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BACKGROUND: Fast low angle shot hyperfractionation (FLASH) radiotherapy (RT) holds promise for improving treatment outcomes and reducing side effects but poses challenges in radiation delivery accuracy due to its ultra-high dose rates. This necessitates the development of novel imaging and verification technologies tailored to these conditions. PURPOSE: Our study explores the effectiveness of proton-induced acoustic imaging (PAI) in tracking the Bragg peak in three dimensions and in real time during FLASH proton irradiations, offering a method for volumetric beam imaging at both conventional and FLASH dose rates. METHODS: We developed a three-dimensional (3D) PAI technique using a 256-element ultrasound detector array for FLASH dose rate proton beams. In the study, we tested protoacoustic signal with a beamline of a FLASH-capable synchrocyclotron, setting the distal 90% of the Bragg peak around 35 mm away from the ultrasound array. This configuration allowed us to assess various total proton radiation doses, maintaining a consistent beam output of 21 pC/pulse. We also explored a spectrum of dose rates, from 15 Gy/s up to a FLASH rate of 48 Gy/s, by administering a set number of pulses. Furthermore, we implemented a three-dot scanning beam approach to observe the distinct movements of individual Bragg peaks using PAI. All these procedures utilized a proton beam energy of 180 MeV to achieve the maximum possible dose rate. RESULTS: Our findings indicate a strong linear relationship between protoacoustic signal amplitudes and delivered doses (R2 = 0.9997), with a consistent fit across different dose rates. The technique successfully provided 3D renderings of Bragg peaks at FLASH rates, validated through absolute Gamma index values. CONCLUSIONS: The protoacoustic system demonstrates effectiveness in 3D visualization and tracking of the Bragg peak during FLASH proton therapy, representing a notable advancement in proton therapy quality assurance. This method promises enhancements in protoacoustic image guidance and real-time dosimetry, paving the way for more accurate and effective treatments in ultra-high dose rate therapy environments.
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Objective.Radiation-induced acoustic (RA) computed tomographic (RACT) imaging is being thoroughly explored for radiation dosimetry. It is essential to understand how key machine parameters like beam pulse, size, and energy deposition affect image quality in RACT. We investigate the intricate interplay of these parameters and how these factors influence dose map resolution in RACT.Approach.We first conduct an analytical assessment of time-domain RA signals and their corresponding frequency spectra for certain testcases, and computationally validate these analyses. Subsequently, we simulated a series of x-ray-based RACT (XACT) experiments and compared the simulations with experimental measurements.In-silicoreconstruction studies have also been conducted to demonstrate the resolution limits imposed by the temporal pulse profiles on RACT. XACT experiments were performed using clinical machines and the reconstructions were analyzed for resolution capabilities.Main results.Our paper establishes the theory for predicting the time- and frequency-domain behavior of RA signals. We illustrate that the frequency content of RA signal is not solely dependent on the spatial energy deposition characteristics but also on the temporal features of radiation. The same spatial energy deposition through a Gaussian pulse and a rectangular pulse of equal pulsewidths results in different frequency spectra of the RA signals. RA signals corresponding to the rectangular pulse exhibit more high-frequency content than their Gaussian pulse counterparts and hence provide better resolution in the reconstructions. XACT experiments with â¼3.2 us and â¼4 us rectangular radiation pulses were performed, and the reconstruction results were found to correlate well with thein-silicoresults.Significance.Here, we discuss the inherent resolution limits for RACT-based radiation dosimetric systems. While our study is relevant to the broader community engaged in research on photoacoustics, x-ray-acoustics, and proto/ionoacoustics, it holds particular significance for medical physics researchers aiming to set up RACT for dosimetry and radiography using clinical radiation machines.
