Combination Of Imaging Techniques Research Articles

Preoperative assessment of peritoneal carcinomatosis of colorectal origin

The goal of preoperative assessment of patients with peritoneal carcinomatosis (PC) from colorectal origin is to select candidates for curative surgery by evaluating the possibility of complete resection, and to plan the surgical procedure. Quantitative and qualitative evaluation of lesional localization remains difficult even with current technical progress in imaging. Computed tomography (CT), the reference imaging technique, allows detection of both peritoneal and extra-peritoneal lesions. Sensitivity and specificity for detecting PC are 83% (95%CI: 79-86%) and 86% (95%CI: 82-89%), respectively. Functional imaging, with diffusion-weighted magnetic resonance imaging (MRI) and positron emission tomography PET-CT allows efficient exploration of peritoneal lesions. MRI is operator-dependent, with a long learning curve, and is, at present, essentially used only in expert centers. A standardized protocol provided by the radiologists working with the French National Center for rare peritoneal tumors RENA-RAD(http://www.renape-online.fr/fr/espace-professionnel/rena-rad.html) is however available on line. PET-CT is particularly useful for identifying and defining extra-peritoneal disease. Combining imaging techniques, particular CT with MRI, seems to improve the calculation of the Peritoneal Cancer Index compared to CT alone. Surgical exploration is the reference technique to evaluate PC. Currently, the literature cannot confirm whether laparoscopy performs as well as laparotomy, but laparoscopy is, de facto, the fundamental tool to decrease the number of unnecessary laparotomies in these patients. To optimize the pre-, intra- and postoperative reporting of the extent of PC, the French National Network for management of PC (RENAPE and BIG-RENAPE: http://www.e-promise.org/) has offered on-line a free-of-charge, standardized, multidisciplinary and transversal software.

A combined diffusion tensor imaging and Ki-67 labeling index study for evaluating the extent of tumor infiltration using the F98 rat glioma model.

Diffusion tensor imaging (DTI) has been proven to be a sophisticated and useful tool for the delineation of tumors. In the present study, we investigated the predictive role of DTI compared to other magnetic resonance imaging (MRI) techniques in combination with Ki-67 labeling index in defining tumor cell infiltration in the peritumoral regions of F98 glioma-bearing rats. A total of 29 tumor-bearing Fischer rats underwent T2-weighted imaging, contrast-enhanced T1-weighted imaging, and DTI of their brain using a 7.0-T MRI scanner. The fractional anisotropy (FA) ratios were correlated to the Ki-67 labeling index using the Spearman correlation analysis. A receiver operating characteristic curve (ROC) analysis was established to evaluate parameters with sensitivity and specificity in order to identify the threshold values for predicting tumor infiltration. Significant correlations were observed between the FA ratios and Ki-67 labeling index (r = - 0.865, p < 0.001). The ROC analysis demonstrated that the apparent diffusion coefficient (ADC) and FA ratios could predict 50% of the proliferating cells in the regions of interest (ROI), with a sensitivity of 88.1 and 81.3%, and a specificity of 86.2 and 90.2%, respectively (p < 0.001). Meanwhile, the two ratios could also predict 10% of the proliferating cells in the ROI, with a sensitivity of 82.5 and 94.9%, and a specificity of 100 and 88.9%, respectively (p < 0.001). The present study demonstrated that the FA ratios are closely correlated with the Ki-67 labeling index. Furthermore, both ADC and FA ratios, derived from DTI, were useful for quantitatively predicting the Ki-67 labeling of glioma cells.

An Ex Vivo Comparison of 2 Cyanoacrylate Skin Protectants

The purpose of these experiments was to compare 2 commercially available skin protectants with different chemical compositions. Two materially different skin protectants were applied to ex vivo pig skin, subjected to stresses, and the resulting skin was observed and analyzed. Using ex vivo pig skin, we sought to better understand the physical differences between a cyanoacrylate-based and a mixed cyanoacrylate/acrylic polymer-based skin protectant. A combination of imaging techniques and microscopic analyses was used to observe and quantify differences in layer thickness and the degree of steadfastness of the layers to liquid stresses. The experiments revealed that the solely cyanoacrylate-based protectant created a layer that was, on average, 5.1 times thicker than the mixed polymer product (p= 1.8 × 10). Observation via electron microscopy also revealed that the extent of coverage varied between the 2 products. In a final experiment, we observed that the mixed polymer product maintained a high degree of adhesiveness, which led to the removal of sheets of epithelium upon gentle blotting. The experiments revealed that while the 2 skin protectants share a common ingredient, both the quantity of that ingredient and the inclusion of other materials in one of them lead to substantially different properties when tested in the research setting.

