Intravoxel incoherent motion diffusion weighted imaging for preoperative evaluation of liver regeneration after hepatectomy in hepatocellular carcinoma.

OBJECTIVES: To explore whether intravoxel incoherent motion (IVIM) parameters could evaluate liver regeneration preoperatively. METHODS: A total of 175 HCC patients were initially recruited. The apparent diffusion coefficient, true diffusion coefficient (D), pseudodiffusion coefficient (D*), pseudodiffusion fraction (f), diffusion distribution coefficient, and diffusion heterogeneity index (Alpha) were measured by two independent radiologists. Spearman's correlation test was used to assess correlations between IVIM parameters and the regeneration index (RI), calculated as 100% × (the volume of the postoperative remnant liver - the volume of the preoperative remnant liver) / the volume of the preoperative remnant liver. Multivariate linear regression analyses were used to identify the factors for RI. RESULTS: Finally, 54 HCC patients (45 men and 9 women, mean age 51.26 ± 10.41 years) were retrospectively analyzed. The intraclass correlation coefficient ranged from 0.842 to 0.918. In all patients, fibrosis stage was reclassified as F0-1 (n = 10), F2-3 (n = 26), and F4 (n = 18) using the METAVIR system. Spearman correlation test showed D* (r = 0.303, p = 0.026) was associated with RI; however, multivariate analysis showed that only D value was a significant predictor (p < 0.05) of RI. D and D*showed moderate correlations with fibrosis stage (r = -0.361, p = 0.007; r = -0.457, p = 0.001). Fibrosis stage showed a negative correlation with RI (r = -0.263, p = 0.015). In the 29 patients who underwent minor hepatectomy, only the D value showed a positive association (p < 0.05) with RI, and a negative correlation with fibrosis stage (r = -0.360, p = 0.018). However, in the 25 patients who underwent major hepatectomy, no IVIM parameters were associated with RI (p > 0.05). CONCLUSIONS: The D and D* values, especially the D value, may be reliable preoperative predictors of liver regeneration. KEY POINTS: • The D and D* values, especially the D value, derived from IVIM diffusion-weighted imaging may be useful markers for the preoperative prediction of liver regeneration in patients with HCC. • The D and D* values derived from IVIM diffusion-weighted imaging show significant negative correlations with fibrosis, an important predictor of liver regeneration. • No IVIM parameters were associated with liver regeneration in patients who underwent major hepatectomy, but the D value was a significant predictor of liver regeneration in patients who underwent minor hepatectomy.

Predictive models and early postoperative recurrence evaluation for hepatocellular carcinoma based on gadoxetic acid-enhanced MR imaging.

BACKGROUND: The prognosis of hepatocellular carcinoma (HCC) is still poor largely due to the high incidence of recurrence. We aimed to develop and validate predictive models of early postoperative recurrence for HCC using clinical and gadoxetic acid-enhanced magnetic resonance (MR) imaging-based findings. METHODS: In this retrospective case-control study, 209 HCC patients, who underwent gadoxetic acid-enhanced MR imaging before curative-intent resection, were enrolled. Boruta algorithm and backward stepwise selection with Akaike information criterion (AIC) were used for variables selection Random forest, Gradient-Boosted decision tree and logistic regression model analysis were used for model development. The area under the receiver operating characteristic curve (AUC), calibration plots, and decision curve analysis were used to evaluate model's performance. RESULTS: One random forest model with Boruta algorithm (RF-Boruta) was developed consisting of preoperative serum ALT and AFP levels and six MRI findings, while preoperative serum AST and AFP levels and four MRI findings were included in one logistic regression model with backward stepwise selection method (Logistic-AIC).The two predictive models demonstrated good discrimination performance in both the training set (RF-Boruta: AUC, 0.820; Logistic-AIC: AUC, 0.853), internal validation set (RF-Boruta: AUC, 0.857, Logistic-AIC: AUC, 0.812) and external validation set(RF-Boruta: AUC, 0.805, Logistic-AIC: AUC, 0.789). Besides, in both the internal validation and external validation sets, the RF-Boruta model outperformed Barcelona Clinic Liver Cancer (BCLC) stage (p < 0.05). CONCLUSIONS: The RF-Boruta and Logistic-AIC models with good prediction performance for early postoperative recurrence may lead to optimal and comprehensive treatment approaches, and further improve the prognosis of HCC after resection.

Preoperative evaluation of liver regeneration following hepatectomy in hepatocellular carcinoma using magnetic resonance elastography.