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Acústica , Radiometria , Radiometria/métodos , Humanos , Tomografia Computadorizada por Raios XRESUMO
(1) Background: Bariatric surgery has demonstrated the capacity to improve metabolic-associated fatty liver disease (MAFLD) in patients with morbid obesity. In addition, the Mediterranean diet contains anti-inflammatory, anti-oxidative, and anti-fibrotic components, promoting a beneficial effect on MAFLD. This study aimed to assess the improvement of MAFLD, specifically liver steatosis, in morbidly obese patients undergoing Roux-en-Y gastric bypass (RYGB) and following a hypocaloric Mediterranean-like diet. (2) Methods: A prospective observational pilot study of 20 patients undergoing RYGB was conducted. The participants underwent a magnetic resonance spectroscopy study 2 weeks before the surgical act and one year postoperatively to assess the percentage of lipid content (PLC). The adherence to the Mediterranean diet was determined by the KIDMED test 1 year after surgery. (3) Results: Mean baseline PLC was 14.2 ± 9.4%, and one year after surgery, it decreased to 4.0 ± 1.8% (p < 0.001). A total of 12 patients (60%) were within the range of moderate adherence to the Mediterranean diet, whereas 8 patients (40%) showed a high adherence. The patients with high adherence to the Mediterranean diet presented significantly lower values of postoperative PLC. (4) Conclusions: Liver steatosis significantly reduces after RYGB. This reduction is further improved when associated with a high adherence to a Mediterranean diet.
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Dieta Mediterrânea , Derivação Gástrica , Espectroscopia de Ressonância Magnética , Obesidade Mórbida , Humanos , Feminino , Obesidade Mórbida/cirurgia , Obesidade Mórbida/dietoterapia , Adulto , Estudos Prospectivos , Pessoa de Meia-Idade , Projetos Piloto , Espectroscopia de Ressonância Magnética/métodos , Hepatopatia Gordurosa não Alcoólica/cirurgia , Período Pós-Operatório , Resultado do TratamentoRESUMO
PURPOSE: Thyroid lobectomy (TL) is an appropriate treatment for up to 4 cm intrathyroidal differentiated thyroid cancer (DTC). There is scarce data regarding TL outside first-world centers. Our aim is to report a cohort of patients with DTC treated with TL in Chile. METHODS: We included DTC patients treated with TL, followed for at least 6 months, characterized their clinicopathological features and classified their risk of recurrence and response to treatment. RESULTS: Eighty-two patients followed for a median of 2.3 years (0.5-7.0). Seventy-three (89%) patients had papillary, 8 (9.8%) follicular and 1 (1.2%) high-grade DTC. The risk of recurrence was low in 56 (68.3%) and intermediate in 26 (31.7%). Eight (9.8%) patients required early completion thyroidectomy and radioiodine. At last follow-up, 52 (70.3%) had excellent, 19 (25.7%) had indeterminate, and 1 (1.4%) had structural incomplete response. CONCLUSION: In a developing country, TL is an adequate option for appropriately selected DTC patients.
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Objective. The primary goal of this research is to demonstrate the feasibility of radiation-induced acoustic imaging (RAI) as a volumetric dosimetry tool for ultra-high dose rate FLASH electron radiotherapy (FLASH-RT) in real time. This technology aims to improve patient outcomes by accurate measurements ofin vivodose delivery to target tumor volumes.Approach. The study utilized the FLASH-capable eRT6 LINAC to deliver electron beams under various doses (1.2 Gy pulse-1to 4.95 Gy pulse-1) and instantaneous dose rates (1.55 × 105Gy s-1to 2.75 × 106Gy s-1), for imaging the beam in water and in a rabbit cadaver with RAI. A custom 256-element matrix ultrasound array was employed for real-time, volumetric (4D) imaging of individual pulses. This allowed for the exploration of dose linearity by varying the dose per pulse and analyzing the results through signal processing and image reconstruction in RAI.Main Results. By varying the dose per pulse through changes in source-to-surface distance, a direct correlation was established between the peak-to-peak amplitudes of pressure waves captured by the RAI system and the radiochromic film dose measurements. This correlation demonstrated dose rate linearity, including in the FLASH regime, without any saturation even at an instantaneous dose rate up to 2.75 × 106Gy s-1. Further, the use of the 2D matrix array enabled 4D tracking of FLASH electron beam dose distributions on animal tissue for the first time.Significance. This research successfully shows that 4Din vivodosimetry is feasible during FLASH-RT using a RAI system. It allows for precise spatial (â¼mm) and temporal (25 frames s-1) monitoring of individual FLASH beamlets during delivery. This advancement is crucial for the clinical translation of FLASH-RT as enhancing the accuracy of dose delivery to the target volume the safety and efficacy of radiotherapeutic procedures will be improved.
