Clinical outcome is distinct between radiological stricture and endoscopic stricture in ileal Crohn's disease.

OBJECTIVES: Differences in clinical adverse outcomes (CAO) based on different intestinal stricturing definitions in Crohn's disease (CD) are poorly documented. This study aims to compare CAO between radiological strictures (RS) and endoscopic strictures (ES) in ileal CD and explore the significance of upstream dilatation in RS. METHODS: This retrospective double-center study included 199 patients (derivation cohort, n = 157; validation cohort, n = 42) with bowel strictures who simultaneously underwent endoscopic and radiologic examinations. RS was defined as a luminal narrowing with wall thickening relative to the normal gut on cross-sectional imaging (group 1 (G1)), which further divided into G1a (without upstream dilatation) and G1b (with upstream dilatation). ES was defined as an endoscopic non-passable stricture (group 2 (G2)). Strictures met the definitions of RS (with or without upstream dilatation) and ES were categorized as group 3 (G3). CAO referred to stricture-related surgery or penetrating disease. RESULTS: In the derivation cohort, G1b (93.3%) had the highest CAO occurrence rate, followed by G3 (32.6%), G1a (3.2%), and G2 (0%) (p < 0.0001); the same order was found in the validation cohort. The CAO-free survival time was significantly different among the four groups (p < 0.0001). Upstream dilatation (hazard ratio, 1.126) was a risk factor for predicting CAO in RS. Furthermore, when upstream dilatation was added to diagnose RS, 17.6% of high-risk strictures were neglected. CONCLUSIONS: CAO differs significantly between RS and ES, and clinicians should pay more attention to strictures in G1b and G3. Upstream dilatation has an important impact on the clinical outcome of RS but may not be an essential factor for RS diagnosis. CLINICAL RELEVANCE STATEMENT: This study explored the definition of intestinal stricture with the greatest significance for the clinical diagnosis and prognosis of patients with CD, and consequently provided effective auxiliary information for clinicians to formulate strategies for the treatment of CD intestinal strictures. KEY POINTS: • The retrospective double-center study showed that clinical adverse outcome is different between radiological strictures and endoscopic strictures in CD. • Upstream dilatation has an important impact on the clinical outcome of radiological strictures but may not be an essential factor for diagnosis of radiological strictures. • Radiological stricture with upstream dilatation and simultaneous radiological and endoscopic stricture were at increased risk for clinical adverse outcomes; thus, closer monitoring should be considered.

Repression of FBXW7 by HES5 contributes to inactivation of the TGF-ß signaling pathway and alleviation of endometriosis.

Endometriosis (EMS) is a gynecologic disorder associated with infertility and characterized by the endometrial-type mucosa outside the uterine cavity. Currently available treatment modalities are limited to undesirable effects. Thus, in the present study, we sought to study the pathogenesis mechanism of EMS. For this purpose, the ectopic and eutopic endometrial tissues were resected from 86 patients with EMS and 54 infertile patients without EMS, respectively. The regulatory mechanism among HES family bHLH transcription factor 5 (HES5), transforming growth factor-beta (TGF-ß)-induced factor 1 (TGIF1), F-box, and WD repeat domain containing 7 (FBXW7) was studied by performing co-immunoprecipitation, dual-luciferase reporter gene assay, and chromatin immunoprecipitation, respectively. A mouse model of EMS was established to verify the aforementioned regulatory mechanism in vivo. Upregulation of HES5 and TGIF1, as well as downregulation of FBXW7, was observed in EMS endometrial tissues and human endometrial stromal cells (hESCs), respectively. The overexpression of HES5 was found to suppress the FBXW7 transcription and TGIF1 degradation, resulting in the inactivation of the TGF-ß signaling pathway, as well as inhibition of hESC proliferation and invasion, thereby enhancing apoptosis. Results from a mouse model of EMS showed that the presence of HES5 contributed to the alleviation of EMS. Collectively, we attempted to provide a mechanistic insight into the unrecognized roles of the HES5/FBXW7 in EMS progression.

Regional liver function analysis with gadoxetic acid-enhanced MRI and virtual hepatectomy: prediction of postoperative short-term outcomes for HCC.

