Objective To investigate the MRI features of hepatic IgG4?related inflammatory pseudotumor (IPT). Methods Nine patients with 11 histopathologically proven IgG4?related hepatic IPTs were retrospectively analyzed. The clinical, morphological and MRI signal features on T1WI, T2WI, dynamic?enhanced, and diffusion?weighted imaging were assessed in detail and correlated with pathological findings. The paired t test was used to compare the ADC values of the tumors and the hepatic tissue. Results Hepatic IgG4?related IPT displayed certain MRI features. The dominant lesions were subcapsularly distributed (n=7) with a clear boundary (n=8), which typically showed hypointensity on T1WI (n=11), mild hyperintensity on T2WI (n=8), progressive (n=5) or persistent (n=4) enhancement pattern. Accompanied signs included delayed capsule?like enhancement (n=6) and central nonenhanced areas (n=7). Two lesions showed atypical wash?out pattern with iso or hypointensity on portal and delayed phases. In diffusion weighted imaging, all lesions were hyperintense, and the mean ADC value of the lesions [(1.42 ± 0.36) × 10?3mm2/s] was mildly lower than that of surrounding liver [(1.55±0.31)×10?3mm2/s], although no statistical differences were found(t=0.78, P=0.46). Conclusions Hepatic IgG4?related IPTs display various MRI manifestations. The lesions normally show progressive enhancement pattern with diffuse homogeneous or heterogeneous hyperintensity, accompanied by delayed capsule?like enhancement and central nonenhanced areas.

Objectives To analyse the radiological features of dynamic MRI and diffusion weighted imaging for atypical small hepatic hemangiomas (≤2 cm).Methods The MR images of 14 patients with 14 pathologically-confirmed small atypical hepatic hemangiomas were retrospectively analyzed.All these patients underwent MR imaging including plain T1 weighted imaging,T2 weighted imaging,dynamic contrast enhanced scanning,and diffusion weighted imaging.The signal-to-noise ratios of hemangiomas,the portal vein and the aorta,lesion-to-liver contrast-to-noise ratios,ADCs of hemangiomas and the liver,lesion-to-liver signal ratios in DWI were assessed to generalize the MRI features and the key points in differential diagnosis of this type of hepatic hemangioma.Results In dynamic contrast enhanced scanning,the atypical hemangiomas were barely enhanced and they were hypointense most of the time.The lesions might show a faint enhancement in the delayed phase.There were significant differences in the changes in signal-to-noise ratio between hemangiomas and aorta as well as portal vein in all the three phases (P＜0.05).In DWI,the signal intensities and ADCs of the hemangiomas were higher than the liver parenchyma (P＜0.01).Conclusions MRI dynamic contrast enhanced scanning,diffusion weighted imaging and evaluation of the ADCs were important in the diagnosis and differential diagnosis of small atypical hepatic hemangiomas.

Objective To compare the MR features of small hepatocellular carcinoma (sHCC) and small intrahepatic mass-forming cholangiocarcinoma (sIMCC) (≤ 3 cm) and improve the accuracy in diagnosis.Methods Imaging studies of 318 patients with 351 sHCCs and 42 patients with 47 sIMCCs were retrospectively reviewed.Signal intensity on T2WI and on each phase of dynamic enhanced imaging,enhancement patterns,and accompanying findings of the two groups were compared by qualitative and quantitative studies.The qualitative imaging features of tumors were compared by the x2 test and the Fisher exact test,and the statistically significant variables obtained from univariate analysis were used to conduct multivariate stepwise logistic regression analysis.Enhancement pattern between sHCCs with elevated AFP and normal AFP were assessed by thex2 test.Results Multivariate analysis indicated that signal features of enhancement pattern and the accompanying findings of tumor capsule and hepatic capsule retraction were key predictors in differentiating sHCC from sIMCC:Wash-out pattern (276/351) with enhanced tumor capsule (275/351) highly indicated sHCC,while progressive enhancement pattern (27/47) with hepatic capsule retraction (8/47) indicated the diagnosis of sIMCC (P ＜ 0.01).Compared with sHCC with normal AFP,atypical patterns as progressive (n =4) and stable enhancement (n =32) were more commonIy seen in lesions with elevated AFP,dynamic enhancement pattern was different between the two subgroups (x2 =8.241,P ＜ 0.05).Conclusions Enhancement patterns and the accompanying tumor capsule and hepatic capsule retraction were the most important predictors in differentiating sHCC from sIMCC.In addition,enhancement pattern was relatively more typical in sHCCs with normal AFP which provided valuable information in diagnosis for clinicians.