Background: For patients with hepatocellular carcinoma (HCC) undergoing hepatectomy, insufficient remnant liver regenerative capacity can lead to liver failure. The aim of this study was to evaluate the potential role of magnetic resonance elastography (MRE) for the preoperative prediction of liver regeneration in patients with HCC after partial hepatectomy (PH). Methods: A total of 54 patients with HCC undergoing MRE prior to PH were retrospectively included. The total functional liver, volume of preoperative future liver remnant (LVpre), and volume of postoperative liver remnant (LVpost), respectively, were measured, and the regeneration index (RI) and parenchymal hepatic resection rate (PHRR) were manually calculated. Univariate and multivariate logistic regression analyses were conducted to identify factors associated with a high RI, and receiver operating characteristic (ROC) curves were employed to evaluate the diagnostic performance of the liver stiffness (LS) values. Patients were classified into three subgroups based on the value of PHRR: low PHRR (<30%), intermediate PHRR (30-50%), and high PHRR (>50%). Subsequently, Spearman correlation analysis was used to investigate the relationship between LS values and RI in the subgroups. Results: Multivariable analysis revealed a low LS value was associated with greater odds of a high RI [odds ratio (OR), 0.049; 95% confidence interval (CI): 0.002 to 0.980]. An optimal cutoff value of 3.30 kPa was used to divide all patients into a low RI group and a high RI group with an area under the curve (AUC) value of 0.882 (95% CI: 0.767 to 0.996). A significant negative relationship between RI and LS values (r=-0.799; P<0.001) was observed in the intermediate PHRR subgroup. Conclusions: The LS values based on MRE may serve as a potential preoperative predictor of liver regeneration for patients with HCC undergoing PH.

Using arterial phase hyperenhancement on CT instead of gadoxetic acid arterial phase enhancement may improve the diagnostic performance for hepatocellular carcinoma.

Background: The diagnostic performance for hepatocellular carcinoma (HCC) is hampered using gadoxetic acid-enhanced magnetic resonance (MR) imaging due to the high incidence of transient severe motion in arterial phase (AP). Dynamic contrast enhanced computed tomography (CT) imaging yield high detection rate for hepatic nodules in AP, and the combined use of CT arterial phase (CTAP) imaging with gadoxetic acid-enhanced MR imaging may improve the diagnostic performance for HCC. Thus, this study aimed to determine whether the combined use of CTAP and gadoxetic acid-enhanced MR imaging can improve the diagnostic performance for HCC based on various imaging diagnostic criteria. Methods: A total of 169 surgically histologically confirmed hepatic nodules (137 HCCs and 32 non-HCC-nodules) were retrospectively enrolled. Two different imaging protocol sets were reviewed: (I) full gadoxetic acid-enhanced magnetic resonance imaging (MRI) sequences; and (II) CTAP imaging combined with the gadoxetic acid-enhanced MRI but excluding the MR imaging AP images. Three independent reviewers followed the 2018 Liver Reporting and Data System (LI-RADS), European Association for the Study of the Liver (EASL), and 2018 Korean guidelines to characterize these heaptic nodules by reviewing the two imaging protocol sets and the diagnostic peformance were compared by using McNemar test. Results: The detection rate of AP hyperenhancement (APHE) was higher in CTAP than in the MR arterial phase (MRAP) for hepatic nodules (87.57% vs. 75.15%) and HCCs (97.08% vs. 82.48%) (all P<0.001). For the LI-RADS criteria, the Protocol-II increased the sensitivity to 75.91% from 70.80% of Protocol-I (P=0.016), with a minimal decrease of the specificity to 71.88% from 75.00% (P=1.000). For the EASL criteria, the numerical increases were found of Protocol-II than Protocol-I in both sensitivity (81.02% vs. 78.10%) and specificity (75.00% vs.71.88%), but with no statistical significance. For the Korean criteria, the Protocol-II increased the sensitivity to 94.89% from 83.21% of Protocol-I (P<0.001). The specificity increased to 65.63% from 62.50%, with no statistical significance (P=1.000). Conclusions: Using CTAP instead of gadoxetic acid-enhanced MRAP can improve the diagnostic sensitivity for HCC and also yields a comparable specificity. Thus, the combined use of CTAP and gadoxetic acid-enhanced MR imaging may improve the diagnostic performance for HCC.

Identification of diffusion weighted imaging would be affected before and after Gd-EOB-DTPA in patients with focal hepatic lesions: an observational study.

