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1.
Neurourol Urodyn ; 40(1): 319-325, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33141486

RESUMO

AIM: This study aims to evaluate the intracorporeal pressures immediately after the insertion of the catheters for urodynamic testing with a water-filled urodynamic pressure transducer system to determine the relevance of the International Continence Society (ICS) zeroing principles. METHODS: Here, a retrospective analysis of a random series of urodynamic recordings is performed. The initial pressures, immediately after the insertion of the catheters, have been compared with the pressures after some milliliters of filling and flushing away of the gel, used with insertion, and/or the mucus and debris from the inserted catheters. Differences of initially recorded intravesical and intrarectal pressures from those after flushing and filling are analyzed and associated with the ICS standard practice of zeroing. RESULTS: Statistically and clinically significant differences between the initial pressures and the pressures after filling and flushing are observed, with nonphysiological initial pressures in 62% of the studies. Some filling (20 ml or more in the bladder) and flushing of the pressure channels resulted in the registration of physiological pressures and synchronous response from both lines on abdominal pressure increases. CONCLUSIONS: The pressure signal quality of a water-filled urodynamic system immediately after catheter insertion is low with inaccurately displayed pressure values, but it changes to normal after flushing the pressure channels and some filling. Rezeroing of the intracorporeal pressures immediately after catheter insertion for cystometry is the inappropriate correction procedure that misleadingly modifies the false initial pressures, resulting in ongoing unrealistic urodynamic study pressures.


Assuntos
Cateteres/normas , Transdutores de Pressão/normas , Transdutores/normas , Doenças da Bexiga Urinária/cirurgia , Urodinâmica/fisiologia , Água/química , Feminino , Humanos , Estudos Retrospectivos , Cateterismo Urinário/métodos
2.
ACS Sens ; 5(2): 303-307, 2020 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-32039587

RESUMO

The detection of thiocyanate (SCN-) is particularly important in industrial effluents and biological fluids because of the toxic nature of SCN-. Herein, a metal-insulator-metal (MIM) resonator for visual detection of SCN- is presented based on a poly[(2-(methacryloyloxy)ethyl) trimethylammonium chloride] (PMETAC) brush. The MIM resonator exhibits obvious color change as the concentration of SCN- changes, which can be easily distinguished by the naked eyes. In addition, the as-prepared MIM resonator also shows the advantages of good anti-interference, excellent reusability, and fast response rate. Combining the above advantages, the proposed MIM resonator may provide a broad perspective for a wide variety of visible-light applications.


Assuntos
Técnicas Biossensoriais/métodos , Tiocianatos/química , Transdutores/normas
3.
Mil Med ; 185(Suppl 1): 19-24, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-32074341

RESUMO

BACKGROUND: Point-of-injury extended focused assessment with sonography in trauma (eFAST) may identify life-threatening torso hemorrhage and expedite casualty evacuation. The purpose of this study was to compare combat medic eFAST performance between the novel and conventional ultrasound (US) transducers. METHODS: We conducted a randomized crossover trial. Medic participants, previously naïve to US, were randomized to the type of transducer first utilized. The primary outcome was eFAST completion time in seconds. Secondary outcomes included diagnostic accuracy, technical adequacy, and transducer ease-of-use rating. RESULTS: Forty medics performed 160 eFASTs. We found a statistically significant difference in eFAST completion times in favor of conventional transducers (304 vs. 358 s; P = 0.03). There was no statistically significant difference between the conventional and novel transducers in terms of diagnostic accuracy (97.7% vs. 96.0%; P = 0.25) and technical adequacy (65% vs. 72.5%; P = 0.11). Median transducer ease-of-use rating (Likert 1-5 scale) was statistically significant in favor of the conventional transducers (5 vs. 4; P = < 0.001). CONCLUSIONS: Extended focused assessment with sonography in trauma exam times was faster with the conventional transducers. Combat medics performed diagnostically accurate eFASTs with both transducer types in a simulated aid station setting after a brief training intervention. Conventional transducers were rated higher for ease-of-use.


