Objectives The goal of this study is to demonstrate the performance of radiomics and CNN-based classifiers in determining the primary origin of gastrointestinal liver metastases for visually indistinguishable lesions. Methods In this retrospective, IRB-approved study, 31 pancreatic cancer patients with 861 lesions (median age [IQR]: 65.39 [56.87, 75.08], 48.4% male) and 47 colorectal cancer patients with 435 lesions (median age [IQR]: 65.79 [56.99, 74.62], 63.8% male) were enrolled. A pretrained nnU-Net performed automated segmentation of 1296 liver lesions. Radiomics features for each lesion were extracted using pyradiomics. The performance of several radiomics-based machine-learning classifiers was investigated for the lesions and compared to an image-based deep-learning approach using a DenseNet-121. The performance was evaluated by AUC/ROC analysis. Results The radiomics-based K-nearest neighbor classifier showed the best performance on an independent test set with AUC values of 0.87 and an accuracy of 0.67. In comparison, the image-based DenseNet-121-classifier reached an AUC of 0.80 and an accuracy of 0.83. Conclusions CT-based radiomics and deep learning can distinguish the etiology of liver metastases from gastrointestinal primary tumors. Compared to deep learning, radiomics based models showed a varying generalizability in distinguishing liver metastases from colorectal cancer and pancreatic adenocarcinoma.

Background Macrophages engulf particulate contrast media, which is pivotal for biomedical imaging. Purpose To introduce a macrophage ablation animal model by showing its power to manipulate the kinetics of imaging probes. Material and Methods The kinetics of a particulate computed tomography (CT) contrast media was compared in macrophage ablative mice and normal mice. Liposomes (size 220 µg), loaded with clodronate, were injected into the peritoneum of three C57BL/6 mice. On the third day, 200 µL of the particulate agent ExiTron nano 6000 were injected into three macrophage-ablative mice and three control mice. CT scans were acquired before and 3 min, 1 h, 6 h, and 24 h after the ExiTron application. The animals were sacrificed, and their spleens and livers removed. Relative CT values (CTV) were measured and analyzed. Results Liver and spleen enhancement of treated mice and controls were increasing over time. The median peak values were different with 225 CTV for treated mice and 582 CTV for controls in the liver (P = 0.032) and 431 CTV for treated and 974 CTV in controls in the spleen (P = 0.016). Conclusion Macrophage ablation leads to a decrease of enhancement in organs containing high numbers of macrophages, but only marginal changes in macrophage-poor organs. Macrophage ablation can influence the phagocytic activity and thus opens new potentials to investigate and manipulate the uptake of imaging probes.

Since its launch just over a decade ago by the cryptocurrency Bitcoin, the distributed ledger technology (DLT) blockchain has followed a breathtaking trajectory into manifold application spaces. This study aper analyses how key factors underpinning the success of this ground-breaking “Internet of value” technology, such as staking of collateral (“skin in the game”), competitive crowdsourcing, crowdfunding, and prediction markets, can be applied to substantially innovate the legacy organization of science, research, and technology development (RTD). Here, we elaborate a highly integrative, community-based strategy where a token-based crypto-economy supports finding best possible consensus, trust, and truth by adding unconventional elements known from reputation systems, betting, secondary markets, and social networking. These tokens support the holder’s formalized reputation and are used in liquid-democracy style governance and arbitration within projects or community-driven initiatives. This participatory research model serves as a solid basis for comprehensively leveraging collective intelligence by effectively incentivizing contributions from the crowd, such as intellectual property work, validation, assessment, infrastructure, education, assessment, governance, publication, and promotion of projects. On the analogy of its current blockbusters like peer-to-peer structured decentralized finance (“DeFi”), blockchain technology can seminally enhance the efficiency of science and RTD initiatives, even permitting to fully stage operations as a chiefless decentralized autonomous organization (DAOs).

