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The ADC histogram has capability of distinguishing invasive and noninvasive IPNBs, in which skewness was an independent predictive factor.

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ObjectiveTo investigate the diagnostic value of diffusion kurtosis imaging (DKI) histogram analysis in hepatic fibrosis staging.Materials and MethodsThirty-six rats were divided into carbon tetrachloride-induced fibrosis groups (6 rats per group for 2, 4, 6, and 8 weeks) and a control group (n = 12). MRI was performed using a 3T scanner. Histograms of DKI were obtained for corrected apparent diffusion (D), kurtosis (K) and apparent diffusion coefficient (ADC). Mean, median, skewness, kurtosis and 25th and 75th percentiles were generated and compared according to the fibrosis stage and inflammatory activity.ResultsA total of 35 rats were included, and 12, 5, 5, 6, and 7 rats were diagnosed as F0–F4. The mean, median, 25th and 75th percentiles, kurtosis of D map, median, 25th percentile, skewness of K map, and 75th percentile of ADC map demonstrated significant correlation with fibrosis stage (r = −0.767 to 0.339, p < 0.001 to p = 0.039). The fibrosis score was the independent variable associated with histogram parameters compared with inflammatory activity grade (p < 0.001 to p = 0.041), except the median of K map (p = 0.185). Areas under the receiver operating characteristic curve of D were larger than K and ADC maps in fibrosis staging, although no significant differences existed in pairwise comparisons (p = 0.0512 to p = 0.847).ConclusionCorrected apparent diffusion of DKI histogram analysis provides added value and better diagnostic performance to detect various liver fibrosis stages compared with ADC.

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Background: Most intrahepatic cholangiocarcinomas (ICCs) are diagnosed at advanced stage with an extremely poor prognosis. For these patients, combining targeted therapies and immunotherapy may have a promising therapeutic effect, and current Response Evaluation Criteria in Solid Tumors (RECIST) criteria have limited applicability. Purpose: To investigate the associations between pretreatment MRI features and the efficacy of combined targetedimmunotherapy by estimating the risk of early progression (EP) in unresectable ICC, with special emphasis on diffusion-weighted imaging. Study Type: Retrospective. Subjects: A total of 43 unresectable ICC patients (24 with EP [disease progression ≤12 months after treatment] and 19 with nonearly progression [NEP, disease progression >12 months]), who received first-line systemic therapy with lenvatinib plus PD1 antibody combination. Field Strength/Sequence: The 0-T scanner, including T1-and T2-weighted imaging, diffusion-weighted imaging, and dynamic gadopentetate dimeglumine-enhanced imaging. Assessment: Clinical characteristics and MR imaging features including apparent diffusion coefficient (ADC), as well as survival analysis of EP were evaluated. Statistical Tests: Features between EP and NEP groups were compared by univariate analyses and multivariate logistic regression analysis. Diagnostic performance was analyzed by receiver operating characteristic curve. Univariate and multivariate Cox regression models were applied for survival analysis of EP. The progression-free survival (PFS) rates were estimated using the Kaplan-Meier analysis and compared by the log-rank test. The significance threshold was set at P < 0.05. Results: Tumor number, tumor margin, arterial peritumoral enhancement, lymphatic metastasis, and apparent diffusion coefficient (ADC) value were significantly different between EP and NEP groups. At multivariate logistic regression analysis, ADC was the only independent variable associated with EP (odds ratio = 0.012), with an area under the curve of 0.774 (optimal cutoff value was 1.028 Â 10 À3 mm 2 /sec). Multivariate Cox regression model proved that ADC value (hazard ratio = 0.140) and ill-defined margin (hazard ratio = 2.784) were independent risk factors. ICCs with low ADC values showed shorter PFS than those with high values (χ 2 = 9.368). Data Conclusion: Pretreatment MRI features were associated with EP for unresectable ICC treated with combined targeted-immunotherapy, and decreased ADC value was an independent variable.

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3 Technical Efficacy Stage: Stage 2 J. Magn. Reson. Imaging 2018;47:729-736.