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Background: Gadobenate and gadoxetate demonstrate different degrees of intracellular accumulation within hepatocytes, potentially impacting these agents' relative performance for hepatocellular carcinoma (HCC) diagnosis. Objective: To perform an intraindividual comparison of gadobenate-enhanced MRI and gadoxetate-enhanced MRI for detection of HCC, and to assess the impact of inclusion of hepatobiliary phase images on HCC detection for both agents. Methods: This prospective study enrolled 126 patients (112 men, 14 women; mean age 52.3 years) at high risk for HCC who consented to undergo two 3-T liver MRI examinations [one using gadobenate (0.05 mmol/kg), one using gadoxetate (0.025 mmol/kg)], separated by 7-14 days. The order of the two contrast agents was randomized. All examinations included post-contrast dynamic and hepatobiliary phase images (120 minutes for gadobenate; 20 minutes for gadoxetate). Three radiologists independently reviewed the gadobenate and gadoxetate examinations in separate sessions and recorded the location of detected observations. Observations were classified using LI-RADS version 2018 and using a LI-RADS modification whereby hepatobiliary phase hypointensity may upgrade observations from LR-4 to LR-5. Observations classified as LR-5 were considered positive interpretations for HCC. Diagnostic performance for histologically confirmed HCC (n=96) was assessed. Results: Across readers, sensitivity for HCC using dynamic images alone was 74.0%-80.2% for gadobenate versus 54.2%-67.7% for gadoexetate and using dynamic and hepatobiliary phase images was 82.1%-87.4% for gadobenate versus 66.3%-81.1% for gadoxetate. For HCCs measuring 1.0-2.0 cm, sensitivity using dynamic images alone was 61.9% (all readers) for gadobenate versus 38.1%-57.1% for gadoxetate and using dynamic and hepatobiliary phase images was 76.2%-85.7% for gadobenate versus 52.4%-61.9% for gadoxetate. PPV for HCC ranged from 88.6%-97.4% across readers, agents, and image sets. Conclusion: Sensitivity for HCC was higher for gadobenate than for gadoxetate, whether using dynamic images alone or dynamic and hepatobiliary phase images; the improved sensitivity using gadobenate was more pronounced for small HCCs. While hepatobiliary phase images improved sensitivity for both agents, sensitivity of gadobenate using dynamic images alone compared favorably with that of gadoxetate using dynamic and hepatobiliary phase images. Clinical Impact: The findings support gadobenate as a preferred agent over gadoxetate when performing liver MRI in patients at high risk for HCC.

Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA; Gadoxetic acid; Gadoxetate disodium) is a hepatocyte-specific MR contrast agent. It acts as an extracellular contrast agent in the early phase after intravenous injection, and then is taken up by hepatocytes later. Using this contrast agent, we can evaluate the hemodynamics of the liver and liver tumors, and can therefore improve the detection and characterization of hepatocellular carcinoma (HCC). Gd-EOB-DTPA helps in the more accurate detection of hypervascular HCC than by other agents. In addition, Gd-EOB-DTPA can detect hypovascular HCC, which is an early stage of the multi-stage carcinogenesis, with a low signal in the hepatobiliary phase. In addition to tumor detection and characterization, Gd-EOB-DTPA contrast-enhanced MR imaging can be applied for liver function evaluation and prognoses evaluation. Thus, Gd-EOB-DTPA plays an important role in the diagnosis of HCC. However, we have to employ optimal imaging techniques to improve the diagnostic ability. In this review, we aimed to discuss the characteristics of the contrast media, optimal imaging techniques, diagnosis, and applications.

Background Myocardial replacement fibrosis is one of the major histologic features of hypertrophic cardiomyopathy (HCM), but its characteristics have not been well delineated. Purpose To clarify the characteristics of replacement fibrosis in HCM and to evaluate the prognostic value of the regional extent of fibrosis. Materials and Methods This prospective study evaluated participants with HCM who underwent contrast-enhanced cardiac MRI from March 2011 to April 2019. For each participant, global and 16-segment extent of late gadolinium enhancement (LGE) in the left ventricle (LV) at cardiac MRI was analyzed. The primary end point was all-cause death. Results Among the 798 study participants enrolled (median age, 49 years [interquartile range {IQR}: 38-59 years]; 508 men), 588 (74%) underwent whole-exome sequencing. Thirty-five participants (4%) experienced death from any cause during a median follow-up of 2.9 years (IQR: 1.5-4.7 years). Spearman analysis showed weak correlations between the extent of LGE and wall thickness (LGE of global LV and maximal LV wall thickness

PURPOSE To evaluate the utility of T2-enhanced spin-echo imaging using the time-reversed gradient echo sequence (T2FFE imaging) in the hepatobiliary phase (HBP) of gadoxetic acid-enhanced MRI (Gd-EOB-MRI) for differentiating hemangiomas from metastatic tumors. METHODS A total of 61 patients with 133 liver lesions, including 37 hemangiomas and 96 metastatic tumors, were scanned by Gd-EOB-MRI. Four data sets were independently analyzed by two readers: (1) 3D fat-suppressed T2-weighted imaging (FS-T2WI) alone; (2) the combination of 3D FS-T2WI and T2FFE imaging in the HBP of Gd-EOB-MRI; (3) the combination of 3D FS-T2WI, diffusion-weighted imaging (DWI) with the b-value of 1000 s/mm2 and the apparent diffusion coefficient (ADC); and (4) a dynamic study of Gd-EOB-MRI. After classifying the lesion sizes as ≤ 10 mm or > 10 mm, we conducted a receiver-operating characteristic analysis to compare diagnostic accuracies among the four data sets for differentiating hemangiomas from metastatic tumors. RESULTS The areas under the curves (AUCs) of the four data sets of two readers were: (1) ≤ 10 mm (0.85 and 0.91) and > 10 mm (0.88 and 0.97), (2) ≤ 10 mm (0.94 and 0.94) and > 10 mm (0.96 and 0.95), (3) ≤ 10 mm (0.90 and 0.87) and > 10 mm (0.89 and 0.95), and (4) ≤ 10 mm (0.62 and 0.67) and > 10 mm (0.76 and 0.71), respectively. Data sets (2) and (3) showed no significant differences in AUCs, but both showed significantly higher AUCs compared to that of (4) regardless of the lesion size (P < 0.05). CONCLUSION The combination of 3D FS-T2WI and T2FFE imaging in the HBP of Gd-EOB-MRI achieved an accuracy equivalent to that of the combination of 3D FS-T2WI, DWI, and ADC and might be helpful in differentiating hemangiomas from metastatic tumors.

Purpose: The purpose of this study was to compare the value of contrast-enhanced computed tomography (CT) to that of magnetic resonance imaging obtained with extracellular contrast agent (ECA-MRI) for the diagnosis of a tumor capsule in hepatocellular carcinoma (HCC) using histopathologic findings as the standard of reference. Materials and methods: This retrospective study included patients with pathologically-proven resected HCCs with available preoperative contrast-enhanced CT and ECA-MRI examinations. Two blinded radiologists independently reviewed contrast-enhanced CT and ECA-MRI examinations to assess the presence of an enhancing capsule. The histopathological analysis of resected specimens was used as reference for the diagnosis of a tumor capsule. The sensitivity and specificity of CT and ECA-MRI for the diagnosis of a tumor capsule were determined, and an intra-individual comparison of imaging modalities was performed using McNemar test. Inter-reader agreement was assessed using Kappa test. Results: The study population included 199 patients (157 men, 42 women; mean age: 61.3 +/- 13.0 [SD] years) with 210 HCCs (mean size 56.7 +/- 43.7 [SD] mm). A tumor capsule was present in 157/210 (74.8%) HCCs at histopathologic analysis. Capsule enhancement was more frequently visualized on ECA-MRI (R1, 68.6%; R2, 71.9%) than on CT (R1, 44.3%, P < 0.001; R2, 47.6%, P < 0.001). The sensitivity of ECA-MRI was better for the diagnosis of histopathological tumor capsule (R1, 76.4%; R2, 79.6%; P < 0.001), while CT had a greater specificity (R1, 84.9%; R2, 83.0%; P < 0.001). Inter-reader agreement was moderate both on CT (kappa = 0.55; 95% confidence interval [CI]: 0.43-0.66) and ECA-MRI (kappa = 0.57; 95% CI: 0.45-0.70). Conclusion: Capsule enhancement was more frequently visualized on ECA-MRI than on CT. The sensitivity of ECA-MRI was greater than that of CT, but the specificity of CT was better than that of ECA-MRI. (c) 2021 Societe francaise de radiologie. Published by Elsevier Masson SAS. All rights reserved.

Background There is considerable overlap in radiologic features of tubercular and malignant spinal lesions on conventional magnetic resonance imaging (MRI). Purpose To evaluate the role of dynamic contrast-enhanced (DCE) MRI perfusion parameters in differentiating vertebral malignancy from spinal tuberculosis. Material and Methods This was a prospective study and we enrolled consecutive patients presenting with a clinical/radiologic evidence of vertebral lesions. DCE-MRI of the spine was performed using 3D volume interpolated breath-hold examination (VIBE) sequence after intravenously injecting 0.1 mmol/kg body weight of gadopentetate dimeglumine. We used Tofts model to calculate DCE parameters that included Ktrans (transfer constant), kep (rate constant), ve (fractional volume of extracellular extravascular space), and iAUC (initial area under the curve). We compared the mean value of each perfusion parameter by type of lesion (tubercular/malignant) at 0.05 significance level and performed receiver operating characteristic curve analysis. Results We could confirm histologic/cytologic diagnosis in 35 of the 45 patients recruited. Of these, 19 were tubercular and 16 were malignant lesions. The mean (± standard deviation) of kep (min−1) was significantly higher (2.89 ± 3.3) in malignant compared to tubercular lesions (0.81 ± 0.19), whereas ve was significantly lower in malignant (0.27 ± 0.13 mL/g) compared to benign lesions (0.47 ± 0.12 mL/g) at 0.05 significance level. kep cutoff of ≥1.17 min−1 had a sensitivity of 93.8% and specificity of 100% with a diagnostic accuracy of 94.4% in detecting malignant disease. Conclusion High kep is the single best predictor of malignant vertebral lesions. We recommend kep cutoff value of ≥1.17 min−1 that has high diagnostic accuracy in identifying malignant lesions.