Background: Inserting diffusion weighted imaging (DWI) into the time interval between post contrast and hepatobiliary phase (HBP) is time saving and health economic friendly. However, whether DWI would be affected before and after Gd-EOB-DTPA is still unknown. This study aims to validate whether the DWI at both low and high b-values is affected before and after Gd-EOB-DTPA enhancement. Methods: From July 2019 to November 2019, seventy-three patients who satisfied the inclusion criteria were enrolled. Those patients were scanned with multiple b-value (b-value of 0, 50, 800, 1,000, and 1,200 s/mm2) DWI using a 3.0 T magnetic resonance (MR) scanner before and after the injection of Gd-EOB-DTPA. The final imaging diagnosis of the malignant liver lesions were made by histopathological analysis. The lesion-liver contrast intensity ratio (CIR) and the apparent diffusion coefficients (ADCs) of hepatic parenchyma and lesions at each b-value was evaluated. The Student's t-test or Mann-Whitney U test was used to compare the CIR and ADC between the MR images before and after contrast agent injection. In addition, the Student's t-test or Mann-Whitney U test was used to compare the ADC values between benign and malignant lesions. Receiver operating characteristics (ROC) curves were used to assess the area under the curve (AUC) of the ADC values in differentiating between benign and malignant lesions. Results: For the CIRs comparison, the CIRs showed no statistical significance before and after Gd-EOB-DTPA on b =0 (1.34±1.15 vs. 1.45±1.48, P=0.664), b=50 (1.23±1.13 vs. 1.35±1.34, P=0.982), b=800 (1.19±0.87 vs. 1.19±0.94, P=0.946), b=1,000 (1.21±0.90 vs. 1.32±1.05, P=0.294) and b=1,200 (1.25±1.03 vs. 1.45±1.48, P=0.165) s/mm2. For the ADC value comparison, the ADC also showed no statistical significance before and after Gd-EOB-DTPA on b=50 (4.04±2.82 vs. 3.91±3.00, P=0.151), b=800 (1.68±0.71 vs.1.67±0.76, P=0.163), b=1,000 (1.53±0.69 vs.1.50±0.70, P=0.078) and b=1,200 (1.48±0.66 vs. 1.48±0.70, P=0.294) s/mm2. Conclusions: DWI scanned between the interval of dynamic enhanced imaging and HBP imaging can save overall scanning time without influencing the CIRs, ADCs, and diagnostic capabilities of hepatic lesions at both low and high b-values.

New Liver MR Imaging Hallmarks for Small Hepatocellular Carcinoma Screening and Diagnosing in High-Risk Patients.

Objective: Early detection and diagnosis of hepatocellular carcinoma (HCC) is essential for prognosis; however, the imaging hallmarks for tumor detection and diagnosis has remained the same for years despite the use of many new immerging imaging methods. This study aimed to evaluate the detection performance of hepatic nodules in high risk patients using either hepatobiliary specific contrast (HBSC) agent or extracellular contrast agent (ECA), and further to compare the diagnostic performances for hepatocellular carcinoma (HCC) using different diagnostic criteria with the histopathological results as reference standard. Methods: This prospective study included 247 nodules in 222 patients (mean age, 53.32 ± 10.84 years; range, 22-79 years). The detection performance and imaging features of each nodule were evaluated in all MR sequences by three experienced abdominal radiologists. The detection performance of each nodule on all MR sequences were compared and further the diagnostic performance of various diagnostic criteria were evaluated. Results: For those patients who underwent ECA-MRI, the conventional imaging hallmark of "AP + PVP and/or DP" was recommended, as 60.19% diagnostic sensitivity, 80.95% specificity and 100% lesion detection rate. Additionally, for those patients who underwent HBSC-MRI, the diagnostic criteria of "DWI + HBP" was recommended. This diagnostic criteria demonstrated, both in all tumor size and for nodules ≤2 cm, higher sensitivity (93.07 and 90.16%, all p <0.05, respectively) and slightly lower specificity (64.71 and 87.50%, all p >0.05, respectively) than that of the European Association for the Study of the Liver (EASL) criteria. Conclusions: Different abbreviated MR protocols were recommended for patients using either ECA or HBSC. These provided imaging settings demonstrated high lesion detection rate and diagnostic performance for HCC.

Multiparametric Magnetic Resonance Imaging Improves the Prognostic Outcomes in Patients With Intrahepatic Cholangiocarcinoma After Curative-Intent Resection.