Objective To compare the MRI features of hepatic neuroendocrine tumors (NET G1,G2) and neuroendocrine carcinomas (NEC G3),as well as to improve the accuracy in hierarchical diagnosis.Methods Twenty patients with histopathologically proven NET and nineteen patients with histopathologically proven NEC were retrospectively analyzed.The morphological and MR signal features were compared.Results The morphological features of vascular invasion (P ＜ 0.05) and lymphadenectasis or necrosis (P ＜ 0.05),as well as the MR signal features on portal phase (P ＜ 0.05) and delayed phase (P ＜0.05) were different between the NET group and the NEC group;contrast to noise ratios (CNR) were also different between the two groups (x2 =5.14,P ＜ 0.05),CNR of the NEC group on both arterial phase (Z =121.75,P ＜ 0.05) and portal phase (Z =139.31,P ＜ 0.05) were significantly lower than the NET group;ROC analysis of CNR demonstrated an area under the curve of 0.729 (P ＜ 0.05) on portal phase,when the optimal cut-off value of-61.38 was used,a sensitivity of 90.0％ and a specificity of 63.2％ can be achieved.Conclusions MRI plays an important role in the hierarchical diagnosis of hepatic neuroendocrine neoplasms.The signs of vascular invasion,lymphadenectasis or necrosis as well as the MR signal features during dynamic enhanced scanning are of great value in differentiating NETs from NECs.

Objective To investigate the diagnostic value of diffusion kurtosis imaging(DKI)in the classification of hepatic fibrosis. Methods Thirty-five male SD rats were randomly divided into two groups:the hepatic fibrosis group(n=28)and the control group(n=7). The rats in hepatic fibrosis group were randomly divided into 4 subgroups and seven rats per group, the rats were administrated 50％ CCl4 intraperitoneally twice a week to establish hepatic fibrosis , and the four subgroups were injected 2, 4, 6, and 8 weeks, respectively. The rats in the control group were administrated same dose of olive oil for 8 weeks. One rat in hepatic fibrosis group was died of liver failure in the 7th week, and a total of 27 fibrosis experimental rats and 7 control rats were finally included in this study. DKI was performed at the end of the injection period for all rats, the apparent diffusion(D)and kurtosis(K)values were evaluated. Rats were sacrificed immediately after MRI scan and liver specimens were collected. The liver tissues were examined by pathology, liver fibrosis degree, which was graded from S0 to S4, and inflammatory activity, which was graded from G0 to G3 were graded. The difference of D value and K value between different liver fibrosis and inflammatory activity scores was compared by one-way ANOVA(normal distribution)or Kruskal-Wallis test(skewed distribution). Spearman correlation analysis and multiple regression analysis were used to reveal the correlation between DKI parameters and fibrosis staging/necroinflammatory activity grade. To confirm the efficiency of using the ROC curve of DKI parameters to qualify the liver fibrosis grade, which grade was≥3. Results Seven, 6, 6, 7, 8 rats were diagnosed as S0 to S4, respectively. The difference of D value and K value among different fibrosis grades was statistically significant(P<0.05). D value and the degree of fibrosis was negatively correlated(r=-0.650, P<0.01);K value and liver fibrosis grade no correlation(r=0.336, P=0.080). Thirteen, 6, 8, 7 rats were diagnosed as G0 to G3, respectively. D value was negatively correlated with inflammatory activity(r=-0.590, P=0.001);K value was no correlation with inflammatory activity(r=0.169, P=0.389). Compared with inflammatory activity, fibrosis classification was an independent factor in determining D values(P=0.001). ROC analyses demonstrated an area under the curve(AUC)of D value, K value, D value combined with K value in the diagnosis of liver fibrosis grading ≥ 3 level were 0.781, 0.672 and 0.833, respectlively. The sensitivity and specificity of D value combined with K value were 83.3％ and 75.0％, respectively. Conclusion DKI imaging is of great value in the classification of hepatic fibrosis and can be used as an effective method for the diagnosis of fibrosis.