Altered Synaptic Membrane Retrieval after Strong Stimulation of Cerebellar Granule Neurons in Cyclic GMP-Dependent Protein Kinase II (cGKII) Knockout Mice.

The nitric oxide (NO)/cyclic guanosine monophosphate (cGMP)/cGMP-dependent protein kinase (cGK) signaling pathway regulates the clustering and the recruitment of proteins and vesicles to the synapse, thereby adjusting the exoendocytic cycle to the intensity of activity. Accordingly, this pathway can accelerate endocytosis following large-scale exocytosis, and pre-synaptic cGK type II (cGKII) plays a major role in this process, controlling the homeostatic balance of vesicle exocytosis and endocytosis. We have studied synaptic vesicle recycling in cerebellar granule cells from mice lacking cGKII under strong and sustained stimulation, combining imaging techniques and ultrastructural analyses. The ultrastructure of synapses in the adult mouse cerebellar cortex was also examined in these animals. The lack of cGKII provokes structural changes to synapses in cultured cells and in the cerebellar cortex. Moreover, endocytosis is slowed down in a subset of boutons in these cells when they are stimulated strongly. In addition, from the results obtained with the selective inhibitor of cGKs, KT5823, it can be concluded that cGKI also regulates some aspects of vesicle cycling. Overall, these results confirm the importance of the cGMP pathway in the regulation of vesicle cycling following strong stimulation of cerebellar granule cells.

Photodissociation Dynamics of OCS at 217 nm

The S(1D2)+CO(X1Σ+) product channel from photodissociation of OCS at 217 nm has been measured using the DC slice velocity map imaging (VMI) technique in combination with resonance enhanced multiphoton ionization (REMPI). Two different REMPI intermediate states (1F3 and 1P1) and several pump-probe laser polarization geometries are used to detect the angular momentum polarization of the photofragmented S(1D2). The molecular-frame polarization parameters, as well as the laboratory-frame anisotropy parameters, for individual rotational states of co-fragment CO, are determined using two different full quantum theories. The measured total kinetic energy release spectrum from photodissociation of OCS indicates two dissociation channels, corresponding to the fast and slow recoiling velocities of S(1D2), respectively. The slow channel is concluded to originate from an initial photoexcitation to the A(1A′) state, followed by a non-adiabatic transition to the ground state. The fast channel is found to follow a coherent excitation to A(1A′) and B(1A″) states, where contributions of the two states are almost equal at 217 nm. The determined alignment and anisotropy parameters further indicate that the slow channel follows an incoherent excitation, while the fast channel follows a coherent excitation to A(1A′) and B(1A″) states with a phase difference of π/2.

A novel framework for evaluating the image accuracy of dynamic MRI and the application on accelerated breast DCE MRI.

To develop a novel framework for evaluating the accuracy of quantitative analysis on dynamic contrast-enhanced (DCE) MRI with a specific combination of imaging technique, scanning parameters, and scanner and software performance and to test this framework with breast DCE MRI with Time-resolved angiography WIth Stochastic Trajectories (TWIST). Realistic breast tumor phantoms were 3D printed as cavities and filled with solutions of MR contrast agent. Full k-space raw data of individual tumor phantoms and a uniform background phantom were acquired. DCE raw data were simulated by sorting the raw data according to TWIST view order and scaling the raw data according to the enhancement based on pharmaco-kinetic (PK) models. The measured spatial and temporal characteristics from the images reconstructed using the scanner software were compared with the original PK model (ground truth). Images could be reconstructed using the manufacturer's platform with the modified 'raw data.' Compared with the 'ground truth,' the RMS error in all images was <10% in most cases. With increasing view-sharing acceleration, the error of the initial uptake slope decreased while the error of peak enhancement increased. Deviations of PK parameters varied with the type of enhancement. A new framework has been developed and tested to more realistically evaluate the quantitative measurement errors caused by a combination of the imaging technique, parameters and scanner and software performance in DCE-MRI.

