A glance at imaging bladder cancer.

Purpose: Early and accurate diagnosis of Bladder cancer (BCa) will contribute extensively to the management of the disease. The purpose of this review was to briefly describe the conventional imaging methods and other novel imaging modalities used for early detection of BCa and outline their pros and cons. Methods: Literature search was performed on Pubmed, PMC, and Google scholar for the period of January 2014 to February 2018 and using such words as bladder cancer, bladder tumor, bladder cancer detection, diagnosis and imaging . Results: A total of 81 published papers were retrieved and are included in the review. For patients with hematuria and suspected of BCa, cystoscopy and CT are most commonly recommended. Ultrasonography, MRI, PET/CT using 18F-FDG or 11C-choline and recently PET/MRI using 18F-FDG also play a prominent role in detection of BCa. Conclusion: For initial diagnosis of BCa, cystoscopy is generally performed. However, cystoscopy can not accurately detect carcinoma insitu (CIS) and can not distinguish benign masses from malignant lesions. CT is used in two modes, CT and computed tomographic urography (CTU), both for dignosis and staging of BCa. However, they cannot differentiate T1 and T2 BCa. MRI is performed to diagnose invasive BCa and can differentiate muscle invasive bladder carcinoma (MIBC) from non-muscle invasive bladder carcinoma (NMIBC). However, CT and MRI have low sensitivity for nodal staging. For nodal staging PET/CT is preferred. PET/MRI provides better differentiation of normal and pathologic structures as compared with PET/CT. Nonetheless none of the approaches can address all issues related for the management of BCa. Novel imaging methods that target specific biomarkers, image BCa early and accurately, and stage the disease are warranted

The Integration of Positron Emission Tomography With Magnetic Resonance Imaging

A number of laboratories and companies are currently exploring the development of integrated imaging systems for magnetic resonance imaging (MRI) and positron emission tomography (PET). Scanners for both preclinical and human research applications are being pursued. In contrast to the widely distributed and now quite mature PET/computed tomography technology, most PET/MRI designs allow for simultaneous rather than sequential acquisition of PET and MRI data. While this offers the possibility of novel imaging strategies, it also creates considerable challenges for acquiring artifact-free images from both modalities. This paper discusses the motivation for developing combined PET/MRI technology, outlines the obstacles in realizing such an integrated instrument, and presents recent progress in the development of both the instrumentation and of novel imaging agents for combined PET/MRI studies. The performance of the first-generation PET/MRI systems is described. Finally, a range of possible biomedical applications for PET/MRI are outlined

