Lossy compression of multidimensional medical images using sinusoidal activation networks: an evaluation study

In this work, we evaluate how neural networks with periodic activation functions can be leveraged to reliably compress large multidimensional medical image datasets, with proof-of-concept application to 4D diffusion-weighted MRI (dMRI). In the medical imaging landscape, multidimensional MRI is a key area of research for developing biomarkers that are both sensitive and specific to the underlying tissue microstructure. However, the high-dimensional nature of these data poses a challenge in terms of both storage and sharing capabilities and associated costs, requiring appropriate algorithms able to represent the information in a low-dimensional space. Recent theoretical developments in deep learning have shown how periodic activation functions are a powerful tool for implicit neural representation of images and can be used for compression of 2D images. Here we extend this approach to 4D images and show how any given 4D dMRI dataset can be accurately represented through the parameters of a sinusoidal activation network, achieving a data compression rate about 10 times higher than the standard DEFLATE algorithm. Our results show that the proposed approach outperforms benchmark ReLU and Tanh activation perceptron architectures in terms of mean squared error, peak signal-to-noise ratio and structural similarity index. Subsequent analyses using the tensor and spherical harmonics representations demonstrate that the proposed lossy compression reproduces accurately the characteristics of the original data, leading to relative errors about 5 to 10 times lower than the benchmark JPEG2000 lossy compression and similar to standard pre-processing steps such as MP-PCA denosing, suggesting a loss of information within the currently accepted levels for clinical application

Trauma Characteristics Associated with E-Scooter Accidents in Switzerland-A Case Series Study.

E-scooters have gained popularity worldwide in the last few years. Due to the increase in users, more accidents related to e-scooters can be observed. The present study aimed to analyse epidemiological data, characteristics, and severity of injuries in patients admitted to a Level I trauma centre in Switzerland (Inselspital Bern, University Hospital Bern) after accidents associated with e-scooters. This retrospective case series evaluated 23 patients who presented to the University Hospital of Bern between 1 of May 2019 and 31 of October 2021 after an e-scooter accident. Data were collected on patient demographics, time and cause of the accident, speed, alcohol consumption, helmet use, type and localisation of injury, number of injuries per patient, and outcome. Men were most frequently affected (61.9%). The mean age was 35.8 (STD 14.8) years. Slightly more than half (52.2%) of all accidents were self-inflicted. Most accidents were reported during the night (7 p.m. to 7 a.m., 60.9%) and in summer (43.5%). Alcohol consumption was reported in 43.5% of cases, with a mean blood alcohol level of 1.4 g/l. Most injuries were observed in the face (25.3%) and head/neck area (20.25%). Skin abrasions (56.5%) and traumatic brain injury (43.5%) were the most common types of traumata in terms of total number of patients. Only in one case it was reported that a protective helmet had been worn. Five patients required hospitalisation and four patients underwent surgery. Three patients underwent emergency orthopaedic surgery, and one patient underwent emergency neurosurgery. E-scooter accidents result in a significant number of facial and head/neck injuries. E-scooter riders would potentially benefit from a helmet to protect them in the event of an accident. Additionally, the results of this study indicate that a significant number of e-scooter accidents in Switzerland occurred under the influence of alcohol. Prevention campaigns to raise awareness of the risks of driving e-scooters under the influence of alcohol could help prevent future accidents