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Elétrons , Animais , Coelhos , Dosagem Radioterapêutica , Radiometria/métodos , Acústica , Dosimetria in Vivo/métodosRESUMO
Microtubules (MTs) are dynamic components of the cytoskeleton and play essential roles in morphogenesis and maintenance of tissue and cell integrity. Despite recent advances in understanding MT ultrastructure, organization, and growth control, how cells regulate MT organization at the cell cortex remains poorly understood. The EFA-6/EFA6 proteins are recently identified membrane-associated proteins that inhibit cortical MT dynamics. Here, combining visualization of endogenously tagged C. elegans EFA-6 with genetic screening, we uncovered tubulin-dependent regulation of EFA-6 patterning. In the mature epidermal epithelium, EFA-6 forms punctate foci in specific regions of the apical cortex, dependent on its intrinsically disordered region (IDR). We further show the EFA-6 IDR is sufficient to form biomolecular condensates in vitro. In screens for mutants with altered GFP::EFA-6 localization, we identified a novel gain-of-function (gf) mutation in an α-tubulin tba-1 that induces ectopic EFA-6 foci in multiple cell types. tba-1(gf) animals exhibit temperature-sensitive embryonic lethality, which is partially suppressed by efa-6(lf), indicating the interaction between tubulins and EFA-6 is important for normal development. TBA-1(gf) shows reduced incorporation into filamentous MTs but has otherwise mild effects on cellular MT organization. The ability of TBA-1(gf) to trigger ectopic EFA-6 foci formation requires ß-tubulin TBB-2 and the chaperon EVL-20/Arl2. The tba-1(gf)-induced EFA-6 foci display slower turnover, contain the MT-associated protein TAC-1/TACC, and require the EFA-6 MTED. Our results reveal a novel crosstalk between cellular tubulins and cortical MT regulators in vivo.
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Visualizing micro- and nano-scale biological entities requires high-resolution imaging and is conventionally achieved via optical microscopic techniques. Optical diffraction limits their resolution to â¼200 nm. This limit can be overcome by using ions with â¼1 MeV energy. Such ions penetrate through several micrometers in tissues, and their much shorter de Broglie wavelengths indicate that these ion beams can be focused to much shorter scales and hence can potentially facilitate higher resolution as compared to the optical techniques. Proton microscopy with â¼1 MeV protons has been shown to have reasonable inherent contrast between sub-cellular organelles. However, being a transmission-based modality, it is unsuitable for in vivo studies and cannot facilitate three-dimensional imaging from a single raster scan. Here, we propose proton-induced acoustic microscopy (PrAM), a technique based on pulsed proton irradiation and proton-induced acoustic signal collection. This technique is capable of label-free, super-resolution, 3D imaging with a single raster scan. Converting radiation energy into ultrasound enables PrAM with reflection mode detection, making it suitable for in vivo imaging and probing deeper than proton scanning transmission ion microscopy (STIM). Using a proton STIM image of HeLa cells, a coupled Monte Carlo+k-wave simulations-based feasibility study has been performed to demonstrate the capabilities of PrAM. We demonstrate that sub-50 nm lateral (depending upon the beam size and energy) and sub-micron axial resolution (based on acoustic detection bandwidth and proton beam pulse width) can be obtained using the proposed modality. By enabling visualization of biological phenomena at cellular and subcellular levels, this high-resolution microscopic technique enhances understanding of intricate cellular processes.
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BACKGROUND: Actinomyces species are commensal oral cavity flora that can cause jaw osteomyelitis. Osteomyelitis of the jaw by Actinomyces is rare, and its presentation can be confused with many different pathologies. CASE PRESENTATION: This is the case of a 61-year-old female with breast cancer and on chemotherapy as well as non-invasive carcinoma of the tongue who initially presented to the dentist with white spots in the right mandible near the incisors associated with right mandible pain and swelling. Actinomyces-induced osteomyelitis of the mandible was diagnosed. The patient was treated with penicillin V for 6 weeks along with a course of hyperbaric oxygen therapy, which resulted in the complete resolution of the infection. CONCLUSION: In summary, jaw osteomyelitis caused by Actinomyces should always be part of the differential diagnosis; as these organisms are commensal flora. The symptoms manifested are non-specific, and such a diagnosis could be easily missed, resulting in delay of care and disease progression.