Purpose: The prognosis of patients with intrahepatic cholangiocarcinoma remains unclear. Thus, this study aimed at investigating whether additional multiparametric magnetic resonance imaging (mpMRI) would guide additional treatment and improve the prognostic outcomes of intrahepatic cholangiocarcinoma patients. Methods and Materials: This retrospective study included 256 patients undergoing dynamic enhanced computed tomography scan only (CT group) and 31 patients undergoing both mpMRI and computed tomography scans (CT+MR group). Propensity score matching (PSM) was used to minimize the potential selection bias and confounding effects. The overall survival (OS) and recurrence-free survival (RFS) rates were compared between the two groups. Results: More nodules (n = 6), additional biliary dilation (n = 4), and peritumoral parenchymal arterial phase hyperenhancement (n = 18) were found with the additional mpMRI scan, which led to treatment modification. Cox regression analysis revealed the survival advantage of additional mpMRI imaging based on the OS (HR 0.396, 95% CI 0.239-0.657, p < 0.001; PSM HR 0.400, 95% CI 0.218-0.736, p = 0.003) and RFS (HR 0.558, 95% CI 0.352-0.882, p = 0.013; PSM HR 0.508, 95% CI 0.288-0.897, p = 0.020). Conclusions: Additional mpMRI helps clinicians to select better treatment options, lower the risk of tumor recurrence, and improve the overall survival.

Prediction of Remnant Liver Regeneration after Right Hepatectomy in Patients with Hepatocellular Carcinoma Using Preoperative CT Texture Analysis and Clinical Features.

Objectives: To predict the regenerative rate of liver in patients with HCCs after right hepatectomy using texture analysis on preoperative CT combined with clinical features. Materials and Methods: 88 patients with 90 HCCs who underwent right hepatectomy were retrospectively included. The future remnant liver was semiautomatically segmented, and the volume of future remnant liver on preoperative CT (LVpre) and the volume of remnant liver on following-up CT (LVfu) were measured. We calculated the regeneration index (RI) by the following equation: (LVfu - LVpre)/LVpre) × 100 (%). The support vector machine recursive method was used for the feature selection. The Naive Bayes classifier was used to predict liver RI, and 5-fold cross-validation was performed to adjust the parameters. Sensitivity, specificity, and accuracy were calculated to evaluate the diagnostic efficiency of the model. Results: The mean RI was 142.99 ± 92.17%. Of all clinical parameters and texture features, the AST, ALB, PT-INR, Perc.10%, and S(5, -5)Correlat were found to be statistically significant with RI. The diagnostic sensitivity, specificity, and accuracy of the model in the training group were 0.902, 0.634, and 0.768, and the AUC value of the obtained model was 0.841. In the test group, the sensitivity, specificity, and accuracy of the model were 1.0, 0.429, and 0.778, respectively, and the AUC value was 0.844. Conclusion: The use of texture analysis on preoperative CT combined with clinical features can be helpful in predicting the liver regeneration rate in patients with HCCs after right hepatectomy.

Itraconazole Oral Solution for a Case of Infantile Hemangioma: Monitoring the Efficacy by Dermoscopy and MRI.

Infantile hemangioma is a common and challenging benign vascular tumor. Although involution is spontaneous, approximately 10% of infantile hemangioma of large size or in specific locations may cause ulceration, severe cosmetic and functional problems that may require intervention. Treatment options include oral propranolol, topical timolol, and oral corticosteroids. However, the clinical response is not always satisfactory. We report the case of a 4-month-old boy who presented with an irregular erythematous plaque on his left shoulder 3 days after birth. Infantile hemangioma was diagnosed. Topical application of 0.5 ml of 0.5% timolol maleate eye drops for half an hour each time three times a day was initiated. After nearly 3 months of follow-up, the size of the lesion gradually increased. Finally, after 115 days of treatment with itraconazole oral solution (the total dose was about 4025 mg), the refractory infantile hemangioma was successfully treated. Hepatic and renal function remained normal with only mild diarrhea during the course of oral medication. Treatment compliance of oral itraconazole in infants has been reported to be good. Dermoscopy and magnetic resonance imaging (MRI) played a crucial role in in vivo observation of the hemangioma changes with vascular regression during the treatment process.

A New Diagnostic Criterion with Gadoxetic Acid-Enhanced MRI May Improve the Diagnostic Performance for Hepatocellular Carcinoma.