Factors Influencing the Pedestrian Injury Severity of Micromobility Crashes

[EN] The growth of micromobility transport in cities has created a new mobility paradigm, but this has also resulted in increased traffic conflicts and collisions. This research focuses on understanding the impacts of micromobility vehicles on pedestrian injury severity in urban areas of Spain between 2016 and 2021. The Random Forest classification model was used to identify the most significant factors and their combinations affecting pedestrian injury severity. To address the issue of unbalanced data, the synthetic minority oversampling technique was employed. The findings indicate that pedestrians' age, specifically those 70 years or older, is the most important variable in determining injury severity. Additionally, collisions at junctions or on weekends are associated with worse outcomes for pedestrians. The results highlight the combined influence of multiple factors, including offenses and distractions by micromobility users and pedestrians. These factors are more prevalent among younger micromobility users and those riding for leisure or on weekends. To enhance micromobility road safety and reduce pedestrian injuries, separating micromobility traffic from pedestrian areas is recommended, restricting micromobility vehicle use on sidewalks, providing training and information to micromobility users, conducting road safety campaigns, increasing enforcement measures, and incorporating buffer zones in bike lanes near on-street parking.This research is part of the research project PID2019-111744RB-I00, funded by MCIN/AEI/10.13039/501100011033. Likewise, this research has been partially funded by the European Union-Next GenerationEU (RD 289/2021), thanks to the granting of a "Margarita Salas" grant to Almudena Sanjurjo (UP2021-035), researcher at the Universidad Politecnica de Madrid (UPM), to carry out astay at the Universitat Politecnica de Valencia (UPV)Sanjurjo-De-No, A.; Pérez Zuriaga, AM.; García García, A. (2023). Factors Influencing the Pedestrian Injury Severity of Micromobility Crashes. Sustainability. 15(19):1-17. https://doi.org/10.3390/su151914348117151

Expression mapping of GREM1 and functional contribution of its-secreting-cells in the brain using transgenic mouse models

Gremlin 1 (Grem1) is a secreted protein that antagonizes bone morphogenetic proteins (BMPs). While abnormal Grem1 expression has been reported to cause behavioral defects in postpartum mice, the spatial and cellular distribution of GREM1 in the brain and the influence of the Grem1-secreating cells on brain function and behavior remain unclear. To address this, we designed a genetic cassette incorporating a 3 × Flag-TeV-HA-T2A-tdTomato sequence, resulting in the creation of a novel Grem1Tag mouse model, expressing an epitope tag (3 × Flag-TeV-HA-T2A) followed by a fluorescent reporter (tdTomato) under the control of the endogenous Grem1 promoter. This design facilitated precise tracking of the cell origin and distribution of GREM1 in the brain using tdTomato and Flag (or HA) markers, respectively. We confirmed that the Grem1Tag mouse exhibited normal motor, cognitive, and social behaviors at postnatal 60 days (P60), compared with C57BL/6 J controls. Through immunofluorescence staining, we comprehensively mapped the distribution of Grem1-secreting cells across the central nervous system. Pervasive Grem1 expression was observed in the cerebral cortex (Cx), medulla, pons, and cerebellum, with the highest levels in the Cx region. Notably, within the Cx, GREM1 was predominantly secreted by excitatory neurons, particularly those expressing calcium/calmodulin-dependent protein kinase II alpha (Camk2a), while inhibitory neurons (parvalbumin-positive, PV+) and glial cells (oligodendrocytes, astrocytes, and microglia) showed little or no Grem1 expression. To delineate the functional significance of Grem1-secreting cells, a selective ablation at P42 using a diphtheria toxin A (DTA) system resulted in increased anxiety-like behavior and impaired memory in mice. Altogether, our study harnessing the Grem1Tag mouse model reveals the spatial and cellular localization of GREM1 in the mouse brain, shedding light on the involvement of Grem1-secreting cell in modulating brain function and behavior. Our Grem1Tag mouse serves as a valuable tool for further exploring the precise role of Grem1 in brain development and disease

Neurofibromatosis type 1 with interstitial pulmonary lesions diagnosed in adult patient. A case study and literature review

