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1.
J Interprof Care ; : 1-11, 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38978481

RESUMEN

Interprofessional collaboration (IPC) in stroke care is accepted as best practice and necessary given the multi-system challenges and array of professionals involved. Our two-part stroke team simulations offer an intentional interprofessional educational experience (IPE) embedded in pre-licensure occupational therapy, physical therapy, pharmacy, medicine, nursing and speech-language pathology curricula. This six-year mixed method program evaluation aimed to determine if simulation delivery differences necessitated by COVID-19 impacted students' IPC perception, ratings, and reported learning. Following both simulations, the Interprofessional Collaborative Competency Assessment Scale (ICCAS) and free-text self-reported learning was voluntarily and anonymously collected. A factorial ANOVA using the ICCAS interprofessional competency factors compared scores across delivery methods. Content and category analysis was done for free-text responses. Overall, delivery formats did not affect positive changes in pre-post ICCAS scores. However, pre and post ICCAS scores were significantly different for interprofessional competencies of roles/responsibilities and collaborative patient/family centered approach. Analysis of over 10,000 written response to four open-ended questions revealed the simulation designs evoked better understanding of others' and own scope of practice, how roles and shared leadership change based on context and client need, and the value of each team member's expertise. Virtual-experience-only students noted preference for an in-person stroke clinic simulation opportunity.

2.
Optom Vis Sci ; 101(6): 399-407, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38990238

RESUMEN

SIGNIFICANCE: Poor visibility of indoor features such as steps and ramps can pose mobility hazards for people with low vision. For purposes of architectural design, it is important to understand how design parameters such as the illumination level of an indoor space affect the visibility of steps and ramps. PURPOSE: This study was aimed to examine the effect of typical variation in photopic illumination level in an indoor space on the visibility of steps and ramps for individuals with low vision. METHODS: Steps and ramps were constructed in a large windowless room illuminated by overhead lights. Subjects with low vision completed a 5-alternative forced choice task to recognize the targets at three levels of photopic illumination, i.e., 800, 80, and 8 lux, and gave confidence ratings about their judgments on a 5-point scale. Acuities and contrast sensitivities of the subjects were also measured at each illumination level. For comparison, a group of normally sighted subjects with simulated acuity reduction also completed the step-and-ramp recognition task. RESULTS: For both groups of subjects, recognition accuracy was not affected by illumination level. For subjects with low vision, however, there was a significant effect of illumination level on confidence rating: subjects became more confident about their judgments with increasing illumination. There was also a weak effect of illumination level on acuity and contrast sensitivity, both worsening with decreasing illumination. Recognition performance was best predicted by contrast sensitivity, whereas confidence was best predicted by visual acuity. CONCLUSIONS: Illumination variation over a typical photopic range in an indoor space had minimal effect on the objective visibility of steps and ramps for people with low vision. However, illumination level affected subjects' confidence in hazard recognition. Design decisions on parameters such as illumination should consider the consequences on both the objective and the subjective accessibility of a space.


Asunto(s)
Sensibilidad de Contraste , Iluminación , Baja Visión , Agudeza Visual , Humanos , Baja Visión/fisiopatología , Masculino , Femenino , Agudeza Visual/fisiología , Persona de Mediana Edad , Adulto , Sensibilidad de Contraste/fisiología , Anciano
3.
Life Sci Space Res (Amst) ; 42: 74-83, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39067994

RESUMEN

Human space exploration expansion from Low-Earth Orbit to deep space is accelerating the need to monitor and address the known health concerns related to deep space radiation. The human musculoskeletal system is vulnerable to these risks (alongside microgravity) and its health reflects the well-being of other body systems. Multiparametric magnetic resonance imaging (MRI) is an important approach for assessing temporal physiological changes in the musculoskeletal system. We propose that ultra-low-field MRI provides an optimal low Size Weight and Power (SwaP) solution for non-invasively monitoring muscle and bone changes on the planned Gateway lunar space station. Our proposed ultra-low-field Gateway MRI meets low SWaP design specifications mandated by limited room in the lunar space station. This review summarizes the current state of our knowledge on musculoskeletal consequences of spaceflight, especially with respect to radiation, and then elaborates how MRI can be used to monitor the deleterious effects of space travel and the efficacy of putative countermeasures. We argue that an ultra-low-field MRI in cis-lunar space on the Gateway can provide valuable research and medical insights into the effects of deep space radiation exposure on astronauts. Such an MRI would also allow the development of imaging protocols that would facilitate Earth-bound teams to monitor space personnel musculoskeletal changes during future interplanetary spaceflight. It will especially have a role in monitoring countermeasures, such as the use of melanin, in protecting space explorers.


