Non-contrast T1ρ dispersion versus Gd-EOB-DTPA-enhanced T1mapping for the risk stratification of non-alcoholic fatty liver disease in rabbit models.

PURPOSE: To investigate the diagnostic efficacy of T1ρ dispersion and Gd-EOB-DTPAenhanced T1mapping in the identification of early liver fibrosis (LF) and non-alcoholic steatohepatitis (NASH) in a non-alcoholic fatty liver disease (NAFLD) rabbit model induced by a high-fat diet using histopathological findings as the standard reference. METHODS: A total of sixty rabbits were randomly allocated into the standard control group (n = 12) and the NAFLD model groups (8 rabbits per group) corresponding to different high-fat high cholesterol diet feeding weeks. All rabbits underwent noncontrast transverse T1ρ mapping with varying spin-locking frequencies (FSL = 0 Hz and 500 Hz), native T1 mapping, and Gd-EOB-DTPA-enhanced T1 mapping during the hepatobiliary phase. The histopathological findings were assessed based on the NASH CRN Scoring System. Statistical analyses were conducted using the intraclass correlation coefficient, analysis of variance, multiple linear regression, and receiver operating characteristics. RESULTS: Except for native T1, T1ρ, T1ρ dispersion, HBP T1, and △T1 values significantly differed among different liver fibrosis groups (F = 14.414, 18.736, 10.15, and 9.799, respectively; all P < 0.05). T1ρ, T1ρ dispersion, HBP T1, and △T1 values also exhibited significant differences among different NASH groups (F = 4.138, 4.594, 21.868, and 22.678, respectively; all P < 0.05). In the multiple regression analysis, liver fibrosis was the only factor that independently influenced T1ρ dispersion (R2 = 0.746, P = 0.000). Among all metrics, T1ρ dispersion demonstrated the best area under curve (AUC) for identifying early LF (≥ F1 stage) and significant LF (≥ F2 stage) (AUC, 0.849 and 0.916, respectively). The performance of △T1 and HBP T1 (AUC, 0.948 and 0.936, respectively) were better than that of T1ρ and T1ρ dispersion (AUC, 0.762 and 0.769, respectively) for diagnosing NASH. CONCLUSION: T1⍴ dispersion may be suitable for detecting liver fibrosis in the complex background of NAFLD, while Gd-EOB-DTPA enhanced T1 mapping is superior to nonenhanced T1⍴ mapping (T1⍴ and T1⍴ dispersion) for identifying NASH.

Computed Tomography-Based Texture Features for the Risk Stratification of Portal Hypertension and Prediction of Survival in Patients With Cirrhosis: A Preliminary Study.

Objective: Clinical evidence suggests that the risk stratification of portal hypertension (PH) plays a vital role in disease progression and patient outcomes. However, the gold standard for stratifying PH [portal vein pressure (PVP) measurement] is invasive and therefore not suitable for routine clinical practice. This study is aimed to stratify PH and predict patient outcomes using liver or spleen texture features based on computed tomography (CT) images non-invasively. Methods: A total of 114 patients with PH were included in this retrospective study and divided into high-risk PH (PVP ≥ 20 mm Hg, n = 57) or low-risk PH (PVP < 20 mm Hg, n = 57), a progression-free survival (PFS) group (n = 14), or a non-PFS group (n = 51) based on patients with rebleeding or death after the transjugular intrahepatic portosystemic shunt (TIPS) procedure. All patients underwent contrast-enhanced CT, and the laboratory data were recorded. Texture features of the liver or spleen were obtained by a manual drawing of the region of interest (ROI) and were performed in the portal venous phase. Logistic regression analysis was applied to select the significant features related to high-risk PH, and PFS-related features were determined by the Cox proportional hazards model and Kaplan-Meier analysis. Receiver operating characteristic (ROC) curves were used to test the diagnostic capacity of each feature. Results: Five texture features (one first-order feature from the liver and four wavelet features from the spleen) and the international normalized ratio (INR) were identified as statistically significant for stratifying PH (p < 0.05). The best performance was achieved by the spleen-derived feature of wavelet.LLH_ngtdm_Busyness, with an AUC of 0.72. The only log.sigma.3.0.mm.3D_firstorder_RobustMeanAbsoluteDeviation feature from the liver was associated with PFS with a C-index of 0.72 (95% CI 0.566-0.885), which could stratify patients with PH into high- or low-risk groups. The 1-, 2-, and 3-year survival probabilities were 66.7, 50, and 33.3% for the high-risk group and 93.2, 91.5, and 84.4% for the low-risk group, respectively (p < 0.05). Conclusion: CT-based texture features from the liver or spleen may have the potential to stratify PH and predict patient survival.