Chory, lat 43 u którego na podstawie kryteriów klinicznych rozpoznano nerwiakowłókniakowatość typu 1 (NF1, choroba van Recklinghausena), został skierowany na oddział chorób płuc w celu przeprowadzenia diagnostyki przyczyn pogorszenia tolerancji wysiłku fizycznego oraz etiologii torbielowatych zmian w płucach uwidocznionych w tomografii komputerowej wysokiej rozdzielczości (HRCT). Od dzieciństwa pacjent był leczony z powodu padaczki, rozpoznano także niedomykalność zastawki trójdzielnej III stopnia, nie stwierdzając nadciśnienia płucnego w trakcie cewnikowania prawego serca. Ostatecznie przyjęto, że w omawianym przypadku zmiany śródmiąższowe w płucach są związane z chorobą zasadniczą i wymagają dalszej obserwacji klinicznej. Obserwowane pogorszenie tolerancji wysiłku fizycznego było związane z towarzyszącym zakażeniem układu oddechowego bakteriami Klebsiella oxytoca i Staphylococcus auresus u chorego za zmianami torbielkowatymi w płucach i niedomykalnością zastawki trójdzielnej bez współistnienia nadciśnienia w tętnicy płucnej. W doniesieniu omówiono kryteria rozpoznania NF1, a także kontrowersje dotyczące współistnienia śródmiąższowych zmian płucnych w obrazie choroby.A case of a 43-year-old man with clinically diagnosed neurofibromatosis type I (NF-1, von Recklinghausen disease), was referred to a lung disease unit in order to diagnosis of worsening tolerance to physical effort, and aetiology of radiological cystic lesions in the lungs, seen in the high-resolution computed tomography (HRCT). Since childhood the patient has been treated for epilepsy, and a 3rd degree tricuspid valve incompetence, without pulmonary hypertension was detected during right heart catheterization. Finally, the interstitial pulmonary lesions were attributed to the primary disease, and it was said they need further clinical observation in order to determine their dynamics. The observed deterioration in patient’s tolerance to physical effort was connected to the accompanying infection of the respiratory system with Klebsiella oxytoca and Staphylococcus aureus, with cystic lesions in lungs and tricuspid valve incompetence. The report describes the criteria for NF-1 diagnosis, as well as points out the controversies of coexistence of interstitial pulmonary lesions in the clinical picture of the disease

Understanding the landscape of shared-e-scooters in North America; Spatiotemporal analysis and policy insights

Shared-e-scooters are being introduced in cities worldwide, with their introduction often being distant from the actual service characteristics understanding, potential benefits, and threats realization. This research explores scooter use by examining approximately nine million scooter trips from five North American cities (Austin; TX, Calgary; AB, Chicago; IL, Louisville; KY, Minneapolis; MN). By investigating the spatiotemporal hourly and daily use, we found that demand patterns tend to be similar in the different cities. Trip characteristics (speed, duration, and distance) are almost empirically consistent across the five cities; however, there is evidence that trip characteristics change over time in the same city. We also examined the impact of exogenous factors on scooter demand, and found that weather (temperature, wind speed, precipitation, and snow), day of the week, infrastructure (bike lanes, sidewalks, and shared bike stations), sociodemographics (gender, age, and income), land use, and accessibility to transit significantly impact demand. Findings highlight the need for evidence-based examination of shared-e-scooters and regulatory processes to guide policy decisions by the different stakeholders

From mouse to man and back : closing the correlation gap between imaging and histopathology for lung diseases