Asunto(s)
Imagen por Resonancia Magnética , Vuelo Espacial , Humanos , Imagen por Resonancia Magnética/métodos , Sistema Musculoesquelético/diagnóstico por imagen , Sistema Musculoesquelético/efectos de la radiación , Astronautas , Ingravidez , Radiación Cósmica/efectos adversos
4.
Sci Rep ; 14(1): 7911, 2024 04 04.
Artículo en Inglés | MEDLINE | ID: mdl-38575713

RESUMEN

Spatial localization is important for social interaction and safe mobility, and relies heavily on vision and hearing. While people with vision or hearing impairment compensate with their intact sense, people with dual sensory impairment (DSI) may require rehabilitation strategies that take both impairments into account. There is currently no tool for assessing the joint effect of vision and hearing impairment on spatial localization in this large and increasing population. To this end, we developed a novel Dual Sensory Spatial Localization Questionnaire (DS-SLQ) that consists of 35 everyday spatial localization tasks. The DS-SLQ asks participants about their difficulty completing different tasks using only vision or hearing, as well as the primary sense they rely on for each task. We administered the DS-SLQ to 104 participants with heterogenous vision and hearing status. Rasch analysis confirmed the psychometric validity of the DS-SLQ and the feasibility of comparing vision and hearing spatial abilities in a unified framework. Vision and hearing impairment were associated with decreased visual and auditory spatial abilities. Differences between vision and hearing abilities predicted overall sensory reliance patterns. In DSI rehabilitation, DS-SLQ may be useful for measuring vision and hearing spatial localization abilities and predicting the better sense for completing different spatial localization tasks.


Asunto(s)
Pérdida Auditiva , Navegación Espacial , Humanos , Trastornos de la Visión/epidemiología , Pérdida Auditiva/epidemiología , Audición , Encuestas y Cuestionarios
5.
J Vis ; 24(4): 17, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38635281

RESUMEN

Reading is a primary concern of patients with central field loss (CFL) because it is typically performed with foveal vision. Spatial remapping offers one potential avenue to aid in reading; it entails shifting occluded letters to retinal areas where vision is functional. Here, we introduce a method of creating and testing different remapping strategies-ways to remap text-customized for CFL of different shapes. By simulating CFL in typically-sighted individuals, we tested the customization hypothesis-that the benefits of different remapping strategies will depend on the properties of the CFL. That is, remapping strategies will aid reading differentially in the presence of differently shaped CFL. In Experiment 1, letter recognition in the presence of differently shaped CFL was assessed in and around central vision. Using these letter recognition "maps" different spatial remappings were created and tested in Experiment 2 using a word recognition task. Results showed that the horizontal gap remapping, which did not remap any letters vertically, resulted in the best word recognition. Results were also consistent with the customization hypothesis; the benefits of different remappings on word recognition depended on the different CFL shapes. Although the horizontal gap remapping resulted in very good word recognition, tailoring remapping strategies to the shape of patients' CFL may aid reading with the wide range of sizes and shapes encountered by patients with CFL.


Asunto(s)
Fóvea Central , Lectura , Humanos , Reconocimiento en Psicología , Retina
6.
J Homosex ; 71(4): 1099-1135, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-36625553

RESUMEN

The purpose of this enquiry was to understand how gay men form and maintain their attitudes toward HIV transmission preventative behaviors. Autobiographical life histories of sixteen gay men showed that once they acquired knowledge of preventative behavior they consistently adhered to that behavior. They adhered because of fear of HIV infection and because they held a moral norm that obligated them to behave altruistically (Schwartz, 1977) to protect not only themselves, but also their sex partners, loved ones, and their positive self-evaluation. They saw their HIV negative status, and their adherence, as pre-requisite and enabler for achieving their goals in life. Dick and Basu's (1994) Framework for Customer Loyalty, a commercial marketing communications theoretical framework, explains development and maintenance of these men's loyalty (their consistent adherence). This understanding, within a marketing communications framework, will inform development of social marketing communications aiming to increase adherence to behaviors that prevent HIV transmission.