Phosphoric Acid Distribution Patterns in High Temperature PEM Fuel Cells

As the proton conducting medium, phosphoric acid plays a vital role in high temperature PEM fuel cells (HT-PEMFC) operating in the temperature range from 140-200°C. The acid is introduced into the fuel cell by doping the polybenzimidazole (PBI) membrane, and it migrates into the catalyst layer (CL) when the cell is assembled. The acid distribution continues during the activation phase and is influenced by operating conditions such as the cell temperature, reactant flowrates, current density, and electrode potential. The electrochemical active surface area (ECSA), which is critical for the fuel cell performance, is determined by the triple-phase boundary (the common boundary of the catalyst particles, the reactant gases, and the phosphoric acid). Due to the liquid state of the phosphoric acid electrolyte, the triple-phase boundary of the HT-PEMFC may evolve continuously during the cell operation. For better control of this dynamic process, HT-PEMFCs are usually constructed with thick electrodes (≈ 100 µm) and a relatively high platinum loading (≈ 1 mgPt/cm2). A better understanding of the acid distribution patterns would help improve the electrode designs and lower the cost by reducing the Pt loading. In this work, we investigate the distribution of phosphoric acid in gas diffusion electrodes (GDE). The study combines imaging techniques (micro-computed tomography or µCT, FIB-SEM) with modeling (Pore Network Modeling or PNM). To validate the application of PNM, phosphoric acid was injected into different GDEs and the invasion pattern was investigated. The samples were mounted in a sample holder emulating a rib and channel structure, and they were inspected using µCT. The reconstructed 3D image stacks were subsequently segmented into void-, carbon fiber-, MPL-, and CL-voxels1, and the segmented images were then reconstructed into a 3D pore network2. This pore network contains the real shapes of the pores and throats, and therefore the flow characteristics are still representative of the real sample3. The quality of the extracted network is solely limited by the quality of the µCT images. Invasion percolation simulations were performed using the open source package OpenPNM to predict the distribution of phosphoric acid inside GDEs, showing the effect of network parameters on the invasion pattern. We found that the experimentally observed invasion patterns agree very well with the pore network simulation and that invasion percolation is a valid approach to investigate phosphoric acid distributions in GDEs4. The presence of an MPL restricts the intrusion of phosphoric acid into the carbon fiber substrate and significantly reduces the saturation. Figure 1 shows the simulated phosphoric acid invasion pattern into a densely woven carbon fiber layer. The pathway is tortuous and exhibits capillary fingering, and the acid is creeping alongside the bottom of the rib of the sample holder until it emerges into the channel. These observations are all consistent with experiments.

Mathematical and computational modelling of skin biophysics: a review.

The objective of this paper is to provide a review on some aspects of the mathematical and computational modelling of skin biophysics, with special focus on constitutive theories based on nonlinear continuum mechanics from elasticity, through anelasticity, including growth, to thermoelasticity. Microstructural and phenomenological approaches combining imaging techniques are also discussed. Finally, recent research applications on skin wrinkles will be presented to highlight the potential of physics-based modelling of skin in tackling global challenges such as ageing of the population and the associated skin degradation, diseases and traumas.

An imaged-based inverse finite element method to determine in-vivo mechanical properties of the human trabecular meshwork

Aim/Purpose: Previous studies have shown that the trabecular meshwork (TM) is mechanically stiffer in glaucomatous eyes as compared to normal eyes. It is believed that elevated TM stiffness increases resistance to the aqueous humor outflow, producing increased intraocular pressure (IOP).It would be advantageous to measure TM mechanical properties in vivo, as these properties are believed to play an important role in the pathophysiology of glaucoma and could be useful for identifying potential risk factors. The purpose of this study was to develop a method to estimate in-vivo TM mechanical properties using clinically available exams and computer simulations.Design: Inverse finite element simulationMethods: A finite element model of the TM was constructed from optical coherence tomography (OCT) images of a healthy volunteer before and during IOP elevation. An axisymmetric model of the TM was then constructed. Images of the TM at a baseline IOP level of 11, and elevated level of 23 mmHg were treated as the undeformed and deformed configurations, respectively. An inverse modeling technique was subsequently used to estimate the TM shear modulus (G). An optimization technique was used to find the shear modulus that minimized the difference between Schlemm’s canal area in the in-vivo images and simulations.Results: Upon completion of inverse finite element modeling, the simulated area of the Schlemm’s canal changed from 8,889 μm2 to 2,088 μm2, similar to the experimentally measured areal change of the canal (from 8,889 μm2 to 2,100 μm2). The calculated value of shear modulus was found to be 1.93 kPa, (implying an approximate Young’s modulus of 5.75 kPa), which is consistent with previous ex-vivo measurements.Conclusion: The combined imaging and computational simulation technique provides a unique approach to calculate the mechanical properties of the TM in vivo without any surgical intervention. Quantification of such mechanical properties will help us examine the mechanistic role of TM biomechanics in the regulation of IOP in healthy and glaucomatous eyes.