Assuntos
Auxiliares de Emergência/normas , Transdutores/classificação , Ultrassonografia/normas , Adulto , Estudos Cross-Over , Auxiliares de Emergência/estatística & dados numéricos , Feminino , Humanos , Masculino , Militares/educação , Estudos Prospectivos , Transdutores/normas , Transdutores/estatística & dados numéricos , Ultrassonografia/métodos , Ultrassonografia/estatística & dados numéricos , Washington
4.
Clin Hemorheol Microcirc ; 74(2): 167-178, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31306115

RESUMO

BACKGROUND AND AIM: To evaluate the benefits of contrast-enhanced ultrasound (CEUS) with high frequency transducers in characterization of focal gallbladder lesions (FGL). MATERIAL AND METHODS: From January 2017 to April 2019, 59 FGL detected by B mode ultrasound (BMUS) were examined, first with the low frequency convex transducer (1-5 MHz) and afterwards with high frequency transducer (7.5-12 MHz). High frequency dynamic CEUS were applied after bolus injection of 4.8 ml Sulphur hexafluoride microbubbles (SonoVue®, Milan). The BMUS and CEUS imaging features were recorded and compared. All lesions were confirmed by surgical resection and histopathologic results. RESULTS: The final diagnoses of 59 FGL included gallbladder adenocarcinoma (n = 15), gallbladder polyps (n = 11), gallbladder adenomas (n = 18), focal adenomyomatosis (n = 9), and gallbladder Ascariasis debris (n = 6). The mean diameter of FGL was 24.5±11.4 mm, and mean depth to the abdominal wall was 21.2±7.3 mm. While applying CEUS with high frequency transducer, specific diagnostic features, including arterial phase irregular intralesional vascularity (10/15, 66.7%), late phase hypoenhancement (12/15, 80%), destruction of gallbladder wall (8/15, 53.3%), infiltration to the adjacent liver (6/15, 40.0%) were significantly higher in malignant FGL. The overall sensitivity, specificity and diagnostic accuracy for the correct characterization of malignant FGL were significantly improved by CEUS with high frequency transducer (sensitivity 93.3%, specificity 88.5%, accuracy 100%). CONCLUSION: With its superior contrast resolution, CEUS performed with high frequency transducers is helpful to achieve better visualization of gallbladder fundus and make differential diagnosis of gallbladder lesions, which might greatly improve diagnostic confidence between malignant and benign FGL.


Assuntos
Meios de Contraste/uso terapêutico , Doenças da Vesícula Biliar/diagnóstico por imagem , Transdutores/normas , Ultrassonografia/métodos , Adulto , Idoso , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
5.
J Acoust Soc Am ; 145(4): 2480, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-31046335

RESUMO

Significant effort has been made over the last few decades to develop automated passive acoustic monitoring (PAM) systems capable of classifying cetaceans at the species level. The utility of such systems depends on the systems' ability to operate across a wide range of ocean acoustic environments; however, anecdotal evidence suggests that site-specific propagation characteristics impact the performance of PAM systems. Variability in propagation characteristics leads to differences in how each cetacean vocalization is altered as it propagates along the source-receiver path. A propagation experiment was conducted in the Gulf of Mexico to investigate the range-dependent impacts of acoustic propagation on the performance of an automated classifier. Modified bowhead and humpback vocalizations were transmitted over ranges from 1 to 10 km. When the classifier was trained with signals collected near the sound source, it was found that the performance decreased with increasing transmission range-this appeared to be largely explained by decreasing signal-to-noise ratio (SNR). Generation of performance matrices showed that one method to develop a classifier that maintains high performance across many ranges is to include a varied assortment of ranges in the training data; however, if the training set is limited, it is best to train on relatively low SNR vocalizations.


Assuntos
Acústica/instrumentação , Baleia Franca/fisiologia , Jubarte/fisiologia , Vocalização Animal , Animais , Razão Sinal-Ruído , Transdutores/normas
6.
Ultrasound Med Biol ; 45(6): 1483-1488, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30967319

RESUMO

Urethane-based test objects are routinely used for ultrasound quality assurance because of their durability and robustness. The acoustic properties of these phantoms including speed of sound and attenuation, however, have a strong dependence on temperature. Reliable measurement of low-contrast penetration, which is widely used for ultrasound system quality assurance testing, with these phantoms is therefore problematic. To alleviate this, a correction method was proposed using speed of sound estimated by measuring filament target separation. The method was developed using a range of 17 transducer geometry and frequency combinations across 5 ultrasound systems and validated using a further 5 systems. This was found to reduce the uncertainty of low-contrast penetration measurement from an average 17.6 mm to 4.9 mm over the temperature range 8°C to 32°C. This represents a greater than threefold improvement in precision of low-contrast penetration measurement.