OBJECTIVES: To explore the role of quantitative regional liver function assessed by preoperative gadoxetic acid-enhanced MRI with computer-aided virtual hepatectomy to predict short-term outcomes after major hepatectomy for HCC. METHODS: We retrospectively reviewed the records of 133 consecutive patients with HCC who underwent preoperative gadoxetic acid-enhanced MRI and indocyanine green (ICG) test. Forty-five patients received open major hepatectomy. Liver function reserve and the future liver remnant were evaluated by computer-aided virtual hepatectomy. Global liver functional parameters included the T1 relaxation time reduction rate (T1ratio) and functional liver volume (FV), whereas regional parameters included the rT1pos, rT1ratio, remnant FV (rFV), and remnant FV ratio (rFVratio) of the remnant liver. The functional parameters of the MRI and ICG were used to predict the short-term outcomes (liver failure and major complications) after major hepatectomy. RESULTS: The T1ratio and FV were correlated with the ICG test (rho = - 0.304 and - 0.449, p < 0.05). FV < 682.8 ml indicated preoperative ICG-R15 ≥ 14% with 0.765 value of the area under the curve (AUC). No patient who underwent major resection with good liver functional reserve (ICG < 14%) and enough future remnant volume (> 30% standard LV) developed liver failure. Low rT1ratio (< 66.5%) and high rT1pos (> 217.5 ms) may predict major complications (AUC = 0.831 and 0.756, respectively; p < 0.05). The rT1ratio was an independent risk factor for postoperative major complications (odds ratio [OR] = 0.845, 95% CI, 0.736-0.966; p < 0.05). CONCLUSION: Preoperative gadoxetic acid-enhanced MRI with computer-aided virtual hepatectomy may facilitate optimal assessment of regional liver functional reserve to predict short-term outcomes after major hepatectomy for HCC. KEY POINTS: • Preoperative gadoxetic acid-enhanced MRI with virtual hepatectomy and volumetric analysis can provide precise liver volume and regional functional assessment. • Quantitative regional liver function assessed by gadoxetic acid-enhanced MRI can predict the short-term outcomes after major hepatectomy in patients with HCC. • The regional liver function assessed by gadoxetic acid-enhanced MRI is an independent risk factor for postoperative major complications.

Feasibility of multi-parametric magnetic resonance imaging combined with machine learning in the assessment of necrosis of osteosarcoma after neoadjuvant chemotherapy: a preliminary study.

BACKGROUND: Response evaluation of neoadjuvant chemotherapy (NACT) in patients with osteosarcoma is significant for the termination of ineffective treatment, the development of postoperative chemotherapy regimens, and the prediction of prognosis. However, histological response and tumour necrosis rate can currently be evaluated only in resected specimens after NACT. A preoperatively accurate, noninvasive, and reproducible method of response assessment to NACT is required. In this study, the value of multi-parametric magnetic resonance imaging (MRI) combined with machine learning for assessment of tumour necrosis after NACT for osteosarcoma was investigated. METHODS: Twelve patients with primary osteosarcoma of limbs underwent NACT and received MRI examination before surgery. Postoperative tumour specimens were made corresponding to the transverse image of MRI. One hundred and two tissue samples were obtained and pathologically divided into tumour survival areas (non-cartilaginous and cartilaginous tumour viable areas) and tumour-nonviable areas (non-cartilaginous tumour necrosis areas, post-necrotic tumour collagen areas, and tumour necrotic cystic/haemorrhagic and secondary aneurismal bone cyst areas). The MRI parameters, including standardised apparent diffusion coefficient (ADC) values, signal intensity values of T2-weighted imaging (T2WI) and subtract-enhanced T1-weighted imaging (ST1WI) were used to train machine learning models based on the random forest algorithm. Three classification tasks of distinguishing tumour survival, non-cartilaginous tumour survival, and cartilaginous tumour survival from tumour nonviable were evaluated by five-fold cross-validation. RESULTS: For distinguishing non-cartilaginous tumour survival from tumour nonviable, the classifier constructed with ADC achieved an AUC of 0.93, while the classifier with multi-parametric MRI improved to 0.97 (P = 0.0933). For distinguishing tumour survival from tumour nonviable, the classifier with ADC achieved an AUC of 0.83, while the classifier with multi-parametric MRI improved to 0.90 (P < 0.05). For distinguishing cartilaginous tumour survival from tumour nonviable, the classifier with ADC achieved an AUC of 0.61, while the classifier with multi-parametric MRI parameters improved to 0.81(P < 0.05). CONCLUSIONS: The combination of multi-parametric MRI and machine learning significantly improved the discriminating ability of viable cartilaginous tumour components. Our study suggests that this method may provide an objective and accurate basis for NACT response evaluation in osteosarcoma.

Hepatocellular carcinoma with hilar bile duct tumor thrombus versus hilar Cholangiocarcinoma on enhanced computed tomography: a diagnostic challenge.