Slice imaging of the UV photodissociation of CH2BrCl from the maximum of the first absorption band.

The photodissociation dynamics of bromochloromethane (CH2BrCl) have been investigated at the maximum of the first absorption band, at the excitation wavelengths 203 and 210 nm, using the slice imaging technique in combination with a probe detection of bromine-atom fragments, Br(2P3/2) and Br*(2P1/2), via (2 + 1) resonance enhanced multiphoton ionization. Translational energy distributions and angular distributions reported for both Br(2P3/2) and Br*(2P1/2) fragments show two contributions for the Br(2P3/2) channel and a single contribution for the Br*(2P1/2) channel. High level ab initio calculations have been performed in order to elucidate the dissociation mechanisms taking place. The computed absorption spectrum and potential energy curves indicate the main contribution of the populated 4A″, 5A', and 6A' excited states leading to a C-Br cleavage. Consistently with the results, the single contribution for the Br*(2P1/2) channel has been attributed to direct dissociation through the 6A' state as well as an indirect dissociation of the 5A' state requiring a 5A' → 4A' reverse non-adiabatic crossing. Similarly, a faster contribution for the Br(2P3/2) channel characterized by a similar energy partitioning and anisotropy than those for the Br*(2P1/2) channel is assigned to a direct dissociation through the 5A' state, while the slower component appears to be due to the direct dissociation on the 4A″ state.

Imaging macropinosomes during Shigella infections.

Macropinocytosis is the uptake of extracellular fluid within vesicles of varying size that takes place during numerous cellular processes in a large variety of cells. A growing number of pathogens, including viruses, parasites, and bacteria are known to induce macropinocytosis during their entry into targeted host cells. We have recently discovered that the human enteroinvasive, bacterial pathogen Shigella causes in situ macropinosome formation during its entry into epithelial cells. These infection-associated macropinosomes are not generated to ingest the bacteria, but are instead involved in Shigella's intracellular niche formation. They make contacts with the phagocytosed shigellae to promote vacuolar membrane rupture and their cytosolic release. Here, we provide an overview of the different imaging approaches that are currently used to analyze macropinocytosis during infectious processes with a focus on Shigella entry. We detail the advantages and disadvantages of genetically encoded reporters as well as chemical probes to trace fluid phase uptake. In addition, we report how such reporters can be combined with ultrastructural approaches for correlative light electron microscopy either in thin sections or within large volumes. The combined imaging techniques introduced here provide a detailed characterization of macropinosomes during bacterial entry, which, apart from Shigella, are relevant for numerous other ones, including Salmonella, Brucella or Mycobacteria.

Issue Cover (June 2017)

Front cover: Electron micrograph of a synapse between cerebellar granule cells in culture. Image taken at 80000 magnification. Scale 0.72pixel / nm. In cerebellar granule cells, and using FM1-43 dye to follow SV recycling, two main populations of boutons that differ in their membrane recycling efficiency are observed. We have used Brefeldin A (BFA) to inhibit AP3/AP1-mediated recycling and to test whether the contribution of this pathway could account for such heterogeneous responses. Combining imaging techniques (FM1-43 and vGluT1-pH) and ultrastructural analyses, we found that the AP3/AP1 pathway regulates membrane retrieval and vesicle reformation, albeit exerting a distinct weight on the different populations of boutons depending on their functional maturation. Read the full article ‘Brefeldin A sensitive mechanisms contribute to endocytotic membrane retrieval and vesicle recycling in cerebellar granule cells’ by A. Rampérez, J. Sánchez-Prieto and M. Torres (J. Neurochem. 2017, vol. 141 (5), pp. 662–675) on doi: 10.1111/jnc.14017