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Actinomyces , Actinomicose , Osteomielite , Humanos , Osteomielite/microbiologia , Osteomielite/diagnóstico , Osteomielite/tratamento farmacológico , Feminino , Pessoa de Meia-Idade , Actinomicose/diagnóstico , Actinomicose/microbiologia , Actinomicose/tratamento farmacológico , Actinomicose/complicações , Actinomyces/isolamento & purificação , Antibacterianos/uso terapêutico , Mandíbula/microbiologia , Oxigenoterapia Hiperbárica , Diagnóstico Diferencial , Doenças Mandibulares/microbiologia , Doenças Mandibulares/tratamento farmacológico , Neoplasias da Mama/complicações , Neoplasias da Mama/tratamento farmacológicoRESUMO
BACKGROUND: The use of tourniquets and their role in extremity-based microsurgery has not been thoroughly investigated. The purpose of this study was to investigate tourniquet use and its associated outcomes and complications. The authors hypothesize that tourniquets enhance visualization, bloodless approaches to vessel harvest, flap elevation, and anastomosis without added complications. METHODS: A retrospective chart review was completed for patients who had undergone extremity-based microsurgery with the use of a tourniquet between January 2018 and February 2022 at two large academic institutions. Demographic characteristics, initial reasons for surgery, complications, and outcomes were recorded. Patients were separated into groups based on tourniquet use during three operative segments: (1) flap elevation, (2) vessel harvest, and (3) microvascular anastomosis. An internal comparison of complication rate was performed between cases for which a tourniquet was used for one operative segment to all cases in which it was not used for the same operative segment. Univariate and multivariate statistical analyses were performed to identify statistically significant results. RESULTS: A total of 99 patients (106 surgeries) were included in this study across sites. The mean age was 41.2 years and 67.7% of the patients were male. The most common reason for microsurgical reconstruction was trauma (50.5%). The need for an additional unplanned surgery was the most common surgical complication (16%). A total of 70, 61, and 32% of procedures used a tourniquet for flap elevation, vessel harvest, and for anastomosis, respectively. Statistical analyses identified no difference in complication rates for procedures for which a tourniquet was or was not used for interventions. CONCLUSION: Based on these results, the authors state that tourniquets can be utilized for extremity-based microsurgery to enable bloodless dissection without the concern of increased complication rates.
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Microcirurgia , Torniquetes , Humanos , Masculino , Adulto , Feminino , Estudos Retrospectivos , Torniquetes/efeitos adversos , Extremidades/irrigação sanguínea , Retalhos CirúrgicosRESUMO
BACKGROUND: Applying ultra-high dose rates to radiation therapy, otherwise known as FLASH, has been shown to be just as effective while sparing more normal tissue compared to conventional radiation therapy. However, there is a need for a dosimeter that is able to detect such high instantaneous dose, particularly in vivo. To fulfill this need, protoacoustics is introduced, which is an in vivo range verification method with submillimeter accuracy. PURPOSE: The purpose of this work is to demonstrate the feasibility of using protoacoustics as a method of in vivo real-time monitoring during FLASH proton therapy and investigating the resulting protoacoustic signal when dose per pulse and pulsewidth are varied through multiple simulation studies. METHODS: The dose distribution of a proton pencil beam was calculated through a Monte Carlo toolbox, TOPAS. Next, the k-Wave toolbox in MATLAB was used for performing protoacoustic simulations, where the initial proton dose deposition was inputted to model acoustic propagations, which were also used for reconstructions. Simulations involving the manipulation of the dose per pulse and pulsewidth were performed, and the temporal and spatial resolution for protoacoustic reconstructions were investigated as well. A 3D reconstruction was performed with a multiple beam spot profile to investigate the spatial resolution as well as determine the feasibility of 3D imaging with protoacoustics. RESULTS: Our results showed consistent linearity in the increasing dose-per-pulse, even up to rates considered for FLASH. The simulations and reconstructions were performed for a range of pulsewidths from 0.1 to 10 µs. The results show the characteristics of the proton beam after convolving the protoacoustic signal with the varying pulsewidths. 3D reconstruction was successfully performed with each beam being distinguishable using an 8 cm × 8 cm planar array. These simulation results show that measurements using protoacoustics has the potential for in vivo dosimetry in FLASH therapy during patient treatments in real time. CONCLUSION: Through this simulation study, the use of protoacoustics in FLASH therapy was verified and explored through observations of varying parameters, such as the dose per pulse and pulsewidth. 2D and 3D reconstructions were also completed. This study shows the significance of using protoacoustics and provides necessary information, which can further be explored in clinical settings.
