) and validation (N = 74) sets. 57 HCC patients received combination therapy with tyrosine kinase inhibitors (TKIs) and immune checkpoint inhibitors (ICIs)., Field Strength/sequence: 3.0 T, T1- and T2-weighted, diffusion-weighted, in- and out-phase, T1 high resolution isotropic volume excitation and dynamic gadoxetic acid-enhanced imaging., Assessment: LI-RADS v2018 and other MRI features (intratumoral artery, substantial hypoenhancing component, hepatobiliary phase peritumoral hypointensity, and irregular tumor margin) were assessed. A diagnostic model for proliferative HCC was established, stratifying patients into high- and low-risk groups. Follow-up occurred every 3-6 months, and recurrence-free survival (RFS), progression-free survival (PFS) and overall survival (OS) in different groups were compared., Statistical Tests: Fisher's test or chi-square test, t-test or Mann-Whitney test, logistic regression, Harrell's concordance index (C-index), Kaplan-Meier curves, and Cox proportional hazards. Significance level: P < 0.05., Results: The diagnostic model, incorporating corona enhancement, rim arterial phase hyperenhancement, infiltrative appearance, intratumoral artery, and substantial hypoenhancing component, achieved a C-index of 0.823 (training set) and 0.804 (validation set). Median follow-up was 32.5 months (interquartile range [IQR], 25.1 months) for postsurgery patients, and 16.8 months (IQR: 13.2 months) for combination-treated patients. 99 patients experienced recurrence, and 30 demonstrated tumor nonresponse. Differences were significant in RFS and OS rates between high-risk and low-risk groups post-surgery (40.3% vs. 65.8%, 62.3% vs. 90.1%, at 5 years). In combination-treated patients, PFS rates differed significantly (80.6% vs. 7.7% at 2 years)., Data Conclusion: The MR-based model could pre-treatment identify proliferative HCC and assist in prognosis evaluation., Technical Efficacy: Stage 2., (© 2024 International Society for Magnetic Resonance in Medicine.)

Dynamic susceptibility contrast (DSC) MRI is commonly part of brain tumor imaging. For quantitative analysis, measurement of the arterial input function and tissue concentration time curve is required. Usually, a linear relationship between the MR signal changes and contrast agent concentration ([Gd]) is assumed, even though this is a known simplification. The aim of this study was to develop a realistic 3D simulation model as an efficient method to assess the relationship between ΔR 2 (*) and [Gd] both in whole blood and brain tissue. We modified an open-source 3D simulation model to study different red blood cell configurations for assessing whole-blood ΔR 2 (*) versus [Gd]. The results were validated against previously obtained 2D data and in vitro data. Furthermore, hematocrit levels (30%-50%) and field strengths (1.5-3.0-7.0 T) were varied. Subsequently, realistic tumor vascular networks were derived from intraoperative high framerate Doppler ultrasound data to study the influence of vascular structure and orientation with respect to the main magnetic field (1.5-3.0-7.0 T) for the calculation of ΔR 2 (*) versus [Gd] in brain tissue. For whole blood, good agreement of the 3D model was found with in vitro and 2D simulation data when red blood cells were aligned with the blood flow. For brain tissue, minor differences were found between the vascular networks. The effect of vessel direction with respect to B 0 was apparent in case of clear directionality of the main vessels. The dependency on field strength agreed with previous reports. In conclusion, we have shown that the relationship between ΔR 2 (*) and [Gd] is affected by the organization of red blood cells and orientation of blood vessels with respect to the main magnetic field, as well as the field strength. These findings are important for further optimization of the realistic 3D model that could eventually be used to improve the estimation of hemodynamic parameters from DSC-MRI., (© 2024 The Author(s). NMR in Biomedicine published by John Wiley & Sons Ltd.)