Assuntos
Imagens de Fantasmas , Temperatura , Transdutores/normas , Ultrassonografia/instrumentação , Ultrassonografia/normas , Uretana , Controle de Qualidade
7.
Am J Emerg Med ; 37(12): 2182-2185, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-30890289

RESUMO

INTRODUCTION: Ultrasound has been increasingly utilized for the identification of endotracheal tube (ETT) location after an intubation attempt, particularly among patients in cardiac arrest. However, prior studies have varied with respect to the choice of transducer and no studies have directly compared the accuracy between transducer types. Our study is the first to directly compare the accuracy of ETT confirmation between the linear and curvilinear transducer. METHODS: This study was performed in a cadaver lab using three different cadavers chosen to represent varying neck circumferences. Cadavers were randomized to tracheal or esophageal intubation. Blinded sonographers assessed the location of the ETT using either a linear or curvilinear transducer in an alternating sequence. Accuracy of sonographer identification, time to identification, and operator confidence were assessed. RESULTS: Four hundred and five assessments were performed with 198 (48.9%) tracheal and 207 (51.1%) esophageal intubations. The linear transducer was 98% (95% CI 95.1% to 99.2%) accurate. The curvilinear transducer was 95% (95% CI 91.1% to 97.3%) accurate. The mean time to identification was significantly lower with the linear transducer [7.46 s (95% CI 6.23 to 8.7 s)] as compared with the curvilinear transducer [11.63 s (95% CI 9.05 to 14.2 s)]. The mean operator confidence was significantly higher with the linear transducer [4.84/5.0 (95% CI 4.76 to 4.91)] than with the curvilinear transducer [4.44/5.0 (95% CI 4.3 to 4.57)]. All operators preferred the linear transducer over the curvilinear transducer. CONCLUSION: The diagnostic accuracy of ultrasound for ETT confirmation did not significantly differ between ultrasound transducer types, but the curvilinear transducer was associated with a longer time to confirmation and lower operator confidence. Further studies are needed to determine if the accuracy would change with more novice providers or in specific patient populations.


Assuntos
Intubação Intratraqueal/métodos , Transdutores/normas , Ultrassonografia/normas , Cadáver , Esôfago/diagnóstico por imagem , Humanos , Intubação Intratraqueal/efeitos adversos , Distribuição Aleatória , Fatores de Tempo , Traqueia/diagnóstico por imagem
8.
Phys Med Biol ; 63(17): 175009, 2018 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-30088807

RESUMO

Propagation of ultrasound through a complex composite sample may exhibit phase interference between two or more sonic-rays if differences in transit time are less than the pulse length. The transit time spectrum of a test sample, equivalent to its impulse response, was derived through active-set deconvolution of ultrasound signals with, and without, the test sample. The aim of this study was to test the hypothesis that in cases where only the transmit ultrasound transducer's digitally-coded excitation signal is available, hence not the input ultrasound signal without the test sample, incorporation of the transducer impulse response may increase both accuracy and precision of ultrasound transit time spectroscopy. A digital 1 MHz sinusoid signal was used to create an ultrasound pulse that was propagated through a 5 step-wedge acrylic sample immersed in water. Transit time spectra were obtained through deconvolution utilising an ultrasound input signal, along with a digital input signal, with and without incorporation of the transducer impulse response. Incorporation of the transducer impulse response reduced a quantitative measure of noise-to-signal ratio by a factor of 12. The paper has demonstrated the potential for increased accuracy and precision of transit time spectroscopy when the transducer impulse response is incorporated within active-set deconvolution analysis.