BACKGROUND: Hepatocellular carcinoma (HCC) with hilar bile duct tumor thrombus (HBDTT) often mimic hilar cholangiocarcinoma (hilar CC). The purpose of this study is to analyze the Computed Tomography (CT) characteristics of HCC with HBDTT and to identify imaging features to aid its differentiation from hilar CC on enhanced CT. METHODS: We retrospectively identified 58 cases with pathologically proved HCC with HBDTT between 2011 and 2018. Seventy-seven cases of pathologically proven hilar CCs were selected during the same period. The clinical features and CT findings of the two groups were reviewed and compared. RESULTS: HCC with HBDTTs are more commonly found in men (87.9% vs 63.6%, p = 0.001) with lower age of onset (49.84 vs 58.61 years; p < 0.001) in comparison to hilar CCs. Positive correlation were identified between HCC with HBDTTs and chronic HBV infection (72.4% vs 11.7%; p <  0.001), increased serum AFP (67.2% vs 1.3%; p <  0.001), CA19-9 level (58.6% vs 85.7%; p <  0.001) and CEA level (3.4% vs 29.9%; p = 0.001), parenchymal lesion with intraductal lesion (100% vs 18.2%; p <  0.001), washout during the portal venous phase (84.5% vs 6.5%; p <  0.001), thickened bile duct wall (8.6% vs 93.5%; p <  0.001), intrahepatic vascular embolus (44.8% vs 7.8%; p <  0.001), splenomegaly (34.5% vs 2.6%, p <  0.001). A scoring system consisting of the five parameters obtained from characteristics mentioned above was trialed. The sensitivity and specificity for diagnosing HCC with HBDTT were 96.39, 100 and 92.5% respectively when the total score was 2 or more. CONCLUSIONS: HCC with HBDTTs are often distinguishable from hilar CCs based on washout during portal venous phase without thickened bile duct wall. HBV infection and serum AFP level facilitate the differentiation.

Preoperative Prediction of Pancreatic Neuroendocrine Neoplasms Grading Based on Enhanced Computed Tomography Imaging: Validation of Deep Learning with a Convolutional Neural Network.

INTRODUCTION: The pathological grading of pancreatic neuroendocrine neoplasms (pNENs) is an independent predictor of survival and indicator for treatment. Deep learning (DL) with a convolutional neural network (CNN) may improve the preoperative prediction of pNEN grading. METHODS: Ninety-three pNEN patients with preoperative contrast-enhanced computed tomography (CECT) from Hospital I were retrospectively enrolled. A CNN-based DL algorithm was applied to the CECT images to obtain 3 models (arterial, venous, and arterial/venous models), the performances of which were evaluated via an eightfold cross-validation technique. The CECT images of the optimal phase were used for comparing the DL and traditional machine learning (TML) models in predicting the pathological grading of pNENs. The performance of radiologists by using qualitative and quantitative computed tomography findings was also evaluated. The best DL model from the eightfold cross-validation was evaluated on an independent testing set of 19 patients from Hospital II who were scanned on a different scanner. The Kaplan-Meier (KM) analysis was employed for survival analysis. RESULTS: The area under the curve (AUC; 0.81) of arterial phase in validation set was significantly higher than those of venous (AUC 0.57, p = 0.03) and arterial/venous phase (AUC 0.70, p = 0.03) in predicting the pathological grading of pNENs. Compared with the TML models, the DL model gave a higher (although insignificantly) AUC. The highest OR was achieved for the p ratio <0.9, the AUC and accuracy for diagnosing G3 pNENs were 0.80 and 79.1% respectively. The DL algorithm achieved an AUC of 0.82 and an accuracy of 88.1% for the independent testing set. The KM analysis showed a statistical significant difference between the predicted G1/2 and G3 groups in the progression-free survival (p = 0.001) and overall survival (p < 0.001). CONCLUSION: The CNN-based DL method showed a relatively robust performance in predicting pathological grading of pNENs from CECT images.

Magnetisation transfer imaging adds information to conventional MRIs to differentiate inflammatory from fibrotic components of small intestinal strictures in Crohn's disease.

OBJECTIVES: Identifying inflammation- or fibrosis-predominant strictures in Crohn's disease (CD) is crucial for treatment strategies. We evaluated the additive value of magnetisation transfer (MT) to conventional MRI for differentiating CD strictures using surgical histopathology as a reference standard. METHODS: Twenty-eight consecutive CD patients who underwent MRI preoperatively were recruited. MRI parameters included T2-weighted imaging (T2WI) hyperintensity, bowel wall thickness, enhancement pattern changes over time, enhancement pattern and gain ratio in dynamic contrast-enhanced phases, and MT ratio. Correlation analysis was performed using Spearman's rank test. Receiver operating characteristic curve analysis and Cohen's κ were used. A model with combined MRI variables characterising intestinal strictures was proposed and validated in 14 additional CD patients. RESULTS: Significant correlations with histological inflammation scores were shown for wall thickness (r = 0.361, p = 0.001) and T2WI hyperintensity (r = 0.396, p < 0.001), whereas histological fibrosis scores were significantly correlated with MT ratio (r = 0.681, p < 0.001) and wall thickness (r = 0.461, p < 0.001). T2WI hyperintensity could differentiate mild from moderate-to-severe inflammation with a sensitivity of 0.871 and a specificity of 0.800. MT ratio could discriminate mild from moderate-to-severe fibrosis with a sensitivity and a specificity of 0.913 and 0.923, respectively. Combining MT ratio and T2WI hyperintensity, the MRI classification moderately agreed with the pathological stricture classification (p < 0.01, κ = 0.549). In the validation set, the diagnostic accuracy of T2WI hyperintensity and MT ratio were 86% and 89%, with good agreement between MRI and histopathological classification (p < 0.01, κ = 0.665). CONCLUSIONS: MT ratio combined with conventional MRI improves the differentiation of fibrotic from inflammatory components of small-bowel strictures in CD patients. KEY POINTS: • MT ratio from magnetisation transfer imaging combined with T2WI from conventional MRI can simultaneously characterise bowel fibrosis and inflammation in adult Crohn's disease.