Asunto(s)
Síndrome de Inmunodeficiencia Adquirida , Infecciones por VIH , Minorías Sexuales y de Género , Masculino , Humanos , Síndrome de Inmunodeficiencia Adquirida/prevención & control , Infecciones por VIH/prevención & control , Homosexualidad Masculina , Altruismo , Principios Morales , Conducta Sexual , Conocimientos, Actitudes y Práctica en Salud
7.
J Nutr Health Aging ; 27(12): 1281-1283, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38151880
8.
Med Phys ; 50(12): 7441-7461, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37830895

RESUMEN

BACKGROUND: The Tomosynthesis Mammography Imaging Screening Trial (TMIST), EA1151 conducted by the Eastern Cooperative Oncology Group (ECOG)/American College of Radiology Imaging Network (ACRIN) is a randomized clinical trial designed to assess the effectiveness for breast cancer screening of digital breast tomosynthesis (TM) compared to digital mammography (DM). Equipment from multiple vendors is being used in the study. PURPOSE: For the findings of the study to be valid and capture the true capacities of the two technology types, it is important that all equipment is operated within appropriate parameters with regard to image quality and dose. A harmonized QC program was established by a core physics team. Since there are over 120 trial sites, a centralized, automated QC program was chosen as the most practical design. This report presents results of the weekly QC testing program. A companion paper will review quality monitoring based on data from the headers of the patient images. METHODS: Study images are collected centrally after de-identification using the "TRIAD" application developed by ACR. The core physics team devised and implemented a minimal set of quality control (QC) tests to evaluate the tomosynthesis and 2D mammography systems. Weekly, monthly and annual testing is performed by the site mammography technologists with images submitted directly to the physics core. The weekly physics QC tests are described: SDNR of a low-contrast mass object, artifact spread, spatial resolution, tracking of technical factors, and in-slice noise power spectra. RESULTS: As of December 31, 2022 (5 years), 145 sites with 411 machines had submitted QC data. A total of 136 742 TMIST participant screening imaging studies had been performed. The 5th and 95th percentile mean glandular doses for a single tomosynthesis exposure to a 4.0 cm thick PMMA phantom ("standard breast phantom") were 1.24 and 1.68 mGy respectively. The largest sources of QC non-conformance were: operator error, not following the QC protocol exactly, unreported software updates and preventive maintenance activities that affected QC setpoints. Noise power spectra were measured, however, standardization of performance targets across machine types and software revisions was difficult. Nevertheless, for each machine type, test measurement results were very consistent when the protocol was followed. Deviations in test results were mostly related to software and hardware changes. CONCLUSION: Most systems performed very consistently. Although this is a harmonized program using identical phantoms and testing protocols, it is not appropriate to apply universal threshold or target metrics across the machine types because the systems have different non-linear reconstruction algorithms and image display filters. It was found to be more useful to assess pass/fail criteria in terms of relative deviations from baseline values established when a system is first characterized and after equipment is changed. Generally, systems which needed repair failed suddenly, but in retrospect, for a few cases, drops in SDNR and increases in mAs were observed prior to tube failure. TMIST is registered as NCT03233191 by Clinicaltrials.gov.


Asunto(s)
Neoplasias de la Mama , Mamografía , Humanos , Femenino , Mamografía/métodos , Mama , Neoplasias de la Mama/diagnóstico por imagen , Algoritmos , Control de Calidad , Fantasmas de Imagen
9.
J Vis ; 23(12): 3, 2023 10 04.
Artículo en Inglés | MEDLINE | ID: mdl-37801321