We outline the concept of an open technology platform that builds upon a publicly accessible library of fluidic designs, manufacturing processes, and experimental characterization, as well as virtualization by a “digital twin” based on modeling, simulation, and cloud computing. Backed by the rapidly emerging Web3 technology “Blockchain,” we significantly extend traditional approaches to effectively incentivize broader participation by an interdisciplinary “value network” of diverse players. Ranging from skilled individuals (the “citizen scientist” and the “garage entrepreneur”) and more established research institutions to companies with their infrastructures, equipment, and services, the novel platform approach enables all stakeholders to jointly contribute to value creation along more decentralized supply chain designs including research and technology development (RTD). A blockchain-enabled token economy efficiently leverages the “Wisdom of the Crowds” and secures “trust” and transparency by reputation systems requiring “skin in the game” from contributors. Prediction markets are created for guiding decision making, planning, and allocation of funding; competitive parallelization of work and its validation from independent participants substantially enhances quality, credibility, and speed of project outcomes in the real world along the entire path from RTD, fabrication, and testing to eventual commercialization. This novel, Blockchain-backed, open platform concept can be led by a corporation, academic entity, a loosely organized group, or even “chieflessly” within a smart-contract encoded Decentralized Autonomous Organization (DAO). The proposed strategy is particularly attractive for highly interdisciplinary fields like microfluidic Lab-on-a-Chip systems in the context of manifold applications in the Life Sciences. As an exemplar, we outline the centrifugal “Lab-on-a-Disc” technology. Rather than engaging in all sub-disciplines themselves, many smaller, highly innovative actors can focus on strengthening the product component distinguishing their unique selling point (USP), e.g., a particular bioassay, detection scheme, or application scenario. In this effort, system integrators access underlying commons like fluidic design, manufacture, instrumentation, and software from a more resilient and diversified supply chain, e.g., based on a verified pool of community-endorsed or certified providers.

An overwhelming majority of experts has been flagging for decades that “Saving the Planet” requires immediate, persistent and drastic action to curb a variety of catastrophic risks over the 21st century. However, despite compelling evidence and a range of suggested solutions, transnational coordination of effective measures to protect our biosphere continues to fall short. To remedy, we propose a novel platform for addressing the central issue of affording trust, transparency and truth while minimizing administrative overheads. This will empower an even loosely organized, global grass-roots community to coordinate a large-scale project on a shared goal (“Commons”) spanning the digital and real world. The Web3 concept is based on the swiftly emerging “Blockchain” and related cryptographic, distributed and permissionless technologies. “Wisdom of the crowds” mechanisms involving competitive parallelization and prediction markets are enabled by formalized reputation and staking to incentivize high-quality work, fair validation and best management practice. While these mechanisms have been (mostly separately) applied to science, business, governance, web, sensor, information and communication technologies (ICT), our integrative approach around Blockchain-enabled ‘operating principles and protocols’ sets the basis for designing novel forms of potentially crowdfunded Decentralized Autonomous Organizations (DAOs).

