Radiological biomarkers reflecting visceral fat distribution help distinguish inflammatory bowel disease subtypes: a multicenter cross-sectional study.

OBJECTIVES: To achieve automated quantification of visceral adipose tissue (VAT) distribution in CT images and screen out parameters with discriminative value for inflammatory bowel disease (IBD) subtypes. METHODS: This retrospective multicenter study included Crohn's disease (CD) and ulcerative colitis (UC) patients from three institutions between 2012 and 2021, with patients with acute appendicitis as controls. An automatic VAT segmentation algorithm was developed using abdominal CT scans. The VAT volume, as well as the coefficient of variation (CV) of areas within the lumbar region, was calculated. Binary logistic regression and receiver operating characteristic analysis was performed to evaluate the potential of indicators to distinguish between IBD subtypes. RESULTS: The study included 772 patients (365 CDs, median age [inter-quartile range] = 31.0. (25.0, 42.0) years, 255 males; 241 UCs, 46.0 (34.0, 55.5) years, 138 males; 166 controls, 40.0 (29.0, 53.0) years, 80 males). CD patients had lower VAT volume (CD = 1584.95 ± 1128.31 cm3, UC = 1855.30 ± 1326.12 cm3, controls = 2470.91 ± 1646.42 cm3) but a higher CV (CD = 29.42 ± 15.54 %, p = 0.006 and p ˂ 0.001) compared to UC and controls (25.69 ± 12.61 % vs. 23.42 ± 15.62 %, p = 0.11). Multivariate analysis showed CV was a significant predictor for CD (odds ratio = 6.05 (1.17, 31.12), p = 0.03). The inclusion of CV improved diagnostic efficiency (AUC = 0.811 (0.774, 0.844) vs. 0.803 (0.766, 0.836), p = 0.08). CONCLUSION: CT-based VAT distribution can serve as a potential biomarker for distinguishing IBD subtypes. CRITICAL RELEVANCE STATEMENT: Visceral fat distribution features extracted from CT images using an automated segmentation algorithm (1.14 min) show differences between Crohn's disease and ulcerative colitis and are promising for practical radiological screening. KEY POINTS: • Radiological parameters reflecting visceral fat distribution were extracted for the discrimination of Crohn's disease (CD) and ulcerative colitis (UC). • In CD, visceral fat was concentrated in the lower lumbar vertebrae, and the coefficient of variation was a significant predictor (OR = 6.05 (1.17, 31.12), p = 0.03). • The differences between CD, UC, and controls are promising for practical radiological screening.

Differentiating cellular leiomyoma from uterine sarcoma and atypical leiomyoma using multi-parametric MRI.

Objectives: To evaluate the diagnostic performance of conventional magnetic resonance imaging (cMRI) combined with diffusion-weighted MRI (DWI) in discrimination of cellular leiomyoma, uterine sarcoma, and atypical leiomyoma. Methods: This retrospective study enrolled 106 patients with uterine masses, including 51 cellular leiomyomas (CLs), 32 uterine sarcomas (USs) and 23 degenerated leiomyomas (LMs) confirmed by histopathologic examination. Clinical data and imaging findings were assessed. Chi-squared test for qualitative variables and one way ANOVA analysis for quantitative variables were performed. Logistic regression analysis and the receiver operating characteristic (ROC) analysis were performed to determine the cut-off point and diagnostic performances for significant numeric values or multiple models. Results: Morphology (Odds ratio [OR] = 6.36) and margin (OR = 13.84) derived from cMRI were independent indicators for differentiating CLs from USs, and T2WI signal (OR = 0.23) were an independent indicator for differentiating CLs from degenerated LMs (all P < 0.05). The cutoff value of apparent diffusion coefficient (ADC) derived from DWI for differentiating CLs from USs was 839 ×10-6 mm2/sec and was 1239 ×10-6 mm2/sec for differentiating CLs from degenerated LMs. Compared with the use of cMRI features and ADC value alone, combination of independent indicators and ADC value achieved higher AUCs for both differentiations (all P < 0.05). Conclusions: cMRI is a reliable tool for differentiating CLs from USs and atypical leiomyoma, especially degenerated LMs. The combined use of cMRI and DWI can improve the differential diagnostic performance.

Evaluation of dynamic contrast-enhanced magnetic resonance imaging and diffusion-weighted imaging for predicting muscular hyperplasia/hypertrophy in Crohn's disease.