BACKGROUND: To prospectively establish and validate new diagnostic criterion (DC) for liver-specific contrast agents and further compared the diagnostic sensitivity and specificity with conventional DC. METHODS: Institutional Review Board approved and written informed consent were obtained for this prospective study. Two board-certified reviewers established the reference standard as hepatocellular carcinoma (HCC), non-HCC lesions by using marks on all cross-sectional MR images. Another 2 abdominal radiologists independently performed the marked lesion observations using 5 different DCs, including DC-1: arterial phase hyperenhancement (APHE) and portal venous phase washout; DC-2: APHE and hepatobiliary phase (HBP) hypointensity; DC-3: APHE and diffusion-weighted imaging (DWI) hyperintensity; DC-4: HBP hypointensity and DWI hyperintensity; DC-5: HBP hypointensity, DWI hyperintensity and excluded these markedly T2 hyperintensity. Diagnostic performance of sensitivity, specificity, and accuracy for each imaging DC was calculated, per-lesion diagnostic sensitivity and specificity of imaging criteria were compared by using McNemars test. RESULTS: A total of 215 patients were included (mean age 53.82 ± 11.24 years; range 24-82 years) with 265 hepatic nodules (175 HCCs and 90 non-HCCs). The DC-4 (93.71%; 164/175) and DC-5 (92.57%; 162/175) yielded the highest diagnostic sensitivity and was better than DC-1 (72.57%; 127/175), DC-2 (82.86%; 145/175), and DC-3 (82.29%; 144/175) (all p < 0.001). The specificity of DC-1 (94.44%; 85/90) was significantly higher than that with DC-2 (83.33%; 75/90), DC-3 (84.44%; 76/90), DC-4 (74.44%; 67/90), and DC-5 (82.22%; 74/90) (all p < 0.05). Additionally, the DC-4 and DC-5 achieved the highest area under curve value of 0.841 (95% CI 0.783-0.899) and 0.874 (95% CI 0.822-0.925). CONCLUSIONS: The combined use of HBP hypointensity and DWI hyperintensity as a new DC for HCC enables a high diagnostic sensitivity and comparable specificity.

IVIM improves preoperative assessment of microvascular invasion in HCC.

PURPOSE: To prospectively evaluate the potential role of intravoxel incoherent motion (IVIM) and conventional radiologic features for preoperative prediction of microvascular invasion (MVI) in patients with hepatocellular carcinoma (HCC). METHODS: Institutional review board approval and written informed consent were obtained for this study. A cohort comprising 115 patients with 135 newly diagnosed HCCs between January 2016 and April 2017 were evaluated. Two radiologists independently reviewed the radiologic features and the apparent diffusion coefficient (ADC), true diffusion coefficient (D), pseudodiffusion coefficient (D*), and pseudodiffusion component fraction (f) were also measured. Interobserver agreement was checked and univariate and multivariate logistic regressions were used for screening the risk factors. Receiver operating characteristics (ROC) curve analyses were performed to evaluate the diagnostic performance. RESULTS: Features significantly related to MVI of HCC at univariate analysis were reduced ADC (odds ratio, 0.341; 95% CI, 0.211-0.552; p < 0.001), D (odds ratio, 0.141; 95% CI, 0.067-0.299; p < 0.001), and irregular circumferential enhancement (odds ratio, 9.908; 95% CI, 3.776-25.996; p < 0.001). At multivariate analysis, only D value (odds ratio, 0.096; 95% CI, 0.025-0.364; p < 0.001) was the independent risk factor for MVI of HCC. The mean D value for MVI of HCC showed an area under ROC curves of 0.815 (95% CI, 0.740-0.877). CONCLUSION: IVIM model-derived D value is superior to ADC measured with mono-exponential model for evaluating the MVI of HCC. Among MR imaging features, tumor margin, enhancement pattern, tumor capsule, and peritumoral enhancement were not predictive for MVI. KEY POINTS: • Diffusion MRI is useful for non-invasively evaluating the microvascular invasion of hepatocellular carcinoma. • IVIM model is advantageous over mono-exponential model for assessing the microvascular invasion of hepatocellular carcinoma. • Decreased D value was the independent risk factor for predicting MVI of HCC.

Esophageal carcinoma: Intravoxel incoherent motion diffusion-weighted MRI parameters and histopathological correlations.