Radiological evaluation of biomarkers for renal cell carcinoma

Role of MRI DWI sequences in the evaluation of early response to neo- angiogenesis inhibitors in metastatic renal cell carcinoma Purpose: Angiogenesis inhibitors have a potential role in treating metastatic renal cell carcinoma, but it is still not clear why some patients don't respond. Our objective was to look for DWI parameters able to identify patients with metastatic renal cell carcinoma who would not benefit from target therapy. RECIST1.1 was considered as Reference Standard. Methods & Materials: We prospectively enrolled 43 patients candidate to start angiogenesis inhibitors with at least one target lesion and who underwent 1,5T MRI examination with multiple bvalues DWI sequences (0,40,200,300,600): one week before (t0), 2 weeks after (t2) and 8 weeks (t8) after treatment beginning. ADC value was calculated drawing ROIs on 3 different planes. 33 patients with 38 lesions had suitable data for comparative evaluation. Results: At T8 follow-up 9 patients had partial response (PR), 20 table disease (SD), 4 progression disease (PD); average progression free survival was 272 days. PD group, as compared to DC or to PR showed significantly lower ADC values at b40 at t0 (p<0.05): we can assess that more vascularised lesions are more responsive to treatment. PD group have significantly lower ADC values then both other groups, at t0, t2 and t8, for all b-values (p<0.05). PFS and OS correlates well with ADC, in particular OS with ADC b40 at t0 (r=0,69). Coclusions: Results show that PD group has significantly lower ADC values than PR or DC everytime (t0, t2, t8) At t0 there is a better correlation between PFS or OS & ADC than PFS & dimensional criteria. ADC at t0 may help selecting patients with promising good response to angiogenesis inhibitors. Moreover at t0 and at t2 ADC has the potential to select patients who wouldn't benefit from angiogenesis inhibitors Nowadays, in the era of target therapy, it is crucial to select patients potentially responders. We have to look at cost/benefit ratio and at increasing costs of treatment options. DWI has the potential role to identify patients whose's tumor wouldn't benefit from target therapy, adding a value (ADC) to other imaging (e.g. DCE-MRI, texture imaging) and clinical parameters (e.g. miRNA) in a hypothetic multiparametric analysis.CT Texture Analysis in Clear Cell Renal Cell Carcinoma: a Radiogenomics Prospective Purpose: The aim of this study was to investigate whether quantitative parameters obtained from CT Texture Analysis (CTTA) correlate with expression of miRNA in clear cell Renal Cell Carcinoma (ccRCC). Methods and Materials: In a retrospective single centre study, multiphasic CT examination (with arterial, portal, equilibrium and urographic phases) was performed on 20 patients with clear cell renal carcinomas (14 men and 6 women; mean age 65 years ± 13). Measures of heterogeneity were obtained in post-processing by placing a ROI on the entire tumour and CTTA parameters such as entropy, kurtosis, skewness, mean, mean of positive pixels, and SD of pixel distribution histogram were measured using multiple filter settings. Quantitative data were correlated with the expression of miRNAs obtained from the same cohort of patients: 8 fresh frozen samples and 12 formalin-fixed paraffin-embedded samples (miR-21-5p, miR-210-3p, miR-185-5p, miR-221-3p, miR-145-5p). Both evaluations (miRNAs and CTTA) were performed on tumour tissues as well as on normal cortico-medullar tissues. Analysis of Variance with linear multiple regression model methods were obtained with SPSS statistic software. For all comparisons, statistical significance was assumed p<0.05 Results: We evidenced that CTTA has robust parameters (e.g. entropy, mean, sd) to distinguish normal from pathological tissues. Moreover, a higher coefficient of determination between entropy and miR-21-5p expression (R2 =0,25) was evidenced in tumour tissues as compared to normal tissues (R2 =0,15). Interestingly, excluding four patients with extreme over-expression of miR-21-5p, excellent relation between entropy and miR21-5p levels was found specifically in tumour samples (R2= 0,64; p<0.05). Conclusion: Entropy and miRNA-21-5p show promising correlation in ccRCC; in addiction CTTA features, in particular mean and entropy show a statistically significant increase in ccRCC as compared with normal renal parenchyma

imaging biomarkers in upper gastrointestinal cancers

In parallel with the increasingly widespread availability of high performance imaging platforms and recent progresses in pathobiological characterisation and treatment of gastrointestinal malignancies, imaging biomarkers have become a major research topic due to their potential to provide additional quantitative information to conventional imaging modalities that can improve accuracy at staging and follow-up, predict outcome, and guide treatment planning in an individualised manner. The aim of this review is to briefly examine the status of current knowledge about imaging biomarkers in the field of upper gastrointestinal cancers, highlighting their potential applications and future perspectives in patient management from diagnosis onwards

Large-area epitaxial growth of curvature-stabilized ABC trilayer graphene.

The properties of van der Waals (vdW) materials often vary dramatically with the atomic stacking order between layers, but this order can be difficult to control. Trilayer graphene (TLG) stacks in either a semimetallic ABA or a semiconducting ABC configuration with a gate-tunable band gap, but the latter has only been produced by exfoliation. Here we present a chemical vapor deposition approach to TLG growth that yields greatly enhanced fraction and size of ABC domains. The key insight is that substrate curvature can stabilize ABC domains. Controllable ABC yields ~59% were achieved by tailoring substrate curvature levels. ABC fractions remained high after transfer to device substrates, as confirmed by transport measurements revealing the expected tunable ABC band gap. Substrate topography engineering provides a path to large-scale synthesis of epitaxial ABC-TLG and other vdW materials

Nanoscale electrochemical patterning reveals the active sites for catechol oxidation at graphite surfaces

Graphite-based electrodes (graphite, graphene, and nanotubes) are used widely in electrochemistry, and there is a long-standing view that graphite step edges are needed to catalyze many reactions, with the basal surface considered to be inert. In the present work, this model was tested directly for the first time using scanning electrochemical cell microscopy reactive patterning and shown to be incorrect. For the electro-oxidation of dopamine as a model process, the reaction rate was measured at high spatial resolution across a surface of highly oriented pyrolytic graphite. Oxidation products left behind in a pattern defined by the scanned electrochemical cell served as surface-site markers, allowing the electrochemical activity to be correlated directly with the graphite structure on the nanoscale. This process produced tens of thousands of electrochemical measurements at different locations across the basal surface, unambiguously revealing it to be highly electrochemically active, with step edges providing no enhanced activity. This new model of graphite electrodes has significant implications for the design of carbon-based biosensors, and the results are additionally important for understanding electrochemical processes on related sp2-hybridized materials such as pristine graphene and nanotubes