OBJECTIVES: The existence of smooth muscle alteration in Crohn's disease (CD) is often neglected. It has been found that muscular hyperplasia/hypertrophy rather than fibrosis was the primary component of bowel wall thickening. This study aimed to assess the value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion weighted imaging for the characterization of histopathologic tissue composition of CD, particularly smooth muscle hypertrophy, as well as inflammation and fibrosis. METHODS: The study included patients diagnosed with CD who received MRI examination 30 days before resection from August 2016 to December 2020. A semiquantitative histological grading scheme was employed to evaluate the pathological tissues. Resected sections were matched with MRI according to pathological marks. Parameters evaluated included: mural thickness, T2 ratio, apparent diffusion coefficient value; and maximum enhancement, initial slope of increase, perfusion parameters of DCE-MRI and enhancement pattern. These parameters were compared with location-matched histopathological grade. RESULTS: Ninety-one sections were enrolled in this retrospective study. When active inflammation is moderate or severe, volume transfer coefficient (Ktrans), maximum enhancement (ME) and initial slope of increase (ISI) are lower, mural thickness is higher when a certain degree of smooth muscle alteration is present. When active inflammation is absent or mild, ME, mural thickness and ISI can differentiate the presence of predominant muscular alteration. By combining ME and thickness comparisons against their cutoff values to create a combined ordinal parameter, the area under the curve value for whether significant muscular alteration coexists with moderate or severe active inflammation was found to be 0.953. CONCLUSIONS: MRI predicts the degree of inflammation, and can distinguish the degree of muscular alteration coexists with moderate or severe active inflammation with reasonable accuracy.

Dynamic contrast-enhanced magnetic resonance imaging and diffusion-weighted imaging in the activity staging of terminal ileum Crohn's disease.

BACKGROUND: The activity staging of Crohn's disease (CD) in the terminal ileum is critical in developing an accurate clinical treatment plan. The activity of terminal ileum CD is associated with the microcirculation of involved bowel walls. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion-weighted imaging (DWI) can reflect perfusion and permeability of bowel walls by providing microcirculation information. As such, we hypothesize that DCE-MRI and DWI parameters can assess terminal ileum CD, thereby providing an opportunity to stage CD activity. AIM: To evaluate the value of DCE-MRI and DWI in assessing activity of terminal ileum CD. METHODS: Forty-eight patients with CD who underwent DCE-MRI and DWI were enrolled. The patients' activity was graded as remission, mild and moderate-severe. The transfer constant (Ktrans), wash-out constant (Kep), and extravascular extracellular volume fraction (Ve) were calculated from DCE-MRI and the apparent diffusion coefficient (ADC) was obtained from DWI. Magnetic Resonance Index of Activity (MaRIA) was calculated from magnetic resonance enterography. Differences in these quantitative parameters were compared between normal ileal loop (NIL) and inflamed terminal ileum (ITI) and among different activity grades. The correlations between these parameters, MaRIA, the Crohn's Disease Activity Index (CDAI), and Crohn's Disease Endoscopic Index of Severity (CDEIS) were examined. Receiver operating characteristic curve analyses were used to determine the diagnostic performance of these parameters in differentiating between CD activity levels. RESULTS: Higher Ktrans (0.07 ± 0.04 vs 0.01 ± 0.01), Kep (0.24 ± 0.11 vs 0.15 ± 0.05) and Ve (0.27 ± 0.07 vs 0.08 ± 0.03), but lower ADC (1.41 ± 0.26 vs 2.41 ± 0.30) values were found in ITI than in NIL (all P < 0.001). The Ktrans, Kep, Ve and MaRIA increased with disease activity, whereas the ADC decreased (all P < 0.001). The Ktrans, Kep, Ve and MaRIA showed positive correlations with the CDAI (r = 0.866 for Ktrans, 0.870 for Kep, 0.858 for Ve, 0.890 for MaRIA, all P < 0.001) and CDEIS (r = 0.563 for Ktrans, 0.567 for Kep, 0.571 for Ve, 0.842 for MaRIA, all P < 0.001), while the ADC showed negative correlations with the CDAI (r = -0.857, P < 0.001) and CDEIS (r = -0.536, P < 0.001). The areas under the curve (AUC) for the Ktrans, Kep, Ve, ADC and MaRIA values ranged from 0.68 to 0.91 for differentiating inactive CD (CD remission) from active CD (mild to severe CD). The AUC when combining the Ktrans, Kep and Ve was 0.80, while combining DCE-MRI parameters and ADC values yielded the highest AUC of 0.95. CONCLUSION: DCE-MRI and DWI parameters all serve as measures to stage CD activity. When they are combined, the assessment performance is improved and better than MaRIA.