BACKGROUND: The pathological grade of esophageal carcinoma is highly determinant of patient prognosis, but it still cannot be adequately evaluated preoperatively. Compared with conventional diffusion-weighted imaging (DWI), intravoxel incoherent motion (IVIM) diffusion-weighted MRI can separate true molecular diffusion and perfusion in tissues and has been shown to be useful in characterizing malignant tumors. There is no report that compared IVIM and conventional DWI in grading esophageal carcinoma. PURPOSE: To prospectively determine the diagnostic performance of conventional DWI and IVIM models in differentiating the pathological differentiated grade of esophageal carcinoma. STUDY TYPE: Prospective. POPULATION: A cohort comprising 81 patients with newly diagnosed esophageal squamous cell carcinoma (ESCC) between December 2015 and August 2017 were evaluated. FIELD STRENGTH/SEQUENCE: 3.0T, axial echo-planer imaging, fast spin echo (FSE) sequence, IVIM sequence (b = 0, 20, 50, 80, 100, 150, 200, 400, 600, 800, 1000, 1200). ASSESSMENT: Apparent diffusion coefficient (ADC), true ADC (ADCslow ), pseudo ADC (ADCfast ), and perfusion fraction (f) of each tumor were calculated by two independent radiologists. Histopathologic grade was used as the reference standard. STATISTICAL TESTS: Games-Howell test; diagnostic accuracy; Spearman correlation; intraclass correlation coefficient; and Bland-Altman analysis. Receiver operating characteristics (ROC) curves. RESULTS: ADCslow demonstrated the highest area under curve (AUC) with a value of 0.830 (95% confidence interval [CI]: 0.730-0.904) and 0.816 (95% CI: 0.714-0.893) by two radiologists, followed by ADC with a value of 0.754 (95% CI: 0.646-0.843) and 0.761 (95% CI: 0.653-0.848). Good correlation was obtained between the histologic grade and ADCslow (r(R1) = 0.748, r(R2) = 0.720) and ADC (r(R1) = 0.576, r(R2) = 0.571). DATA CONCLUSION: ADCslow and ADC had a significantly higher performance than the ADCfast and f, and ADCslow had a significantly higher performance than the ADC. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:253-261.

Intravoxel incoherent motion diffusion-weighted imaging for assessment of histologic grade of hepatocellular carcinoma: comparison of three methods for positioning region of interest.

OBJECTIVES: To prospectively compare the diagnostic performances of three methods of region of interest (ROI) placement for the measurements of intravoxel incoherent motion (IVIM) diffusion-weighted MR imaging in differentiating the histologic grade of hepatocellular carcinoma (HCC). METHODS: Eighty-seven patients with 91 newly diagnosed HCCs were studied using IVIM imaging. Two attending radiologists separately identified the selection of tumour tissue for ROI positioning. Three different ROI positioning methods, namely the whole tumour volume (WTV) method, three-ROI method and one-section method, were used for the measurement. Kruskal-Wallis rank test or one-way ANOVA was used to compare the difference in IVIM parameters and ADC across the three different ROI positioning methods. Spearman correlation analysis was used to determine the correlation between each parameter and Edmondson-Steiner (E-S) grade. Receiver operating characteristics (ROC) curve analyses were performed to evaluate the diagnostic performance. RESULTS: For the ADC and ADCslow, the mean value measured by using the WTV method was significant higher than the one-section and three-ROI methods (all p < 0.01). For the ADCslow, the highest area under curve (AUC) with a value of 0.969 was obtained by using the WTV method, followed by the one-section method (AUC = 0.938) and three-ROI method (AUC = 0.873). Additionally, for the ADC, AUC values were 0.861 for WTV method, 0.840 for one-section method and 0.806 for three-ROI method. CONCLUSIONS: Different ROI positioning methods used significantly affect the IVIM parameters and ADC measurements. Measurements of ADCslow value derived from WTV method entailed the highest diagnostic performance in grading HCC. KEY POINTS: • Diffusion MRI is useful for non-invasively differentiating the histologic grade of hepatocellular carcinoma. • Different ROI positioning methods used significantly affect the IVIM parameters and ADC measurements. • IVIM model is advantageous over mono-exponential model for assessing the histologic grade of hepatocellular carcinoma.

A cohort study of relationship between serum calcium levels and cerebral microbleeds (CMBs) in ischemic stroke patients with AF and/or RHD.

Calcium is an essential element for life and has cerebroprotective property in stroke patients. Low serum calcium levels were found to be related to large hematoma volumes in intracerebral hemorrhagic patients and hemorrhagic transformation in ischemic stroke patients after thrombolysis. However, their impact on hemorrhage-prone small vessel disease represented by cerebral microbleeds (CMBs) is uncertain. We aim to investigate whether low serum calcium levels are associated with presence and location of CMBs.Ischemic stroke patients with atrial fibrillation (AF) and/or rheumatic heart disease admitted to our hospital were consecutively and prospectively enrolled. Demographic and clinical information were collected and analyzed according to the occurrence and location of CMBs, and levels of serum calcium. We used logistic regression analysis to estimate the multivariable adjusted relationship between serum calcium levels and the presence or location of CMBs.Among the 67 patients (28 males; mean age, 67.3 years) in the final analysis, 39 (58.2%) were found to have CMBs. After adjustment for age, sex, smoking habits, drinking habits, and renal impairment, the presence of CMBs and deep CMBs was, respectively, 4.96- and 4.83-fold higher in patients with lower serum calcium levels (≤2.15 mmol/L) than in patients with higher serum calcium levels.Lower serum calcium levels (≤2.15 mmol/L) are independently associated with the presence of CMBs and deep CMBs in ischemic stroke patients with AF and/or rheumatic heart disease, which should be verified and extended in large cohorts, with other types of stroke patients and the general population.