Rationale: Frailty represents an increased vulnerability to adverse health outcomes. The frailty phenotype conceptual model (three or more patient attributes of wasting, exhaustion, low activity, slowness, and weakness) is associated with increased morbidity and mortality in geriatric populations. Objectives: Our objective was to describe the risks associated with frailty in patients with chronic obstructive pulmonary disease. Methods: Data from the National Emphysema Treatment Trial (NETT) were retrospectively analyzed. The frailty phenotype conceptual model was operationalized as three or more frailty parameters (a body mass index decrease >= 5% of over 12 months, self-reported exhaustion, low 6-minute walk distance, or physical activity or respiratory muscle strength in the lowest quartile). Frail participants were compared with participants with two or fewer frailty parameters. Participants were followed starting 12 months after NETT randomization (to minimize surgical effect) for 24 months. Univariate, multivariate, Kaplan-Meier, and Cox proportional hazard analyses were performed, adjusting for treatment arm, age, modified Medical Research Council dyspnea scale, sex, and baseline forced expiratory volume in 1 second (FEV1). Multiple imputation was used for missing values. Results: The participants (N = 902) were predominantly white (94.5%) males (59.5%), with a median age of 67 years (interquartile range, 63-70 yr) and a median FEV1 % predicted of 26 (interquartile range, 20-33). Six percent of the participants (95% confidence interval [CI], 4.5 to 7.6) were frail. The incidence rate of frailty was 6.4 per 100 person-years. Frail participants reported significantly worse disease-specific and overall quality of life by St. George's Respiratory Questionnaire total score (mean difference of 11.6; 95% CI, 7.6 to 15.6; P < 0.001), mental composite on Medical Outcomes Survey Short Form-36 (mean difference 6.8; 95% CI, 10.0 to -3.6; P < 0.001), and physical composite scores on Medical Outcomes Survey Short Form-36 (mean difference -16.7; 95% CI, - 21.3 to 12.1; P = 0.001). Frail participants had an increased rate of hospitalization (adjusted hazard ratio, 1.6; 95% CI, 1.1 to 2.5; P= 0.02) and an adjusted increase in hospital use of 8.0 days (95% CI, 4.4 to 11.6; P < 0.001) compared with nonfrail participants. Frail participants had a higher mortality rate (adjusted hazard ratio, 1.4; 95% CI, 0.97 to 2.0; P = 0.07). Conclusions: Among adults with chronic obstructive pulmonary disease, our measure of frailty (modified from the Fried frailty phenotype) was associated with incident and longer-duration hospitalization, and with poor quality of life.

Blockchain is a computer protocol involving cryptography, a new way to look at databases, and a socio-cultural-legal-political-economic (r)evolution and knowledge creation will be affected by it. Blockchain has the capacity to make digital goods immutable, transparent, externally provable, decentralized, valuable, and distributed (and potentially permanent). Besides the initial experiment and data acquisition, all remaining parts of the research cycle could take place within a blockchain system. Attribution, data, subject anonymity, data post processing (e.g., via smart contracts) and archiving, publication, research evaluation, incentivization, and research fund distribution would thereby become time-stamped, comprehensible, open (at will), and provable to the external world. Currently, scientists must be trusted to provide a true and useful representation of their research results in their final publication; blockchain would make much larger parts of the research cycle open to scientific self-correction. This bears the potential to be a new approach to the current reproducibility crisis in science, and could “reduce waste and make more research results true”. Beyond that, blockchain could be used to reduce overhead, and accelerate the scientific process and incentivize true innovation.

This chapter discusses technologies and methods required to add another dimension to the process, four-dimensional dynamic imaging using time-elapsed three-dimensional tomographic views. Two non-invasive imaging techniques—magnetic resonance (MR) and computed tomography (CT)—can be utilized in image coronary stenosis. MR has the ability to detect coronary stenosis in proximal vessels. However, artifacts due to cardiac and respiratory motion, limited through-plane resolution, and long overall imaging times make coronary MR imaging a significant challenge. In order to understand dynamic imaging of a beating heart, one must consider two unique technical aspects of Cardiac CT: Projection data acquisition and reconstruction, and cardiac synchronization. The flat-panel (FP) detector technology was originally developed to improve the standard radiography by providing a higher absorption coefficient and a wider dynamic range than available with X-ray film. A C-arm gantry is equipped with an X-ray source and a FP detector that can acquire projections for slightly more than a 180° angular span.

Implementation of real-time, continuous, and three-dimensional imaging (4D intervention guidance) would be a quantum leap for minimally-invasive medicine. It allows guidance during interventions by assessing the spatial position of instruments continuously in respect to their surroundings. Recent research showed that it is feasible using X-ray and novel tomographic reconstruction approaches. Radiation dose stays within reasonable limits. This article provides abstractions and background information together with an outlook on these prospects. There are explanations of how situational awareness during interventions is generated today and how they will be in future. The differences between fluoroscopically and CT-guided interventions are eluted to within the context of these developments. The exploration of uncharted terrain between these current methods is worth pursuing. Necessary image quality of 4D intervention guidance varies relevantly from that of standard computed tomography. Means to analyze the risk-benefit ratio of 4D intervention guidance are provided and arguments for gantry-based setups vs C-arm based setups are given. Due to the lack of moving organs, neuro-interventions might be the first field in which 4D intervention guidance might become available, however, registration and fusion algorithms might make it applicable in complex whole-body interventions such as aortic valve replacement soon thereafter.

Aims To evaluate the incremental value of low endothelial shear stress (ESS) combined with high-resolution magnetic resonance imaging (MRI)- and computed tomography angiography (CTA)-based imaging for the prediction of inflamed plaque. Methods and results Twelve hereditary hyperlipidaemic rabbits underwent quantitative analysis of plaque in the thoracic aorta with 256-slice CTA and USPIO-enhanced (ultra-small superparamagnetic nanoparticles, P904) 1.5-T MRI at baseline and at 6-month follow-up. Computational fluid dynamics using CTA-based 3D reconstruction of thoracic aortas identified the ESS patterns in the convex and concave curvature subsegments of interest. Subsegments with low baseline ESS exhibited significant increase in wall thickness and plaque inflammation by MRI, in non-calcified plaque burden by CTA, and developed increased plaque size, lipid and inflammatory cell accumulation (high-risk plaque features) at follow-up by histopathology. Multiple regression analysis identified baseline ESS and inflammation by MRI to be independent predictors of plaque progression, while receiver operating curve analysis revealed baseline ESS alone or in combination with inflammation by MRI as the strongest predictor for augmented plaque burden and inflammation (low ESS at baseline: AUC = 0.84, P < 0.001; low ESS and inflammation by molecular MRI at baseline: AUC = 0.89, P < 0.001). Conclusion Low ESS predicts progression of plaque burden and inflammation as assessed by non-invasive USPIO-enhanced MRI. Combined non-invasive assessment of ESS and imaging of inflammation may serve to predict plaque with high-risk features.

OBJECTIVE Evaluation of absolute radiation exposure values for interventional radiologists (IRs) using a multiaxis interventional flat-panel C-arm cone beam CT (CBCT) system with three-dimensional laser guidance for biopsy in a triple-modality, abdominal phantom. METHODS In the phantom, eight lesions were punctured in two different angles (in- and out-of-plane) using CBCT. One C-arm CT scan was performed to plan the intervention and one for post-procedural evaluation. Thermoluminescent dosemeters (TLDs) were used for dose measurement at the level of the eye lens, umbilicus and ankles on a pole representing the IRs. All measurements were performed without any lead protection. In addition, the dose-area product (DAP) and air kerma at the skin entrance point was documented. RESULTS Mean radiation values of all TLDs were 190 µSv for CBCT (eye lens: 180 µS, umbilicus: 230 µSv, ankle: 150 µSv) without a significant difference (p > 0.005) between in- and out-of-plane biopsies. In terms of radiation exposure of the phantom, the mean DAP was not statistically significantly different (p > 0.05) for in- and out-of-plane biopsies. Fluoroscopy showed a mean DAP of 7 or 6 μGym(2), respectively. C-arm CT showed a mean DAP of 5150 or 5130 μGym(2), respectively. CONCLUSION In our setting, the radiation dose to the IR was distinctly high using CBCT. For dose reduction, it is advisable to pay attention to lead shielding, to increase the distance to the X-ray source and to leave the intervention suite for C-arm CT scans. ADVANCES IN KNOWLEDGE The results indicate that using modern navigation tools and CBCT can be accompanied with a relative high radiation dose for the IRs since detector angulation can make the use of proper lead shielding difficult.

Es wurde bereits gezeigt, dass mittels neuartiger, tomografischer Rekonstruktionsverfahren eine 4D Interventionsführung (3 Raumdimensionen + Zeit) mit einer akzeptablen Strahlendosis möglich ist. Die Komplexität neuroradiologischer Interventionen als auch die günstigen Aufnahmebedingungen im Kopfbereich (keine Bewegung, kleines FOV) macht eine Anwendung hierbei besonders vielversprechend. In dieser Arbeit wurde mittels mathematischer Simulationen, Phantomen und Tierexperimenten (Schweine, n = 5) eine frühe Analyse des Potentials dieser neuartigen Technologie durchgeführt.

This paper presents a single inductor energy harvesting and power management (EHM) unit for ultra-low power (ULP) systems. The proposed circuit harvests energy from solar cells from 0.38V input voltage (Vin) and provides 4 output voltages - storage at 5V and VDDs at 3.3V, 1.5V and 1.2V. A peak inductor current control scheme enables high efficiency operation across wide input and output voltage range. The IC supports maximum power point tracking, battery management, and cold starts from 0.38V Vin.

OBJECTIVES:To determine impedance values and charge consumption following cochlear implantation post-meningitic deaf children depending on the grade of cochlear ossification and obliteration. METHODS:Post-meningitic deaf (n=49) and control (n=43) children treated with cochlear implants were included in the study. Impedance and charge values were calculated for each group. The degree of ossification of the cochlea was evaluated from a high-resolution computed tomography (HRCT) scan whereas the degree of obliteration was determined intraoperatively by the surgeon. RESULTS:Pneumococci were the principal pathogen responsible for bacterial meningitis, followed by meningococci. In HRCT scans, the degree of ossification was 1 and 2 in 29% of patients. The results of the intraoperative assessment of the cochlea showed obliteration grade 1 in 38% and grade 2 in 23% of cases. Children in the meningitis group showed significant higher impedances comparing to the control group. A significantly increased charge consumption was observed in patients with a grade 2 ossification when compared to those without ossification (P=0.02). Discussion Cochlea implanted children with meningitis-related deafness exhibit higher impedances, especially in the region of the basal and middle turn, however, not depending on the degree of cochlear ossification. High impedances and charge in the meningitis group may be explained by alterations in the central auditory pathway or on the electrode surface. CONCLUSION:To optimize the outcome in post-meningitic deaf children, surgery is advisable at an early stage prior to the onset of cochlear ossification.

Cardiac perfusion studies using computed tomography are a common tool in clinical practice. Recent technical advances and the availability of dedicated small animal scanners allow the transfer of these techniques to the preclinical sector in general and to mouse models of cardiac diseases in particular. This necessitates new requirements for contrast injection techniques as a rapid transport of contrast media from the intravenous access to the animal heart. Clinical contrast agents containing high iodine concentrations are used within small animal studies although they exhibit a high viscosity which might limit their transport within the vasculature. The authors provide a comparison of the transport of contrast media following an injection into the lateral tail vein and an injection into the retrobulbar sinus and discuss the anatomy involved. The temporal evolution of a contrast bolus and its in vivo distribution is visualized. It is demonstrated that injecting contrast agents into the lateral tail vein of mice results in a retrograde blood flow to the liver veins and therefore does not deliver a detectable contrast bolus to the heart, and thus it cannot be used for cardiac perfusion studies. By contrast, boli injected into the retrobulbar sinus are rapidly transported to the heart and provide ventricular contrast enabling perfusion studies similar to those in human patients. The results demonstrate that an injection into the retrobulbar sinus is superior to an injection into the lateral tail vein for the delivery of contrast boli to the animal heart, while all drawbacks of an injection into the lateral tail vein are overcome.

Die Möglichkeit einer 4D Interventionsführung ist für Organbereiche ohne physiologische Bewegungen vor kurzem gezeigt worden. Das Dosisniveau ist dabei vergleichbar zu dem der Röntgenfluoroskopie. Ziel dieser Arbeit ist es, die Möglichkeiten einer 4D Interventionsführung auch für Organbereiche mit physiologischer Bewegung aufzuzeigen.

Ein multimodal – in Fluorskopie, Computer- und Magnetresonanztomotraphie – sichtbares Embolisat wurde in einem neuartigen, automatisierten Verfahren hergestellt. Die Embolisatpartikel können damit in definierten Größen und minimaler Größenvariation unter 100%-iger Qualitätskontrolle in verkürzter Zeit produziert werden. In dieser Studie wurde die multimodale Sichtbarkeit und die Anwendbarkeit im Tiermodell im Rahmen selektiver Embolisationen überprüft.