RESUMEN

When an observer moves in space, the retinal projection of a stationary object either expands if the motion is toward the object or shifts horizontally if the motion contains a lateral component. This study examined the impact of expansive optic flow and lateral motion parallax on the accuracy of depth perception for observers with normal or artificially reduced acuity and asked whether any benefit is due to the continuous motion or to the discrete object image displacement. Stationary participants viewed a virtual room on a computer screen. They used an on-screen slider to estimate the depth of a target object relative to a reference object after seeing 2-second videos simulating five conditions: static viewing, expansive optic flow, and lateral motion parallax in either continuous motion or image displacement. Ten participants viewed the stimuli with normal acuity in Experiment 1 and 11 with three levels of artificially reduced acuity in Experiment 2. Linear regression models represented the relationship between the depth estimates of participants and the ground truth. Lateral motion parallax produced more accurate depth estimates than expansive optic flow and static viewing. Depth perception with continuous motion was more accurate than that with displacement under mild and moderate, but not severe, acuity reduction. For observers with both normal and artificially reduced acuity, lateral motion parallax was more helpful for object depth estimation than expansive optic flow, and continuous motion parallax was more helpful than object image displacement.


Asunto(s)
Percepción de Movimiento , Flujo Optico , Humanos , Percepción de Profundidad , Movimiento (Física) , Retina
10.
Med Phys ; 50(12): 7427-7440, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37824821

RESUMEN

PURPOSE: A comprehensive, centrally-monitored physics quality control (QC) program was developed for the Tomosynthesis Imaging Screening Trial (TMIST), a randomized controlled trial of digital breast tomosynthesis (TM) versus digital mammography (DM) for cancer screening. As part of the program, in addition to a set of phantom-based tests, de-identified data on image acquisition and processing parameters were captured from the DICOM headers of all individual patient images in the trial. These data were analyzed to assess the potential usefulness of header data from digital mammograms and tomosynthesis images of patients for quality assurance in breast imaging. METHODS: Data were automatically extracted from the headers of all de-identified patient mammograms and tomosynthesis images in the TMIST study. Image acquisition parameters and estimated radiation doses were tracked for individual sites, systems and across system types. These parameters included (among others) kV, target/filter use, number of acquired views per examination, AEC mode, compression thickness and force and detector temperature. Consistency of manually entered study data parameters (subject ID, screening time-point) from TMIST was evaluated. Preliminary observations from the program are presented. RESULTS: We report on data from 812 651 images from 135 525 examinations acquired between October, 2017 and December, 2022. Data came from 6 system models from 3 manufacturers. There was greater variability both in the number of views used and in the estimated (proxy) doses received in DM exams compared to TM. Mean proxy doses per examination varied among manufacturers from 2.76-4.54 mGy for DM and 3-4.84 mGy for the tomosynthesis component in the TM arm with maximum examination proxy doses of 20 and 26 mGy for DM and TM respectively. Mean proxy doses per examination for the combination examination in TM (tomosynthesis plus digital mammography) varied from 6.6 to 7.6 mGy among manufacturers with a maximum of 44.5 mGy. CONCLUSIONS: Overall, modern digital mammography and tomosynthesis systems used in TMIST have operated very reliably. Doses vary considerably due to variation in the number of views per examination, thickness and fibro-glandularity of the breast, and choices in the use of synthesized versus actual 2D mammography in the TM examination. These data may also be useful in predicting equipment problems. Header information is valuable not only for automated QC, but also for cross-checking accuracy and consistency of data in a clinical study.


Asunto(s)
Neoplasias de la Mama , Detección Precoz del Cáncer , Humanos , Femenino , Dosis de Radiación , Mamografía/métodos , Mama/diagnóstico por imagen , Fantasmas de Imagen , Neoplasias de la Mama/diagnóstico por imagen
11.
Invest Ophthalmol Vis Sci ; 64(12): 23, 2023 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-37703039

RESUMEN

Purpose: In the United States, AMD is a leading cause of low vision that leads to central vision loss and has a high co-occurrence with hearing loss. The impact of central vision loss on the daily functioning of older individuals cannot be fully addressed without considering their hearing status. We investigated the impact of combined central vision loss and hearing loss on spatial localization, an ability critical for social interactions and navigation. Methods: Sixteen older adults with central vision loss primarily due to AMD, with or without co-occurring hearing loss, completed a spatial perimetry task in which they verbally reported the directions of visual or auditory targets. Auditory testing was done with eyes open in a dimly lit room or with a blindfold. Twenty-three normally sighted, age-matched, and hearing-matched control subjects also completed the task. Results: Subjects with central vision loss missed visual targets more often. They showed increased deviations in visual biases from control subjects as the scotoma size increased. However, these deficits did not generalize to sound localization. As hearing loss became more severe, the sound localization variability increased, and this relationship was not altered by coexisting central vision loss. For both control and central vision loss subjects, sound localization was less reliable when subjects wore blindfolds, possibly due to the absence of visual contextual cues. Conclusions: Although central vision loss impairs visual localization, it does not impair sound localization and does not prevent vision from providing useful contextual cues for sound localization.


