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1.
Sci Rep ; 13(1): 14390, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37658125

RESUMO

Breast cancer screening has substantially reduced mortality across screening populations. However, a clinical need persists for more accessible, cost-effective, and robust approaches for increased-risk and diverse patient populations, especially those with dense breasts where screening mammography is suboptimal. We developed and validated a cost-effective, portable, patient-dedicated three-dimensional (3D) automated breast ultrasound (ABUS) system for point-of-care breast cancer screening. The 3D ABUS system contains a wearable, rapid-prototype 3D-printed dam assembly, a compression assembly, and a computer-driven 3DUS scanner, adaptable to any commercially available US machine and transducer. Acquisition is operator-agnostic, involves a 40-second scan time, and provides multiplanar 3D visualization for whole-breast assessment. Geometric reconstruction accuracy was evaluated with a 3D grid phantom and tissue-mimicking breast phantoms, demonstrating linear measurement and volumetric reconstruction errors < 0.2 mm and < 3%, respectively. The system's capability was demonstrated in a healthy male volunteer and two healthy female volunteers, representing diverse patient geometries and breast sizes. The system enables comfortable ultrasonic coupling and tissue stabilization, with adjustable compression to improve image quality while alleviating discomfort. Moreover, the system effectively mitigates breathing and motion, since its assembly affixes directly onto the patient. While future studies are still required to evaluate the impact on current clinical practices and workflow, the 3D ABUS system shows potential for adoption as an alternative, cost-effective, dedicated point-of-care breast cancer screening approach for increased-risk populations and limited-resource settings.


Assuntos
Neoplasias da Mama , Detecção Precoce de Câncer , Humanos , Feminino , Masculino , Neoplasias da Mama/diagnóstico por imagem , Análise Custo-Benefício , Sistemas Automatizados de Assistência Junto ao Leito , Mamografia
2.
Eur Phys J E Soft Matter ; 45(10): 85, 2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36289136

RESUMO

We describe a new nanoscale morphology that is produced when polymer surfaces are exposed to a poor solvent. We have measured the morphology on polystyrene surfaces after exposure to pentane, heptane, or dodecane as well as poly(methyl methacrylate) exposed to propanol or methanol. The length scale of the morphology was determined by analyzing images obtained by atomic force microscopy. For the case of polystyrene, we perform a detailed characterization of the morphology for all solvents and molecular weight values [Formula: see text] ranging from 8 to 995 kg/mol. Comparing the results to models of dimpling morphology in densely grafted chains suggests the same mechanism is responsible.


Assuntos
Polímeros , Poliestirenos , Solventes , Pentanos , Propriedades de Superfície , Polimetil Metacrilato , Metanol , Heptanos , Propanóis
3.
Brachytherapy ; 17(2): 506-513, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29241704

RESUMO

PURPOSE: To develop an anthropomorphic breast phantom for use in credentialing of permanent breast seed implant brachytherapy. METHODS AND MATERIALS: A representative external contour and target volume was used as the basis of mold manufacturing for anthropomorphic breast phantom development. Both target and normal tissue were composed of gel-like materials that provide suitable computed tomography and ultrasound contrast for brachytherapy delivery. The phantoms were evaluated for consistency in construction (target location) and Hounsfield unit (computed tomography contrast). For both target and normal tissue, the speed of sound was measured and compared to the image reconstruction algorithm's expectation value. Five phantoms were imaged preimplant and postimplant to assess interphantom similarity as well as to evaluate the uncertainty in quantifying seed position. RESULTS: The average Hounsfield units of the target and normal tissue gels is -146 ± 5 and 23 ± 1, respectively. The average speed of sound of the target and normal tissue gels is 1485 ± 7 m/s and 1558 ± 9 m/s, respectively, resulting in an estimated 0.4 mm uncertainty in image guidance. The registration/deformation uncertainty was determined to be 0.8 mm. The standard combined uncertainty in assessing seed position spatial accuracy, also including a 0.9 mm estimate based on literature for seed localization, is estimated to be 1.3 mm. CONCLUSIONS: The development of the anthropomorphic breast phantom and evaluation of both the consistency as well as overall seed position uncertainty illustrates the suitability of this phantom for use in brachytherapy end-to-end delivery and implant accuracy evaluation. When evaluating a user's implant accuracy, we estimate a standard combined uncertainty of 1.3 mm.


Assuntos
Braquiterapia/normas , Mama , Credenciamento , Imagens de Fantasmas , Algoritmos , Braquiterapia/métodos , Mama/diagnóstico por imagem , Humanos , Dosagem Radioterapêutica , Tomografia Computadorizada por Raios X , Incerteza
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