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Método de Monte Carlo , Terapia com Prótons , Radiometria , Dosagem Radioterapêutica , Terapia com Prótons/métodos , Radiometria/métodos , Acústica , Fatores de Tempo , Simulação por Computador , Estudos de Viabilidade , HumanosRESUMO
Functional trait-based approaches provide an opportunity to assess how changes in habitat affect the structure of associated communities. Global analyses have found a similarity in the composition of reef fish functional traits despite differences in species richness, environmental regimes, and habitat components. These large-scale patterns raised the question of whether this same stability can be observed at smaller spatial scales. Here, we compared the fish trait composition and their functional diversity in two Caribbean shallow coral reefs with contrasting levels of habitat degradation: Limones (>30% cover), constituted mainly by colonies of Acropora palmata and Bonanza, a reef with extensive areas of dead Acropora structures, dominated by algae. To characterize the functional structure of fishes on each reef, we calculated the community-weighted mean trait values (CWM), functional richness, functional evenness, functional dispersion, and functional originality. Despite the differences in habitat quality, reefs exhibited a similar proportion and common structure on fish functional traits. Functional richness and functional evenness differed significantly, but functional dispersion and functional originality did not show differences between reefs. The greater niche complexity driven by the high availability of microhabitats provided by A. palmata may explain the higher functional richness in Limones, whereas the reef degradation in Bonanza may contribute to a higher functional evenness because of a similar distribution of abundance per fish trait combinations. Our results suggest that widespread degradation on Caribbean reefs has limited the type, variety, and range of traits, which could lead to a functional homogenization of fish communities even at local scales.
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Antozoários , Recifes de Corais , Animais , Ecossistema , Peixes , Região do Caribe , BiodiversidadeRESUMO
The use of dietary supplements, including pre-workout formulations, has gained widespread popularity among individuals engaged in sports and fitness. This case report presents a unique instance of pre-workout-induced pancreatitis in a previously healthy young adult. The patient, a 35-year-old male, presented to the emergency department with abdominal pain, elevated pancreatic enzymes, and characteristic radiological findings indicative of acute pancreatitis. The patient's history revealed no prior predisposing factors for pancreatitis such as alcohol consumption or gallstone disease. Extensive diagnostic evaluation excluded other potential causes leading to the suspicion of his pre-workout supplement as the source. Pre-workout supplements contain a blend of stimulants, amino acids, and other metabolic ingredients designed to enhance exercise and muscle performance. Research shows that some of these ingredients, such as amino acids, induce metabolic chain reactions which may damage pancreatic cells. However, there is extremely limited literature regarding these amino acids in combination such as in workout supplements. This case prompts an examination of the potential adverse effects of pre-workout supplements, highlighting the need for increased vigilance among healthcare providers and consumers alike. As the use of these products grows, further research is warranted to allow for safe commercial distribution and to protect consumers from serious harm.
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Radiation-induced acoustic (RA) imaging is a promising technique for visualizing the invisible radiation energy deposition in tissues, enabling new imaging modalities and real-time therapy monitoring. However, RA imaging signal often suffers from poor signal-to-noise ratios (SNRs), thus requiring measuring hundreds or even thousands of frames for averaging to achieve satisfactory quality. This repetitive measurement increases ionizing radiation dose and degrades the temporal resolution of RA imaging, limiting its clinical utility. In this study, we developed a general deep inception convolutional neural network (GDI-CNN) to denoise RA signals to substantially reduce the number of frames needed for averaging. The network employs convolutions with multiple dilations in each inception block, allowing it to encode and decode signal features with varying temporal characteristics. This design generalizes GDI-CNN to denoise acoustic signals resulting from different radiation sources. The performance of the proposed method was evaluated using experimental data of x-ray-induced acoustic, protoacoustic, and electroacoustic signals both qualitatively and quantitatively. Results demonstrated the effectiveness of GDI-CNN: it achieved x-ray-induced acoustic image quality comparable to 750-frame-averaged results using only 10-frame-averaged measurements, reducing the imaging dose of x-ray-acoustic computed tomography (XACT) by 98.7%; it realized proton range accuracy parallel to 1500-frame-averaged results using only 20-frame-averaged measurements, improving the range verification frequency in proton therapy from 0.5 to 37.5 Hz; it reached electroacoustic image quality comparable to 750-frame-averaged results using only a single frame signal, increasing the electric field monitoring frequency from 1 fps to 1k fps. Compared to lowpass filter-based denoising, the proposed method demonstrated considerably lower mean-squared-errors, higher peak-SNR, and higher structural similarities with respect to the corresponding high-frame-averaged measurements. The proposed deep learning-based denoising framework is a generalized method for few-frame-averaged acoustic signal denoising, which significantly improves the RA imaging's clinical utilities for low-dose imaging and real-time therapy monitoring.