Assuntos
Análise Espectral/normas , Transdutores/normas , Ultrassonografia/normas , Acrilatos/efeitos da radiação , Razão Sinal-Ruído , Análise Espectral/instrumentação , Tempo , Ondas Ultrassônicas , Ultrassonografia/instrumentação
9.
Phys Med Biol ; 63(12): 125010, 2018 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-29794329

RESUMO

Current clinical ultrasound scanners cannot be used to image the interior morphology of bones because these scanners fail to address the complicated physics involved for exact image reconstruction. Here, we show that if the physics is properly addressed, bone cortex can be imaged using a conventional transducer array and a programmable ultrasound scanner. We provide in vivo proof for this technique by scanning the radius and tibia of two healthy volunteers and comparing the thickness of the radius bone with high-resolution peripheral x-ray computed tomography. Our method assumes a medium that is composed of different homogeneous layers with unique elastic anisotropy and ultrasonic wave-speed values. The applicable values of these layers are found by optimizing image sharpness and intensity over a range of relevant values. In the algorithm of image reconstruction we take wave refraction between the layers into account using a ray-tracing technique. The estimated values of the ultrasonic wave-speed and anisotropy in cortical bone are in agreement with ex vivo studies reported in the literature. These parameters are of interest since they were proposed as biomarkers for cortical bone quality. In this paper we discuss the physics involved with ultrasound imaging of bone and provide an algorithm to successfully image the first segment of cortical bone.


Assuntos
Osso Cortical/diagnóstico por imagem , Ultrassonografia/métodos , Algoritmos , Anisotropia , Densidade Óssea , Humanos , Rádio (Anatomia)/diagnóstico por imagem , Tíbia/diagnóstico por imagem , Transdutores/normas , Ultrassonografia/instrumentação
10.
J Appl Clin Med Phys ; 19(2): 265-274, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29322614

RESUMO

The purpose of the present study was to test an idea of and describe a concept of a novel method of detecting defects related to horizontal nonuniformities in ultrasound equipment. The method is based on the analysis of ultrasound images collected directly from the clinical workflow. In total over 31000 images from three ultrasound scanners from two vendors were collected retrospectively from a database. An algorithm was developed and applied to the images, 150 at a time, for detection of systematic dark regions in the superficial part of the images. The result was compared with electrical measurements (FirstCall) of the transducers, performed at times when the transducers were known to be defective. The algorithm made similar detection of horizontal nonuniformities for images acquired at different time points over long periods of time. The results showed good subjective visual agreement with the available electrical measurements of the defective transducers, indicating a potential use of clinical images for early and automatic detection of defective transducers, as a complement to quality control.


Assuntos
Algoritmos , Processamento de Imagem Assistida por Computador/métodos , Neoplasias/diagnóstico por imagem , Imagens de Fantasmas , Garantia da Qualidade dos Cuidados de Saúde/normas , Transdutores/normas , Ultrassonografia/normas , Desenho de Equipamento , Análise de Falha de Equipamento , Humanos , Controle de Qualidade
11.
Sci Rep ; 7(1): 10969, 2017 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-28887532

RESUMO

The development of sensitive platforms for the detection of biomolecules recognition is an extremely important problem in clinical diagnostics. In microcantilever (MC) transducers, surface-stress is induced upon bimolecular interaction which is translated into MC deflection. This paper presents a cost-effective and ultra-sensitive MC-based biosensing platform. To address these goals, the need for costly high-resolution read-out system has been eliminated by reducing the cantilever compliance through developing a polymer-based cantilever. Furthermore a microfluidic system has been integrated with the MC in order to enhance sensitivity and response time and to reduce analytes consumption. Gold nanoparticles (AuNPs) are synthesized on the surface of suspended microfluidics as the selective layer for biomolecule immobilization. The biosensing results show significant improvement in the sensitivity of the proposed platform compared with available silicon MC biosensor. A detection limit of 2 ng/ml (100pM) is obtained for the detection of bovine growth hormones. The results validated successful application of suspended polymeric microfluidics (SPMF) as the next generation of biosensing platforms which could enable femtomolar (fM) biomolecular recognition detection.


Assuntos
Técnicas Biossensoriais/instrumentação , Hormônio do Crescimento/análise , Microfluídica/instrumentação , Transdutores/normas , Animais , Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/normas , Bovinos , Ouro/química , Nanopartículas Metálicas/química , Microfluídica/métodos , Microfluídica/normas , Sensibilidade e Especificidade
12.
Ultrasound Med Biol ; 43(9): 1930-1937, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28634042

RESUMO

The importance of quality assurance (QA) in medical ultrasound (US) has been widely recognized and recommendations concerning technical QA have been published over the years. However, the demonstrated impact of a properly working QA protocol on clinical routine has been scarce. We investigated the transducer write-off causes for a 5-y period in a multi-unit radiology department with an annual average of 230 transducers in demanding diagnostic use. The transducer faults and the initial observers of the faults leading to transducer write-offs were traced and categorized. The most common cause of transducer write-off was an image uniformity problem or element failure. Mechanical faults or excessive leakage current and defects in the lens constituted smaller yet substantial shares. Our results suggest that a properly working routine QA program can detect majority of the faults before they are reported by users.