Objective To value the capability of MRI in assessing invasiveness of intraductal papillary neoplasms of the bile duct(IPNB). Methods Thirty-nine patients with pathologically confirmed IPNB, who had upper abdominal MR examination within 6 weeks before complete resection of the tumor, were included in the retrospective study. Patients were divided into noninvasive and invasive groups pathologically. Eighteen cases were noninvasive and 21 were invasive. All had undergone MRI plain scans, MR cholangiopancreatography as well as contrast enhanced scans including arterial, portal and delayed phases. Tumor size, location, biliary dilation, thread signs, lesion morphology, lobe atrophy, cholelithiasis, biliary hemorrhage, vascular invasion and intraperitoneal lymphadenopathy were observed on MRI. ADC values and enhancement level of lesions were also measured. Between invasive and noninvasive groups, laboratory results, enhancement levels and ADC values were compared by t test or Mann-Whitney U test, and categorical variables like location and lesion morphology were compared by χ2 test. The diagnostic accuracy was calculated using receiver operating characteristic(ROC)curve analysis. Results No difference was found between invasive and noninvasive groups on gender, age, lesion morphology, bile duct diameter, location, existence of thread signs or cholelithiasis(P>0.05). While the differences on serum CA19-9 level, lesion size, ADC value, and lymph nodes/vascular invasion between groups reached statistical significance (P<0.05). Other than on plain scan(P>0.05), CNR and enhancement levels were also statistically different on arterial, portal and delayed phases between both groups(P<0.05). CA199, enhancement level and CNR of portal phase, as well as ADC value exhibited areas under the ROC curve(AUC)of 0.790, 0.891, 0.817 and 0.882 respectively in invasiveness judgment. Conclusion MR demonstrated relatively high value in assessing invasiveness of IPNB.

Objective To investigate the MRI findings of combined hepatocellular cholangio-carcinoma(cHCC-CC)and their correlation with pathologic types. Methods Twenty-nine patients with surgical pathology-confirmed cHCC-CC(20 patients with 24 cHCC-CCs were categorized as classical, and 9 patients with 10 cHCC-CCs as subtypes with stem cell features)were retrospectively analyzed. The clinical features, morphological and MRI signal characteristics on T1WI, T2WI, dynamic enhancement patterns and diffusion-weighted imaging were evaluated in detail and compared these imaging findings with pathologic types. The ADC values of 17 patients with 24 cHCC-CCs were measured. The imaging features were compared by using t test and Fisher test. Results The average maximum diameter of classical type and stem cell feature type were (3.8 ± 2.5) cm and (4.5 ± 1.8) cm, respectively, there was no significant difference(t=0.749,P=0.462). Seven cHCC-CCs showed heterogeneously high signal and twenty-seven cHCC-CCs showed low signal on T1WI. Seventeen cHCC-CCs showed hypointense in the central with mixed high and low signal on T2WI. Twenty-one cHCC-CCs showed peripheral enhancement and 13 lesions showed heterogeneously enhancement during arterial phase. The enhancement pattern of quickly wash-in and quickly wash-out were seen in 17 lesions, the other 17 lesions showed reversal enhancement. Twenty-five lesions presented with pseucapsule. There was no significant difference in clinical features and MRI findings between the two pathologic tumor types(classical type versus stem cell feature type)except for the enhancement pattern in arterial phase and peri-tumoral bile duct dilatation(P<0.05).The mean ADC value of the tumors with stem cell feature type(1.41 ± 0.52) × 10-3mm2/s was mildly lower than that of classical type (1.60 ± 0.39) × 10-3mm2/s, and no statistical differences were found(t=-1.005,P=0.326). Conclusions The MRI findings of cHCC-CCs has specificity. However, it is not easy to distinguish the classical type and stem cell feature type of cHCC-CC only by MRI findings.