Lung diseases such as fibrosis, asthma, cystic fibrosis, infection and cancer are life-threatening conditions that slowly deteriorate quality of life and for which our diagnostic power is high, but our knowledge on etiology and/or effective treatment options still contains important gaps. In the context of day-to-day practice, clinical and preclinical studies, clinicians and basic researchers team up and continuously strive to increase insights into lung disease progression, diagnostic and treatment options. To unravel disease processes and to test novel therapeutic approaches, investigators typically rely on end-stage procedures such as serum analysis, cyto-/chemokine profiles and selective tissue histology from animal models. These techniques are useful but provide only a snapshot of disease processes that are essentially dynamic in time and space. Technology allowing evaluation of live animals repeatedly is indispensable to gain a better insight into the dynamics of lung disease progression and treatment effects. Computed tomography (CT) is a clinical diagnostic imaging technique that can have enormous benefits in a research context too. Yet, the implementation of imaging techniques in laboratories lags behind. In this review we want to showcase the integrated approaches and novel developments in imaging, lung functional testing and pathological techniques that are used to assess, diagnose, quantify and treat lung disease and that may be employed in research on patients and animals. Imaging approaches result in often novel anatomical and functional biomarkers, resulting in many advantages, such as better insight in disease progression and a reduction in the numbers of animals necessary. We here showcase integrated assessment of lung disease with imaging and histopathological technologies, applied to the example of lung fibrosis. Better integration of clinical and preclinical imaging technologies with pathology will ultimately result in improved clinical translation of (therapy) study results

Дифференциальная диагностика острой и хронической тромбоэмболии легочной артерии по данным МСКТ

Introduction. One of the important problems of medical imaging is the differential diagnosis of patients with acute and chronic pulmonary embolism. The widely used minimally invasive technique of multispiral computed tomography with intravenous bolus contrast enhancement can serve to solve this problem, in particular, to assess the state of the parenchyma and vascular structures of the lungs.The purpose. To assess the state of bronchial arteries and parenchymal changes in the lungs in pulmonary thromboembolism based on the results of multispiral computed tomography and their role in the more precise diagnosis of this disease.Materials and methods. An analysis of CT-angiopulmonography of 600 patients with suspected PE was performed. 87 patients with confirmed pulmonary thromboembolism were selected and divided into groups according to the final diagnosis: group 1 — acute pulmonary embolism, group 2 — chronic pulmonary embolism. CT data were analyzed for the presence of pathologically changed bronchial arteries, as well as lung's parenchymal changes (including mosaic perfusion, fibrotic changes, bronchial dilatation with or without wall thickening).Results. Bronchial arteries were assessed in patients with acute and chronic pulmonary embolism and the diagnostic value of the detected changes was determined. Acute pulmonary embolism does not lead to such dilatation of the bronchial arteries as chronic pulmonary embolism. In diagnostically unclear cases, secondary parenchymal signs visible on CT (mosaic perfusion and dilated bronchi without wall thickening) can be useful in the differential diagnosis of acute and chronic pulmonary embolism.Conclusions. Most patients with chronic pulmonary embolism demonstrated dilated bronchial arteries, in contrast to patients with acute pulmonary embolism. Lung's parenchymal changes (a mosaic perfusion pattern and bronchial dilation without wall thickening) were more common in patients with chronic pulmonary embolism. These CT-signs can help differentiate acute from chronic pulmonary embolism in unclear clinical situations.Введение. Одной из важных проблем медицинской визуализации является дифференциальная диагностика пациентов с острой и хронической тромбоэмболией легочной артерии. Решению этой задачи, в частности оценке состояния паренхимы и сосудистых структур легких, может служить широко применяемая малоинвазивная методика мультиспиральной компьютерной томографии с внутривенным болюсным контрастированием.Цель: оценить состояние бронхиальных артерий и паренхиматозные изменения в легких при тромбоэмболии легочных артерий по результатам мультиспиральной компьютерной томографии и их роль в уточненной диагностике данного заболевания.Материалы и методы. Выполнен анализ данных МСКТ-ангиопульмонографии 600 пациентов с подозрением на тромбоэмболию легочной артерии. 87 пациентов с подтвержденной тромбоэмболией легочной артерии были отобраны и разделены на группы в соответствии с окончательным диагнозом: 1-я группа — острая ТЭЛА, 2-я группа — хроническая ТЭЛА. МСКТ-данные были проанализированы на предмет наличия измененных бронхиальных артерий, а также паренхиматозных изменений (таких как «мозаичная перфузия», очаги или участки уплотнения паренхимы легких, расширение бронхов с утолщением стенок и без).Результаты. Произведена оценка состояния бронхиальных артерий у пациентов с острой и хронической ТЭЛА и определена диагностическая ценность выявленных изменений. Установлено, что острая ТЭЛА не приводит к такому расширению бронхиальных артерий, как хроническая ТЭЛА. В диагностически неясных случаях вторичные паренхиматозные признаки, выявляемые при МСКТ (симптом мозаичной перфузии и расширенные бронхи без утолщения стенок), могут быть полезными в дифференциальной диагностике острой и хронической тромбоэмболии легочной артерии.Заключение. У большинства пациентов с хронической ТЭЛА выявлялись расширенные бронхиальные артерии, в отличие от пациентов с острой ТЭЛА. Паренхиматозные изменения в легких, которые были более характерны для пациентов с хронической ТЭЛА, включали в себя: паттерн «мозаичной перфузии» и расширение бронхов без утолщения стенок. Вышеперечисленные МСКТ-признаки могут помочь дифференцировать острую от хронической ТЭЛА в неясных клинических ситуациях