Assuntos
Análise de Falha de Equipamento/métodos , Garantia da Qualidade dos Cuidados de Saúde/métodos , Serviço Hospitalar de Radiologia , Transdutores/normas , Ultrassonografia/instrumentação , Ultrassonografia/normas , Análise de Falha de Equipamento/estatística & dados numéricos , Humanos , Estudos Retrospectivos , Transdutores/estatística & dados numéricos
13.
Europace ; 19(10): 1624-1629, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-28340242

RESUMO

Minor surgical procedures are increasingly being performed as outpatient procedures in settings outside hospital operating rooms (ORs). In electrophysiology, the recent miniaturization of insertable cardiac monitors (ICMs) has enabled the routine insertion of the device as a minimally invasive procedure without the need of a catheter OR. However, a shift to office-based environments for minor surgical procedures is associated with some concerns, particularly with respect to patient- and procedure-related safety in the new setting. In the present document, the authors provide practical advice on facilities, practices, and adaptations necessary when performing ICM insertions in office settings, based on available recommendations as well as their own experience with the use of the novel Reveal LINQ ICM. The main differences from in-hospital implant settings are simplified requirements of room, equipment, and insertion procedures, while ensuring and maintaining an adequate, sterile environment. Patient selection is important: certain groups of patients are recommended to be treated in the catheter OR (e.g. those at increased risk for bleeding or very frail elderly individuals). Insertion in alternative positions, as is sometimes performed for cosmetic reasons, should be referred to dedicated hospitals. Quality assurance and internal quality control are critical in the new procedural landscape, and it is important not to trivialize minor surgical procedures. Operators' sharing of experiences and lessons learned, e.g. in the form of registries, should be encouraged.


Assuntos
Assistência Ambulatorial , Procedimentos Cirúrgicos Ambulatórios/instrumentação , Procedimentos Cirúrgicos Cardíacos , Técnicas de Diagnóstico Cardiovascular/instrumentação , Telemetria/instrumentação , Transdutores , Assistência Ambulatorial/organização & administração , Assistência Ambulatorial/normas , Procedimentos Cirúrgicos Ambulatórios/normas , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Procedimentos Cirúrgicos Cardíacos/normas , Tomada de Decisão Clínica , Protocolos Clínicos , Técnicas de Diagnóstico Cardiovascular/normas , Desenho de Equipamento , Humanos , Miniaturização , Segurança do Paciente , Valor Preditivo dos Testes , Controle de Qualidade , Indicadores de Qualidade em Assistência à Saúde , Fatores de Risco , Telemetria/normas , Transdutores/normas
14.
J Electromyogr Kinesiol ; 30: 243-8, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27566005

RESUMO

Quantitative assessment of force in masticatory muscles is not a routine clinical test, probably due to the lack of an "easy-to-use" device. Aim of this study is (1) to present a low cost bite force instrument located in a custom-made housing, designed to guarantee a comfortable and effective bite action, (2) to evaluate its mechanical characteristics, in order to implement it in clinical settings and in experimental setups. Linearity, repeatability and adaptation over time were assessed on a set of four different sensors in bare and housed condition. Application of the housing to the transducer may appreciably alter the transducer's response. Calibration of the housed transducer is thus necessary in order to correctly record real bite force. This solution may represent a low cost and reliable option for biting force measurement and objective assessment of individual force control in the scientific and clinical setting.


Assuntos
Força de Mordida , Eletromiografia/instrumentação , Transdutores/normas , Adulto , Calibragem , Custos e Análise de Custo , Eletromiografia/métodos , Eletromiografia/normas , Feminino , Humanos , Masculino , Músculos da Mastigação/fisiologia , Transdutores/economia
15.
An Bras Dermatol ; 91(3): 262-73, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27438191

RESUMO

Ultrasonography is a method of imaging that classically is used in dermatology to study changes in the hypoderma, as nodules and infectious and inflammatory processes. The introduction of high frequency and resolution equipments enabled the observation of superficial structures, allowing differentiation between skin layers and providing details for the analysis of the skin and its appendages. This paper aims to review the basic principles of high frequency ultrasound and its applications in different areas of dermatology.