Asunto(s)
Sordera , Pérdida Auditiva , Localización de Sonidos , Humanos , Anciano , Escotoma , Pérdida Auditiva/diagnóstico , Ojo
12.
QJM ; 116(10): 845-849, 2023 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-37467071

RESUMEN

BACKGROUND: Even though frailty has been extensively measured in the acute care setting, relatively little is known about the frailty of younger adult inpatients. AIM: This study aimed to measure frailty in a sample of hospitalized adults aged 18 years and over and to examine how frailty in younger adult inpatients differs from middle-aged and older adult inpatients. DESIGN: Secondary analyses of prospectively collected cohort data. METHODS: Research nurses assessed 910 patients at admission to four Australian hospitals using the interRAI Acute Care instrument. Comparison of frailty index (FI) scores and domains was conducted across three age groups: younger (18-49 years), middle-aged (50-69 years) and older adults (≥70 years). Multivariable logistic regression examined risk of prolonged length of stay and unfavourable discharge destination. RESULTS: Younger adults (n = 214; 23.5%) had a mean (SD) FI of 0.19 (0.10). Approximately 27% (n = 57) of younger adults were frail (FI > 0.25). Mood and behaviour, health symptoms and syndromes, nutrition and pain were the most frequently affected domains in younger adults and 50% had ≥3 comorbidities. Frailty increased the risk of long length of stay (odds ratio (OR) = 1.77, P < 0.001) but not the risk of an unfavourable discharge (OR = 1.40, P = 0.20) in younger adults. CONCLUSIONS: This study showed that frailty is prevalent in younger patients admitted to acute care and is associated with adverse outcomes. This study was a critical first step towards establishing an understanding of frailty in younger hospitalized adults.


Asunto(s)
Fragilidad , Anciano , Humanos , Adolescente , Adulto , Persona de Mediana Edad , Adulto Joven , Fragilidad/epidemiología , Fragilidad/diagnóstico , Anciano Frágil , Tiempo de Internación , Australia/epidemiología , Hospitales , Evaluación Geriátrica
13.
BMC Anesthesiol ; 23(1): 234, 2023 07 12.
Artículo en Inglés | MEDLINE | ID: mdl-37438685

RESUMEN

BACKGROUND: Advanced respiratory support modalities such as non-invasive positive pressure ventilation (NiPPV) and heated and humidified high flow nasal canula (HFNC) served as useful alternatives to invasive mechanical ventilatory support for acute respiratory failure (ARF) during the peak of the SARS-CoV-2/COVID-19 pandemic. Unlike NiPPV, HFNC is a newer modality and its role in the treatment of patients with severe ARF is not yet clearly defined. Furthermore, the characteristics of responders versus non-responders to HFNC have not been determined. Although recent evidence indicates that many patients with ARF treated with HFNC survive without needing intubation, those who fail and are subsequently intubated have worse outcomes. Given that prolonged use of HFNC in patients with ARF might exacerbate patient self-inflicted lung injury, we hypothesized that among those patients with ARF due to COVID-19 pneumonia, prolonged HFNC beyond 24 h before intubation would be associated with increased in-hospital mortality. METHODS: This was a retrospective, multicenter, observational cohort study of 2720 patients treated for ARF secondary to SARS-CoV-2/COVID-19 pneumonia and initially managed with HFNC within the Banner Health system during the period from March 1st, 2020, to July 31st, 2021. In the subgroup of patients for went from HFNC to IMV, we assessed the effect of the duration of HFNC prior to intubation on mortality. RESULTS: 1392 (51%) were successfully treated with HFNC alone and 1328 (49%) failed HFNC and were intubated (HFNC to IMV). When adjusted for the covariates, HFNC duration less than 24 h prior to intubation was significantly associated with reduced mortality. CONCLUSIONS: Among patients with ARF due to COVID-19 pneumonia who fail HFNC, delay of intubation beyond 24 h is associated with increased mortality.