4D ultra-short TE (UTE) phase-contrast MRI for assessing stenotic flow and hemodynamics.

Phase-contrast (PC) MRI is a non-invasive technique to assess cardiovascular blood flow. However, this technique is not accurate in the case of atherosclerotic disease and vascular and valvular stenosis due to intravoxel dephasing secondary to disturbed blood flow, flow recirculation, and turbulence distal to the narrowing, resulting in flow-related artifacts. Previous studies have shown that reducing the echo time (TE) decreases the errors associated with phase incoherence due to random motions as observed in unsteady and turbulent flows. As part of this dissertation, a novel 3-D cine Ultra-Short (UTE)-PC imaging method has been developed, and implemented to measure the blood velocity using a UTE center-out radial k-space trajectory with short TE time compared to standard PC MRI sequences. 3D UTE characterizes flow in one direction in a 3D volume, resulting in a single component of the flow velocities. In order to obtain a comprehensive flow assessment in three directions, the 3D UTE sequence needs to be repeated three times, which can be inefficient and time consuming. 4-D flow MRI has been recently used for quantitative flow assessment and visualization of complex flow patterns resulting in more anatomical information and comprehensive assessment of blood flow. With 4D flow MRI method, all the flow information in three direction in a 3D volume though the time can be achieved as part of a single scan. In this dissertation, a novel 4D UTE flow MRI technique has also been designed and implemented which is capable of deriving the three orthogonal components of the velocity field in the flow in a single scan, while achieving very short echo times. In flow phantom studies, comprehensive investigation of several different flow rates revealed significant improvement in flow quantification and reduction of flow artifacts when compared to conventional 4D flow. Furthermore, a reduced TE 4D Spiral flow MRI method has also been implemented which reduces scan times when compared to conventional 4D flow MRI (as well as 4D UTE flow). Despite reduction of scan time as well as TE relative to conventional 4D flow, the achieved TE with the 4D spiral technique is indeed longer than 4D UTE flow. In order to assess clinical feasibility and in order to perform further validation of 4D UTE flow, in an IRB-approved study, twelve aortic stenosis (AS) patients underwent Doppler Ultrasound, conventional 4D flow, and 4D UTE flow scans for a 3 way comparison. 4D UTE flow displayed good correlation with Doppler Ultrasound in patients with moderately severe aortic stenosis, though with the added benefit of not having confounding factors encountered in Doppler Ultrasound (e.g., angle dependence, 2D measurement, and difficulty in locating a proper acoustic window). The proposed 4D UTE flow permits 4D visualization of flow and true 3D measurement of all flow quantities, not possible with Doppler. Further investigations will be required to test the technique in patients with severe or critical aortic stenosis wherein conventional 4D flow will be less accurate due to intravoxel dephasing and spin incoherence