Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
1.
AJR Am J Roentgenol ; 201(5): 1049-56, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24147476

RESUMO

OBJECTIVE: During this study, we instituted a phased quality improvement initiative designed to educate referring clinicians and departmental radiologists about the recommendations of the American College of Radiology (ACR) Appropriateness Criteria for dual-phase (without and with contrast material) head CT examinations. The primary aims of the study were to evaluate whether the quality improvement initiative was associated with an improvement in ACR Appropriateness Criteria appropriateness ratings and a reduction in the number of unindicated dual-phase head CT examinations performed. A secondary aim was to assess the impact of the quality improvement initiative on health care costs. MATERIALS AND METHODS: This study included-with the exception of the examinations performed during a 3-month training period-all single- and dual-phase head CT examinations performed of adult patients at a tertiary care medical center from January 2009 through October 2011. Both inpatients and outpatient examinations were included. There were no exclusion criteria. RESULTS: Implementation of the initiative enhanced patient safety and reduced health care costs by achieving a significant reduction (p = 0.006) in the number of unindicated dual-phase head CT examinations performed from a median number of 40 per month to 17 per month. CONCLUSION: Although there are potential benefits for dual-phase head CT examinations, the medical and economic risks should be measured against these potential benefits. Incorporating the ACR Appropriateness Criteria applies evidence-based medicine to this algorithm. In this outcomes-driven study, the number of unindicated dual-phase head CT examinations was reduced and imaging efficacy improved primarily through physician education and monitoring.


Assuntos
Padrões de Prática Médica/estatística & dados numéricos , Melhoria de Qualidade , Tomografia Computadorizada por Raios X/estatística & dados numéricos , Procedimentos Desnecessários/estatística & dados numéricos , Meios de Contraste/economia , Redução de Custos , Feminino , Humanos , Masculino , Doses de Radiação , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/economia
2.
JAMIA Open ; 6(2): ooad030, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37124675

RESUMO

Objective: The aim of this study was to design and assess the formative usability of a novel patient portal intervention designed to empower patients with diabetes to initiate orders for diabetes-related monitoring and preventive services. Materials and Methods: We used a user-centered Design Sprint methodology to create our intervention prototype and assess its usability with 3 rounds of iterative testing. Participants (5/round) were presented with the prototype and asked to perform common, standardized tasks using think-aloud procedures. A facilitator rated task performance using a scale: (1) completed with ease, (2) completed with difficulty, and (3) failed. Participants completed the System Usability Scale (SUS) scored 0-worst to 100-best. All testing occurred remotely via Zoom. Results: We identified 3 main categories of usability issues: distrust about the automated system, content concerns, and layout difficulties. Changes included improving clarity about the ordering process and simplifying language; however, design constraints inherent to the electronic health record system limited our ability to respond to all usability issues (eg, could not modify fixed elements in layout). Percent of tasks completed with ease across each round were 67%, 60%, and 80%, respectively. Average SUS scores were 87, 74, and 93, respectively. Across rounds, participants found the intervention valuable and appreciated the concept of patient-initiated ordering. Conclusions: Through iterative user-centered design and testing, we improved the usability of the patient portal intervention. A tool that empowers patients to initiate orders for disease-specific services as part of their existing patient portal account has potential to enhance the completion of recommended health services and improve clinical outcomes.

3.
Magn Reson Med ; 67(5): 1427-33, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-21954094

RESUMO

Measurements of relaxation rates in the rotating frame with spin-locking techniques are sensitive to substances with exchanging protons with appropriate chemical shifts. The authors develop a novel approach to exchange-rate selective imaging based on measured T(1ρ) dispersion with applied locking field strength, and demonstrate the method on samples containing the X-ray contrast agent Iohexol with and without cross-linked bovine serum albumin. T(1ρ) dispersion of water in the phantoms was measured with a Varian 9.4-T magnet by an on-resonance spin-locking pulse with fast spin-echo readout, and the results used to estimate exchange rates. The Iohexol phantom alone gave a fitted exchange rate of ~1 kHz, bovine serum albumin alone was ~11 kHz, and in combination gave rates in between. By using these estimated rates, we demonstrate how a novel spin-locking imaging method may be used to enhance contrast due to the presence of a contrast agent whose protons have specific exchange rates.