Assessment of pediatric Crohn's disease activity: validation of the magnetic resonance enterography global score (MEGS) against endoscopic activity score (SES-CD).

OBJECTIVE: The aim of this study is to evaluate the ability of magnetic resonance enterography global score (MEGS) to diagnose the activity of pediatric Crohn's disease (CD) and its correlation with endoscopic activity score. MATERIALS AND METHODS: 70 pediatric CD patients (between the ages of 6 and 17) were enrolled who underwent ileocolonoscopy and magnetic resonance enterography (MRE) within 7 days. The simplified endoscopic activity score for Crohn's disease (SES-CD) and MEGS were acquired in the terminal ileum. Sensitivity and specificity of MEGS for detection disease activity against SES-CD was compared using the McNemar test. The correlation between MEGS and SES-CD was assessed by Spearman's rank estimation. The diagnostic accuracy of MEGS for active disease defined by SES-CD was calculated. Receiver operating characteristic curves (ROC) were constructed. RESULTS: Fifty-two pediatric CD patients (median age, 12 years old; 28 girls, 24 boys) were included. The incidence of upper gastrointestinal (GI) tract (23%) involvement and perianal lesions (42%) is high in pediatric Crohn's patients, and most of them suffer from internal hemorrhoids (86.5%). MEGS showed strong correlation to SES-CD (r = 0.70, P < 0.001). With endoscopic as the standard of reference, the MEGS had a high accuracy for the detection of inflammation (area under the ROC curve (AUC) of 0.89, sensitivity 0.95 and specificity 0.82) and for disease activity (AUC of 0.81, sensitivity 0.88 and specificity 0.75) in the terminal ileum. CONCLUSION: Pediatric Crohn's disease is unique. Our study has shown a good correlation between MEGS and endoscopy activity score with equal diagnostic efficacy. MEGS is a promising method to assess disease activity and perhaps be a valuable tool in following therapeutic changes.

Quantitative assessment of microenvironment characteristics and metabolic activity in glioma via multiphoton microscopy.

Tumor microenvironment and metabolic activity in gliomas are the important biomarkers to evaluate the progression of gliomas. Many evidences have suggested that the targeting of metabolic activity and tumor microenvironment simultaneously can be more effective to take the tumor therapy. Therefore, the noninvasive, accurate assessment of tumor microenvironment and metabolic activity is quite important in clinical practice. Multiphoton microscopy (MPM), based on two-photon-excited fluorescence and second harmonic generation was performed on unstained glioma tissues. With our combined image analysis approaches, our research findings indicate that MPM is able to qualitatively and quantitatively describe the microenvironment characteristics in gliomas, such as collage deposition in extracellular matrix, lymphocyte infiltration and tumor angiogenesis, etc. Meanwhile, the metabolic activity can also be quantitatively evaluated by optical redox ratio, NADH and FAD intensity. With the microendoscope and fiberscope are portable, MPM technique can be used to perform in-vivo studies and clinical examinations in gliomas.

Automatic and label-free identification of blood vessels in gliomas using the combination of multiphoton microscopy and image analysis.

Currently, the targeted treatment of tumor based on the tumor microenvironment is newly developed. Blood vessels are the key parts in the tumor microenvironment, which is taken as a new visible target for tumor therapy. Multiphoton microscopy (MPM), based on the second harmonic generation and two-photon excited fluorescence, is available to make the label-free analysis on the blood vessels in human gliomas. MPM can reveal the vascular morphological characteristics in gliomas, including vascular malformation, intense vascular proliferation, perivascular collagen deposition, perivascular lymphocytes aggregation and microvascular proliferation. In addition, the image analysis algorithms were developed to automatically calculate the perivascular collagen content, vascular cavity area, lumen area, wall area and vessel number. Thus, the vascular morphology, the perivascular collagen deposition and intense vascular proliferation degree can be further quantitatively characterized. Compared with the pathological analysis, the combination of MPM and image analysis has potential advantages in making a quantitative and qualitative analyzing on vascular morphology in glioma microenvironment. As micro-endoscope and two-photon fiberscope are technologically improved, this combined method will be a useful imaging way to make the real-time research on the targeting tumor microenvironment in gliomas.