Assuntos
Dermatologia/métodos , Pele/diagnóstico por imagem , Ultrassonografia Doppler/métodos , Dermatologia/instrumentação , Humanos , Inflamação/diagnóstico por imagem , Pele/fisiopatologia , Dermatopatias Infecciosas/diagnóstico por imagem , Neoplasias Cutâneas/diagnóstico por imagem , Transdutores/normas , Ultrassonografia Doppler/instrumentação , Ultrassonografia Doppler/tendências
16.
Mov Disord ; 31(9): 1327-36, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27273470

RESUMO

The International Parkinson and Movement Disorder Society established a task force on tremor that reviewed the use of transducer-based measures in the quantification and characterization of tremor. Studies of accelerometry, electromyography, activity monitoring, gyroscopy, digitizing tablet-based measures, vocal acoustic analysis, and several other transducer-based methods were identified by searching PubMed.gov. The availability, use, acceptability, reliability, validity, and responsiveness were reviewed for each measure using the following criteria: (1) used in the assessment of tremor; (2) used in published studies by people other than the developers; and (3) adequate clinimetric testing. Accelerometry, gyroscopy, electromyography, and digitizing tablet-based measures fulfilled all three criteria. Compared to rating scales, transducers are far more sensitive to changes in tremor amplitude and frequency, but they do not appear to be more capable of detecting a change that exceeds random variability in tremor amplitude (minimum detectable change). The use of transducer-based measures requires careful attention to their limitations and validity in a particular clinical or research setting. © 2016 International Parkinson and Movement Disorder Society.


Assuntos
Técnicas e Procedimentos Diagnósticos/normas , Transdutores/normas , Tremor/diagnóstico , Humanos
17.
An. bras. dermatol ; 91(3): 262-273, tab, graf
Artigo em Inglês | LILACS | ID: lil-787290

RESUMO

Abstract: Ultrasonography is a method of imaging that classically is used in dermatology to study changes in the hypoderma, as nodules and infectious and inflammatory processes. The introduction of high frequency and resolution equipments enabled the observation of superficial structures, allowing differentiation between skin layers and providing details for the analysis of the skin and its appendages. This paper aims to review the basic principles of high frequency ultrasound and its applications in different areas of dermatology.


Assuntos
Humanos , Pele/diagnóstico por imagem , Ultrassonografia Doppler/métodos , Dermatologia/métodos , Pele/fisiopatologia , Dermatopatias Infecciosas/diagnóstico por imagem , Neoplasias Cutâneas/diagnóstico por imagem , Transdutores/normas , Ultrassonografia Doppler/instrumentação , Ultrassonografia Doppler/tendências , Dermatologia/instrumentação , Inflamação/diagnóstico por imagem
18.
J Magn Reson Imaging ; 44(5): 1354-1359, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27115311

RESUMO

PURPOSE: To date, few studies have validated the Prostate Imaging Reporting and Data System Version 2 (PI-RADS v. 2) for the diagnosis of prostate cancer. Our aim was to validate PI-RADS v.2 using 3 Tesla (T) MRI. MATERIALS AND METHODS: This is a retrospective study of 54 consecutive patients who underwent 3T MRI with a body-array coil for diagnostic confirmation of prostate cancer or cancer staging between June 2013 and June 2015. Sensitivity, specificity, and agreement were calculated based on a criterion of PI-RADS score = 3. Inter-examiner agreement was determined by the weighted kappa statistic. RESULTS: Histological findings were positive for cancer in 33 patients and negative in 21 patients. Considering a PI-RADS score of 3 as positive for cancer, the accuracy of each reader was 85.20% and 70.40%, respectively, and agreement coefficients were κ = 0.69 and κ = 0.35. Considering PI-RADS 3 as absence of cancer, the accuracy of each reader was 77.80% and 77.80%, respectively, and agreement was κ = 0.55 and κ = 0.54. Inter-reader agreement was moderate/good (weighted κ = 0.53; 95% confidence interval: 0.39-0.66; P = 0.038). CONCLUSION: High accuracy was obtained for the diagnosis of prostate cancer using 3T MRI with a body coil and the PI-RADS v.2 score. J. Magn. Reson. Imaging 2016;44:1354-1359.