Assuntos
Aumento da Imagem/métodos , Iohexol/química , Imageamento por Ressonância Magnética/métodos , Albumina Sérica/química , Meios de Contraste/química , Imageamento por Ressonância Magnética/instrumentação , Imagens de Fantasmas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Marcadores de Spin
4.
Magn Reson Med ; 66(6): 1563-71, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21590720

RESUMO

Variations in T(1ρ) with locking-field strength (T(1ρ) dispersion) may be used to estimate proton exchange rates. We developed a novel approach utilizing the second derivative of the dispersion curve to measure exchange in a model system of cross-linked polyacrylamide gels. These gels were varied in relative composition of comonomers, increasing stiffness, and in pH, modifying exchange rates. Magnetic resonance images were recorded with a spin-locking sequence as described by Sepponen et al. These measurements were fit to a mono-exponential decay function yielding values for T(1ρ) at each locking-field measured. These values were then fit to a model by Chopra et al. for estimating exchange rates. For low stiffness gels, the calculated exchange values increased by a factor of 4 as pH increased, consistent with chemical exchange being the dominant contributor to T(1ρ) dispersion. Interestingly, calculated chemical exchange rates also increased with stiffness, likely due to modified side-chain exchange kinetics as the composition varied. This article demonstrates a new method to assess the structural and chemical effects on T(1ρ) relaxation dispersion with a suitable model. These phenomena may be exploited in an imaging context to emphasize the presence of nuclei of specific exchange rates, rather than chemical shifts.


Assuntos
Algoritmos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Modelos Biológicos , Simulação por Computador , Aumento da Imagem/métodos , Imageamento por Ressonância Magnética/instrumentação , Imagens de Fantasmas , Prótons , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
5.
Nanomedicine ; 7(4): 489-96, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21215329

RESUMO

A transfecting agent-coated hybrid imaging nanoprobe (HINP) composed of visible and near-infrared (NIR) light emitting quantum dots (QDs) tethered to superparamagnetic iron oxide (SPIO) nanoparticles was developed. The surface modification of QDs and SPIO particles and incorporation of dual QDs within the SPIO were characterized by dynamic light scattering (DLS), quartz crystal microbalance (QCM) analysis and atomic force microscopy (AFM). The optical contrasting properties of HINP were characterized by absorption and photoluminescence spectroscopy and fluorescence imaging. Multicolor HINP was used in imaging the migration of dendritic cells (DCs) by optical, two-photon and magnetic resonance imaging techniques. FROM THE CLINICAL EDITOR: The development of a transfecting agent-coated hybrid imaging nanoprobe (HINP) composed of visible and near-infrared light emitting quantum dots (QDs) tethered to superparamagnetic iron oxide nanoparticles is reported in this paper. Multicolor HINP was used in imaging the migration of dendritic cells by optical, two-photon and magnetic resonance imaging techniques.


Assuntos
Células Dendríticas/citologia , Diagnóstico por Imagem/métodos , Nanotecnologia/métodos , Animais , Células Cultivadas , Nanopartículas de Magnetita/química , Camundongos , Camundongos Endogâmicos C57BL , Microscopia de Força Atômica , Pontos Quânticos
6.
Magn Reson Med ; 63(5): 1383-90, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20432309

RESUMO

We report the development of superparamagnetic iron oxide (SPIOs) nanoparticles and investigate the migration of SPIO-labeled dendritic cells (DCs) in a syngeneic mouse model using magnetic resonance (MR) imaging. The size of the dextran-coated SPIO is roughly 30 nm, and the DCs are capable of independent uptake of these particles, although not at levels comparable to particle uptake in the presence of a transfecting reagent. On average, with the assistance of polylysine, the particles were efficiently delivered inside DCs within one hour of incubation. The SPIO particles occupy approximately 0.35% of cell surface and are equivalent to 34.6 pg of iron per cell. In vivo imaging demonstrated that the labeled cells migrated from the injection site in the footpad to the corresponding popliteal lymph node. The homing of labeled cells in the lymph nodes resulted in a signal drop of up to 79%. Furthermore, labeling DCs with SPIO particles did not compromise cell function, we demonstrated that SPIO-enhanced MR imaging can be used to track the migration of DCs effectively in vivo.