[The Iron Content of Hepatocellular Carcinoma Associated Nodules: Study of Histopathology and MR Imaging].

OBJECTIVE: To explore the clinical value of MRI imaging of measuring the iron content for hepatocellular carcinoma (HCC) associated nodules. METHODS: 55 male Wistar rats were randomly allocated into a treatment and a control group, which were administered with diethyl nitrosamine (DEN) and the sterilized tap water. According to the macro pathology differences, the treatment groups were divided into three groups: cirrhotic nodules group, cirrhotic nodules with HCC group, and HCC group; According to the micro pathology differences, the treatment groups were divided into four groups: regenerative nodules (RN) group, low grade dysplastic nodules (LGDN) group, high grade dysplastic nodules (HGDN) group, and HCC group. After 13 weeks, the rats were scanned by MRI T2WI and T2 * WI. The next day all rats were sacrificed for histological tests and tissue iron level determination. The correlations were statically analyzed between the values of T2, T2 * and the grades of iron stain, the quantification of tissue iron. RESULTS: With macro pathology observation, the values of T2, T2 * among control group (normal rats) , cirrhotic nodules group, cirrhotic nodules with HCC group, HCC group were increased, while the quantification of tissue iron were decreased. Significant differences were found for T2, T2 * and quantification of tissue iron in three groups (P < 0.05). Low-grade negative correlations could be found between T2, T2 * and quantification of tissue iron in whole samples (r1 = -0.364, P1 = 0.000; r2 = -0.245, P2 = 0.018). With micro pathology observation, there were significant differences among the control (normal rats), RN, LGDN, HGDN, and HCC groups for the grades of iron stain both in the essence and the interstitial (P < 0.05). After comparison each two groups, significant differences were found among some groups for the grades of iron stain both in the essence and the interstitial (P < 0.05). Generally the grades of iron stain for HCCs were lower than non-HCC both in the essence and the interstitial. CONCLUSION: Negative correlation between T2, T2 * and iron content demonstrats that T2 and T2 * could roughly estimate the iron content in the cirrhotic nodules. T2 and T2 * measurements could contribute to differential diagnosis of HCC nodules.

Short-term cognitive changes after surgery in patients with unilateral mesial temporal lobe epilepsy associated with hippocampal sclerosis.

We investigated the short-term postoperative cognitive function of patients with unilateral mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE/HS). Fourteen unilateral MTLE/HS patients who had undergone selective amygdalohippocampectomy (SAH) or anterior temporal lobectomy (ATL) were enrolled. Cognitive functions related to the frontal and temporal lobes were evaluated using a battery of neuropsychological tests administered before surgery and 3months after surgery. The battery included the Verbal Fluency Test (VFT), Boston Naming Test (BNT), Stroop Color-Word Test (TST), Trail Making Test (TMT) and Wechsler Memory Scale (WMS). MTLE/HS patients demonstrated significantly improved postoperative performance on the TST regardless of the surgical method or side of resection. There was no significant difference in any of the other neuropsychological tests before and after surgery. After left-side resection, performance on the VFT and the TMT-B was worse than at baseline. After right-side resection, performance on the VFT and WMS short-term memory improved; however, these differences were not statistically significant. SAH patients exhibited improved TST performance but worse TMT-A performance; however, performance on all tests was not significantly different after surgery in ATL patients. In summary, MTLE/HS patients demonstrated improved frontal lobe-related cognitive function after surgery, but no such improvement in temporal lobe-related function was observed. Based on cognitive evaluation, right-sided MTLE/HS patients may be more appropriate surgical candidates than left-sided MTLE/HS patients. SAH may not be better than ATL in improving cognitive function. We hypothesise that postoperative cognitive changes depend on whether the excised cerebral regions are related to the neuropsychological functions examined by specific assessment instruments.

[Comparison of the efficacy of gadobutrol and multihance in contrast-enhanced MRI for diagnosis of brain metastasis in lung cancer].

OBJECTIVE: To investigate the diagnostic efficacy of gadobutrol for assessing brain metastases in lung cancer patients in comparison with multihance. METHODS: 21 patients with lung cancer suspected of brain metastasis were enrolled in this study. All patients underwent twice MRI scans on a 3.0T MRI scanner (Siemens MAGENETOM Trio) with 8-channel head coil, first with 0.5 mol/L multihance and then with 1.0 mol/L gadobutrol as contrast agent. The dosage of contrast agent was set at 0.1 mmol/kg body mass. The interval between the two scans was 24-72 hours. The detection and delineation of lesions were evaluated visually. The signal-to-noise ratios (SNR), contrast-to-noise ratios (CNR) of lesion to normal brain white matter and the percentage of lesion enhancement were calculated and compared between the two scans by 2 experienced neuroradiologists. RESULTS: One patient was excluded because he received radiation therapy between the two scans. 15 patients were found to have brain metastases with a total of 35 lesions. There were no statistical differences between the two scans in SNR, CNR and percentage enhancement for both normal brain and lesions (t = 0.545, P = 0.592; t = 1.143, P = 2.267; t = 0.592, P = 0.557; t = 0.473, P = 0.639). CONCLUSION: Half-dose gadobutrol (1.0 mol/L) can achieve the same enhancement effects compared with full-dose multihance (0.5 mol/L).

[MR DTI and DTT study on the development of optic radiation in patients with anisometropia amblyopia].

OBJECTIVE: To evaluate the development of optic radiations (ORs) in patients with anisometropia amblyopia using magnetic resonance diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT), and to explore possible mechanism of pathogenesis of amblyopia. METHODS: Brain scan was performed with 3.0 Tesla scanner on 8 patients with anisometropia amblyopia and 15 control subjects with normal sights. The fractional anisotropy (FA) values, the apparent diffusion coefficient (ADC) values, the numbers of neural fiber bundle of ORs, and the voxel numbers of ORs were compared between the patients with anisometropia amblyopia and those with normal sights and between the ipsilateral ORs and the contralateral ORs in the patients with amblyopia. RESULTS: No differences in the FA values, the ADC values, the numbers of neural fiber bundle of ORs and the voxel numbers of ORs were found between the ipsilateral ORs and the contralateral ORs in the patients with amblyopia (P > 0.05). Significant decreases in the FA values and the voxel numbers of ORs were found in the patients with amblyopia compared with the controls (P < 0.05). No differences in the voxel numbers of both ORs in the anterior parts were found between the patients with amblyopia and the controls (P > 0.05). However, the patients with amblyopia had more voxel numbers of ORs in the posterior parts than the controls (P < 0.05). The differences in the ADC values and the numbers of neural fiber bundle of ORs between the patients with amblyopia and the controls were not significant (P > 0.05). CONCLUSION: The compactability, integrity and directivity of ORs decrease in patients with anisometropia amblyopia. The projection of OR fibers is abnormal. The ORs are underdeveloped, especially in the posterior parts, although no abnormal morphologic changes occur. The DTI and DTT can detect the underdevelopment of optic radiations in patients with anisometropia amblyopia indirectly.

Self-assembly of SiO2/Gd-DTPA-polyethylenimine nanocomposites as magnetic resonance imaging probes.

Controlled self-assembly of organic/inorganic magnetic hybrid materials have important applications in magnetic resonance imaging (MRI). In this study, a widely used polycation polyethylenimine was conjugated with gadopentetic acid (Gd-DTPA) as a gadolinium bearing polyelectrolyte (Gd-DTPA-PEI). Next, multilayers of Gd-DTPA-PEI were coated on silica nanoparticles through layer-by-layer (LbL) self-assembly with polyanions as monitored by dynamic light scattering, zeta-potential, and scanning electron microscopy. The thickness of the multilayer film was estimated from quartz crystal microbalance based on counting frequency change of each adsorbed layer. The magnetic relaxation of SiO2/(Gd-DTPA-PEl/polyanion), core-shell nanocomposite was tested at 1.5 T magnetic field in a clinical MRI scanner, and a 3-fold increase in T1 relaxivity to 15.1 Gd mM(-1)s(-1) was noticed comparing to Gd-DTPA small molecules. Dextran sulfate was coated as the outermost layer on the nanocomposite for better biocompatibility as verified by in vitro cytotoxicity studies. This formulation provides good signal intensity enhancement of mouse liver in vivo with only 1/25 dose of clinical standard at 30 and 60 minutes after intravenous injection. This sensitive imaging probe with unique core-shell structures may find broad applications in cellular and molecular imaging.