The RAF1 expression affects prognosis in patients with hepatocellular carcinoma (HCC) treated with sorafenib. We examined the expression of sorafenib-targeted gene RAF1 to ascertain its relationship with gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (MRI) characteristics. We also explored the predictive potential of RAF1 expression markers in the treatment of HCC. Sixty-five patients with HCC who underwent preoperative enhanced MRI scanning were included in this study. We analyzed the qualitative and quantitative characteristics of enhanced MRI findings in patients with HCC. Immunohistochemistry (IHC) and reverse transcription-polymerase chain reaction (RT-PCR) analyses were used to detect the protein and mRNA expression levels of RAF1 in HCC. Correlation and logistic regression analyses were used to evaluate the relationship between these image features and the RAF1 gene expression levels in HCC. The IHC analysis indicated a significant difference in tumor thrombus group (P = 0.037), RT-PCR results revealed a significant between-group difference for both tumor margins (P = 0.033) and capsule (P = 0.04). Binary logistic regression analysis results suggest that independent MRI predictors were regular tumor margins [P = 0.035, odds ratio (OR) = 3.145, 95% confidence interval (CI) 1.087–9.103] and thrombus (P = 0.046, OR = 4.421, 95% CI 1.024–19.08) with high RAF1expression; the tumor capsule was not an independent predictor. We found a correlation between MRI features and the RAF1 gene expression, Regular tumor margin and the presence of tumor thrombus are indicators of high RAF1 expression in HCC. Enhanced MRI may be useful for identifying patients with HCC eligible for targeted treatment.

Background: Post-operative pancreatic fistula (POPF) can be life-threatening, and gadoxetic acid-enhanced MRI is routinely performed in patients undergoing pancreatic surgery. However, previous reports have not investigated if gadoxetic acid-enhanced MRI can be used to predict POPF risk. Objective: This study aims to explore if gadoxetic acid-enhanced MRI can predict pancreatic fibrosis and the need for POPF treatment before surgery. Methods: We retrospectively analyzed gadoxetic acid-enhanced MR images from 142 patients who underwent pancreatic surgery between January 1, 2011, and April 30, 2018. Pre-dynamic signal intensity (SI) and values for the portal, transitional, and hepatobiliary phase standardized based on pre-dynamic study values were analyzed. The diameter of the main pancreatic duct (DMPD) was measured, and the degree of pancreatic fibrosis was classified as F0 – F3. We defined POPF higher than grade B as significant. Results: Odds ratios for combinations that led to any degree of fibrosis higher than grade B were defined as significant risk factors. The highest odds ratio was obtained for F0 vs. F1 – F3 (p = 0.038). DMPD (p < 0.001), pre-SI (p = 0.008), portal-SI/pre-SI (p < 0.001), transitional-SI/pre-SI (p < 0.001), and hepatobiliary-SI/pre-SI (p = 0.012) were significantly correlated with the presence of fibrosis. Moreover, the presence of fibrosis was best detected by DMPD (AUC = 0.777). Individual specificity values of transitional-SI/pre-SI and DMPD were 95.5% and 86.6%, respectively, and their combined specificity was 97.7%. Conclusion: The absence of pancreatic fibrosis is a risk factor for developing POPF higher than grade B. DMPD was the most useful diagnostic indicator for the presence of fibrosis among our analysis, and its specificity increased when combined with transitional-SI/pre-SI.

Background Sinusoidal obstruction syndrome (SOS) due to chemotherapy can cause severe hepatotoxicity, leading to impaired outcome in patients with colorectal cancer. A previous study introduced gadoxetic acid-enhanced magnetic resonance imaging (Gd-EOB-MRI) to diagnose SOS. Purpose To assess the reproducibility of Gd-EOB-MRI-based SOS diagnosis and its relationship with response to chemotherapy and long-term outcome. Material and Methods Twenty-six Gd-EOB-MRI scans of patients undergoing chemotherapy for colorectal liver metastases (CRLM) were retrospectively analyzed. Three radiologists, blinded to clinical data, independently scored presence and severity of SOS on a 5-point scale (0, definitely not present to 4, definitely present). Patients with a score ≥3 were considered SOS+. Inter-observer agreement between readers was assessed with kappa statistics. Response (RECIST 1.1.), occurrence of new CRLM during follow-up (hepatic progression) and overall survival (OS) were compared between patients with and without SOS. Results The inter-observer agreement of SOS scores was poor, with quadratic kappas of 0.17–0.40. For the binary outcome of SOS+ (confidence level [CL] 3–4) vs. SOS– (CL 0–2) agreement was poor, with kappas of 0.03–0.37. Median follow-up was 24 months (range 4–44 months). Response and OS between patients with and without SOS did not differ significantly for any of the readers. Conclusion Inter-observer agreement for the diagnosis of SOS on Gd-EOB-MRI is poor. No significant correlation with relevant outcomes was found for any of the readers. Therefore, MRI for SOS diagnosis might be less useful than previously reported. Other techniques should be explored to accurately diagnose SOS in absence of histological confirmation.

BACKGROUND/AIM Detection of hepatocellular carcinoma using intraoperative ultrasonography (IOUS) is indispensable for successful laparoscopic hepatectomy (LH). This study was performed to evaluate patients with intraoperatively unidentified tumours undergoing LH. PATIENTS AND METHODS Seven patients who underwent LH for hepatocellular carcinoma and whose tumours were not detected using IOUS were included in this study. Clinical features, preoperative imaging, intraoperative imaging, surgical procedures, and pathological findings were evaluated. RESULTS Using gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging, all the tumours were enhanced in the arterial phase and rapidly washed out, becoming hypointense to the remainder of the liver. All tumours except one were

Background Hepatocellular carcinomas (HCCs) are heterogeneous neoplasms, and the prognosis varies based on the subtype. Two broad molecular classes of HCC have been proposed: a proliferative and a nonproliferative class. Purpose To evaluate the gadoxetate-enhanced MRI findings of the proliferative class HCC and its prognostic significance after surgery. Materials and Methods This retrospective cohort study evaluated patients with surgically resected treatment-naive single HCC (≤5 cm) who underwent hepatic resection from January 2010 through February 2013 and preoperative gadoxetate-enhanced MRI. A Cox proportional hazards model was used to determine the predictive factors for overall survival (OS), intrahepatic distant recurrence, and extrahepatic metastasis (EM). The mean follow-up period was 75.5 months ± 30.2 (standard deviation). Multivariable logistic regression was performed to determine factors associated with proliferative class HCC. Results A total of 158 patients (mean age, 57 years ± 11; 128 men and 30 women) were evaluated. Forty-two of the 158 HCCs (26.6%) were proliferative class HCCs (17 macrotrabecular-massive HCCs, 14 keratin 19-positive HCCs, 10 scirrhous HCCs, and one sarcomatoid HCC). The proliferative class was associated with worse OS (hazard ratio [HR], 3.1; 95% CI: 1.5, 6.0; P = .01) and higher rates of intrahepatic distant recurrence (HR, 1.83; 95% CI: 1.1, 2.9; P = .01) and EM (HR, 9.97; 95% CI: 3.2, 31.4; P 100 ng/mL) (OR, 4.18; 95% CI: 1.64, 10.7; P = .01) were independent predictors for proliferative HCC. The presence of rim APHE was associated with poor OS (HR, 2.4; 95% CI: 1.2, 4.9; P = .02) and higher rates of EM (HR, 7.4; 95% CI: 2.5, 21.7; P < .01). Conclusion The proliferative class of hepatocellular carcinoma (HCC) is an independent factor for poor overall survival with increased rates of intrahepatic and extrahepatic metastasis. Rim arterial phase hyperenhancement at gadoxetate-enhanced MRI may help to identify proliferative class HCC and predict poor overall survival and an increased incidence of extrahepatic metastasis. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Krinsky and Shanbhogue in this issue.

Objectives To evaluate the correlation between liver enhancement on hepatobiliary phase and liver function parameters in a multicenter, multivendor study. Methods A total of 359 patients who underwent gadoxetic acid–enhanced MRI using a standardized protocol with various scanners within a prospective multicenter phase II trial (SORAMIC) were evaluated. The correlation between liver enhancement on hepatobiliary phase normalized to the spleen (liver-to-spleen ratio, LSR) and biochemical laboratory parameters, clinical findings related to liver functions, liver function grading systems (Child-Pugh and Albumin-Bilirubin [ALBI]), and scanner characteristics were analyzed using uni- and multivariate analyses. Results There was a significant positive correlation between LSR and albumin (rho = 0.193; p < 0.001), platelet counts (rho = 0.148; p = 0.004), and sodium (rho = 0.161; p = 0.002); and a negative correlation between LSR and total bilirubin (rho = −0.215; p < 0.001) and AST (rho = −0.191; p < 0.001). Multivariate analysis confirmed independent significance for each of albumin (p = 0.022), total bilirubin (p = 0.045), AST (p = 0.031), platelet counts (p = 0.012), and sodium (p = 0.006). The presence of ascites (1.47 vs. 1.69, p < 0.001) and varices (1.55 vs. 1.69, p = 0.006) was related to significantly lower LSR. Similarly, patients with ALBI grade 1 had significantly higher LSR than patients with grade 2 (1.74 ± 0.447 vs. 1.56 ± 0.408, p < 0.001); and Child-Pugh A patients had a significantly higher LSR than Child-Pugh B (1.67 ± 0.44 vs. 1.49 ± 0.33, p = 0.021). Also, LSR was negatively correlated with MELD-Na scores (rho = −0.137; p = 0.013). However, one scanner brand was significantly associated with lower LSR (p < 0.001). Conclusions The liver enhancement on the hepatobiliary phase of gadoxetic acid–enhanced MRI is correlated with biomarkers of liver functions in a multicenter cohort. However, this correlation shows variations between scanner brands. Key Points • The correlation between liver enhancement on the hepatobiliary phase of gadoxetic acid–enhanced MRI and liver function is consistent in a multicenter-multivendor cohort. • Signal intensity–based indices (liver-to-spleen ratio) can be used as an imaging biomarker of liver function. • However, absolute values might change between vendors.