Rationale and Objectives: Proliferative hepatocellular carcinoma (HCC) is associated with high invasiveness and poor prognosis. This study aimed to investigate the preoperative risk prediction and prognostic value of different radiomics models and a nomogram for proliferative HCC., Materials and Methods: Patients were randomly divided into a training cohort (n = 156) and a validation cohort (n = 66) in a 7:3 ratio. Original and delta (the different value between imaging features extracted from two different phases) radiomics features were extracted from T1-weighted imaging (T1WI), arterial, and hepatobiliary phases to construct models using different machine learning algorithms. Logistic regression was used to select clinical independent risk factors. A nomogram was constructed by integrating the optimal radiomics model score with independent risk factors. The diagnostic efficacy and clinical utility of the models were assessed. Subsequently, patients were stratified into high-risk and low-risk subgroups based on radiomics model scores and nomogram scores, and both recurrence-free survival (RFS) and overall survival (OS) were evaluated., Results: Multivariate logistic regression analysis showed that BCLC stage and combined radscore were independent predictors of proliferative HCC. The area under the curve (AUC) of the nomogram incorporating these factors was 0.838 and 0.801 in the training and validation cohorts, respectively, with good predictive performance. Multivariate Cox regression analysis shows that the delta radiomics model (DR)-predicted proliferative HCC can independently predict RFS and OS, with scores from the delta radiomics model performing best in prognostic risk stratification., Conclusion: The nomogram can effectively predict proliferative HCC, while different radiomics models and the nomogram can offer varying prognostic stratification values., Competing Interests: Conflict of Interest The authors declare that they have no conflict of interest., (Copyright © 2024 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)

Aim: To assess the diagnostic accuracy and inter-reader agreement of a simulated abbreviated gadoxetate liver magnetic resonance imaging (MRI) protocol together with contrast-enhanced computed tomography (CE-CT) against a standard gadoxetate MRI for the detection of colorectal liver metastases at baseline., Materials and Methods: Three readers independently evaluated two sets of images per patient, recording number and location of metastases and benign lesions. Set 1 comprised T1w, T2w, DWI, multiphase CE-T1w, and hepatobiliary phase (HBP) images (standard). Set 2 included T2w, HBP, DWI (from Set 1) and CE-CT (simulated abbreviated). Diagnostic performance was compared using McNemar's test. The level of agreement between sets 1 and 2 was determined with Cohen kappa. For agreement in the number of benign lesions and metastases, we applied intraclass correlation coefficient (ICC)., Results: Seventy-five patients (245 metastases, 122 benign lesions) were evaluated. There was no significant difference in diagnostic accuracy between set 1 and 2 for each reader (mean P = 0.74). The total number of metastases and benign lesions showed high agreement between reading set 1 and 2 (κ = 0.81, 0.78). The total number of metastases showed substantial agreement between readers for set 1 and 2 (ICC = 0.99, 0.99). Good agreement was seen for metastatic segmental involvement (κ = 0.84-0.99)., Conclusion: At baseline, using a simulated abbreviated liver MRI together with CE-CT showed excellent agreement with standard MRI protocol for liver metastasis detection., Competing Interests: Conflict of interest The authors declare no conflict of interest., (Copyright © 2024 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.)

Gadoxetic acid is both an extracellular- and hepatocyte-specific contrast agent. Signals from the extracellular space may lower the contrast between lesions and the surrounding hepatic parenchyma. To improve hepatocyte-specific enhancement, we developed an intracellular contrast-enhancing fat-saturated T1-weighted gradient-echo nature of the sequence (ICE-TIGRE). It incorporates the motion-sensitized driven-equilibrium (MSDE) pulse to suppress signals from the blood flow. We investigated the optimal ICE-TIGRE scanning parameters, i.e., the order of the MSDE and the fat saturation pulses, the duration time, and the b value of the MSDE pulse, using a phantom and three volunteers without applying gadoxetic acid. ICE-TIGRE successfully increased the contrast between the liver parenchyma and the portal vein. To maintain fat saturation, the preparation pulse order should be MSDE-fat saturation. A duration time of 21 ms should be applied to minimize the effect of the T2 factor on the T1 contrast, and a b value of 60 s/mm 2 should be applied to maximize the diffusion contrast for ICE-TIGRE with the imaging system used in this study.