Assuntos
Interpretação de Imagem Assistida por Computador/normas , Imageamento por Ressonância Magnética/instrumentação , Imageamento por Ressonância Magnética/normas , Guias de Prática Clínica como Assunto , Neoplasias da Próstata/diagnóstico por imagem , Sistemas de Informação em Radiologia/normas , Transdutores/normas , Idoso , Idoso de 80 Anos ou mais , Desenho de Equipamento , Humanos , Interpretação de Imagem Assistida por Computador/instrumentação , Internacionalidade , Masculino , Pessoa de Meia-Idade , Neoplasias da Próstata/patologia , Doses de Radiação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
19.
Clinics (Sao Paulo) ; 71(3): 140-4, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27074174

RESUMO

OBJECTIVE: The assessment of fracture union includes physical examination and radiographic imaging, which depend on the examiner's experience. The development of ancillary methods may avoid prolonged treatments and the improper removal of implants. Quantitative bone ultrasonometry has been studied for this purpose and will soon be included in clinical practice. The aims of the present study were to assess the feasibility of using this technique on the clavicle and to standardize its in vivo application. METHODS: Twenty adult volunteers, including 10 men and 10 women without medical conditions or a previous history of clavicle fracture, underwent axial quantitative ultrasonometric assessment using transducers in various positions (different distances between the transducers and different angulations relative to the clavicle). RESULTS: Similar values of wave propagation velocity were obtained in the different tested set-ups, which included distinct distances between the transducers and angular positions relative to the clavicle. There were significant differences only in the transducers positioned at 0° and at 5 or 7 cm apart. CONCLUSIONS: The use of bone ultrasonometry on the clavicle is feasible and the standardization of the technique proposed in this study (transducers placed at 45° and at 7 cm apart) will allow its future application in clinical trials to evaluate the healing process of diaphyseal fractures of the clavicle.


Assuntos
Clavícula/diagnóstico por imagem , Adulto , Osso e Ossos/diagnóstico por imagem , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Padrões de Referência , Transdutores/normas , Ondas Ultrassônicas , Ultrassonografia
20.
Ultraschall Med ; 37(2): 137-9, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27058433