Asunto(s)
COVID-19 , Síndrome de Dificultad Respiratoria , Insuficiencia Respiratoria , Humanos , Mortalidad Hospitalaria , COVID-19/terapia , Pandemias , Estudios Retrospectivos , SARS-CoV-2 , Insuficiencia Respiratoria/terapia , Intubación Intratraqueal
15.
Chem Rev ; 123(10): 6413-6544, 2023 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-37186959

RESUMEN

Interfacial reactions drive all elemental cycling on Earth and play pivotal roles in human activities such as agriculture, water purification, energy production and storage, environmental contaminant remediation, and nuclear waste repository management. The onset of the 21st century marked the beginning of a more detailed understanding of mineral aqueous interfaces enabled by advances in techniques that use tunable high-flux focused ultrafast laser and X-ray sources to provide near-atomic measurement resolution, as well as by nanofabrication approaches that enable transmission electron microscopy in a liquid cell. This leap into atomic- and nanometer-scale measurements has uncovered scale-dependent phenomena whose reaction thermodynamics, kinetics, and pathways deviate from previous observations made on larger systems. A second key advance is new experimental evidence for what scientists hypothesized but could not test previously, namely, interfacial chemical reactions are frequently driven by "anomalies" or "non-idealities" such as defects, nanoconfinement, and other nontypical chemical structures. Third, progress in computational chemistry has yielded new insights that allow a move beyond simple schematics, leading to a molecular model of these complex interfaces. In combination with surface-sensitive measurements, we have gained knowledge of the interfacial structure and dynamics, including the underlying solid surface and the immediately adjacent water and aqueous ions, enabling a better definition of what constitutes the oxide- and silicate-water interfaces. This critical review discusses how science progresses from understanding ideal solid-water interfaces to more realistic systems, focusing on accomplishments in the last 20 years and identifying challenges and future opportunities for the community to address. We anticipate that the next 20 years will focus on understanding and predicting dynamic transient and reactive structures over greater spatial and temporal ranges as well as systems of greater structural and chemical complexity. Closer collaborations of theoretical and experimental experts across disciplines will continue to be critical to achieving this great aspiration.

16.
Neurosci Biobehav Rev ; 147: 105068, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36738813

RESUMEN

Freezing of gait (FOG) is a common and disabling symptom in people with Parkinson's Disease (PwPD). Although cognition is thought to be worse in PwPD who freeze, a comprehensive analysis of this relationship will inform future research and clinical care. This systematic review and meta-analysis compared cognition between PwPD who do and do not exhibit FOG across a range of cognitive domains and assessed the impact of disease severity and medication status on this relationship. 145 papers (n = 9010 participants) were included in the analysis, with 144 and 138 articles meeting the criteria to assess moderating effects of disease severity and medication status, respectively. PwPD who freeze exhibited worse cognition than PwPD without FOG across global cognition, executive function/attention, language, memory, and visuospatial domains. Greater disease severity and "ON" levodopa medication status moderated the FOG status-cognition relationship in global cognitive performance but not in other cognitive domains. This meta-analysis confirmed that cognition is worse in PwPD with FOG and highlights the importance of disease severity and medication status in this relationship.


Asunto(s)
Trastornos Neurológicos de la Marcha , Enfermedad de Parkinson , Humanos , Enfermedad de Parkinson/complicaciones , Enfermedad de Parkinson/tratamiento farmacológico , Trastornos Neurológicos de la Marcha/etiología , Cognición , Levodopa , Marcha
17.
MAGMA ; 36(4): 671-686, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36417013