Objectives The aim of the set of studies was to compare gadopiclenol, a new high relaxivity gadolinium (Gd)-based contrast agent (GBCA) to gadobenate dimeglumine in terms of small brain lesion enhancement and Gd retention, including T1 enhancement in the cerebellum. Materials and methods In a first study, T1 enhancement at 0.1 mmol/kg body weight (bw) of gadopiclenol or gadobenate dimeglumine was evaluated in a small brain lesions rat model at 2.35 T. The 2 GBCAs were injected in an alternated and cross-over manner separated by an interval of 4.4 ± 1.0 hours (minimum, 3.5 hours; maximum, 6.1 hours; n = 6). In a second study, the passage of the GBCAs into cerebrospinal fluid (CSF) was evaluated by measuring the fourth ventricle T1 enhancement in healthy rats at 4.7 T over 23 minutes after a single intravenous (IV) injection of 1.2 mmol/kg bw of gadopiclenol or gadobenate dimeglumine (n = 6/group). In a third study, Gd retention at 1 month was evaluated in healthy rats who had received 20 IV injections of 1 of the 2 GBCAs (0.6 mmol/kg bw) or a similar volume of saline (n = 10/group) over 5 weeks. T1 enhancement of the deep cerebellar nuclei (DCN) was assessed by T1-weighted magnetic resonance imaging at 2.35 T, performed before the injection and thereafter once a week up to 1 month after the last injection. Elemental Gd levels in central nervous system structures, in muscle and in plasma were determined by inductively coupled plasma mass spectrometry (ICP-MS) 1 month after the last injection. Results The first study in a small brain lesion rat model showed a ≈2-fold higher number of enhanced voxels in lesions with gadopiclenol compared with gadobenate dimeglumine. T1 enhancement of the fourth ventricle was observed in the first minutes after a single IV injection of gadopiclenol or gadobenate dimeglumine (study 2), resulting, in the case of gadopiclenol, in transient enhancement during the injection period of the repeated administrations study (study 3). In terms of Gd retention, T1 enhancement of the DCN was noted in the gadobenate dimeglumine group during the month after the injection period. No such enhancement of the DCN was observed in the gadopiclenol group. Gadolinium concentrations 1 month after the injection period in the gadopiclenol group were slightly increased in plasma and lower by a factor of 2 to 3 in the CNS structures and muscles, compared with gadobenate dimeglumine. Conclusions In the small brain lesion rat model, gadopiclenol provides significantly higher enhancement of brain lesions compared with gadobentate dimeglumine at the same dose. After repeated IV injections, as expected for a macrocyclic GBCA, Gd retention is minimalized in the case of gadopiclenol compared with gadobenate dimeglumine, resulting in no T1 hypersignal in the DCN.

Repeated administrations of linear gadolinium-based contrast media (GBCM) are associated with T1-weighted (T1-W) signal intensity change in brain structures. The purpose of this study was to compare different brain structures in children after unconfounded, repeated administrations of either a macrocyclic or linear GBCM. We performed a retrospective cohort study, identifying subjects with ≥5 unconfounded administrations of gadoterate meglumine. We matched subjects with repeated administrations of gadopentetate dimeglumine to the gadoterate meglumine arm based on the number of unconfounded GBCM administrations. Two reviewers drew regions of interest on 27 structures in and around the brain. We recorded demographic, modality and study parameters and evaluated them to determine whether they were associated with T1-W signal intensity (SI) changes. Linear mixed effects models evaluated the relationships between the number of GBCM doses and T1-W SI ratio. Finally, we identified differences in the rate of T1-W SI ratio change among individuals using a linear mixed effects model with random slope. We included a total of 52 patients (age range at first MRI: 6.0 months to 17.1 years), 26 in each arm. We detected a significant change in the T1-W SI ratio with repeated administrations of GBCM in one location in the gadoterate meglumine arm and in four locations in the gadopentetate dimeglumine arm. Patient gender and age were not associated with T1-W SI change. Modality vendor, imaging sequence and field strength were variably associated with a systematic difference in the ability to detect a T1-W SI change. Finally, linear mixed effects model with random slope showed that there were individual differences in the slope of SI change at various structures among individuals for both arms. This effect was present in more brain structures in the gadopentetate dimeglumine arm (14 vs. 8). There is a significant change in the T1-W SI ratio over time in multiple brain structures after repeated gadopentetate dimeglumine administrations. This effect was only seen in one ratio after repeated administrations of gadoterate meglumine. There are individual differences in the rate of change of SI ratios over time after repeated administration of gadopentetate dimeglumine and gadoterate meglumine, suggesting that individual differences are present.

BACKGROUND & AIMS Liver Imaging Reporting and Data System (LI-RADS) and European Association for the Study (EASL) criteria for hepatocellular carcinoma (HCC) diagnosis have been updated in 2018. We aimed to compare the HCC diagnostic performance of LI-RADS and EASL criteria with extracellular contrast agents-MRI (ECA-MRI) and hepatobiliary agents-MRI (HBA-MRI). METHODS We prospectively evaluated 179 participants with cirrhosis (n = 105) or non-cirrhotic chronic hepatitis B (CHB) (n = 74) who underwent both ECA-MRI and HBA-MRI before surgery for de novo nodule(s) measuring 10-30 mm. We compared the HCC diagnostic performance of EASL and LR-5 in both MRIs. RESULTS In an analysis of 215 observations (175 HCCs, 17 non-HCC malignancies and 23 benign lesions) identified from cirrhotic or non-cirrhotic CHB participants, LR-5 with ECA-MRI provided the highest sensitivity (80.7%), followed by EASL with ECA-MRI (76.2%), LR-5 with HBA-MRI (67.3%) and EASL with HBA-MRI (63.0%, all P

Gadolinium-based contrast agents are used across species to better visualize abnormalities during MRI and are considered generally safe in clinical practice. The aim of this study was to investigate central nervous system (CNS) gadolinium deposition in 11 dogs that had an MRI performed, received 0.22 mL/kg (0.1 mmol/kg) of gadopentetate dimeglumine, and were necropsied on the same hospital admission. The index case was a 5-year-old castrated male Australian Shepherd that presented for ataxia and following MRI developed seizure-like activity that became refractory to anticonvulsant therapy. Gadolinium concentration was quantified in CNS tissues by inductively-coupled plasma mass spectrometry and was 43-fold higher in the index case. These findings suggest the possibility of gadolinium toxicity in select patients.

BACKGROUND The Liver Imaging Reporting and Data System (LI-RADS) is widely accepted as a reliable diagnostic scheme for hepatocellular carcinoma (HCC) in at-risk patients. However, its application is hampered by substantial complexity and suboptimal diagnostic sensitivity. PURPOSE To propose data-driven modifications to the LI-RADS version 2018 (v2018) major feature system (rLI-RADS) on gadoxetate disodium (EOB)-enhanced magnetic resonance imaging (MRI) to improve sensitivity and simplicity while maintaining high positive predictive value (PPV) for detecting HCC. STUDY TYPE Retrospective. POPULATION Two hundred and twenty-four consecutive at-risk patients (training dataset: 169, independent testing dataset: 55) with 742 LR-3 to LR-5 liver observations (HCC: N = 498 [67%]) were analyzed from a prospective observational registry collected between July 2015 and September 2018. FIELD STRENGTH/SEQUENCE 3.0 T/T2-weighted fast spin-echo, diffusion-weighted spin-echo based echo-planar and three-dimensional (3D) T1-weighted gradient echo sequences. ASSESSMENT All images were evaluated by three independent abdominal radiologists who were blinded to all clinical, pathological, and follow-up information. Composite reference standards of either histopathology or imaging follow-up were used. STATISTICAL TESTS In the training dataset, LI-RADS v2018 major features were used to develop rLI-RADS based on their associated PPV for HCC. In an independent testing set, diagnostic performances of LI-RADS v2018 and rLI-RADS were computed using a generalized estimating equation model and compared with McNemar's test. A P value

Objectives We examined the effects of aging and of gadolinium-based contrast agent (GBCA) exposure on MRI measurements in brain nuclei of healthy women. Methods This prospective, IRB-approved single-center case-control study enrolled 100 healthy participants of our high-risk screening center for hereditary breast cancer, who had received at least six doses of macrocyclic GBCA (exposed group) or were newly entering the program (GBCA-naïve group). The cutoff “at least six doses” was chosen to be able to include a sufficient number of highly exposed participants. All participants underwent unenhanced 3.0-T brain MRI including quantitative T1, T2, and R2* mapping and T1- and T2-weighted imaging. The relaxation times/signal intensities were derived from region of interest measurements in the brain nuclei performed by a radiologist and a neuroradiologist, both board certified. Statistical analysis was based on descriptive evaluations and uni-/multivariable analyses. Results The participants (exposed group: 49, control group: 51) were aged 42 ± 9 years. In a multivariable model, age had a clear impact on R2* (p < 0.001–0.012), T2 (p = 0.003–0.048), and T1 relaxation times/signal intensities (p < 0.004–0.046) for the majority of deep brain nuclei, mostly affecting the substantia nigra, globus pallidus (GP), nucleus ruber, thalamus, and dentate nucleus (DN). The effect of prior GBCA administration on T1 relaxation times was statistically significant for the DN, GP, and pons (p = 0.019–0.037). Conclusions In a homogeneous group of young to middle-aged healthy females aging had an effect on T2 and R2* relaxation times and former GBCA applications influenced the measured T1 relaxation times. Key Points The quantitative T1, T2, and R2* relaxation times measured in women at high risk of developing breast cancer showed characteristic bandwidth for all brain nuclei examined at 3.0-T MRI. The effect of participant age had a comparatively strong impact on R2*, T2, and T1 relaxation times for the majority of brain nuclei examined. The effect of prior GBCA administrations on T1 relaxation times rates was comparatively less pronounced, yielding statistically significant results for the dentate nucleus, globus pallidus, and pons. Summary statement Healthy women with and without previous GBCA-enhanced breast MRI exhibited age-related T2* and T2 relaxation alterations at 3.0 T-brain MRI. T1 relaxation alterations due to prior GBCA administration were comparatively less pronounced.