Objective To investigate the MRI findings of combined hepatocellular cholangio-carcinoma(cHCC-CC)and their correlation with pathologic types. Methods Twenty-nine patients with surgical pathology-confirmed cHCC-CC(20 patients with 24 cHCC-CCs were categorized as classical, and 9 patients with 10 cHCC-CCs as subtypes with stem cell features)were retrospectively analyzed. The clinical features, morphological and MRI signal characteristics on T1WI, T2WI, dynamic enhancement patterns and diffusion-weighted imaging were evaluated in detail and compared these imaging findings with pathologic types. The ADC values of 17 patients with 24 cHCC-CCs were measured. The imaging features were compared by using t test and Fisher test. Results The average maximum diameter of classical type and stem cell feature type were (3.8 ± 2.5) cm and (4.5 ± 1.8) cm, respectively, there was no significant difference(t=0.749,P=0.462). Seven cHCC-CCs showed heterogeneously high signal and twenty-seven cHCC-CCs showed low signal on T1WI. Seventeen cHCC-CCs showed hypointense in the central with mixed high and low signal on T2WI. Twenty-one cHCC-CCs showed peripheral enhancement and 13 lesions showed heterogeneously enhancement during arterial phase. The enhancement pattern of quickly wash-in and quickly wash-out were seen in 17 lesions, the other 17 lesions showed reversal enhancement. Twenty-five lesions presented with pseucapsule. There was no significant difference in clinical features and MRI findings between the two pathologic tumor types(classical type versus stem cell feature type)except for the enhancement pattern in arterial phase and peri-tumoral bile duct dilatation(P<0.05).The mean ADC value of the tumors with stem cell feature type(1.41 ± 0.52) × 10-3mm2/s was mildly lower than that of classical type (1.60 ± 0.39) × 10-3mm2/s, and no statistical differences were found(t=-1.005,P=0.326). Conclusions The MRI findings of cHCC-CCs has specificity. However, it is not easy to distinguish the classical type and stem cell feature type of cHCC-CC only by MRI findings.

Gadoxetate magnetic resonance imaging (MRI) is widely used in clinical practice for liver imaging. For optimal use, we must understand both its advantages and limitations. This article is the outcome of an online advisory board meeting and subsequent discussions by a multidisciplinary group of experts on liver diseases across the Asia-Pacific region, first held on September 28, 2020. Here, we review the technical considerations for the use of gadoxetate, its current role in the management of patients with hepatocellular carcinoma (HCC), and its relevance in consensus guidelines for HCC imaging diagnosis. In the latter part of this review, we examine recent evidence evaluating the impact of gadoxetate on clinical outcomes on a continuum from diagnosis to treatment decision-making and follow-up. In conclusion, we outline the potential future roles of gadoxetate MRI based on an evolving understanding of the clinical utility of this contrast agent in the management of patients at risk of, or with, HCC.

OBJECTIVETo investigate the correlation between magnetic resonance imaging (MRI) characteristics and intrahepatic recurrence of small hepatocellular carcinoma (HCC) after radiofrequency ablation (RFA).

METHODSA total of 34 patients with 39 small HCC who underwent RFA were included in our study.MRI characteristics were compared between the recurrence group and the non-recurrence group; and a subgroup comparison was also made between the solitary recurrence group and the multiple recurrence group.Kaplan-Meier test,t-test/Mann-Whitney U test,Fisher's exact test and F-test were used for statistical analyses.

RESULTSThe median follow-up period was 25 (4-45) months and recurrence was observed in 19 (55.9%) of the patients.The 12-and 24-month cumulative recurrence-free survival rates were 71.3% and 51.8%,respectively.The recurrence group had a higher prevalence of lack of tumour capsule before RFA (P =0.017),no or disrupted periablational enhancement within 24 hours after RFA (P =0.012),and a smaller ablative margin (P=0.037).Meanwhile,the average apparent diffusion coefficient value within 24 hours after RFA was higher in the multiple recurrence group (1.57 * 10-3mm2/s) than in the solitary recurrence group (1.34 * 10(-3) mm2/s) (P =0.04).

CONCLUSIONMRI can provide early noninvasive findings useful for advanced warning ofintrahepatic recurrence after RFA.

Carcinoma, Hepatocellular ; pathology ; Catheter Ablation ; Humans ; Kaplan-Meier Estimate ; Liver Neoplasms ; pathology ; Magnetic Resonance Imaging ; Recurrence ; Retrospective Studies ; Survival Rate ; Treatment Outcome