RESUMEN

OBJECTIVE: The design of an MRI for use in space requires that the hardware be kept to an absolute minimum in terms of mass, complexity, and power. In addition, NASA requirements are that the external stray field needs to be less than 3.2 Gauss, 7 cm from the MRI enclosure. THEORY: RF encoding designs with Halbach magnets offer the best chance of meeting those requirements. Spatially non-uniform magnetic fields with foliations of isomagnetic surfaces, or natural slices, may be used to provide slice selection, and to reduce further the hardware complexity, for TRansmit Array Spatial Encoding (TRASE) Magnetic Resonance Imaging (MRI) or potentially for other radio frequency (RF) encoding methods. The design of such non-uniform magnetic fields in a Halbach configuration with built-in axial gradients leads to pairs of isomagnetic surfaces centered on either side of a central maximum field strength slice. If TRASE images from slices other than the central isomagnetic surface are desired, then the Nuclear Magnetic Resonance (NMR) signals originating from the twin natural slices must be separated during image reconstruction. Here, a design for simultaneously imaging on twin slices in such an inhomogeneous magnetic field using multiple receiver coils with spatially varying RF profiles is described mathematically and numerical simulation examples are given. DESIGN APPROACH: To achieve RF encoding on the natural slices, at least three TRASE transmit coils are required. Here a solution with twisted solenoid coils is given. To achieve the twin slice separation at least two receive coils are required. Here a solution with two solenoids is given. DISCUSSION: The MRI design presented here uses a combination of RF encoding (TRASE), a spatial encoding magnetic field (SEM, pairs of natural slices) and receive coil spatial profiles to encode enough information into the NMR signal for image slice reconstruction. The design presented here enables using Halbach magnets with a built-in axial gradient to be used for MRI. CONCLUSION: The result is a new gradient-free TRASE MRI design capable of imaging pairs of electronically selectable axial slices.


Asunto(s)
Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Imagen por Resonancia Magnética/métodos , Espectroscopía de Resonancia Magnética , Procesamiento de Imagen Asistido por Computador/métodos , Simulación por Computador , Ondas de Radio , Fantasmas de Imagen , Diseño de Equipo
18.
Ultrasound Obstet Gynecol ; 61(5): 610-616, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36206549

RESUMEN

OBJECTIVE: To compare the prevalence of preterm birth (PTB) (delivery before 37 weeks) in Israel before and after publication of national guidelines recommending second-trimester sonographic cervical-length (CL) measurement. METHODS: The Israeli Society of Obstetrics and Gynecology (ISOG) guidelines, issued on 1 January 2012, specified that CL should be measured transabdominally or, if this is not possible, transvaginally, at the 19-25-week ultrasound anomaly scan and that CL < 25 mm should indicate further work-up and treatment, although the type of treatment was unspecified. In 2000, the Israel Ministry of Health issued a legal requirement for the submission of delivery records to a national registry. These data were used to compare PTB prevalence in the period before (2000-2011) and that after (2012-2020) publication of the guidelines, as well as trends within each time period. Information was available on singleton and multiple pregnancy and maternal age and parity, as well as low birth weight (< 2500 g). RESULTS: During the period 2000-2020, there were 3 403 976 infants liveborn in Israel: 1 797 657 before and 1 606 319 after publication of the ISOG guidelines. There were 247 187 PTBs overall, with a prevalence of 7.64% (95% CI, 7.52-7.77%) before publication of the guidelines and 6.84% (95% CI, 6.43-7.24%) afterwards (P < 0.0002, two-tailed). The annual PTB prevalence was static in the first time period but declined by 0.18% per annum during the second period, after publication of the guidelines. The proportionate reduction in PTB prevalence after compared with before publication of the guidelines was 10% overall, 9% for PTB at 33-36 weeks, 18% for PTB at 28-32 weeks and 24% for PTB at < 28 weeks. After publication of the guidelines, reduced prevalence of PTB was observed among singletons (5.49% before vs 4.83% after, P < 0.0001), but not among infants in twin or higher-order multiple pregnancy. There was a statistically significant reduction in the rate of PTB following publication of the guidelines in both nulliparous and parous women and in the 19-39-year-old maternal-age group. Although reductions in PTB prevalence were also noted in high-risk age groups (maternal age < 19 years and ≥ 40 years), these did not reach statistical significance. Following publication of the guidelines, there was a statistically significant reduction in the prevalence of birth weight under 2500 g, of a magnitude similar to that for PTB prevalence. CONCLUSIONS: The publication of national guidelines recommending routine CL measurement at the time of the second-trimester anomaly scan was associated with a fall in PTB prevalence in singleton pregnancies. Whilst direct evidence linking screening with this fall in prevalence is lacking, it is likely that implementation of routine CL screening played an important role in the reduction of PTB rate. Our experience indicates that screening can be incorporated into the second-trimester anomaly scan. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.