Brefeldin A sensitive mechanisms contribute to endocytotic membrane retrieval and vesicle recycling in cerebellar granule cells

The recycling of synaptic vesicle (SV) proteins and transmitter release occur at multiple sites along the axon. These processes are sensitive to inhibition of the small GTP binding protein ARF1, which regulates the adaptor protein 1 and 3 complex (AP-1/AP-3). As the axon matures, SV recycling becomes restricted to the presynaptic bouton, and its machinery undergoes a complex process of maturation. We used the styryl dye FM1-43 to highlight differences in the efficiency of membrane recycling at different sites in cerebellar granule cells cultured for 7days invitro. We used Brefeldin A (BFA) to inhibit AP-1/AP-3-mediated recycling and to test the contribution of this pathway to the heterogeneity of the responses when these cells are strongly stimulated. Combining imaging techniques and ultrastructural analyses, we found a significant decrease in the density of functional boutons and an increase in the presence of endosome-like structures within the boutons of cells incubated with BFA prior to FM1-43 loading. Such effects were not observed when BFA was added 5min after the end of the loading step, when endocytosis was almost fully completed. In this situation, vesicles were found closer to the active zone (AZ) in boutons exposed to BFA. Together, these data suggest that the AP-1/AP-3 pathway contributes to SV recycling, affecting different steps in all boutons but not equally, and thus being partly responsible for the heterogeneity of the different recycling efficiencies. Cover Image for this issue: doi. 10.1111/jnc.13801.

In-vivo Elongation Patterns of the Anteromedial and Posterolateral Bundles of the ACL at Low Flexion Angles

The kinematics of the anteromedial (AM) and posterolateral (PL) bundles of the anterior cruciate ligament (ACL) in hyperextension was not well understood. This study investigated elongations of the two bundles in hyperextended knee. Twenty living knees were CT-scanned and fluoroscopy-imaged during a weight-bearing flexion–extension cycle from hyperextension to maximal flexion. The knee positions and the relative elongations of the two bundles were reproduced along the motion path using a combined fluoroscopic imaging and CT modeling technique. Results showed the elongation patterns of the two bundles were distinctively different (p < 0.01). The elongation of the PL bundle was slightly higher than that of the AM bundle at hyperextension and then decreased sharply with flexion. The elongation of the AM bundle was highest between the full extension and 10° flexion, and then decreased gradually with flexion angles. In every 10° from hyperextension to 30° flexion, the increasing rates of the PL bundle elongation were significantly higher than those of the AM bundle (p < 0.01). These data may provide important implications for selection of knee flexion angles for fixation of the AM and PL graft bundles in an anatomic ACL reconstruction that can help prevent over-stretching of the graft and reduce the risk of graft failure.

Multispectral Imaging in Combination with Multivariate Analysis Discriminates Selenite Induced Cataractous Lenses from Healthy Lenses of Sprague-Dawley Rats

Cataracts are the leading cause of blindness worldwide. Current methods for discriminating cataractous lenses from healthy lenses of Sprague-Dawley rats during preclinical studies are based on either histopathological or clinical assessments which are weakened by subjectivity. In this work, both cataractous and healthy lens tissues of Sprague-Dawley rats were studied using multispectral imaging technique in combination with multivariate analysis. Multispectral images were captured in transmission, reflection and scattering modes. In all, five spectral bands were found to be markers for discriminating cataractous lenses from healthy lenses; 470 nm and 625 nm discriminated in reflection mode whereas 435 nm, 590 nm and 700 nm discriminated in transmission mode. With Fisher’s Linear discriminant analysis, the midpoints for classifying cataractous from healthy lenses were found to be 14.718 × 10−14 and 3.2374 × 10−14 for the two spectra bands in the reflection mode and the three spectral bands in the transmission mode respectively. Images in scattering mode did not show significant discrimination. These spectral bands in reflection and transmission modes may offer potential diagnostic markers for discriminating cataractous lenses from healthy lenses thereby promising multispectral imaging applications for characterizing cataractous and healthy lenses.