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Aprendizado Profundo , Redes Neurais de Computação , Tomografia Computadorizada por Raios X/métodos , Razão Sinal-Ruído , Acústica , Processamento de Imagem Assistida por Computador/métodosRESUMO
Molecular testing contributes to improving the diagnosis of indeterminate thyroid nodules (ITNs). ThyroidPrint® is a ten-gene classifier aimed to rule out malignancy in ITN. Post-validation studies are necessary to determine the real-world clinical benefit of ThyroidPrint® in patients with ITN. A single-center, prospective, noninterventional clinical utility study was performed, analyzing the impact of ThyroidPrint® in the physicians' clinical decisions for ITN. Demographics, nodule characteristics, benign call rates (BCRs), and surgical outcomes were measured. Histopathological data were collected from surgical biopsies of resected nodules. Of 1272 fine-needle aspirations, 109 (8.6%) were Bethesda III and 135 (10.6%) were Bethesda IV. Molecular testing was performed in 155 of 244 ITN (63.5%), of which 104 were classified as benign (BCR of 67.1%). After a median follow-up of 15 months, 103 of 104 (99.0%) patients with a benign ThyroidPrint® remained under surveillance and one patient underwent surgery which was a follicular adenoma. Surgery was performed in all 51 patients with a suspicious for malignancy as per ThyroidPrint® result and in 56 patients who did not undergo testing, with a rate of malignancy of 70.6% and 32.1%, respectively. A higher BCR was observed in follicular lesion of undetermined significance (87%) compared to atypia of undetermined significance (58%) (P < 0.05). False-positive cases included four benign follicular nodules and six follicular and four oncocytic adenomas. Our results show that, physicians chose active surveillance instead of diagnostic surgery in all patients with a benign ThyroidPrint® result, reducing the need for diagnostic surgery in 67% of patients with preoperative diagnosis of ITN.
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Neoplasias da Glândula Tireoide , Nódulo da Glândula Tireoide , Humanos , Estudos Prospectivos , Perfilação da Expressão Gênica/métodos , Estudos Retrospectivos , Neoplasias da Glândula Tireoide/diagnóstico , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/cirurgia , Nódulo da Glândula Tireoide/diagnóstico , Nódulo da Glândula Tireoide/genética , Nódulo da Glândula Tireoide/cirurgia , Biópsia por Agulha FinaRESUMO
BACKGROUND: The national immunization program in Mexico includes a 3-dose primary series of pertussis vaccine and a toddler booster dose. In Mexico, whole-cell pertussis vaccines (wP) were switched in 2007 to acellular pertussis vaccines (aP). METHODS: This retrospective study using Mexican National Databases of Health and population surveillance (2000-2019) assessed the incidence of pertussis, infant pertussis vaccination coverage, and vaccine effectiveness (VE) against clinically-diagnosed and/or laboratory-confirmed pertussis in children aged 6.5-18.5 or 24.5 months for the primary series, and children aged 18.5 or 24.5-48.5 months for the toddler booster. RESULTS: The incidence of pertussis sharply increased in 2012 and was highest in 2012, 2015, and 2016 (0.84-0.94/100,000 person-years). Coverage was highest for the first dose in the primary series, decreasing for each subsequent dose. The VE against notified pertussis was 96.4% (95% CI: 94.7, 97.6) for the first three doses of wP vaccine (2000-2007) and 95.7% (95% CI: 95.1, 96.2) for the first three doses of aP vaccine (2008-2019). CONCLUSIONS: Our findings suggested high levels of vaccine effectiveness overall were achieved for the aP and wP vaccines in Mexico between 2000 and 2019.