Objectives The goal of this study was to investigate the precise timeline of respiratory events occurring after the administration of two gadolinium-based contrast agents, gadoxetate disodium and gadoterate meglumine. Materials and methods This retrospective study examined 497 patients subject to hepatobiliary imaging using the GRASP MRI technique (TR/TE = 4/2 ms; ST = 2.5 mm; 384 × 384 mm). Imaging was performed after administration of gadoxetate (N = 338) and gadoterate (N = 159). All GRASP datasets were reconstructed using a temporal resolution of 1 s. Four regions-of-interest (ROIs) were placed in the liver dome, the right and left cardiac ventricle, and abdominal aorta detecting liver displacement and increasing vascular signal intensities over time. Changes in hepatic intensity reflected respiratory dynamics in temporal correlation to the vascular contrast bolus. Results In total, 216 (67%) and 41 (28%) patients presented with transient respiratory motion after administration of gadoxetate and gadoterate, respectively. The mean duration from start to acme of the respiratory episode was similar (p = 0.4) between gadoxetate (6.0 s) and gadoterate (5.6 s). Its mean onset in reference to contrast arrival in the right ventricle differed significantly (p < 0.001) between gadoxetate (15.3s) and gadoterate (1.8 s), analogously to peak inspiration timepoint in reference to the aortic enhancement arrival (gadoxetate: 0.9s after, gadoterate: 11.2 s before aortic enhancement, p < 0.001). Conclusions The timepoint of occurrence of transient respiratory anomalies associated with gadoxetate disodium and gadoterate meglumine differs significantly between both contrast agents while the duration of the event remains similar. Key Points • Transient respiratory anomalies following the administration of gadoterate meglumine occurred during a time period usually not acquired in MR imaging. • Transient respiratory anomalies following the administration of gadoxetate disodium occurred around the initiation of arterial phase imaging. • The estimated duration of respiratory events was similar between both contrast agents.

OBJECTIVES The aims of this study were to determine the incidence of transient severe motion artifact (TSM) on arterial phase gadoxetic acid-enhanced magnetic resonance imaging of the liver and to investigate the causes of heterogeneity in the published literature. MATERIALS AND METHODS Original studies reporting the incidence of TSM were identified in searches of PubMed, Embase, and Cochrane Library databases. The pooled incidence of TSM was calculated using random-effects meta-analysis of single proportions. Subgroup analyses were conducted to explore causes of heterogeneity. RESULTS A total of 24 studies were finally included (single arterial phase, 19 studies with 3065 subjects; multiple arterial phases, 8 studies with 2274 subjects). Studies using single arterial phase imaging reported individual TSM rates varying from 4.8% to 26.7% and a pooled incidence of TSM of 13.0% (95% confidence interval, 10.3%-16.2%), which showed substantial study heterogeneity. The pooled incidence of TSM in the studies using multiple arterial phase imaging was 3.2% (95% confidence interval, 1.9%-5.2%), which was significantly less than in those studies using single arterial phase imaging (P < 0.001). In the subgroup analysis, the geographical region of studies and the definition of TSM were found to be causes of heterogeneity. The incidence of TSM was higher in studies with Western populations from Europe or North America than in those with Eastern (Asia/Pacific) populations (16.0% vs 8.8%, P = 0.005). Regarding the definition of TSM, the incidence of TSM was higher when a 4-point scale was used for its categorization than when a 5-point scale was used (20.0% vs 11.0%, P = 0.008), and a definition considering motion artifact on phases other than arterial phase imaging lowered the incidence of TSM compared with it being defined only on arterial phase imaging (11.3% vs 20.3%, P = 0.018). CONCLUSIONS The incidence of TSM on arterial phase images varied across studies and was associated with the geographical region of studies and the definition of TSM. Careful interpretation of results reporting TSM might therefore be needed.

Purpose The aim of this study was to investigate the feasibility of measuring early changes in serum cytokine levels after intravenous diethylenetriaminepentaacetic acid (Ca-DTPA) chelation in patients manifesting either gadolinium deposition disease (GDD) or gadolinium storage condition (GSC) and the possible usefulness of this method in further research. Methods Four patients with recent-onset GDD (≤1 year) and 2 patients with long-standing GSC (4 and 9 years) underwent chelation with intravenous bolus administration of Ca-DTPA. Multiple blood draws were performed to measure serum cytokines: at T = 0 (before Ca-DTPA injection) and 1, 5, 10, 30, 60 minutes, and 24 hours after Ca-DTPA injection. Patients rated the severity of GDD symptom flare at 24 hours. The 24-hour urine Gd amounts were measured prechelation and for the 24 hours after chelation. Serum samples were analyzed blind to whether patients had GDD or GSC but with knowledge of the time points characterizing each sample. Results Urine samples for both GDD and GSC patients showed increases in Gd postchelation. All GDD patients experienced flare reactions postchelation; the 2 GSC patients did not. Two cytokines, EGF and sCD40L, peaked at 30 minutes postchelation in at least 4 of the 6 participants. Three cytokines, ENA78/CXCL5, EOTAXIN/CCL11, and LEPTIN, peaked at 24 hours in at least 4 of the 6 participants. Two participants were high outliers for a large number of cytokines across time points. No clear distinction between GDD and GSC was apparent from the cytokine patterns, although differences were present. Conclusions This pilot study describes precise temporal resolution (in the range of minutes) after a cytokine-inciting event. Select cytokines exhibited peak values at different time points. At this preliminary stage of investigation, peak cytokine release seems to reflect the amount of Gd mobilized rather than the severity of the patient symptomatic reaction. Too few subjects were studied to support statistical analysis between GDD and GSC groups, although differences were observed through visual data analysis.

Background Nuclear protein Ki-67 indicates the status of cell proliferation and has been regarded as an attractive biomarker for the prognosis of HCC. The aim of this study is to investigate which radiomics model derived from different sequences and phases of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI was superior to predict Ki-67 expression in hepatocellular carcinoma (HCC), then further to validate the optimal model for preoperative prediction of Ki-67 expression in HCC. Methods This retrospective study included 151 (training cohort: n = 103; validation cohort: n = 48) pathologically confirmed HCC patients. Radiomics features were extracted from the artery phase (AP), portal venous phase (PVP), hepatobiliary phase (HBP), and T2-weighted (T2W) images. A logistic regression with the least absolute shrinkage and selection operator (LASSO) regularization was used to select features to build a radiomics score (Rad-score). A final combined model including the optimal Rad-score and clinical risk factors was established. Receiver operating characteristic (ROC) curve analysis, Delong test and calibration curve were used to assess the predictive performance of the combined model. Decision cure analysis (DCA) was used to evaluate the clinical utility. Results The AP radiomics model with higher decision curve indicating added more net benefit, gave a better predictive performance than the HBP and T2W radiomic models. The combined model (AUC = 0.922 vs. 0.863) including AP Rad-score and serum AFP levels improved the predictive performance more than the AP radiomics model (AUC = 0.873 vs. 0.813) in the training and validation cohort. Calibration curve of the combined model showed a good agreement between the predicted and the actual probability. DCA of the validation cohort revealed that at a range threshold probability of 30–60%, the combined model added more net benefit compared with the AP radiomics model. Conclusions A combined model including AP Rad-score and serum AFP levels based on enhanced MRI can preoperatively predict Ki-67 expression in HCC.

Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) has high diagnostic accuracy in the detection of liver lesions. There is a demand for computer-aided detection/diagnosis software for Gd-EOB-DTPA-enhanced MRI. We propose a deep learning-based method using one three-dimensional fully convolutional residual network (3D FC-ResNet) for liver segmentation and another 3D FC-ResNet for simultaneous detection and classification of a focal liver lesion in Gd-EOB-DTPA-enhanced MRI. We prepared a five-phase (unenhanced, arterial, portal venous, equilibrium, and hepatobiliary phases) series as the input image sets and labeled focal liver lesion (hepatocellular carcinoma, metastasis, hemangiomas, cysts, and scars) images as the output image sets. We used 100 cases to train our model, 42 cases to determine the hyperparameters of our model, and 42 cases to evaluate our model. We evaluated our model by free-response receiver operating characteristic curve analysis and using a confusion matrix. Our model simultaneously detected and classified focal liver lesions. In the test cases, the detection accuracy for whole focal liver lesions had a true-positive ratio of 0.6 at an average of 25 false positives per case. The classification accuracy was 0.790. We proposed the simultaneous detection and classification of a focal liver lesion in Gd-EOB-DTPA-enhanced MRI using multichannel 3D FC-ResNet. Our results indicated simultaneous detection and classification are possible using a single network. It is necessary to further improve detection sensitivity to help radiologists.

Background An association between consecutive administrations of macrocyclic gadolinium-based contrast agent (mcGBCA) gadobutrol and linear (L)-GBCA gadopentetate dimeglumine and gadolinium retention in the pediatric brain remains incompletely understood. Purpose To compare signal intensity (SI) changes in the dentate nucleus (DN) on unenhanced T1-weighted imaging (T1WI) in children who obtained mcGBCA gadobutrol with those who had previously received L-GBCA gadopentetate dimeglumine. Material and Methods This retrospective study included 27 children who received L-GBCA gadopentetate dimeglumine followed by mcGBCA gadobutrol and two different control groups matched for age and sex for both periods, each involving 27 individuals with no GBCA administration from January 2010 to January 2020. DN-to-middle cerebellar peduncle (MCP) SI ratios on T1WI were determined. A repeated-measures ANOVA was performed to compare the T1WI SI ratio between children exposed to GBCA in each of the two periods and controls. Pearson correlation analysis was conducted to determine any correlation between SI ratios and confounding parameters. Results T1WI SI ratio was significantly higher in those who had only L-GBCA (1.005±0.087) or subsequent mcGBCA gadobutrol (1.002±0.104) than in control groups 1 (0.927±0.041; PConclusion Previous administration of gadopentetate dimeglumine is associated with increased T1WI SI in the DN, while subsequent administration of gadobutrol does not demonstrate any additional SI increase in the pediatric brain.