A Bounding Box-Based Radiomics Model for Detecting Occult Peritoneal Metastasis in Advanced Gastric Cancer: A Multicenter Study.

PURPOSE: To develop a bounding box (BBOX)-based radiomics model for the preoperative diagnosis of occult peritoneal metastasis (OPM) in advanced gastric cancer (AGC) patients. MATERIALS AND METHODS: 599 AGC patients from 3 centers were retrospectively enrolled and were divided into training, validation, and testing cohorts. The minimum circumscribed rectangle of the ROIs for the largest tumor area (R_BBOX), the nonoverlapping area between the tumor and R_BBOX (peritumoral area; PERI) and the smallest rectangle that could completely contain the tumor determined by a radiologist (M_BBOX) were used as inputs to extract radiomic features. Multivariate logistic regression was used to construct a radiomics model to estimate the preoperative probability of OPM in AGC patients. RESULTS: The M_BBOX model was not significantly different from R_BBOX in the validation cohort [AUC: M_BBOX model 0.871 (95% CI, 0.814-0.940) vs. R_BBOX model 0.873 (95% CI, 0.820-0.940); p = 0.937]. M_BBOX was selected as the final radiomics model because of its extremely low annotation cost and superior OPM discrimination performance (sensitivity of 85.7% and specificity of 82.8%) over the clinical model, and this radiomics model showed comparable diagnostic efficacy in the testing cohort. CONCLUSIONS: The BBOX-based radiomics could serve as a simpler reliable and powerful tool for the preoperative diagnosis of OPM in AGC patients. And M_BBOX-based radiomics is simpler and less time consuming.

Relationship of epicardial fat volume with coronary plaque characteristics, coronary artery calcification score, coronary stenosis, and CT-FFR for lesion-specific ischemia in patients with known or suspected coronary artery disease.

BACKGROUND: We explored the association of epicardial fat volume (EFV) with coronary plaque characteristics, coronary artery calcification (CAC) score, coronary stenosis, lesion-specific ischemia in patients with known or suspected coronary artery disease (CAD). METHODS: 88 controls and 221 patients were analyzed in the study. High-risk plaque was defined as existing≥2 features, including positive remodeling, low attenuation, napkin-ring sign and spotty calcification. EFV, CAC score was measured. The severity of coronary stenosis was quantified using Gensini score. CT-FFR was performed in three major coronary arteries, with a threshold of ≤0.8 considered the presence of ischemia. Univariate and multivariate regression was used to evaluate the association of EFV with CAD, palque characteristics, CAC score, Gensini score, and lesion-specific ischemia derived from CT-FFR. RESULTS: Median EFV was 104.97 cm3 (85.47-136.09) in controls and 129.28cm3 (101.19-159.44) in patients (P < 0.001). Logistic regression analysis revealed a significant association of EFV with CAD even after adjusting for confounding factors (P < 0.05). At linear regression analysis, EFV was significantly correlated with high-risk plaque and lesion-specific ischemia, but not with non-calcified plaque, mixed plaque, calcified plaque, CAC score and Gensini score (P ≥ 0.05). CONCLUSION: We found that EFV was associated with CAD, suggesting that it may be a promising marker of CAD. EFV was also correlated with high-risk plaque and lesion-specific ischemia, indicating that EAT was likely to be involved in myocardial ischemia and had the potential to definite patients' risk profile.