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Coqueluche , Lactente , Humanos , Coqueluche/epidemiologia , Coqueluche/prevenção & controle , Cobertura Vacinal , Incidência , México/epidemiologia , Eficácia de Vacinas , Estudos RetrospectivosRESUMO
Magnetic resonance imaging (MRI) of the brain has benefited from deep learning (DL) to alleviate the burden on radiologists and MR technologists, and improve throughput. The easy accessibility of DL tools has resulted in a rapid increase of DL models and subsequent peer-reviewed publications. However, the rate of deployment in clinical settings is low. Therefore, this review attempts to bring together the ideas from data collection to deployment in the clinic, building on the guidelines and principles that accreditation agencies have espoused. We introduce the need for and the role of DL to deliver accessible MRI. This is followed by a brief review of DL examples in the context of neuropathologies. Based on these studies and others, we collate the prerequisites to develop and deploy DL models for brain MRI. We then delve into the guiding principles to develop good machine learning practices in the context of neuroimaging, with a focus on explainability. A checklist based on the United States Food and Drug Administration's good machine learning practices is provided as a summary of these guidelines. Finally, we review the current challenges and future opportunities in DL for brain MRI.
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Aprendizado Profundo , Imageamento por Ressonância Magnética , Encéfalo/diagnóstico por imagem , Neuroimagem , Espectroscopia de Ressonância MagnéticaRESUMO
The Dengue virus (DENV) constitutes a major vector borne virus disease worldwide. Prediction of the DENV spread dynamics, prevalence and infection rates are crucial elements to guide the public health services effort towards meaningful actions. The existence of four DENV serotypes further complicates the virus proliferation forecast. The different serotypes have varying clinical impacts, and the symptomatology of the infection is dependent on the infection history of the patient. Therefore, changes in the prevalent DENV serotype found in one location have a profound impact on the regional public health. The prediction of the spread and intensity of infection of the individual DENV serotypes in specific locations would allow the authorities to plan local pesticide spray to control the vector as well as the purchase of specific antibody therapy. Here we used a mathematical model to predict serotype-specific DENV prevalence and overall case burden in Mexico.
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Vírus da Dengue , Dengue , Humanos , Sorogrupo , México/epidemiologia , Anticorpos Antivirais , Modelos TeóricosRESUMO
Purpose: High-precision radiation therapy is crucial for cancer treatment. Currently, the delivered dose can only be verified via simulations with phantoms, and an in-tumor, online dose verification is still unavailable. An innovative detection method called x-ray-induced acoustic computed tomography (XACT) has recently shown the potential for imaging the delivered radiation dose within the tumor. Prior XACT imaging systems have required tens to hundreds of signal averages to achieve high-quality dose images within the patient, which reduces its real-time capability. Here, we demonstrate that XACT dose images can be reproduced from a single x-ray pulse (4 µs) with sub-mGy sensitivity from a clinical linear accelerator. Methods and Materials: By immersing an acoustic transducer in a homogeneous medium, it is possible to detect pressure waves generated by the pulsed radiation from a clinical linear accelerator. After rotating the collimator, signals of different angles are obtained to perform a tomographic reconstruction of the dose field. Using 2-stage amplification with further bandpass filtering increases the signal-to-noise ratio (SNR). Results: Acoustic peak SNR and voltage values were recorded for singular and dual-amplifying stages. The SNR for single-pulse mode was able to satisfy the Rose criterion, and the collected signals were able to reconstruct 2-dimensional images from the 2 homogeneous media. Conclusions: By overcoming the low SNR and requirement of signal averaging, single-pulse XACT imaging holds great potential for personalized dose monitoring from each individual pulse during radiation therapy.
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Radiation-induced acoustic (RA) imaging is a promising technique for visualizing radiation energy deposition in tissues, enabling new imaging modalities and real-time therapy monitoring. However, it requires measuring hundreds or even thousands of averages to achieve satisfactory signal-to-noise ratios (SNRs). This repetitive measurement increases ionizing radiation dose and degrades the temporal resolution of RA imaging, limiting its clinical utility. In this study, we developed a general deep inception convolutional neural network (GDI-CNN) to denoise RA signals to substantially reduce the number of averages. The multi-dilation convolutions in the network allow for encoding and decoding signal features with varying temporal characteristics, making the network generalizable to signals from different radiation sources. The proposed method was evaluated using experimental data of X-ray-induced acoustic, protoacoustic, and electroacoustic signals, qualitatively and quantitatively. Results demonstrated the effectiveness and generalizability of GDI-CNN: for all the enrolled RA modalities, GDI-CNN achieved comparable SNRs to the fully-averaged signals using less than 2% of the averages, significantly reducing imaging dose and improving temporal resolution. The proposed deep learning framework is a general method for few-frame-averaged acoustic signal denoising, which significantly improves RA imaging's clinical utilities for low-dose imaging and real-time therapy monitoring.