Asunto(s)
Nacimiento Prematuro , Embarazo , Femenino , Recién Nacido , Humanos , Adulto Joven , Adulto , Nacimiento Prematuro/epidemiología , Nacimiento Prematuro/prevención & control , Israel/epidemiología , Prevalencia , Embarazo Múltiple , Segundo Trimestre del Embarazo , Medición de Longitud Cervical
19.
Brachytherapy ; 21(6): 806-813, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36220758

RESUMEN

AIMS: Interstitial brachytherapy (ISBT) is an effective option for delivering conformal high dose radiation to the target volume with better organ-at risk sparing but is thought to be more invasive and painful than other methods. This study investigated pain levels and opioid consumption in patients who received spinal anesthesia (SA) or general anesthesia (GA) for their ISBT. MATERIALS AND METHODS: Patients that underwent ISBT from April 2014 to September 2018 were analyzed from a prospective institutional database. The most prevalent malignancies were cervical (45%), recurrent endometrial (27%) and vaginal (20%) cancers. Baseline patient characteristics, radiation treatment details, anesthesia records, and inpatient charts were obtained. Opioid consumption was quantified as oral morphine equivalent per day (OMEq/day) from implantation until removal. Pain score levels were collected by using an 11-point scoring system. RESULTS: Ninety nine patients received GA and 40 patients received SA as their anesthesia for ISBT. During their first admission, 76 patients (55%) required intravenous opioids. Patients receiving SA had significantly lower mean pain scores on the morning of their procedure 6 (Interquartile range [IQR] 2-8) vs. 0 (IQR: 0-1); p < 0.001]. Pain did not significantly differ between cohorts at any other time. During the first admission, SA patients had a lower median opioid usage of 23 (IQR: 9-47) mg/day compared to GA patients at 38 (IQR: 21-71) mg/day (p = 0.011). No difference in opioid consumption was seen during subsequent admissions. CONCLUSIONS: In patients undergoing ISBT, SA provides better immediate pain control post insertion compared to GA. Patients who received SA used lower amounts of opioids during their first ISBT insertion.


Asunto(s)
Anestesia Raquidea , Braquiterapia , Neoplasias de los Genitales Femeninos , Femenino , Humanos , Braquiterapia/métodos , Analgésicos Opioides/uso terapéutico , Estudios Prospectivos , Neoplasias de los Genitales Femeninos/radioterapia , Neoplasias de los Genitales Femeninos/patología , Anestesia General/métodos , Dolor
20.
Cortex ; 155: 277-286, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36054997

RESUMEN

Braille reading and other tactile discrimination tasks recruit the visual cortex of both blind and normally sighted individuals undergoing short-term visual deprivation. Prior functional magnetic resonance imaging (fMRI) work in patient 'S', a visually impaired adult with the rare ability to read both highly magnified print visually and Braille by touch, found that foveal representations of S's visual cortex were recruited during tactile perception, whereas peripheral regions were recruited during visual perception. Here, we test the causal nature of tactile responses in the visual cortex of S by combining tactile and visual psychophysics with repetitive transcranial magnetic stimulation. First, we replicate the previous fMRI findings in S. Second, we demonstrate that transient disruption of S's foveal visual cortex has no measurable impact on S's tactile processing performance compared to that of healthy controls - a pattern not predicted by the fMRI results. Third, stimulation of foveal visual cortex maximally disrupted visual processing performance in both S and controls, suggesting the possibility of preserved visual processing within S's foveal representation. Finally, stimulation of somatosensory cortex induced the expected disruption to tactile processing performance in both S and controls. These data suggest that tactile responses in S's foveal representation reflect unmasking of latent connections between visual and somatosensory cortices and not behaviourally relevant cross-modal plasticity. Unlike studies in congenitally blind individuals, it is possible that the absence of complete visual loss in S has limited the degree of causally impactful cross-modal reorganisation.


Asunto(s)
Percepción del Tacto , Baja Visión , Corteza Visual , Adulto , Ceguera , Humanos , Imagen por Resonancia Magnética , Lectura , Corteza Somatosensorial/fisiología , Tacto/fisiología , Percepción del Tacto/fisiología , Corteza Visual/fisiología
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