3D Multi-Echo Dixon technique for simultaneous assessment of liver steatosis and iron overload in patients with chronic liver diseases: a feasibility study.

BACKGROUND: Patients with chronic liver diseases (CLDs) often suffer from lipidosis or siderosis. Proton density fat fraction (PDFF) and R2* can be used as quantitative parameters to assess the fat/iron content of the liver. The aim of this study was to evaluate the influence of liver fibrosis and inflammation on the 3D Multi-echo Dixon (3D ME Dixon) parameters (MRI-PDFF and R2*) in patients with CLDs and to determine the feasibility of 3D ME Dixon technique for the simultaneous assessment of liver steatosis and iron overload using histopathologic findings as the reference standard. METHODS: Ninety-nine consecutive patients with CLDs underwent T1-independent, T2*-corrected 3D ME Dixon sequence with reconstruction using multipeak spectral modeling on a 3T MR scanner. Liver specimen was reviewed in all cases, grading liver steatosis, siderosis, fibrosis, and inflammation. Spearman correlation analysis was performed to determine the relationship between 3D ME Dixon parameters (MRI-PDFF and R2*) and histopathological and biochemical features [liver steatosis, iron overload, liver fibrosis, inflammation, alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL)]. Multiple regression analysis was applied to identify variables associated with 3D ME Dixon parameters. Receiver operating characteristic (ROC) analysis was performed to determine the diagnostic performance of these parameters to differentiate liver steatosis or iron overload. RESULTS: In multivariate analysis, only liver steatosis independently influenced PDFF values (R2=0.803, P<0.001), liver iron overload and fibrosis influenced R2* values (R2=0.647, P<0.001). The Spearman analyses showed that R2* values were moderately correlated with fibrosis stages (r=0.542, P<0.001) in the subgroup with the absence of iron overload. The area under the ROC curve of PDFF was 0.989 for the diagnosis of steatosis grade 1 or greater, and 0.986 for steatosis grade 2 or greater. The area under the ROC curve of R2* was 0.815 for identifying iron overload grade 1 or greater, and 0.876 for iron overload grade 2 or greater. CONCLUSIONS: 3D Multi-Echo Dixon can be used to simultaneously evaluate liver steatosis and iron overload in patients with CLDs, especially for quantification of liver steatosis. However, liver R2* value may be affected by the liver fibrosis in the setting of CLDs with absence of iron overload.

Evaluation of Early Gadolinium Enhancement (EGE) and Cardiac Functional Parameters in Cine-Magnetic Resonance Imaging (MRI) on Artificial Intelligence in Patients with Acute Myocarditis: A Case-Controlled Observational Study.

BACKGROUND The diagnosis of myocarditis is challenging, and the treatment is generally delayed due to misdiagnosis or missed diagnosis. Endomyocardial biopsy (EMB) is not a specific or sensitive method. A case-controlled observational study was conducted to evaluate early gadolinium enhancement (EGE) and left ventricular functional parameters on Artificial Intelligence in cine-MRI in patients with acute myocarditis. MATERIAL AND METHODS We selected 21 patients with pathologically proven acute myocarditis. We analyzed the EGE findings (total/serial number and location of positive-segments using the 17-segment model according to the American Heart Association) and clinical characteristics (symptoms, arrhythmias in ECG, coronary angiography, and EMB). All patients were divided into positive EGE and negative EGE groups to analyze left ventricular functional parameters (LVEF, FS, LVEDD, LVEDV, LVESV, LVMM, LVSV, CO, and CI) on Artificial Intelligence. RESULTS We enrolled 21 patients (11 males) with a mean age of 32.6±9.8 years (range, 16 to 51 years). Abnormalities on EGE were found in 2/3 of patients, involving 41 segments among multiple locations on the myocardium. The differences in LVEF (40.2±10.2% vs. 51.3±3.6%), LVESV (69.0±16.1ml vs. 52.5±10.6ml) and LVSV (42.6±11.4 vs. 52.8±2.8 ml) on Artificial Intelligence was statistically significant between the positive EGE and negative EGE groups (p<0.05). CONCLUSIONS Our results suggest a significant role of EGE on the basis of Lake Louise criteria in evaluating patients with clinical suspicion of acute myocarditis. Parameters, including LVEF, LVESV, and LVSV, on Artificial Intelligence, may be useful independent predictors for capillary leakage and microcirculatory disturbance in myocarditis.

Hepatocellular Carcinoma: In Vivo Evaluation of Water Percentage as a Prognostic Biomarker Using Magnetic Resonance Imaging 3D-VIBE Multiecho Dixon.

INTRODUCTION: It is urgent to find an effective method to diagnose and prognose early hepatocellular carcinoma (HCC). The purpose of this study was to investigate the correlation between HCC histological degree and water percentage (WP) obtained from magnetic resonance imaging 3D-VIBE multiecho Dixon, and to evaluate the feasibility of WP in the postoperative prediction of early HCC recurrence. METHODS AND MATERIALS: From June 2016 to July 2017, 76 patients with diagnostic HCC all underwent 3D-VIBE Multiecho Dixon and ultrahigh b value diffusion-weighted imaging (DWI) examination. Freehand regions of interests were placed to measure the WP and apparent diffusion coefficient (ADC) value. The Edmondson-Steiner (E-S) grades proved by histopathological results were acquired from all patients. Comparisons between mean WP and ADC with E-S grades I-IV were performed using Kruskal-Wallis test and one-way ANOVA. Least Significant Difference t-test (LSD-t test) was applied to compare particular pairs of mean ADC value between every two E-S groups. Correlations between WP, ADC, and E-S grades were assessed by Spearman's rank correlation test. The Mann-Whitney U test was utilized to compare the difference of mean WP between recurrence and nonrecurrence group. The receiver operating characteristic (ROC) curves were calculated to estimate the diagnostic effect of 3D-VIBE Multiecho Dixon and ultrahigh b value DWI to HCC. Kaplan-Meier method was used to evaluate the recurrence free survival (RFS) after surgical resection. RESULTS: Mean WP values among groups E-S I to IV were 91.8%, 95.2%, 96.4%, and 97.7%, respectively. A positive correlation was exhibited between the WP and histopathological E-S grades (r = 0.480, p < 0.01). The ADC values based on E-S grades were 0.93, 0.82, 0.74, and 0.62 × 10-3 mm2/s, respectively. Significant differences were found between every two E-S groups (p < 0.01), and a negative correlation between ADC and E-S grades (r = -0.784, p = 0.000) was observed. Mean value of WP was 97.2% in recurrence group and 94.6% in nonrecurrence group (p < 0.01). The optimal cutoff value was 95.7%. The maximal area under the ROC curve was 0.747 ± 0.06 for WP, 0.631 ± 0.07 for ADC, and 0.753 ± 0.06 for the combination of WP and ADC. Mean RFS was 18.1 months in the lower WP and 10.7 months in higher WP group (p < 0.01). CONCLUSIONS: WP can be used as a potential biomarker for the diagnosis and prognosis of HCC. A lower value of WP may imply a better outcome in patients after surgical resection.

Intrahepatic cholangiocarcinoma in the setting of HBV-related cirrhosis: Differentiation with hepatocellular carcinoma by using Intravoxel incoherent motion diffusion-weighted MR imaging.