BackgroundKnowledge of the three-dimensional (3D) infarct structure and fiber orientation remodeling is essential for complete understanding of infarct pathophysiology and post-infarction electromechanical functioning of the heart. Accurate imaging of infarct microstructure necessitates imaging techniques that produce high image spatial resolution and high signal-to-noise ratio (SNR). The aim of this study is to provide detailed reconstruction of 3D chronic infarcts in order to characterize the infarct microstructural remodeling in porcine and human hearts.MethodsWe employed a customized diffusion tensor imaging (DTI) technique in conjunction with late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) on a 3T clinical scanner to image, at submillimeter resolution, myofiber orientation and scar structure in eight chronically infarcted porcine hearts ex vivo. Systematic quantification of local microstructure was performed and the chronic infarct remodeling was characterized at different levels of wall thickness and scar transmurality. Further, a human heart with myocardial infarction was imaged using the same DTI sequence.ResultsThe SNR of non-diffusion-weighted images was >100 in the infarcted and control hearts. Mean diffusivity and fractional anisotropy (FA) demonstrated a 43% increase, and a 35% decrease respectively, inside the scar tissue. Despite this, the majority of the scar showed anisotropic structure with FA higher than an isotropic liquid. The analysis revealed that the primary eigenvector orientation at the infarcted wall on average followed the pattern of original fiber orientation (imbrication angle mean: 1.96 ± 11.03° vs. 0.84 ± 1.47°, p = 0.61, and inclination angle range: 111.0 ± 10.7° vs. 112.5 ± 6.8°, p = 0.61, infarcted/control wall), but at a higher transmural gradient of inclination angle that increased with scar transmurality (r = 0.36) and the inverse of wall thickness (r = 0.59). Further, the infarcted wall exhibited a significant increase in both the proportion of left-handed epicardial eigenvectors, and in the angle incoherency. The infarcted human heart demonstrated preservation of primary eigenvector orientation at the thinned region of infarct, consistent with the findings in the porcine hearts.ConclusionsThe application of high-resolution DTI and LGE-CMR revealed the detailed organization of anisotropic infarct structure at a chronic state. This information enhances our understanding of chronic post-infarction remodeling in large animal and human hearts.

PurposeHyperpolarized 13 C MRI is a powerful tool for studying metabolism, but can lack tissue specificity. Gadoxetate is a gadolinium-based MRI contrast agent that is selectively taken into hepatocytes. The goal of this project was to investigate whether gadoxetate can be used to selectively suppress the hyperpolarized signal arising from hepatocytes, which could in future studies be applied to generate specificity for signal from abnormal cell types.MethodsBaseline gadoxetate uptake kinetics were measured using T1 -weighted contrast enhanced imaging. Relaxivity of gadoxetate was measured for [1-13 C]pyruvate, [1-13 C]lactate, and [1-13 C]alanine. Four healthy rats were imaged with hyperpolarized [1-13 C]pyruvate using a three-dimensional (3D) MRSI sequence prior to and 15 min following administration of gadoxetate. The lactate:pyruvate ratio and alanine:pyruvate ratios were measured in liver and kidney.ResultsOverall, the hyperpolarized signal decreased approximately 60% as a result of pre-injection of gadoxetate. In liver, the lactate:pyruvate and alanine:pyruvate ratios decreased 42% and 78%, respectively (P

PurposeThe aim of this study was to determine whether gadoxetate-enhanced magnetic resonance imaging (MRI) improves lesion characterization in patients at risk for hepatocellular carcinoma compared with computed tomography (CT).Materials and methodsForty-nine patients with indeterminate lesions found at contrast-enhanced CT were prospectively enrolled and imaged using gadoxetate-enhanced hepatobiliary phase (HBP) MRI within 30 days of their initial CT. Three readers graded each lesion at CT and MRI using the Liver Imaging Reporting and Data System (LI-RADS) v2014 major criteria and HBP characterization as an ancillary feature. Patients were followed for an average of 1.8 years to document growth or stability of each lesion.ResultsThe Liver Imaging Reporting and Data System categorization changed for 71% (52/73) of lesions based on HBP MRI compared with CT, with 30% (22/73) of lesions upgraded and 41% (30/73) of lesions downgraded. There was almost perfect agreement between readers for arterial phase hyperintensity and HBP hypointensity, with lower interreader agreement for washout and capsule appearance. On the basis of composite clinical follow-up, lesions that were subsequently classified as hepatocellular carcinoma were assigned a higher LI-RADS category on HBP MRI when compared with CT.ConclusionsFor patients with indeterminate lesions seen on contrast-enhanced CT, HBP MRI using gadoxetate improves lesion characterization when using LI-RADS v2014 criteria.