RESUMO

Vaginal ultrasound probes are semi-critical Group A medical products which must be disinfected following the manufacturer's instructions after every patient examination. According to the "Essential Requirements for Medical Devices (Directive 93/42/EEC, Annex I, paragraph 13)" the manufacturer's instructions for use for reusable products must contain suitable instructions for preparation processes. This presumes both an effective and material-compatible method. Evidence of effectiveness must be validated.In the Editorial in issue 1 Ultraschall in der Medizin/European Journal of Ultrasound 2005 we discussed the topic of transducer hygiene and stated that proper handling and cleaning as well as disinfection of probes in daily use are indispensable. This applies particularly to vaginal ultrasound probes routinely used in gynecological and obstetrical clinics, gynecological practices as well as IVF centers Normally the probe used in a transvaginal ultrasound examination is covered with a latex protective cover (with CE marking) which contains a certain amount of ultrasound gel. After the examination, the cover is removed and disposed of, and the gel is removed from the transducer. Since handling of the probe, ultrasound gel and cover can result in smear infections and cross-contamination with various pathogens (e. g. MRSA, HBV, HCV, HIV, herpes papilloma and cytomegalic viruses), after the protective cover is removed, the probe must be cleaned and subjected to disinfection with a bactericidal, fungicidal and virucidal effect. This is especially important in the event the cover ruptures during the vaginal examination, and the probe comes into direct contact with vaginal secretions or blood. The same likewise applies if the sterile protective cover is perforated during a follicular puncture. Usually special bactericidal, levurocidal and virucidal wipes or special submersion disinfection methods are available for disinfecting the vaginal ultrasound probes 11. Using special virucidal wipes on the probes is considered low-level disinfection. Primarily quaternary ammonia compounds are employed for this procedure. This method is easily applicable, has good cleaning characteristics, is effective against HPV and has high skin tolerance. However, it has the disadvantage of not removing all microorganisms during the disinfection process. Immersion procedures are high-level disinfection methods during which the transducer head is dipped in a special fluid for a certain amount of time. The disinfectants used for this include e. g. preparations based on glutaraldehyde or succinic aldehyde. However, in practice immersion disinfection has a number of disadvantages 13: 1. The procedure cannot be validated. 2. The probe permanently attached to the device must be placed in a separate holder and disinfected for at least 15 minutes. This is impracticable in routine operations in a clinic, outpatient facility or practice with a high number of examinations. 3. After this disinfection method, the probe has to be thoroughly rinsed with potable or higher-quality water in order to remove remnants of allergenic or locally toxic substances. 4. Frequently examinations take place in small interior areas with poor ventilation, thus under some circumstances posing an inhalant-related health hazard. 5. The required virucidal effect is frequently not achieved within 15 minutes 13. Furthermore, extended probe contact with liquid disinfecting agents in the long run results in increased wear of the transducer head membrane.Therefore it was interesting to note that in 2009 a fully-automatic disinfection system for ultrasound probes was introduced to the market (Trophon(EPR). This product, developed in Australia, promised relatively rapid high-level disinfection (HLD). During this software-controlled, mechanical disinfection procedure, the entire ultrasound probe (transducer head and handle) is placed in a sealed disinfection chamber, then hydrogen peroxide (H2O2) is discharged as an anti-microbial aerosol into the closed chamber.  The ultra-fine mist wets the entire surface of the probe with H2O2, thereby achieving high-level disinfection of the entire ultrasound probe. At the end of the process, a catalytic decomposition system breaks down the H2O2 into environmentally-friendly oxygen and water. When the chamber is opened, the probe is dry and ready for immediate use. The fully-automatic device was designed as a table unit to be placed directly next to the ultrasound equipment so that the probe does not need to be disconnected from the base unit. The entire disinfection process lasts 7 minutes: 2 minutes for the application and 5 minutes to remove the aerosol residue. In a validation study using carrier tests, Heeg and Gauer in 2014 showed that this procedure genuinely achieved HLD of ultrasound probes within 7 minutes, thus making it suitable for daily clinical routine. The procedure fulfills all requirements for HLD based on the medical device classification according to the legally-prescribed recommendation of the Commission for Hospital Hygiene and Prevention of Infection and the Federal Institute for Drugs and Medical Products (KRINKO/BfArM) in Germany. In the USA, this method was approved by the FDA as well as the leading probe manufacturers, and bears the testing certificate of the German Society for Hospital Hygiene (DGKH).All in all, it should be stated that the sole use of a latex protective cover when using a vaginal probe does not meet the necessary standard of care required for the provision of semi-critical medical products according to the joint recommendation of the German Federal Institute for Drugs and Medical Products (BfArM) and Commission for Hospital Hygiene and Prevention of Infection of the Robert Koch Institute, and constitutes a contravention of necessary patient and user protections. Use of the protective cover does not rule out smear infections and cross-contamination; therefore after each examination, the probe, after removal of the cover, must undergo disinfection measures providing bactericidal, fungicidal and virucidal effects. Since the transducer handle also poses a significant risk of transmission of germs, this component must likewise be sufficiently disinfected. In the event of perforation or rupture of the latex cover, thus resulting in the probe coming into contact with vaginal secretions or blood, the probe must be not only cleaned, but effectively disinfected with a virucide as well. It should also be noted that infection by bacteria and viruses can be caused not only by a contaminated probe, but by the ultrasound gel as well. According to studies by Heeg and Gauer 15, Buescher et al. as well as Ryndock et al., the fully automatic HLD system operated with hydrogen peroxide is currently the only validated system proven to provide HLD of ultrasound probes in a 7-minute cycle, thus suitable for application in the daily routine. Likewise it can also be presumed that this procedure also offers good material compatibility.


Assuntos
Desinfecção/instrumentação , Desinfecção/normas , Endossonografia/instrumentação , Endossonografia/normas , Reutilização de Equipamento/normas , Transdutores/normas , Ultrassonografia Pré-Natal/instrumentação , Ultrassonografia Pré-Natal/normas , Vagina/diagnóstico por imagem , Desenho de Equipamento , Feminino , Humanos
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