Imaging biomarkers for well and moderate hepatocellular carcinoma: preoperative magnetic resonance image and histopathological correlation.

BACKGROUND: Our aim of the study is to investigate the feasibility of preoperative prediction for hepatocellular carcinoma (HCC) histological grading using gadoxetic acid-enhanced magnetic resonance imaging (MRI). METHODS: This study included one hundred and fifty-six patients with solitary HCC. Preoperative gadoxetic acid-enhanced MRI findings were retrospectively analyzed. MRI qualitative features such as tumor size, margin, capsule status, signal homogeneity, intratumoral vessels, peritumoral enhancement during mid-arterial phase, peritumoral hypointensity during the hepatobiliary phase (HBP) were investigated. Apparent diffusion coefficients (ADCs), T1 reduction ratio of pre- and post-contrast enhanced images of the tumors were calculated. HCC histological grading in surgical specimens were confirmed by Edmonson's criteria. Correlations between these MRI features and HCC histological grading were analyzed using multivariate logistic regression. The receiver operating characteristic (ROC) curve was used to assess the predictive efficacy of the model. RESULTS: Univariate analysis showed that maximum tumor diameter (p = 0.004), tumor margin (p = 0.006), intratumoral vessels (p = 0.001) and peritumoral hypointensity during HBP (p = 0.000), were significantly correlated with HCC histological grading. There was no relationship between capsule, tumor signal, venous thrombosis, peritumoral enhancement during mid-arterial phase, ADC value, T1 reduction ratio, and HCC histological grading. Multivariate logistic regression analysis demonstrated that the maximum tumor diameter (p = 0.012, odds ratio = 1.002, 95% confidence interval: 1.007-1.046)) was an independent risk factor for high grade HCC. CONCLUSIONS: Greater tumor size, a more irregular margin, presence of intratumoral vessels, and peritumoral hypointensity during HBP were indicators for high grade HCC. The maximum tumor diameter was an independent risk factor for high grade HCC.

Prediction of sorafenib treatment-related gene expression for hepatocellular carcinoma: preoperative MRI and histopathological correlation.

PURPOSE: To investigate the feasibility of prediction for targeted therapy-related gene expression in hepatocellular carcinoma (HCC) using preoperative gadoxetic acid-enhanced magnetic resonance imaging (MRI). MATERIALS AND METHODS: Ninety-one patients (81 men, mean age 53.9 ± 12 years) with solitary HCC who underwent preoperative enhanced MRI were retrospectively analyzed. Features including tumor size, signal homogeneity, tumor capsule, tumor margin, intratumoral vessels, peritumor enhancement, peritumor hypointensity, signal intensity ratio on DWI, T1 relaxation times, and the reduction rate between pre- and post-contrast enhancement images were assessed. The operation and histopathological evaluation were performed within 2 weeks after MRI examination (mean time 7 days). The expression levels of BRAF, RAF1, VEGFR2, and VEGFR3 were evaluated. The associations between these imaging features and gene expression levels were investigated. RESULTS: Tumor incomplete capsules or non-capsules (p = 0.001) and intratumoral vessels (p = 0.002) were significantly associated with BRAF expression, and tumor incomplete capsules or non-capsules (p = 0.001) and intratumoral vessels (p = 0.013) with RAF1 expression. There was no significant association between the expression of VEGFR2, VEGFR3, and all examined MRI features. Multivariate logistic regression showed that incomplete tumor capsule (p = 0.002) and non-capsule (p = 0.004) were independent risk factors of HCC with high BRAF expression; incomplete tumor capsule (p < 0.001) and non-capsule (p = 0.040) were independent risk factors of HCC with high RAF1 expression. CONCLUSION: The presence of incomplete capsule or intratumoral vessels and the absence of capsule are potential indicators of high BRAF and RAF1 expression. Gadoxetic acid-enhanced MRI may facilitate the choice of gene therapy for patients with HCC. KEY POINTS: • Incomplete tumor capsule and non-capsule were independent risk factors of HCC with high BRAF and RAF1 expression. • The presence of intratumoral vessels was a potential indicator of high BRAF and RAF1 expression. • Gadoxetic acid-enhanced MRI may be a predictor of efficacy of treatment with sorafenib.

Ability of DWI to characterize bowel fibrosis depends on the degree of bowel inflammation.

OBJECTIVES: Although diffusion-weighted imaging (DWI) is reported to be accurate in detecting bowel inflammation in Crohn's disease (CD), its ability to assess bowel fibrosis remains unclear. This study assessed the role of DWI in the characterization of bowel fibrosis using surgical histopathology as the reference standard. METHODS: Abdominal DWI was performed before elective surgery in 30 consecutive patients with CD. The apparent diffusion coefficients (ADCs) in pathologic bowel walls were calculated. Region-by-region correlations between DWI and the surgical specimens were performed to determine the histologic degrees of bowel fibrosis and inflammation. RESULTS: ADCs correlated negatively with bowel inflammation (r = - 0.499, p < 0.001) and fibrosis (r = - 0.464, p < 0.001) in 90 specimens; the ADCs in regions of nonfibrosis and mild fibrosis were significantly higher than those in regions of moderate-severe fibrosis (p = 0.008). However, there was a significant correlation between the ADCs and bowel fibrosis (r = - 0.641, p = 0.001) in mildly inflamed segments but not in moderately (r = - 0.274, p = 0.255) or severely (r = - 0.225, p = 0.120) inflamed segments. In the mildly inflamed segments, the ADCs had good accuracy with an area under the receiver-operating characteristic curve of 0.867 (p = 0.004) for distinguishing nonfibrosis and mild fibrosis from moderate-severe fibrosis. CONCLUSIONS: ADC can be used to assess bowel inflammation in patients with CD. However, it only enables the accurate detection of the degree of bowel fibrosis in mildly inflamed bowel walls. Therefore, caution is advised when using ADC to predict the degree of intestinal fibrosis. KEY POINTS: • Diffusion-weighted imaging was used to assess bowel inflammation in patients with Crohn's disease. • The ability of diffusion-weighted imaging to evaluate bowel fibrosis decreased with increasing bowel inflammation. • Diffusion-weighted imaging enabled accurate detection of the degree of fibrosis only in mildly inflamed bowel walls.

IVIM with fractional perfusion as a novel biomarker for detecting and grading intestinal fibrosis in Crohn's disease.

OBJECTIVES: Intravoxel incoherent motion (IVIM) diffusion-weighted magnetic resonance imaging (MRI) provides information on both perfusion and diffusion and has been used to evaluate Crohn's disease (CD) activity and fibrosis in children; however, there are no reports on its use in adults. We aimed to determine its value for detecting and grading intestinal fibrosis in adults with CD compared with contrast-enhanced imaging and traditional diffusion-weighted imaging using surgical histopathology as a reference standard. METHODS: Twenty-four adults with CD underwent preoperative IVIM, traditional diffusion-weighted, and contrast-enhanced imaging. Region-by-region correlations between MRI findings and histologic findings of the surgical specimens were performed. Imaging parameters including fractional perfusion, perfusion coefficient, and diffusion coefficient for IVIM and apparent diffusion coefficient value for traditional diffusion-weighted imaging and contrast-enhanced parameter of 95 bowel lesions were measured. Intestinal fibrosis was histologically scored from 0 to 3. RESULTS: The fractional perfusion (r = - 0.629, p < 0.001) and apparent diffusion coefficient values (r = - 0.495, p < 0.001) were significantly correlated with fibrosis scores. Fractional perfusion decreased following increases in fibrosis severity from mild, to moderate, to severe (p < 0.001). The area under the receiver operating characteristic curve for distinguishing moderate-severe from mild fibrosis was 0.876 (p < 0.001) for fractional perfusion, followed by 0.802 for apparent diffusion coefficient value (p < 0.001). Perfusion coefficient, diffusion coefficient, and contrast-enhanced parameter were uncorrelated with histological fibrosis. CONCLUSIONS: IVIM diffusion-weighted magnetic resonance imaging outperforms traditional diffusion-weighted and contrast-enhanced imaging in grading bowel fibrosis, and fractional perfusion may be a promising biomarker for fibrosis severity in adults with CD. KEY POINTS: • Intravoxel incoherent motion diffusion-weighted MRI outperforms contrast-enhanced imaging and traditional diffusion-weighted MRI for detecting and grading intestinal fibrosis in adult Crohn's disease. • The parameter fractional perfusion, a promising biomarker for fibrosis severity, may be beneficial for treatment planning and monitoring of bowel fibrosis in adult Crohn's disease. • Perfusion coefficient, diffusion coefficient, and the percentage of enhancement gain between 70 s and 7 min were uncorrelated with histological fibrosis.

A novel collagen area fraction index to quantitatively assess bowel fibrosis in patients with Crohn's disease.

BACKGROUND: A validated histopathological tool to precisely evaluate bowel fibrosis in patients with Crohn's disease is lacking. We attempted to establish a new index to quantify the severity of bowel fibrosis in patients with Crohn's disease-associated fibrostenosis. METHODS: We analyzed the histopathological data of 31 patients with Crohn's disease strictures undergoing surgical resection. The most representative sections of resected strictured segments were stained with Masson trichrome to manifest bowel fibrosis. The collagen area fraction and histological fibrosis score were simultaneously calculated for the same section to evaluate the severity of bowel fibrosis. RESULTS: Collagen area fraction strongly correlated with histological fibrosis scores (r = 0.733, P < 0.001). It showed a stronger correlation (r = 0.561, P < 0.001) with the degree of bowel strictures than the histological fibrosis score did (r = 0.468, P < 0.001). It was also shown to be more accurate for diagnosing Crohn's disease strictures (area under the receiver operating characteristic curve = 0.815, P < 0.001) compared with the histological fibrosis score (area under the curve = 0.771, P < 0.001). High repeatability was observed for the collagen area fraction, with an intraclass correlation coefficient of 0.915 (P < 0.001). CONCLUSIONS: Collagen area fraction is a simple and reliable index to quantify the severity of bowel fibrosis in patients with Crohn's disease-associated fibrostenosis.

Characterization of Degree of Intestinal Fibrosis in Patients with Crohn Disease by Using Magnetization Transfer MR Imaging.

Purpose To evaluate the role of magnetization transfer (MT) magnetic resonance (MR) imaging for the characterization of intestinal fibrosis compared with contrast material-enhanced and diffusion-weighted MR imaging and its capability for differentiating fibrotic from inflammatory strictures in humans with Crohn disease (CD) by using surgical histopathologic analysis as the reference standard. Materials and Methods Institutional review board approval and informed consent were obtained for this prospective study. Abdominal MT imaging, contrast-enhanced imaging, and diffusion-weighted imaging of 31 consecutive patients with CD were analyzed before elective surgery. The bowel wall MT ratio normalized to skeletal muscle, the apparent diffusion coefficient (ADC), and the percentage of enhancement gain were calculated; region-by-region correlations with the surgical specimen were performed to determine the histologic degree of fibrosis and inflammation. The performance of MT imaging was validated in five new patients. One-way analysis of variance test, Spearman rank correlation, and receiver operating characteristic curve were used for statistical analysis. Results Normalized MT ratios strongly correlated with fibrosis scores (r = 0.769; P = .000) but did not correlate with inflammation scores (r = -0.034; P = .740). Significant differences (F = 49.002; P = .000) in normalized MT ratios were found among nonfibrotic, mildly, moderately, and severely fibrotic walls. The normalized MT ratios of mixed fibrotic and inflammatory bowel walls were significantly higher than those of bowel walls with only inflammation present (t = -8.52; P = .000). A high accuracy of normalized MT ratios was shown with an area under the receiver operating characteristic curve (AUC) of 0.919 (P = .000) for differentiating moderately to severely fibrotic bowel walls from nonfibrotic and mildly fibrotic bowel walls, followed by ADC (AUC, 0.747; P = .001) and the percentage of enhancement gain (AUC, 0.592; P = .209). The sensitivity, specificity, and AUC of MT imaging for diagnosing moderate to severe fibrosis in the validation data set were 80% (12 of 15), 100% (three of three), and 0.9 (P = .033), respectively. Conclusion MT imaging outperforms ADC and contrast-enhanced imaging in detecting and distinguishing varying degrees of bowel fibrosis with or without coexisting inflammation. MT imaging could potentially be used as a method to differentiate fibrotic from inflammatory intestinal strictures in patients with CD. © RSNA, 2018 Online supplemental material is available for this article.

Diffusion kurtosis MRI versus conventional diffusion-weighted imaging for evaluating inflammatory activity in Crohn's disease.

PURPOSE: To assess the efficacy of diffusion kurtosis imaging (DKI) and to compare DKI-derived parameters with that of conventional diffusion-weighted imaging (DWI) for grading the inflammatory activity of Crohn's disease (CD). MATERIALS AND METHODS: In all, 38 patients with CD underwent 3T magnetic resonance enterography (MRE) with DKI (b values of 0-2000 s/mm2 ). The inflammatory activity of the bowel segments was graded by magnetic resonance index of activity (MaRIA) as inactive (<7), mild (≥7 and <11), or moderate-severe (≥11). Apparent diffusion for non-Gaussian distribution (Dapp ) and apparent kurtosis coefficient (Kapp ) on DKI as well as apparent diffusion coefficient (ADC) on DWI were compared. RESULTS: In all, 86 bowel segments including inactive (20), mild (19), and moderate-severe (47) CD were analyzed. The differences in Kapp , Dapp , and ADC among inactive, mild, and moderate-severe CD were significant (all P < 0.05). Kapp (r = 0.862), Dapp (r = -0.755), and ADC (r = -0.713) correlated well with MaRIA in all segments. Stronger correlation with MaRIA in moderate-severe CD was found for Kapp (r = 0.647) than that of Dapp (r = -0.414) and ADC (r = -0.580). Receiver operating characteristic (ROC) curve analysis showed high accuracy of Kapp , Dapp , and ADC for differentiating active from inactive CD (AUC: 0.953 for Kapp , 0.944 for Dapp , 0.907 for ADC) as well as differentiating inactive-mild from moderate-severe CD (AUC: 0.946 for Kapp , 0.887 for Dapp , 0.846 for ADC). The threshold Kapp of 0.731 allowed differentiation of active from inactive CD with 89.4% sensitivity and 95% specificity. CONCLUSION: DKI of CD is clinically feasible and might be superior to conventional DWI for grading the inflammatory activity of CD. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:702-709.