Tumor-infiltrating CD8 cells and expression of programmed cell death ligand 1 (PD-L1) are immune checkpoint markers in patients with hepatocellular carcinoma (HCC). We aimed to determine the ability of preoperative gadoxetic acid-enhanced magnetic resonance imaging (MRI) findings to predict CD8 cell density and PD-L1 expression in HCC. A total of 120 patients with HCC who underwent 3.0-T gadoxetic acid-enhanced MRI before curative resection from January 2016 to June 2020 were enrolled and divided into a training set (n = 84) and a testing set (n = 36). Thirty-four patients with advanced stage HCC who received anti-PD-1 inhibitor between January 2017 and April 2020 and underwent pretreated gadoxetic acid-enhanced MRI scans were enrolled in an independent validation set. PD-L1 expression and CD8 cell infiltration were assessed with immunohistochemical staining, respectively. Two radiologists blinded to pathology results evaluated the pretreated MR features in consensus. Logistic regression and the receiver operating characteristic curve (ROC) analyses were used to determine the value of image features to predict high CD8 cell density, PD-L1 positivity and the combination of high CD8 cell density and PD-L1 positivity in HCC in the training set and validated the findings in the testing set. The associations of MRI predictors with the objective response to immunotherapy were assessed in the independent validation. In the training set, the independent MRI predictors were irregular tumor margin (ITM, P = 0.008) and peritumoral low signal intensity (PLSI) on hepatobiliary phase (HBP) images (P

BACKGROUND Studies of gadolinium (Gd) clearance from animals in the first weeks after administration of gadolinium-based contrast agents (GBCAs) have previously looked at solitary timepoints only. However, this does not give information on differences between GBCAs and between organs in terms of Gd elimination kinetics. PURPOSE To compare Gd levels in rat cerebellum, cerebrum, skin, and blood at 1, 2, 3, and 5 weeks after repeated administration of macrocyclic GBCAs. STUDY TYPE Prospective. ANIMAL MODEL One hundred eighty male Sprague-Dawley rats randomized to three groups (n = 60/group), received intravenous administrations of gadoteridol, gadoterate meglumine, or gadobutrol (0.6 mmol/kg for each) four times/week for 5 consecutive weeks. Rats were sacrificed after washout periods of 1, 2, 3, or 5 weeks. FIELD STRENGTH/SEQUENCE Not applicable. ASSESSMENT Cerebellum, cerebrum, skin, and blood were harvested for Gd determination by inductively coupled plasma-mass spectrometry (15 animals/group/all timepoints). STATISTICAL TESTS Anova and Dunnett's test (data with homogeneous variances and normal distribution). Kruskal-Wallis and Wilcoxon's rank sum tests (data showing nonhomogeneous variances or a non-normal distribution, significance levels: P

AIM To establish the diagnostic accuracy of the Liver Imaging Reporting and Data System (LI-RADS) for hepatocellular carcinoma (HCC) and compare its performance to that of international criteria from European Assofor the Study of the Liver (EASL), Japan Society of Hepatology (JSH), Asian Pacific Association for the Study of the Liver (APASL), and Organ Procurement and Transplantation Network (OPTN), and to the reporting radiologist's overall opinion regarding the probability of a nodule being a HCC by correlating with a histological diagnosis from whole liver explants. MATERIALS AND METHODS The present single-centre, retrospective review selected participants based on the following criteria: adults (≥18 years) listed for liver transplantation in 2014/2015, with liver cirrhosis at the time of magnetic resonance imaging (MRI) with hepatocyte specific contrast agent, and at least one liver lesion ≥10 mm on MRI with histology from subsequent liver explant for comparison. Each lesion was assessed against international criteria and given a “radiologist opinion” score of 1–5 (1 = definitely benign, 5 = definitely HCC). RESULTS Total 268 patient records were reviewed, with 105 eligible lesions identified from 47 patients. Median lesion size was 15.5 mm (range 10–68 mm). Sensitivity (%), specificity (%), and positive predictive value (PPV; %) for LI-RADS LR5 was 45, 89, and 89, for LI-RADS LR4+5 + TIV was 61, 80, and 86, for EASL was 44, 86 and 86, for JSH/APASL was 64, 81, and 87, for OPTN was 36, 90, and 88, and for “radiologist impression” of probably or definitely HCC was 79, 79, and 88 respectively. CONCLUSIONS MRI has moderate sensitivity and good specificity for the diagnosis of HCC with considerable variation depending on criteria used. OPTN criteria have the best specificity, but low sensitivity. “Radiologist opinion” gives highest overall accuracy with increases in sensitivity and reduction in specificity when compared to the imaging criteria.

This study aimed to elucidate the relationship between gadoxetic acid–enhanced magnetic resonance imaging (MRI) features—enhancing capsule, corona enhancement or hypointense rim—observed in hepatocellular carcinomas (HCCs). Of the HCCs surgically confirmed during a 5-year period (2013–2017), ≤ 3-cm lesions (n = 83) in 78 patients were evaluated. Presence of corona enhancement and enhancing capsule on multiphasic dynamic imaging and presence of hypointense rim on hepatobiliary phase imaging were determined retrospectively by two independent observers. The relationship among the three imaging features was statistically analysed and correlated with the presence of histologic fibrous capsules, tumour differentiation and gross morphologic type. There was substantial overall interobserver agreement in determining the presence of the three imaging features. Sixty (72.3%) lesions had histologic fibrous capsule positively correlated with all three imaging features (p < 0.05). Corona enhancement was the most common (66.3%) feature followed by enhancing capsule (61.4%) and hypointense rim (33.7%), and the correspondence rate of enhancing capsule to corona enhancement was 68.6% (p = 0.004). Corona enhancement was more frequently observed in moderately differentiated HCCs than other lesions (p = 0.012) and not dependent (p = 0.465) on the tumour size, while enhancing capsule was significantly dependent on tumour size, as indicated by univariate (p < 0.001) and multivariate analyses (odds ratio, 4.241; p = 0.002). Among the capsular features, corona enhancement might closely relate to enhancing capsule in HCCs. Corona enhancement was not dependent on tumour size and had the highest incidence of appearance on gadoxetic acid–enhanced multiphasic dynamic MRI. • Enhancing capsule has a limited role in the LI-RADS categorisation during gadoxetic acid–enhanced MRI. • Appearance of corona enhancement is closely related to enhancing capsule and is not dependent on size of HCCs. • Corona enhancement can substitute enhancing capsule in the diagnosis of HCCs during multiple arterial and portal venous phase gadoxetic acid–enhanced MRI.

BACKGROUND AND PURPOSE: Gadolinium complexes have paramagnetic properties; thus, we aimed to determine the susceptibility changes in the globus pallidus and dentate nucleus following administration of linear or macrocyclic gadolinium-based contrast agents in children. MATERIALS AND METHODS: Thirty-three patients with linear gadolinium-based contrast agent gadopentetate dimeglumine administration, 33 age- and sex-matched patients with macrocyclic gadolinium-based contrast agent gadobutrol administration, and 33 age- and sex-matched control subjects without gadolinium exposure were enrolled in this retrospective study. The signal intensity on SWI and T1WI was determined in the dentate nucleus, middle cerebellar peduncle, globus pallidus, and pulvinar of the thalamus in an ROI-based analysis to calculate dentate nucleus–to–middle cerebellar peduncle and globus pallidus–to–thalamus ratios. A repeated measures ANOVA was performed to compare SWI(minimum), SWI(mean), and T1WI signal intensity ratios between gadolinium-based contrast agent groups and control subjects. Pearson correlation analysis was performed to determine any correlation between signal intensity ratios and variables. RESULTS: Dentate nucleus–to–middle cerebellar peduncle and globus pallidus–to–thalamus ratios for both SWI(mean) and SWI(minimum) were lower for the linear gadolinium-based contrast agent group compared with macrocyclic gadolinium-based contrast agent and control groups (P < .05). No significant difference of the SWI(mean) and SWI(minimum) ratios were noted between the macrocyclic gadolinium-based contrast agent group and the control group (P > .05). Both dentate nucleus–to–middle cerebellar peduncle and globus pallidus–to–thalamus ratios on T1WI in the linear gadolinium-based contrast agent group were higher than in the control group and the macrocyclic gadolinium-based contrast agent group (P < .05). A negative correlation was identified between SWI(mean) and SWI(minimum) ratios and the number of linear gadolinium-based contrast agent administrations (dentate nucleus–to–middle cerebellar peduncle ratio: SWI(mean), r = –0.43, P = .005; SWI(minimum), r = –0.38, P = .011; globus pallidus–to–thalamus ratio: SWI(mean), r = –0.39, P = .009; SWI(minimum), r = –0.33, P = .017). CONCLUSIONS: SWI analysis of the pediatric brain demonstrated a statistically significant decrease in SWI(minimum) and SWI(mean) values for the dentate nucleus and globus pallidus after administration of linear gadolinium-based contrast agents but not macrocyclic gadolinium-based contrast agents.

To evaluate the value of gadobenate dimeglumine–enhanced MRI in predicting the pathologic grade of hepatocellular carcinoma (HCC). Patients with pathologically proven HCC who underwent preoperative gadobenate dimeglumine–enhanced dynamic MRI were included. Two radiologists blinded to pathology results evaluated images in consensus. Lesions were evaluated quantitatively in terms of ratio of enhancement (RE), and qualitatively based on image features related to tumor aggressiveness. Logistic regression and ROC analyses were used to determine the value of these parameters to predict pathologic grade. In total, 221 patients (194 males, 27 females, aged 52.9 ± 11.7 years) with 49 poorly differentiated HCCs and 172 well/moderately differentiated HCCs were evaluated. Features significantly related to poorer pathologic grade at univariate analysis included lower RE in the early arterial phase (EAP) (p = 0.001), nonsmooth margins (p = 0.001), absence of capsule (p < 0.001), arterial peritumoral hyperenhancement (p < 0.001), higher AFP (p = 0.004), multiple tumors (p = 0.026), and larger tumor size (p = 0.028). At multivariate analysis, lower RE (EAP) (OR = 0.144, p = 0.002), absence of capsule (OR = 0.281, p = 0.004), and arterial peritumoral hyperenhancement (OR = 4.117, p < 0.001) were independent predictive factors for poorer pathologic grade. ROC analysis showed lower RE (EAP) was predictive of poorer pathologic grade (AUC = 0.667). AUC increased to 0.797 when combined with absence of capsule and presence of peritumoral hyperenhancement. Lower RE (EAP), absence of capsule, and arterial peritumoral hyperenhancement were predictive biomarkers for poorer pathologic grade of HCC on gadobenate dimeglumine–enhanced dynamic MRI. • Gadobenate dimeglumine–enhanced dynamic MRI was a useful quantitative biomarker for preoperative prediction of pathologic grade in patients with HCC. • Lower RE in the early arterial phase, absence of capsule, and arterial peritumoral hyperenhancement were potential imaging indicators for preoperative prediction of poorer pathologic grade of HCC on gadobenate dimeglumine–enhanced MRI. • A lower RE in the early arterial phase was effective at predicting poorer pathologic grade of HCCs but prediction is improved when combined with absence of capsule and presence of peritumoral hyperenhancement.

To identify image features of macrotrabecular-massive (MTM) hepatocellular carcinoma (HCC) and to determine its role in predicting MTM-HCC. Patients who underwent preoperative gadoxetic acid-enhanced MRI and with surgery proven HCC were retrospectively included. Imaging features were assessed according to Liver Imaging Reporting and Data System. Quantitative measurements were recorded. Clinical characteristics and imaging findings were compared between MTM-HCCs and non-MTM-HCCs. Predictive factors of MTM-HCC were screened with univariate analyses and then identified with multivariate logistic regression. A regression-based diagnostic model was constructed. ROC analyses were used to determine cutoff values, AUC, and corresponding 95% confidence interval (CI) of findings. The diagnostic performance was validated by 10-fold cross-validation. One hundred and forty-one patients with 37 MTM-HCCs were included. Multivariate analyses identified high platelet count (≥ 163.5 × 103/ul, odds ratio = 3.20; 95% CI: 1.29, 7.96; p = 0.012), low tumor-to-liver ADC ratio (≤ 1.05, odds ratio = 3.05; 95% CI, 1.23 - 7.55; p = 0.016), and necrosis or severe ischemia (odds ratio = 11.61; 95% CI, 3.99 - 33.76, p < 0.001) as independent predictors of MTM-HCC. Necrosis or severe ischemia alone helped identify 86% MTM-HCCs with a specificity of 66%. The average AUCs were 0.81 (95% CI: 0.71, 0.90) for the regression-based diagnostic model, with a sensitivity of 57% and specificity of 92%. Necrosis or severe ischemia was a sensitive imaging feature of MTM-HCC. Noninvasive prediction of this subtype can be achieved with good accuracy and excellent specificity when findings were combined. • The macrotrabecular-massive (MTM) hepatocellular carcinoma (HCC) represents an aggressive subtype of HCC and is associated with poor prognosis. • Imaging features of necrosis or severe ischemia alone helped identify 86% MTM-HCCs with a specificity of 66%. • A regression-based diagnostic model including high platelet count (≥ 163.5 × 10 3 /ul), low tumor-to-liver ADC ratio (≤ 1.05), and necrosis or severe ischemia can provide noninvasive assessment of MTM-HCC with good accuracy and high specificity.

Magnetic resonance imaging is used for evaluating focal liver lesions, hepatic vascular diseases, biliary diseases and diffuse liver diseases in children. MRI examinations take a long time, often requiring sedation or anesthesia in smaller children. This makes it essential to understand the concepts and technique necessary to obtain an optimal examination for answering the clinical question while minimizing the need for sedation/anesthesia. We discuss key concepts including appropriate sequence selection, choice of contrast media, dynamic imaging, phases of contrast enhancement and protocol organization.

Objectives To evaluate image quality by first use of LumiVision® in dynamic MR swallowing, a contrast medium consisting of biological substances versus a gadolinium-buttermilk mixture in patients who underwent Nissen fundoplication due to gastroesophageal reflux disease (GERD). Methods The protocol of this retrospective study was approved by the local Institutional Review Board. A hundred twenty-nine patients (146 examinations) underwent a dynamic MR swallowing study (at 1.5 T or 3.0 T) and received an oral contrast agent. Two readers evaluated the distention of the esophagus, contrast, and traceability of the bolus in a 3-point scale. A steady-state coherent sequence (B-FFE, TrueFISP) was used. The patients were divided into 3 different groups: 53 patients received gadolinium chelate (Dotarem®)–buttermilk mixture (GBM) in a dilution of 1:40 as an oral contrast agent; 44 patients received LumiVision® water mixture (LWM) in a dilution of 1:1 and 49 patients received LumiVision® (L) undiluted. Results GBM showed significantly better results in overall evaluation for both readers in contrast to LWM (p = .003, p = .002). L also reached significantly better results in overall evaluation than LWM in both readers (p = .004, p = .042). There was no significant difference in the overall evaluation between L and GBM (p = .914, p = .376).According to Landis and Koch, interobserver agreement was “substantial” (Cohen’s kappa = 0.738) between both readers. Conclusion LumiVision® undiluted showed equal image quality compared to gadolinium-buttermilk mixture. The constellation of LumiVision® water mixture led to a clearly negative result in relation to the image quality compared to LumiVision® undiluted. Therefore, oral ingestion of LumiVision® undiluted is recommended for MR swallowing examinations. Key Points • LumiVision® undiluted shows significantly better image quality in comparison to LumiVision® diluted in oral application in swallowing MRI. • LumiVision® undiluted shows equal image quality in comparison to gadolinium-buttermilk mixture in oral application. • Oral ingestion of LumiVision® undiluted can replace gadolinium-buttermilk mixture in oral MR examinations.

To develop a prediction model that combined magnetic resonance images (MRI)-based radiomics features with clinical factors to predict recurrence-free survival (RFS) of hepatocellular carcinoma (HCC) patients treated with surgical resection. HCC patients treated with surgical resection (n = 153) were randomly divided into training (n = 107) and validation (n = 46) datasets. The volumes of interest were manually outlined around the lesion and additional 2 mm and 5 mm peritumoral areas were created with automated dilatation in MRI to extract tumoral (T) and peritumoral (PT) radiomics features. The radiomics models were constructed using least absolute shrinkage and selection operator Cox regression. The combined model incorporated clinical factors and radiomics features using multivariable Cox regression based on the Akaike information criterion principle. Predictive performance of different models were evaluated by receiver operating characteristic (ROC) curves, decision curves, and calibration curves. Among the radiomics models, similar performance was observed in the 2 mm and 5 mm PT models (C-index both 0.657), which were better than the T model or T + PT model (C-index 0.607 and 0.641, respectively) in the validation dataset, whereas the model combined with the three identified clinical risk factors showed the best performance (C-index 0.725). Results of the ROC curves, decision curves, and the calibration curves indicated that the combined model and the derived nomogram had better prediction performance, greater clinical benefits, and fair calibration efficiency. The prediction model that combined MRI radiomics signatures with clinical factors can effectively predict the prognosis of patients with HCC treated with surgical resection.

Background The prognostic value of left atrial (LA) size and function in hypertrophic cardiomyopathy (HCM) is well recognized, but LA function is difficult to routinely analyze. Fast LA long-axis strain (LA-LAS) analysis is a novel technique to assess LA function on cine cardiovascular magnetic resonance (CMR). We aimed to assess the association between fast LA-LAS and adverse clinical outcomes in patients with HCM. Methods 359 HCM patients and 100 healthy controls underwent routine CMR imaging. Fast LA-LAS was analyzed by automatically tracking the length between the midpoint of posterior LA wall and the left atrioventricular junction based on standard 2- and 4-chamber balanced steady-state free precession cine-CMR. Three strain parameters including reservoir strain (εs), conduit strain (εe), and active strain (εa) were assessed. The endpoint was set as composite adverse events including cardiovascular death, resuscitated cardiac arrest, sudden cardiac death aborted by appropriate implantable cardioverter-defibrillator discharge, and hospital admission related to heart failure. Results During an average follow-up of 40.9 months, 59 patients (19.7%) reached endpoints. LA strains were correlated with LA diameter, LA volume index (LAVI) and LA empty fraction (LAEF) (all p Conclusions Fast LA reservoir and conduit strains are independently associated with adverse outcomes in HCM.

Background Non-ischemic cardiomyopathy (NICM) is a heterogeneous disease, and its prognosis varies. Although late gadolinium enhancement (LGE)-cardiovascular magnetic resonance (CMR) demonstrates a linear pattern in the mid-wall of the septum or multiple LGE lesions in patients with NICM, the therapeutic response and prognosis of multiple LGE lesions have not been elucidated. This study aimed to investigate the frequency of left ventricular (LV) reverse remodeling (LVRR) and prognosis in patients with NICM who have multiple LGE lesions. Methods This single-center retrospective study included 101 consecutive patients with NICM who were divided into 3 groups according to LGE-CMR results: patients without LGE (no LGE group = 48 patients), patients with a typical mid-wall LGE pattern (n = 29 patients), and patients with multiple LGE lesions (n = 24 patients). LVRR was defined as an increase in LV ejection fraction (LVEF) ≥ 10 % and a final value of LVEF > 35 %, which was accompanied by a decrease in LV end-systolic volume ≥ 15 % at 12-month follow-up using echocardiography. The frequency of composite cardiac events, defined as sudden cardiac death (SCD), aborted SCD (non-fatal ventricular fibrillation, sustained ventricular tachycardia, or adequate implantable cardioverter-defibrillator therapies), and heart failure death or hospitalization for worsening heart failure, were summarized and compared between the groups. Results Among the 3 groups, the frequency of LVRR was significantly lower in the multiple lesions group than in the no LGE and mid-wall groups (no LGE vs. mid-wall vs. multiple lesions: 49 % vs. 52 % vs. 19 %, p = 0.03). There were 24 composite cardiac events among the patients: 2 in patients without LGE (hospitalization for worsening heart failure; 2), 7 in patients of the mid-wall group (SCD; 1, aborted SCD; 1 and hospitalization for worsening heart failure; 5), and 15 in patients of the multiple lesions group (SCD; 1, aborted SCD; 8 and hospitalization for worsening heart failure; 6). The multiple LGE lesions was an independent predictor of composite cardiac events (hazard ratio: 11.40 [95 % confidence intervals: 1.49−92.01], p = 0.020). Conclusions Patients with multiple LGE lesions have a higher risk of cardiac events and poorer LVRR. The LGE pattern may be useful for an improved risk stratification in patients with NICM.

Background The objective of this study was to analyze the accuracy of gadolinium–ethoxybenzyl–diethylenetriamine penta–acetic acid enhanced magnetic resonance imaging (Gd–EOB–DTPA–MRI) for predicting microvascular invasion (MVI) in patients with small hepatocellular carcinoma (sHCC) preoperatively. Methods A total of 60 sHCC patients performed with preoperative Gd–EOB–DTPA–MRI in the Harbin Medical University Cancer Hospital from October 2018 to October 2019 were involved in the study. Univariate and multivariate analyses were performed by chi–square test and logistic regression analysis. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of Gd–EOB–DTPA–MRI were performed by receiver operating characteristic (ROC) curves. Results Univariate analysis indicated that alanine aminotransferase (≥ 39.00U/L), poorly differentiated pathology, and imaging features including grim enhancement, capsule enhancement, arterial halo sign and hepatobiliary features (tumor highly uptake, halo sign, spicule sign and brush sign) were associated with the occurrence of MVI (p p Conclusions The morphologies of hepatobiliary phase imaging, especially the spicule sign, showed high accuracy in diagnosing MVI of sHCC. Rim enhancement played a significant role in diagnosing MVI of sHCC.

Objectives The 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. Methods As 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 conclusions Gadoxetic 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.

Objectives To develop radiomics-based nomograms for preoperative microvascular invasion (MVI) and recurrence-free survival (RFS) prediction in patients with solitary hepatocellular carcinoma (HCC) ≤ 5 cm. Methods Between March 2012 and September 2019, 356 patients with pathologically confirmed solitary HCC ≤ 5 cm who underwent preoperative gadoxetate disodium–enhanced MRI were retrospectively enrolled. MVI was graded as M0, M1, or M2 according to the number and distribution of invaded vessels. Radiomics features were extracted from DWI, arterial, portal venous, and hepatobiliary phase images in regions of the entire tumor, peritumoral area ≤ 10 mm, and randomly selected liver tissue. Multivariate analysis identified the independent predictors for MVI and RFS, with nomogram visualized the ultimately predictive models. Results Elevated alpha-fetoprotein, total bilirubin and radiomics values, peritumoral enhancement, and incomplete or absent capsule enhancement were independent risk factors for MVI. The AUCs of MVI nomogram reached 0.920 (95% CI: 0.861–0.979) using random forest and 0.879 (95% CI: 0.820–0.938) using logistic regression analysis in validation cohort (n = 106). With the 5-year RFS rate of 68.4%, the median RFS of MVI-positive (M2 and M1) and MVI-negative (M0) patients were 30.5 (11.9 and 40.9) and > 96.9 months (p < 0.001), respectively. Age, histologic MVI, alkaline phosphatase, and alanine aminotransferase independently predicted recurrence, yielding AUC of 0.654 (95% CI: 0.538–0.769, n = 99) in RFS validation cohort. Instead of histologic MVI, the preoperatively predicted MVI by MVI nomogram using random forest achieved comparable accuracy in MVI stratification and RFS prediction. Conclusions Preoperative radiomics-based nomogram using random forest is a potential biomarker of MVI and RFS prediction for solitary HCC ≤ 5 cm. Key Points • The radiomics score was the predominant independent predictor of MVI which was the primary independent risk factor for postoperative recurrence. • The radiomics-based nomogram using either random forest or logistic regression analysis has obtained the best preoperative prediction of MVI in HCC patients so far. • As an excellent substitute for the invasive histologic MVI, the preoperatively predicted MVI by MVI nomogram using random forest (MVI-RF) achieved comparable accuracy in MVI stratification and outcome, reinforcing the radiologic understanding of HCC angioinvasion and progression.

To evaluate and compare the diagnostic performance of the updated HCC guidelines using gadoxetic acid-enhanced MRI.In this study, patients at risk of HCC who underwent gadoxetic acid-enhanced MRI following US/CT surveillance were retrospectively recruited from 3 centers. Three radiologists independently evaluated hepatic nodule imaging features relevant to the diagnostic criteria outlined in each guideline. Per-lesion sensitivity, specificity, and accuracy were compared between guidelines using logistic regression with a generalized estimating equation. Inter-observer agreements on imaging features were determined using Fless κ statistics.Altogether, 447 nodules (310 HCCs, 20 combined hepatocellular-cholangiocarcinomas, 2 cholangiocarcinomas, and 115 benign entities) measuring 1-3 cm from 386 patients were assessed. The KLCA-NCC and APASL guidelines showed the highest sensitivity (82.3-90.6%, p.001) and accuracy (83.9-88.6%) among the five guidelines. The OPTN/UNOS guideline showed the highest specificity (94.9-97.1%), followed by the AASLD/LI-RADS, EASL, KLCA-NCC, and APASL guidelines, with significant difference only with the APASL guideline. The diagnostic performance of the updated AASLD/LI-RADS and EASL guidelines and of the KLCA-NCC and APASL guidelines was comparable (p.05). Inter-observer agreement was substantial to almost perfect (κ = 0.73-0.87).For the diagnosis of HCC using gadoxetic acid-enhanced MRI, the KLCA-NCC and APASL guidelines showed the highest sensitivity and accuracy. The OPTN/UNOS guideline showed the highest specificity. Acknowledging their relative strengths and weaknesses could help adapt the diagnostic criteria according to the clinical context.• APASL and KLCA-NCC provided significantly the highest sensitivity and accuracy, followed by AASLD/LI-RADS and EASL in an endemic area for hepatitis B. • OPTN/UNOS showed the highest specificity, followed by AASLD/LI-RADS, EASL, KLCA-NCC, and APASL guidelines, with significant difference only with APASL. • Broadened definition of arterial hyperenhancement, washout, and the size of the lesion eligible to apply diagnostic criteria may improve the diagnostic performance for HCC in an endemic area for hepatitis B.

Purpose To determine the optimal combination of gadoxetate disodium-enhanced magnetic resonance imaging (MRI) findings for the diagnosis of hepatocellular carcinoma (HCC) and to compare its diagnostic ability to that of dynamic computed tomography (CT) in patients with chronic liver disease. Methods This multi-institutional study consisted of two parts: Study 1, a retrospective study to determine the optimal combination of gadoxetate disodium-enhanced MRI findings (decision tree and logistic model) to distinguish HCC (n = 199) from benign (n = 81) or other malignant lesions (n = 95) (375 nodules in 269 patients) and Study 2, a prospective study to compare the diagnostic ability of gadoxetate disodium-enhanced MRI to distinguish HCC (n = 73) from benign (n = 15) or other malignant lesions (n = 12) with that of dynamic CT (100 nodules in 83 patients). Two radiologists independently evaluated the imaging findings (Study 1 and 2) and made a practical diagnosis (Study 2). Results In Study 1, rim or whole enhancement on arterial phase images, signal intensities on T2-weighted/diffusion-weighted/portal venous/transitional/hepatobiliary phase images, and signal drop on opposed-phase images were independently useful for differential diagnosis. In Study 2, the accuracy, sensitivity, negative predictive value, and negative likelihood ratio of the CT decision tree (reader 2) were higher than those of MRI Model 2 (P = 0.015-0.033). There were no other significant differences in diagnostic ability (P = 0.059-1.000) and radiologist-made practical diagnosis (P = 0.059-1.000) between gadoxetate disodium-enhanced MRI and CT. Conclusion We identified the optimal combination of gadoxetate disodium-enhanced MRI findings for HCC diagnosis. However, its diagnostic ability was not superior to that of dynamic CT.

Purpose: To investigate whether the contrast enhancement effect in hepatobiliary phase (HBP) images can be predicted using transitional phase (3-min delay) images on liver magnetic resonance imaging (MRI) based on the quantitative liver–spleen contrast ratio (Q-LSC) and albumin–bilirubin (ALBI) grade. Methods: Overall, 212 patients (124 men and 88 women; mean age 66.7 ± 11.1 years) who underwent blood tests (assessed within 1 month of performing MRI) were included; patients with diffuse tumor, hepatectomy, splenectomy, Gamna–Gandy bodies in the spleen, and movement artifacts were excluded. Q-LSC was calculated using the signal intensity of the liver divided that of the spleen. Q-LSC > 1.5 (cut-off value) indicates a relatively higher sensitivity for detecting of hepatic lesions. To predict the contrast enhancement effect in HBP using Q-LSC of 3-min delay images, Q-LSC of 10- and 15-min delay images were compared for each ALBI grade based on Q-LSC of 3-min delay images. Furthermore, to verify the accuracy of this prediction, the proportion of cases with Q-LSC > 1.5 in 10- and 15 min delay images was calculated based on Q-LSC on 3-min delay images. Results: The higher the Q-LSC on the 3-min delay image, the higher was the Q-LSC on its 10- and 15-min delay images. The proportion of cases with Q-LSC > 1.5 in 10- and 15-min delay images was higher for ALBI grade 1 than for ALBI grades 2 and 3 even in the same Q-LSC on 3-min delay images. Q-LSC was

Objectives To develop a nanoparticle-based MRI protocol based on transrectal administration of intestine-absorbable nanoparticle contrast agents to evaluate ulcerative colitis (UC). Methods Solid lipid nanoparticles (SLNs) were synthesized by loading gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) and octadecylamine-fluorescein isothiocyanate to produce Gd-FITC-SLNs as T1 contrast agents. Twenty mice with acute UC were divided into four groups: enema with Gd-FITC-SLNs, intravenous injection of Gd-FITC-SLNs, enema with Gd-DTPA, and intravenous injection of Gd-DTPA. Five mice with chronic UC and five mice without UC underwent enema with Gd-FITC-SLNs. Axial T1- and T2-weighted MR images were obtained before and 20, 40, 60, 80,100, and 120 min after enema or intravenous injection of the contrast agent. The signal-to-noise ratios (SNRs) of the colorectal wall were measured in both groups. The MRI findings were correlated with subsequent histological confirmation. Results At 20 min after enema with Gd-FITC-SLNs, MRI showed the following contrast enhancement pattern: acute UC > normal intestinal wall > chronic UC. A continuous enhancement effect was observed in mice with acute UC, whereas a slight continuous enhancement of the colorectal wall was observed in mice with chronic UC. The normal intestinal wall rapidly metabolized the contrast agent, and the enhancement decreased on sequential scans. There was no significant difference between the SNRs of the intestinal wall at 20 min after intravenous Gd-DTPA and transrectal Gd-FITC-SLN administration. Conclusions Enema with Gd-FITC-SLNs may be helpful for the diagnosis and differential diagnosis of acute and chronic UC and can confer the same or better results than with intravenous Gd-DTPA. Key Points • Enema with Gd-FITC-SLNs may be helpful for the diagnosis and differential diagnosis of acute and chronic UC. • Enema with Gd-FITC-SLNs can achieve the same or better result than that with intravenous Gd-DTPA. • SLN-based MR colonography enhances the colorectal wall inflammation, based on the colonic absorption of the nanoparticle contrast agents.

The purpose of this study was to compare the image quality and accuracy of axial vs coronal contrast-enhanced magnetic resonance cholangiography (CE-MRC) for assessing bile duct anatomy.Data from 313 healthy donors who underwent axial and coronal CE-MRC before liver donation were retrospectively analyzed. Motion artifacts and bile duct visibility were assessed using 4-point scales, with scores ≥3 considered interpretable. The sensitivity and specificity of axial and coronal CE-MRC for diagnosing anatomic variations were compared, as were the proportions of correctly categorized biliary anatomic types.Axial CE-MRC provided better image quality than coronal CE-MRC in terms of both motion artifacts (3.83 vs 3.17; P .001) and duct visibility (3.50 vs 3.17, P .001), resulting in more interpretable images with axial than coronal CE-MRC (92.7% vs 82.1%; P .001). Among 249 donors with interpretable images, coronal CE-MRC performed significantly better for identifying duct anatomic variation than axial CE-MRC (sensitivity, 96.9% vs 80.4%, P .001; specificity, 100% vs 96.7%, P = .025). Coronal CE-MRC was significantly better than axial CE-MRC at correctly categorizing anatomic types of right posterior hepatic duct into left hepatic duct and accessory duct with incomplete right hepatic duct.With interpretable image quality, coronal CE-MRC performed better than axial CE-MRC for evaluating bile duct anatomy.

Purpose To investigate whether shortened acquisition or multiple arterial phase acquisition improves image quality of the arterial phase compared with conventional protocol. Methods This retrospective study was approved by the relevant Institutional Review Board. A total of 615 consecutive patients who underwent gadoxetate disodium-enhanced MRI including one of the following three sequences in three different periods were included: (i) conventional liver acquisition with volume acceleration (LAVA) (between October 2014 and January 2015, n = 149), (ii) Turbo-LAVA (between March and August 2016, n = 216), and (iii) differential sub-sampling with Cartesian ordering (DISCO) (between January and September 2015, n = 250). We monitored the respiratory bellows waveform during breath holding for each patient and recorded breath-hold fidelity of the patients. Two radiologists independently evaluated the degree of respiratory artifact and scan timing on the arterial phase and compared them between the three protocols (i.e., conventional LAVA, Turbo-LAVA, and DISCO), with conventional LAVA as control. Results The ratio of patients with breath-hold failure was not significantly different among the three protocols (P = 0.6340 and 0.1085). Respiratory artifact was significantly lower in DISCO than in conventional LAVA (P = 0.0424), while there was no significant difference between Turbo-LAVA and conventional LAVA (P = 0.2593). The ratio of adequate scan timing and diagnosable image defined as no or mild artifact and adequate scan timing were higher in DISCO than in conventional LAVA (P = 0.0025 and 0.0019), while there was no significant difference between Turbo-LAVA and conventional LAVA (P = 0.0780 and 0.0657). Conclusion Compared with conventional protocol, multiple arterial phase acquisition (DISCO) obtained a higher number of diagnosable images by reducing respiratory motion artifact and optimizing the scan timing of arterial phase.

Purpose This study aims to evaluate the effectiveness of breast magnetic resonance imaging (MRI) in detecting residual breast cancer in patients after vacuum-assisted breast biopsy (VABB). Methods Between 2012 and 2019, 26 patients with breast cancer who underwent VABB were enrolled. Breast MRI was conducted after VABB. Imaging findings were then compared with the histopathological results. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated. Results Residual cancer was confirmed histologically in 8 of the 26 patients after VABB. The overall sensitivity, specificity, PPV, NPV, and accuracy of MRI for diagnosing residual cancer were 79.9%, 73.0%, 87.1%, 61.3%, and 77.8%, respectively. The sensitivity and NPV improved to 100%, when the number of biopsy specimens was larger than five. Conclusion Breast MRI showed high sensitivity and NPV in detecting residual breast tumor after VABB.

Background Gadoxetic acid (GA) has distinctive pharmacokinetic properties with important applications in hepatobiliary imaging. However, there are limited data evaluating the safety of GA administration in patients with impaired kidney function and the incidence of nephrogenic systemic fibrosis (NSF). Purpose To evaluate safety of GA regarding risk of NSF in patients with impaired kidney function. Materials and Methods This retrospective study identified all GA-enhanced MRI (hereafter, GA MRI) examinations performed between July 2008 and December 2019 through a search of the electronic medical record. Serum creatinine values within 180 days or less of each GA MRI examination were retrieved and estimated glomerular filtration rate (eGFR) was calculated. The eGFR value nearest to each MRI examination was used. A separate search in the electronic medical record was also performed to identify patients with NSF. Dermatologists, nephrologists, and nephrologists at our institution were surveyed for any cases of NSF. In patients with NSF, all MRI examinations performed and contrast agents administered to these patients were recorded. Results Overall, 7820 GA MRI examinations were identified, performed in 5351 patients (3022 women and 2329 men). These included 299 examinations (242 patients) with eGFR of 30-44 mL/min/1.73 m2 and 183 examinations (157 patients) with eGFR less than 30 mL/min/1.73 m2. There were 109 examinations (in 94 patients) with eGFR of 15-29 mL/min/1.73 m2, 40 examinations (in 39 patients) with eGFR less than 15 mL/min/1.73 m2, and 34 examinations in 27 patients undergoing hemodialysis. Seventeen patients with eGFR less than 30 mL/min/1.73 m2 or undergoing dialysis underwent GA MRI two or more times. Eighteen patients with biopsy-confirmed NSF were identified, none of whom were exposed to GA. The mean follow-up period for GA MRI examinations performed in patients with severe kidney impairment was 4.2 years (range, 0.2-11.3 years). Conclusion Gadoxetic acid may be safe with respect to nephrogenic systemic fibrosis in this patient population, although further studies are needed to confirm this. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Davenport and Shankar in this issue.

To evaluate the postoperative prognostic value of the Liver Imaging Reporting and Data System (LI-RADS) category on gadoxetic acid-enhanced MRI and 18F-fluorodeoxyglucose PET-CT in patients with primary liver carcinomas (PLCs).A total of 189 patients with chronic liver disease and surgically proven single PLC (42 intrahepatic cholangiocarcinomas and 21 combined hepatocellular-cholangiocarcinomas and 126 hepatocellular carcinomas [2:1 matching to non-HCC malignancies]) were retrospectively evaluated with gadoxetic acid-enhanced MRI and PET-CT. Two independent reviewers assigned an LI-RADS category for each observation. The tumor-to-liver standardized uptake value ratio (TLR) was calculated. The overall survival (OS), recurrence-free survival (RFS), and the associated factors were evaluated.In multivariable analysis, LI-RADS category (LR-4 or LR-5 [LR-4/5] vs. LR-M; OS, hazard ratio [HR] 2.24, p = 0.006; RFS, HR 1.61, p = 0.028) and TLR (low, 2.3 vs. high, ≥ 2.3; OS, HR 2.09, p = 0.014; RFS, HR 2.17, p 0.001) were the independent factors for OS and RFS. For the LR-M group, the high TLR group showed lower OS and RFS rates than the low TLR group (OS, p = 0.008; RFS, p 0.001). For the LR-4/5 group, the OS and RFS rates were not significantly different between the high TLR and low TLR groups (both p 0.05).Both LI-RADS category on MRI and TLR on PET-CT are associated with the postoperative prognosis of PLCs. The prognosis of PLCs classified as LR-M can be further stratified according to the TLR group, but not for the PLCs classified as LR-4/5.• The LI-RADS category (LR-4/5 vs. LR-M) and tumor-to-liver standardized uptake value ratio (TLR, low vs. high) were independent factors for postoperative prognosis of primary liver carcinomas (PLCs). • For PLCs classified as LR-M, the TLR group helps stratify the postoperative prognosis of PLCs, with the high TLR group having a poor prognosis and the low TLR group having a better prognosis (p = 0.008 for OS and p 0.001 for RFS). • For PLCs classified as LR-4/5, the OS and RFS rates were not significantly different between the high TLR and low TLR groups (both p 0.05).

Background Repeated transarterial chemoembolization (TACE) can be associated with loss of its efficacy and subsequent tumor progression. Purpose To identify features of gadoxetic acid-enhanced magnetic resonance imaging (MRI) associated with TACE refractoriness and to develop a prediction model for estimating the risk of TACE refractoriness. Material and Methods Among 1025 patients with intermediate-stage hepatocellular carcinoma (HCC) who underwent TACE as a first-line treatment during 2010–2017, 427 patients who underwent preoperative gadoxetic acid-enhanced MRI were analyzed. According to the date of initial TACE, patients were divided into the development cohort (n = 211) and the test cohort (n = 216). TACE refractoriness was determined according to the Japan Society of Hepatology guidelines. Univariable and multivariable analyses were performed to investigate the association between clinical/MRI features and TACE refractoriness. The performance of the prediction model was internally and externally assessed using the C-index of discrimination and a Hosmer-Lemeshow goodness-of-fit test for calibration. Results By analyzing 427 patients, we constructed a prediction model with the following independent features associated with TACE refractoriness: maximum tumor size; tumor number; peritumoral hypointensity on hepatobiliary phase (HBP); and the presence of non-hypervascular hypointense nodule on HBP. This system enabled the prediction of TACE refractoriness in the development cohort (C-index, 0.796) and the test cohort (C-index, 0.738) with good discrimination and calibration abilities. Conclusion The prediction model based on gadoxetic acid-enhanced MRI features in addition to the known predictors including tumor size and number can be used to estimate the risk of TACE refractoriness in patients with intermediate-stage HCC.