Cerebral blood flow and vasoreactivity in aging: an arterial spin labeling study.

Regional cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) in young and elderly participants were assessed using pulsed arterial spin labeling (ASL) and blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) techniques in combination with inhalation of CO2. Pulsed ASL and BOLD-MRI were acquired in seventeen asymptomatic volunteers (10 young adults, age: 30±7 years; 7 elderly adults, age: 64±8 years) with no history of diabetes, hypertension, and neurological diseases. Data from one elderly participant was excluded due to the incorrigible head motion. Average baseline CBF in gray matter was significantly reduced in elderly (46±9 mL·100 g-1·min-1) compared to young adults (57±8 mL·100 g-1·min-1; P=0.02). Decreased pulsed ASL-CVR and BOLD-CVR in gray matter were also observed in elderly (2.12±1.30 and 0.13±0.06 %/mmHg, respectively) compared to young adults (3.28±1.43 and 0.28±0.11 %/mmHg, respectively; P<0.05), suggesting some degree of vascular impairment with aging. Moreover, age-related decrease in baseline CBF was observed in different brain regions (inferior, middle and superior frontal gyri; precentral and postcentral gyri; superior temporal gyrus; cingulate gyri; insula, putamen, caudate, and supramarginal gyrus). In conclusion, CBF and CVR were successfully investigated using a protocol that causes minimal or no discomfort for the participants. Age-related decreases in baseline CBF and CVR were observed in the cerebral cortex, which may be related to the vulnerability for neurological disorders in aging.

Noninvasive Electromagnetic Source Imaging and Granger Causality Analysis: An Electrophysiological Connectome (eConnectome) Approach.

Combined source-imaging techniques and directional connectivity analysis can provide useful information about the underlying brain networks in a noninvasive fashion. Source-imaging techniques have been used successfully to either determine the source of activity or to extract source time-courses for Granger causality analysis, previously. In this work, we utilize source-imaging algorithms to both find the network nodes [regions of interest (ROI)] and then extract the activation time series for further Granger causality analysis. The aim of this work is to find network nodes objectively from noninvasive electromagnetic signals, extract activation time-courses, and apply Granger analysis on the extracted series to study brain networks under realistic conditions. Source-imaging methods are used to identify network nodes and extract time-courses and then Granger causality analysis is applied to delineate the directional functional connectivity of underlying brain networks. Computer simulations studies where the underlying network (nodes and connectivity pattern) is known were performed; additionally, this approach has been evaluated in partial epilepsy patients to study epilepsy networks from interictal and ictal signals recorded by EEG and/or Magnetoencephalography (MEG). Localization errors of network nodes are less than 5 mm and normalized connectivity errors of ∼20% in estimating underlying brain networks in simulation studies. Additionally, two focal epilepsy patients were studied and the identified nodes driving the epileptic network were concordant with clinical findings from intracranial recordings or surgical resection. Our study indicates that combined source-imaging algorithms with Granger causality analysis can identify underlying networks precisely (both in terms of network nodes location and internodal connectivity). The combined source imaging and Granger analysis technique is an effective tool for studying normal or pathological brain conditions.

NEN - the role of somatostatin receptor scintigraphy in clinical setting.

Detection of neuroendocrine neoplasms (NENs) and monitoring of their response to therapy is still challenging due to huge heterogeneity of that group of tumors. Actually, NENs visualization is mainly based on molecular imaging while in the past it was relied on less effective structural imaging including CT and MRI. Molecular imaging techniques in combination with structural imaging (hybrid imaging), especially in patients with well-differentiated NENs, in addition to morphological provide the functional information about tumor which benefits in a more accurate patient management, including more sensitive visualization of primary tumors, more precise staging and better therapy follow-up. Overexpression of somatostatin receptors (SSTR) on NENs' cell membrane was a basis for development of somatostatin receptor scintigraphy (SRS) using single photon emission tomography SPECT, which is today a well-established standard in molecular imaging of NENs, and further imaging improvement in the field of positron emission tomography (PET). Use of hybrid imaging (SPECT/CT, PET/CT) increased sensitivity of examination, mainly resulting in better detection of small lesions. Generally, somatostatin receptor imaging with PET/CT is an emerging technique, although still with limited access, but due to several advantages over SSTR SPECT/CT, should be used if available. It is worth mentioning, that both SSTR PET/CT and SSTR SPECT/CT have some limitations, such as relatively low detection rate of benign insulinomas, poorly differentiated GEP-NETs and liver metastases. For that reason further improvement of NETs imaging is necessary. The most promising new tracers' families are based on SSTR antagonists, 64Cu-radiolabeled ligands and glucagon-like peptide-1 receptor (GLP-1R) imaging. Finally, in case of poor-differentiated neuroendocrine cancers 18F-FDG PET/CT may be beneficial in comparison with molecular imaging based on somatostatin receptor modalities.

A systematic review of tools for determining activity of localized scleroderma in paediatric and adult patients.

Localized scleroderma (LoS) is a rare inflammatory skin disorder that affects the dermis and sometimes subcutaneous tissues. LoS can have very long periods of quiescence followed by reactivation, but the progression or activity of the disease is difficult to measure. To review the measuring tools used for the evaluation of LoS activity, to choose the most appropriate technique to facilitate progress towards properly assessing the disease, a systematic review of the literature was carried out using the PubMed MEDLINE. Sixty-three studies describing groups of children, adults or both were reviewed and included in the analysis. Case reports were excluded. The analysed papers were published between June 1986 and February 2016. Data were extracted with a focus on instruments measuring the clinical signs of LoS, health-related quality of life (HRQoL), laboratory tests and imaging techniques. Perusal of the literature confirmed that clinical characteristics of the lesions were used to identify activity and scoring systems that focused on a series of signs, and were initially validated in cases of childhood-onset disease; however, there were no data concerning the adult-onset form of the disease. Adult patients with LoS scored lower on HDLQI than those with paediatric-onset LoS. No validated biological markers were available as correlative laboratory parameters of LoS activity. For infrared thermography, ultrasound and other imaging techniques, the features of active lesions were described, but were only useful with appropriate clinical correlation. Measuring tools have not been prospectively validated yet. Summarizing, scoring methods seem to provide the most adequate assessment of LoS and deserve to be further investigated. Combined imaging techniques create optimal conditions for the proper interpretation of the temperature at the skin surface, as well as the structure and vascularity of LoS lesions. Additional scores, musculoskeletal or neuroimaging techniques and laboratory parameters are needed for the specific disease subtypes to monitor extracutaneous manifestations.

Timing of anatexis and melt crystallization in the Socorro–Guaxupé Nappe, SE Brazil: Insights from trace element composition of zircon, monazite and garnet coupled to U[sbnd]Pb geochronology

The timing of partial melting and melt crystallization in granulite facies rocks of the Socorro–Guaxupé Nappe (SGN), Brazil is constrained using a combination of imaging techniques, LA-ICP-MS and EPMA dating, trace element geochemistry and thermobarometry. (Orthopyroxene)-garnet-bearing migmatite that records extensive biotite dehydration melting shows evidence for a clockwise P–T–t path. UHT peak conditions were attained at 1030±110°C, 11.7±1.4kbar, with post-peak cooling to 865±38°C, 8.9±0.8kbar. Cryogenian igneous inheritance of ca. 720–640Ma is identified in oscillatory zoned zircon cores (n=167) with steep HREE patterns. Resorbed, Y-rich monazite cores preserve a prograde growth stage at 631±4Ma prior to the partial melting event, providing an upper age limit for the granulite facies metamorphism in the SGN. REE-rich, Th-depleted monazite related to apatite records the initial stages of decompression at 628±4Ma. Multiple monazite growth episodes record melt crystallization events at 624±3Ma, 612±5Ma and 608±6Ma. Stubby, equant “soccer ball” zircon provide evidence for melt crystallization at 613±2Ma and 607±4Ma. The excess scatter in zircon and monazite age populations between 629±4 and 601±3Ma is interpreted as discontinuous and episodic growth within this age range, characterizing a prolonged metamorphic event in the SGN lasting ca. 30m.y. The development of Y+HREE-rich monazite rims at ca. 600Ma documents retrograde garnet breakdown, extensive biotite growth and the final stages of melt crystallization. Th-rich, Y+HREE-poor monazite rims at ca. 590Ma record monazite recrystallization.