T2* Mapping to characterize intestinal fibrosis in crohn's disease.

BACKGROUND: Assessing bowel fibrosis in patients with Crohn's disease (CD) has important therapeutic implications. PURPOSE: To determine the utility of T2* mapping versus that of contrast enhanced (CE) imaging in grading intestinal fibrosis in patients with CD using surgical pathology as the reference standard. STUDY TYPE: Prospective. SPECIMENS: 102 specimens from 27 patients with CD. FIELD STRENGTH/SEQUENCE: 3.0T; T2WI; T1WI; T2*WI. ASSESSMENT: The T2*WI values of the bowel wall targeted for resection were measured by two radiologists by drawing regions of interest on the thickened bowel wall. The resected bowel specimens with pathological fibrosis and type I collagen were classified into four severity grades (0-3) by a pathologist using a semi-quantitative scoring system. STATISTICAL TESTS: The differences in the T2*WI values among the different histological grades were analyzed using one-way analysis of variance or the Kruskal-Wallis test, and their correlations were analyzed. The ability of the T2*WI values to discriminate between various degrees of fibrosis was assessed using a receiver operating characteristic (ROC) curve. RESULTS: Significant differences were observed in the T2* values of mild (23.56 ± 1.60 ms), moderate (16.19 ± 0.55 ms), and severe (13.59 ± 0.53 ms) fibrosis types (F = 35.84; P < 0.001). T2* values were moderately associated with histological fibrosis (r = -0.627; P < 0.001) and type I collagen scores (r = -0.588; P < 0.001). T2* values were highly accurate, with an area under the ROC curve (AUC) of 0.951 (P < 0.001) for differentiating moderate-to-severe fibrosis from nonfibrosis and mild fibrosis, followed by an AUC of 0.508 for the percentage of enhancement gain (P = 0.908). A threshold T2* value of 18.06 ms was recommended for diagnosing moderate-to-severe fibrosis with 94.7% sensitivity and 78.3% specificity. DATA CONCLUSION: MRI T2* mapping outperforms CE parameters in distinction of various degrees of bowel fibrosis in CD. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018.

CT evaluation of response in advanced gastroenteropancreatic neuroendocrine tumors treated with long-acting-repeatable octreotide: what is the optimal size variation threshold?

OBJECTIVE: To identify a reliable early indicator of deriving progression-free survival (PFS) benefit in patients with advanced gastroenteropancreatic neuroendocrine tumors (GEP-NETs) treated with octreotide long-acting repeatable (LAR). METHODS: We investigated the images of 50 patients with well-differentiated advanced GEP-NETs treated with LAR octreotide and underwent baseline and follow-up thoracic, abdominal, and pelvic computed tomography. Receiver-operating characteristic (ROC) analysis and the Kaplan-Meier method were used to identify the optimal threshold to distinguish between those with and without significant improvement of PFS. RESULTS: The optimal threshold for determining a response to octreotide LAR was -10% ΔSLD, with a sensitivity and specificity of 85.7% and 80%, respectively. At this threshold, 19 patients were responders and 31 were non-responders; the median PFS was 20.2 and 7.6 months in responders and non-responders (hazard ratio, 2.66; 95% confidence interval, 1.32-5.36). CONCLUSION: A 10% shrinkage in tumor size is an optimal early predictor of response to octreotide LAR in advanced GEP-NETs. KEY POINTS: • Octreotide LAR can significantly prolong PFS among patients with well-differentiated advanced GEP-NETs. • No optimal tumor size-based response criteria are reported in GEP-NETs with octreotide. • Ten percent tumor shrinkage is a reliable indicator of the response to octreotide for advanced GEP-NETs.

CT Enterography score: a potential predictor for severity assessment of active ulcerative colitis.

BACKGROUND: Evaluate the possibility of CT enterography (CTE) score system as a predictor in assessing active ulcerative colitis (UC) severity. METHODS: Forty-six patients with active UC with CTE and colonoscopy were enrolled. Based on modified Mayo score, patients were divided into three groups: mild (n = 10), moderate (n = 17) and severe (n = 19). A cumulative CTE score was calculated in each patient and its correlation with modified Mayo score was analyzed. The optimal cutoff values of CTE score were determined by receiver operating characteristic (ROC) curves analysis. RESULTS: Significant between-group differences were observed in CTE spectrums of mucosal bubbles, mural stratification, loss of haustration, enlarged mesenteric lymph nodes and engorged mesenteric vessels (P < 0.05). The cumulative CTE scores were significant difference between three groups (CTE score:4.9 ± 2.3, 7.6 ± 2.6, and 10.9 ± 2.0, respectively, P < 0.01). The cumulative CTE score showed a positive correlation with modified Mayo score (r = 0.835, P < 0.05). The optimal cut-off value for CTE score predicting moderate and severe UC was 9.5 (area under the curve [AUC]:0.847, sensitivity:78.9%, specificity:82.4%). CONCLUSION: Disease severity assessment by CTE score demonstrates strong positive correlation with severity established modified Mayo score. CTE score system maybe a potential predictor for active UC severity assessment.

Early evaluation of sunitinib for the treatment of advanced gastroenteropancreatic neuroendocrine neoplasms via CT imaging: RECIST 1.1 or Choi Criteria?

BACKGROUND: The aim of this study was to assess and compare the Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1) and the Choi criteria in evaluating the early response of advanced gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) treated with sunitinib. METHODS: Eighteen patients with pathologically proven advanced GEP-NENs treated with sunitinib were enrolled in the study. Pre- and post-treatment CT scans (plain, biphasic enhanced CT scan) were performed on all patients. Changes in the target tumor size and density from pre-treatment to 1.4-3.1 months after treatment were measured and recorded for each patient. Tumor responses were identified using RECIST 1.1 and Choi criteria. The time to tumor progression (TTP) for each patient was measured and compared between groups using the Kaplan-Meier method. RESULTS: Among the 18 patients, 4 (22%) exhibited a partial response (PR), 9 (50%) exhibited stable disease (SD), and 5 (28%) experienced progressive disease (PD), using RECIST 1.1. However, based on the Choi criteria, 8 (44%) patients exhibited a PR, 4 (22%) exhibited SD, and 6 (33%) experienced PD. According to RECIST 1.1, the median TTP of PR, SD and PD group were 16.6, 10.8 and 2.3 months, respectively. The TTP of the PR group was significantly longer than that of the PD group (P = 0.007) but insignificant when compared to the SD group (P = 0.131). According to Choi criteria, the median TTP of PR, SD and PD group were not reached, 10.8 and 2.3 months, respectively. The TTP of the PR group was significantly longer than that of the SD (P = 0.026) and PD groups (P < 0.001). CONCLUSION: The Choi criteria appear to be more sensitive and more precise than RECIST 1.1 in assessing the early response of advanced GEP-NENs treated with sunitinib.

Pancreatic schwannoma: a case report and an updated 40-year review of the literature yielding 68 cases.

BACKGROUND: Pancreatic schwannoma is a rare tumor. Preoperative diagnosis of pancreatic schwannoma is challenging due to its tendency to mimic other lesions of the pancreas. We describe a case of pancreatic schwannoma and present a review of the cases currently reported in the English literature to identify characteristics of pancreatic schwannoma on imaging. CASE PRESENTATION: A 53-year-old male presented with a history of intermittent periumbilical abdominal pain and lower back pain for 1 week. Based on ultrasound (US) and computed tomography (CT) findings, we made a preoperative diagnosis of solid pseudopapillary tumor and performed a standard pancreaticoduodenectomy. Pathological examination showed that the tumor was composed of spindle cells with a palisading arrangement, and immunohistochemistry revealed strong positive staining for S-100 protein, which was consistent with a diagnosis of pancreatic schwannoma. At the 8-month follow-up visit, the patient was doing well without recurrent disease, and his abdominal pain had resolved. CONCLUSIONS: Although pancreatic schwannoma is rare, it should be included in the list of differential diagnoses of pancreatic masses, both solid and cystic. A tumor size larger than 6.90 cm, vascular encasement, or visceral invasion should elicit suspicion of malignant transformation.

Gd-EOB-DTPA-enhanced magnetic resonance imaging combined with T1 mapping predicts the degree of differentiation in hepatocellular carcinoma.

BACKGROUND: Variable degrees of differentiation in hepatocellular carcinoma(HCC)under Edmondson-Steiner grading system has been proven to be an independent prognostic indicator for HCC. Up till now, there has been no effective radiological method that can reveal the degree of differentiation in HCC before surgery. This paper aims to evaluate the use of Gd-EOB-DTPA-Enhanced Magnetic Resonance Imaging combined with T1 mapping for the diagnosis of HCC and assessing its degree of differentiation. METHODS: Forty-four patients with 53 pathologically proven HCC had undergone Gd-EOB-DTPA enhanced MRI with T1 mapping before surgery. Out of the 53 lesions,13 were grade I, 27 were gradeII, and 13 were grade III. The T1 values of each lesion were measured before and at 20 min after Gd-EOB-DTPA administration (T1p and T1e). The absolute reduction in T1 value (T1d) and the percentage reduction (T1d %) were calculated. The one-way ANOVA and Pearson correlation were used for comparisons between the T1 mapping values. RESULTS: The T1d and T1d % of grade I, II and III of HCC was 660.5 ± 422.8ms、295.0 ± 99.6ms、276.2 ± 95.0ms and 54.0 ± 12.2 %、31.5 ± 6.9 %、27.7 ± 6.7 % respectively. The differences between grade Iand II, grade Iand III were statistically significant (p < 0.05), but there was no statically significant difference between grade II and III. The T1d % was the best marker for grading of HCC, with a Spearman correlation coefficient of -0.676. CONCLUSIONS: T1 mapping before and after Gd-EOB-DTPA administration can predict degree of differentiation in HCC.