Accurate preoperative differentiation of intrahepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma (HCC) in the setting of cirrhotic liver is of great clinical significance because the treatment and prognosis of these entities differ markedly. Through a retrospectively research, we sought to determine the diagnostic performances of intravoxel incoherent motion (IVIM) and diffusion weighted imaging (DWI) parameters in the differentiating of ICC and HCC. According to the results, we found that apparent diffusion coefficient (ADC) derived from mono-exponential model and true ADC (ADCslow) derived from bi-exponential model can be used to distinguish the ICC and HCC, and ADCslowentailed the higher diagnostic performance than ADC. However, pseudo-ADC (ADCfast) and perfusion fraction (f) can not be used to differentiate ICC and HCC. These results suggested that IVIM and DWI parameters can be useful in differentiating ICC and HCC and might be helpful in selecting the treatment plan and predicting prognosis.

Liver fibrosis: in vivo evaluation using intravoxel incoherent motion-derived histogram metrics with histopathologic findings at 3.0 T.

PURPOSE: To retrospectively determine the feasibility of intravoxel incoherent motion (IVIM) imaging based on histogram analysis for the staging of liver fibrosis (LF) using histopathologic findings as the reference standard. METHODS: 56 consecutive patients (14 men, 42 women; age range, 15-76, years) with chronic liver diseases (CLDs) were studied using IVIM-DWI with 9 b-values (0, 25, 50, 75, 100, 150, 200, 500, 800 s/mm2) at 3.0 T. Fibrosis stage was evaluated using the METAVIR scoring system. Histogram metrics including mean, standard deviation (Std), skewness, kurtosis, minimum (Min), maximum (Max), range, interquartile (Iq) range, and percentiles (10, 25, 50, 75, 90th) were extracted from apparent diffusion coefficient (ADC), true diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f) maps. All histogram metrics among different fibrosis groups were compared using one-way analysis of variance or nonparametric Kruskal-Wallis test. For significant parameters, receivers operating characteristic curve (ROC) analyses were further performed for the staging of LF. RESULTS: Based on their METAVIR stage, the 56 patients were reclassified into three groups as follows: F0-1 group (n = 25), F2-3 group (n = 21), and F4 group (n = 10). The mean, Iq range, percentiles (50, 75, and 90th) of D* maps between the groups were significant differences (all P < 0.05). Area under the ROC curve (AUC) of the mean, Iq range, 50, 75, and 90th percentile of D* maps for identifying significant LF (≥F2 stage) was 0.901, 0.859, 0.876, 0.943, and 0.886 (all P < 0.0001), respectively; for diagnosing severe fibrosis or cirrhosis (F4), AUC was 0.917, 0.922, 0.943, 0.985, and 0.939 (all P < 0.0001), respectively. The histogram metrics of ADC, D, and f maps demonstrated no significant difference among the groups (all P > 0.05). CONCLUSION: Histogram analysis of D* map derived from IVIM can be used to stage liver fibrosis in patients with CLDs and provide more quantitative information beyond the mean value.

Thoracic epidural angiolipoma: A case report and review of the literature.

Angiolipoma of the spine is a benign neoplasm consisting of both mature fatty tissue and abnormal vascular elements, and usually presents with a slow progressive clinical course. Our patient presented with bilateral lower extremity weakness and chest-back numbness. Physical examination revealed adipose elements superficial hypesthesia below the T5 level and analgesia below the T6 level. Magnetic resonance imaging (MRI) scan showed an avidly and heterogeneously enhancing mass which was located in the posterior epidural space. Compression of the thoracic cord by the fusiform mass was seen between T3-T4. During the operation, a flesh pink vascular mass (4.7 cm × 1.0 cm × 1.0 cm) with obscure margin and strong but pliable texture was found in the posterior epidural space extending from T3 to T4. There was no infiltration of the dura or the adjacent bony spine. Histopathological study of the surgical specimen showed a typical angiolipoma. We review the previously documented cases of spinal extradural angiolipomas performed with MRI.