Homogenously isoattenuating insulinoma on biphasic contrast-enhanced computed tomography: Little benefits of diffusion-weighted imaging for lesion detection.

The aim of the present study was to evaluate the diagnostic benefit of diffusion-weighted imaging (DWI) in the detection of homogenous isoattenuating insulinoma on biphasic contrast-enhanced computed tomography (CT) preoperatively and to determine which magnetic resonance (MR) sequences exhibited the best diagnostic performance. A total of 44 consecutive patients who underwent biphasic contrast-enhanced CT and conventional MR imaging (MRI), including DWI on a 3T scanner, were identified retrospectively. Apparent diffusion coefficient (ADC) values of insulinomas and the surrounding pancreatic parenchyma were compared using a Wilcoxon signed-rank test. Receiver operating characteristic analysis was used to compare the diagnostic accuracy of four randomized image sets [T2-weighted image (WI), axial T1WI, DWI and T2WI + DWI] for each reader. Axial T1-weighted MRI exhibited the highest relative sensitivity for each reader; DWI alone exhibited the lowest relative sensitivity and the lower inter-reader agreement. There was no significant difference in lesion detection between T2WI and T2WI + DWI image sets for each reader. The ADC values of the insulinoma were significantly lower compared with those of the surrounding parenchyma. In conclusion, DWI does not benefit the detection of homogenous isoattenuating insulinoma. Axial T1WI is the optimal pulse sequence. Quantitative assessment of the tumor ADC values may be a useful tool to characterize identified pancreatic neoplasms.

Nanoscale Polydopamine (PDA) Meets π-π Interactions: An Interface-Directed Coassembly Approach for Mesoporous Nanoparticles.

Well known for the adhesive property, mussel-inspired polydopamine (PDA) has been shown to enhance performance in a wide range of adsorption-based applications. However, imparting porous nanostructures to PDA materials for enhanced loading capacities has not been demonstrated even when surfactants were present in the synthesis. Herein, we report on the preparation of mesoporous PDA particles (MPDA) based on the assembly of primary PDA particles and Pluronic F127 stabilized emulsion droplets on water/1,3,5-trimethylbenzene (TMB) interfaces. The key to the formation of this new type of the MPDA structure is the full utilization of the π-π stacking interactions between PDA structures and the π-electron-rich TMB molecules. Remarkably, this method presents a facile approach for MPDA particles with an average diameter of ∼90 nm, slit-like pores with a peak size of ∼5.0 nm as well as hollow cavities. When used as the adsorbent for a model dye RhB, the MPDA particles achieved an ultrahigh RhB adsorption capacity of 1100 µg mg-1, which is significantly higher than that for the PDA-reactive dyes with Eschenmoser structure. Moreover, it was demonstrated that the cavity space in MPDA can facilitate high volumetric uptake in a capillary filling/stacking manner via the π-π interactions. These developments pave a new avenue on the mechanism and the designed synthesis of functional PDA materials by organic-organic composite assembly for advanced adsorption applications.

Silica-assisted incorporation of polydopamine into the framework of porous nanocarriers by a facile one-pot synthesis.

Mussel-inspired polydopamine (PDA), with its advanced bio-adhesive properties, has shown great potential in drug delivery based on host-guest interaction. However, it is difficult to synthesize PDA NPs of high surface area using the traditional polymerization of dopamine monomers in an alkaline solution. Taking advantage of the interaction between PDA and silicic acid inspired by biosilicification, PDA was rendered with high surface area in 70 nm-sized hybrid porous particles by a silica assisted one-pot preparation. PDA building blocks were successfully incorporated into the silica framework by controlled addition of dopamine (1.25-5 mol% with respect to the silica source) in a typical synthesis of mesoporous silica nanoparticles (MSNs). It is revealed that the cooperative molecular interaction between silicic acid and catechol groups of PDA results in a retardation of the silica condensation during the particle formation process. Moreover, the replacement of dopamine with polyphenols such as epigallocatechin gallate (EGCG) or tannic acid (TA) resulted in complete phase separation of the polymer and silica at the same molar ratio, suggesting the important role of amines in PDA towards stable hybridization in the particles. The application potential of the PDA-MSN hybrid nanocarriers is demonstrated by an unprecedentedly high drug (DOX) loading capacity of 1000 mg g-1, a sustained drug release, as well as enhanced killing efficiency of cancer cells at low dosage. These findings are expected to inspire strategies and pave a way for utilizing PDA for constructing organic-inorganic composite nanocarriers.