Assuntos
Células Dendríticas/citologia , Compostos Férricos/síntese química , Imageamento por Ressonância Magnética/métodos , Nanopartículas/química , Animais , Células Cultivadas , Meios de Contraste/síntese química , Camundongos , Camundongos Endogâmicos C57BL , Tamanho da Partícula , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Coloração e Rotulagem/métodos
7.
J Digit Imaging ; 22(4): 424-36, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18446412

RESUMO

Magnetic resonance imaging (MRI) investigations of breast cancer incorporate computationally intense techniques to develop parametric maps of pathophysiological tissue characteristics. Common approaches employ, for example, quantitative measurements of T (1), the apparent diffusion coefficient, and kinetic modeling based on dynamic contrast-enhanced MRI (DCE-MRI). In this paper, an integrated medical image post-processing and archive system (MIPAS) is presented. MIPAS demonstrates how image post-processing and user interface programs, written in the interactive data language (IDL) programming language with data storage provided by a Microsoft Access database, and the file system can reduce turnaround time for creating MRI parametric maps and provide additional organization for clinical trials. The results of developing the MIPAS are discussed including potential limitations of the use of IDL for the application framework and how the MIPAS design supports extension to other programming languages and imaging modalities. We also show that network storage of images and metadata has a significant (p < 0.05) increase in data retrieval time compared to collocated storage. The system shows promise for becoming both a robust research picture archival and communications system working with the standard hospital PACS and an image post-processing environment that extends to other medical image modalities.


Assuntos
Neoplasias da Mama/diagnóstico , Mama/patologia , Diagnóstico por Computador , Imageamento por Ressonância Magnética/métodos , Software , Feminino , Humanos , Imageamento por Ressonância Magnética/tendências
8.
JAMIA Open ; 2(4): 479-488, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32025645

RESUMO

BACKGROUND AND OBJECTIVE: Patient portal use has increased over the last two decades in response to consumer demand and government regulation. Despite growing adoption, few guidelines exist to direct successful implementation and governance. We describe the policies and procedures that have governed over a decade of continuous My Health at Vanderbilt (MHAV) patient portal use. METHODS: We examined MHAV usage data between May 2007 and November 2017. We classified patient portal activity into eight functional categories: Appointment, Billing, Document Access, Genetics, Health Result, Immunization, Medication, and Messaging. We describe our operating policies and measure portal uptake, patient account activity, and function use over time. RESULTS: By the end of the study period, there were 375 517 registered accounts. Policies made MHAV available to competent adults and adolescents 13 and over. Patients signed up for a limited access account online, which could be upgraded to a full-access account after identity verification. Patients could assign proxy accounts to family and caregivers, which permitted nonpatient access to select MHAV functions. Laboratory and radiology results were accessible via MHAV. Results were classified into three groups based on sensitivity, which govern the length of delay before results appeared in MHAV. DISCUSSION AND CONCLUSION: Patient portals offer significant opportunity to engage patients in their healthcare. However, there remains a need to understand how policies can promote uptake and use. We anticipate that other institutions can apply concepts from our policies to support meaningful patient portal engagement.

9.
Transl Oncol ; 4(1): 1-8, 2011 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-21286372

RESUMO

To investigate the role of enhanced antigen presentation in dendritic cell (DC)-based immunotherapy. Here, we describe the development of a cell-penetrating mucin 1 (MUC1) antigen and its immunotherapeutic potential against tumors. After animal groups received two immunizations of MUC1-MPA(11)P-pulsed DCs, we observed a marked tumor regression compared with the mice treated with DCs alone or DCs pulsed with MUC1 peptide. We confirmed the migration and homing of DCs in the popliteal lymph node using magnetic resonance imaging during the study. In summary, enhanced antigen uptake using an MPA(11)P delivery molecule improves cell therapy.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA