Felipe Wilker Grillo

Universidade de São Paulo

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Antônio Adilton Oliveira Carneiro

Universidade de São Paulo

Theo Z. Pavan

Universidade de São Paulo

Diego R. T. Sampaio

Universidade de Ribeirão Preto

Alexandre Colello Bruno

Clinics Hospital of Ribeirão Preto

Luciana C. Cabrelli

Universidade de São Paulo

Hélio Rubens Machado

Universidade de São Paulo

Carlo Rondinoni

Universidade de São Paulo

Jorge Elías

Universidade de São Paulo

Luiz Otávio Murta

Universidade de São Paulo

Mehran Azimbagirad

Université de Bretagne Occidentale

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Universidade de São Paulo

Universidade de Ribeirão Preto

Clinics Hospital of Ribeirão Preto

Hospital Universitário da Universidade de São Paulo

Universidade Brasil

Universidade Federal de Juiz de Fora

SUPERA Park of Innovation and Technology of Ribeirão Preto

Instituto de Filosofía

Universidade Federal do Paraná

Universidade Estadual Paulista (Unesp)

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CHARACTERIZATION OF TISSUE-MIMICKING MATERIALS USING MAGNETIC INDUCED SHEAR WAVE

Diego R. T. Sampaio Alexandre Colello Bruno Felipe Wilker Grillo Theo Z. Pavan Antônio Adilton Oliveira Carneiro

Estimation of the tissues mechanical properties of is an important information to the pathologies diagnosis. A novel ultrasound-based methods use shear wave dispersion for this purpose. This paper describes the Magneto Motive Ultrasound (MMUs) implementation to evaluate mechanical parameters of paraffin phantoms. This technique can be applied in vivo as an alternative to biopsy. Ultrasound equipment was used with a magnetic system for generating seismic waves in paraffin phantom containing a magnetic inclusion. Consistent values of elastic and viscous modulus (μ1 = 8.4 ± 1.5 kPa; μ2 = 5.3 ± 2.2 Pa.s) were obtained. The evaluation of MMUs technique for estimating mechanical parameters of soft tissue was satisfactory, but for stiffer inclusions higher temporal resolution is needed.

Shear modulus

Shear waves

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Patient-specific neurosurgical phantom: assessment of visual quality, accuracy, and scaling effects

3D Printing in Medicine (2018)

Felipe Wilker Grillo Victor H. Souza Renan H. Matsuda Carlo Rondinoni Theo Z. Pavan

Training in medical education depends on the availability of standardized materials that can reliably mimic the human anatomy and physiology. One alternative to using cadavers or animal bodies is to employ phantoms or mimicking devices. Styrene-ethylene/butylene-styrene (SEBS) gels are biologically inert and present tunable properties, including mechanical properties that resemble the soft tissue. Therefore, SEBS is an alternative to develop a patient-specific phantom, that provides real visual and morphological experience during simulation-based neurosurgical training.A 3D model was reconstructed and printed based on patient-specific magnetic resonance images. The fused deposition of polyactic acid (PLA) filament and selective laser sintering of polyamid were used for 3D printing. Silicone and SEBS materials were employed to mimic soft tissues. A neuronavigation protocol was performed on the 3D-printed models scaled to three different sizes, 100%, 50%, and 25% of the original dimensions. A neurosurgery team (17 individuals) evaluated the phantom realism as "very good" and "perfect" in 49% and 31% of the cases, respectively, and rated phantom utility as "very good" and "perfect" in 61% and 32% of the cases, respectively. Models in original size (100%) and scaled to 50% provided a quantitative and realistic visual analysis of the patient's cortical anatomy without distortion. However, reduction to one quarter of the original size (25%) hindered visualization of surface details and identification of anatomical landmarks.A patient-specific phantom was developed with anatomically and spatially accurate shapes, that can be used as an alternative for surgical planning. Printed models scaled to sizes that avoided quality loss might save time and reduce medical training costs.

10.1186/s41205-018-0025-8

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Citations (36)

Acoustic and Elastic Properties of Glycerol in Oil-Based Gel Phantoms

Ultrasound in Medicine & Biology (2017)

Luciana C. Cabrelli Felipe Wilker Grillo Diego R. T. Sampaio Antônio Adilton Oliveira Carneiro Theo Z. Pavan

Acoustic attenuation

Speed of Sound

Mineral oil

10.1016/j.ultrasmedbio.2017.05.010

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Citations (45)

Relationship between lymphedema after breast cancer treatment and biophysical characteristics of the affected tissue

PLoS ONE (2022)

Carla Silva Perez Carolina Mestriner Leticia T. N. Ribeiro Felipe Wilker Grillo Tenysson Will de Lemos

The treatment of breast cancer is often complicated by lymphedema of the upper limbs. Standard lymphedema evaluation methodologies are not able to measure tissue fibrosis. The ultrasound aspects related to tissue microstructures of lymphedema are neglected in clinical evaluations. The objective of this study was to identify and measure the degree of impairment, topography, and biophysical alterations of subcutaneous lymphedema tissue secondary to the treatment of breast cancer by ultrasonography. Forty-two women at a mean age of 58 (±9.7) years, with unilateral lymphedema due to breast cancer treatment, were evaluated. The upper limbs were divided into affected (affected by lymphedema) and control (contralateral limb). Each limb was subdivided into seven areas, defined by perimetry, evaluated in pairs. The biophysical characteristics thickness, entropy, and echogenicity were evaluated by ultrasonography. The results showed a significant difference in the echogenicity and thickness variables between the affected and unaffected upper limb, in all the extent of the upper limb, while entropy showed no significant difference. The findings indicate that the data presented were consistent both in identifying and measuring the degree of impairment and biophysical changes in the subcutaneous tissue of lymphedema secondary to the treatment of breast cancer.

Echogenicity

Secondary lymphedema

Vascularity

10.1371/journal.pone.0264160

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MAGNETOMOTIVE ULTRASOUND ELASTOGRAPHY: PRELIMINARY EVALUATION IN PHANTOM

Alexandre Colello Bruno Felipe Wilker Grillo Diego R. T. Sampaio Theo Z. Pavan Jason R. Cook

Colorectal cancer (CRC) is the third most common malignant neoplasm worldwide and early diagnosis reduces morbidity. The standard preventive exams methods are uncomfortable for the patient, invasive, and /or are ionizing. Here, we evaluate the potential of magneto-motive ultrasound (MMUS) as a new, minimally invasive CRC screening technique. We developed a hybrid transducer (comprised of an ultrasound probe and a magnetic coil system) to construct relative elastography maps in a paraffin phantom with isoechoic inclusions. The electromagnetic component of our system manipulated ferromagnetic fluid located inside of our synthetic colon, and the captured ultrasound images were used to produce relative elastography maps. The MMUS images reveal by otherwise invisible structures based on differences in stiffness. Ultrasound elastography (relative) images by MMUs technique complements usual preventive CRC exams, is minimally invasive, has relative low cost when compared with others image methods. Also is fast diagnose and more comfortable for patient which prevents withdrawal of the screening.

Ultrasound Elastography

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3D automated breast ultrasound imaging: equipment and image reconstruction

Research on Biomedical Engineering (2021)

Vivian A. S. Luccas Mehran Azimbagirad Luciana C. Cabrelli Felipe Wilker Grillo Theo Z. Pavan

Breast ultrasound

3D ultrasound

10.1007/s42600-021-00159-y

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Influence of attenuation on three-dimensional power Doppler indices and STIC volumetric pulsatility index: a flow phantom experiment

Ultrasound in Obstetrics and Gynecology (2013)

A. H. Miyague Theo Z. Pavan Felipe Wilker Grillo D. M. Teixeira C.O. Nastri

Three-dimensional (3D) power Doppler indices (vascularization index (VI), flow index (FI) and vascularization flow index (VFI)) have been shown to correlate with flow and vascularity1; however, these indices are highly susceptible to machine settings and attenuation2. In this study, we sought to verify whether the volumetric pulsatility index (vPI) based on spatiotemporal image correlation (STIC) power Doppler3 is less dependent on attenuation than the original 3D power Doppler indices obtained from both static 3D and STIC datasets by evaluating a flow phantom. The study model is the same as that described in a previous publication4; essentially, it comprises a flow phantom in which a blood-mimicking fluid flows through a silicon tube, powered by an electric pulsatile pump (Figure 1). We inserted one of two different attenuation blocks, made from the same substances used in the flow phantom structure, each measuring 10 mm in thickness, between the ultrasound probe and the flow phantom5. These blocks had different concentrations of glass beads (1.8% and 4.4%) and therefore different coefficients of attenuation: 0.6 dB/MHz/cm ('low attenuation' experiment) and 1.0 dB/MHz/cm ('high attenuation' experiment). The preset 'gynecologic' was used and the following machine settings were maintained for all acquisitions: depth, 4.2 cm; power, 100%; gain, 0.0; WMF, mid1; PRF, 3.2 KHz; frequency, mid; flow resolution, mid1; balance G, 200; smooth (rise/fall), 2/2; ensemble, 12; line density, 7; PD Map, 5; gently color, on; artifact suppression, on; line filter, 2; scanning angle, 30°. Static 3D acquisitions were made using the quality setting 'max'. STIC acquisitions were made with a time setting of 15 s. Spherical samples with arbitrary volumes of 0.38 cm3 (diameter, 9 mm which is greater than the internal diameter of the silicon tube) were assessed with Virtual Organ Computer-aided AnaLysis. Each STIC dataset contained 40 static datasets ('frames') which were sequentially analyzed, using the lowest VFI value as the first 'frame' when constructing graphs of the curves of VFI values through one cardiac cycle; the other frames were ordered consecutively following the order observed in the STIC dataset. The analysis of each static 3D dataset resulted in 10 VFI values for each of the two models. A total of 10 STIC and 10 static 3D datasets were acquired for each experiment. The VFI values observed in static 3D and STIC datasets were higher when the lower attenuation phantom block was inserted between the probe and the flow phantom (Table 1, Figure 2). The vPI values were not significantly different when comparing the two experiments (Table 1). Although our study has some limitations, we have confirmed that the quantification of VFI using either STIC or static 3D datasets is influenced by attenuation as the interposition of the higher attenuation block decreased the VFI values. On the other hand, our results demonstrate that vPI is less dependent on attenuation than the original 3D power Doppler indices as no significant difference was observed between the two experiments. Financial support for this research was provided by: Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Brazil; Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Brazil; Hospital das Clínicas de Ribeirão Preto, Brazil; Universidade de São Paulo (USP), Brasil; Escola de Ultrasonografia e Reciclagem Médica Ribeirão Preto (EURP), Brazil. A. H. Miyague†‡, T. Z. Pavan§, F. W. Grillo§, D. M. Teixeira†, C. O. Nastri†‡ and W. P. Martins*†‡ †Department of Obstetrics and Gynecology, Medical School of Ribeirao Preto, University of Sao Paulo (FMRP-USP), Ribeirao Preto, Brazil; ‡Department of Ultrasonography and Retraining, Medical School of Ribeirao Preto (EURP), Ribeirao Preto, Brazil; §Department of Physics, School of Philosophy, Sciences and Letters of Ribeirao Preto, University of Sao Paulo (FFCLRP-USP), Ribeirao Preto, Brazil *Correspondence. (e-mail: [email protected])

Pulsatile flow

10.1002/uog.12558

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Citations (18)

A magneto-motive ultrasound platform designed for pre-clinical and clinical applications

Figshare (2018)

Diego R. T. Sampaio Felipe Wilker Grillo Alexandre Colello Bruno Theo Z. Pavan Antônio Adilton Oliveira Carneiro

Abstract Introduction Magneto-motive ultrasound (MMUS) combines magnetism and ultrasound (US) to detect magnetic nanoparticles in soft tissues. One type of MMUS called shear-wave dispersion magneto-motive ultrasound (SDMMUS) analyzes magnetically induced shear waves (SW) to quantify the elasticity and viscosity of the medium. The lack of an established presets or protocols for pre-clinical and clinical studies currently limits the use of MMUS techniques in the clinical setting. Methods This paper proposes a platform to acquire, process, and analyze MMUS and SDMMUS data integrated with a clinical ultrasound equipment. For this purpose, we developed an easy-to-use graphical user interface, written in C++/Qt4, to create an MMUS pulse sequence and collect the ultrasonic data. We designed a graphic interface written in MATLAB to process, display, and analyze the MMUS images. To exemplify how useful the platform is, we conducted two experiments, namely (i) MMUS imaging to detect magnetic particles in the stomach of a rat, and (ii) SDMMUS to estimate the viscoelasticity of a tissue-mimicking phantom containing a spherical target of ferrite. Results The developed software proved to be an easy-to-use platform to automate the acquisition of MMUS/SDMMUS data and image processing. In an in vivo experiment, the MMUS technique detected an area of 6.32 ± 1.32 mm2 where magnetic particles were heterogeneously distributed in the stomach of the rat. The SDMMUS method gave elasticity and viscosity values of 5.05 ± 0.18 kPa and 2.01 ± 0.09 Pa.s, respectively, for a tissue-mimicking phantom. Conclusion Implementation of an MMUS platform with addressed presets and protocols provides a step toward the clinical implementation of MMUS imaging equipment. This platform may help to localize magnetic particles and quantify the elasticity and viscosity of soft tissues, paving a way for its use in pre-clinical and clinical studies.

Magneto

10.6084/m9.figshare.7513790

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Técnica ultrassônica para investigar a hidrocefalia neonatal.

Revista Brasileira de Física Médica (2015)

Vivian Ayres de Souza Luccas Diego R. T. Sampaio Felipe Wilker Grillo Jorge Elías Luíza da Silva Lopes

A hidrocefalia e uma doenca congenita com frequente incidencia em recem-nascidos. O diagnostico e obtido atraves de ultrassonografia convencional (modo-B), utilizando as imagens obtidas para medir as dimensoes das estruturas encefalicas. Estudos preliminares em phantoms, mostraram o uso da elastografia por ultrassom para diferenciar os casos obstrutivo e nao-obstrutivo da doenca. Embora o modo-B venha sendo utilizado para diagnosticar hidrocefalia, nao ha um protocolo que utilize a elastografia para classificar e aprimorar o diagnostico de hidrocefalia. Neste trabalho, apresentamos o desenvolvimento de um protocolo para avaliar a hidrocefalia, utilizando modo-B e elastografia. Primeiramente foi avaliado um phantom com caracteristicas fisicas equivalentes ao tecido cerebral com uma cavidade interna simulando a regiao ventricular. Em seguida, aferimos encefalos post-mortem de ratos saudaveis e hidrocefalicos. A medida da taxa de deformacao relativa entre a regiao do ventriculo e a regiao subjacente e sensivel ao tipo de hidrocefalia, i.e. obstrutiva e nao-obstrutiva. Alem disso, a segmentacao das imagens de ultrassom e a sua reconstrucao 3D, permitiram a obtencao do volume de liquido intraventricular de roedores.

10.29384/rbfm.2015.v9.n3.p15-18

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Glycerol in oil-based phantom with improved performance for photoacoustic imaging

2017 IEEE International Ultrasonics Symposium (IUS) (2017)

Felipe Wilker Grillo Luciana C. Cabrelli Diego R. T. Sampaio Antônio Adilton Oliveira Carneiro Theo Z. Pavan

Photoacoustic imaging is a hybrid imaging modality where ultrasound signal is generated when laser pulses are absorbed by tissue. Tissue-mimicking phantom is a useful tool to characterizing new imaging methods. However, there is still a lack of development of phantoms applied to hybrid modalities such as photoacoustics. SEBS gel is a translucent material and present acoustic and elastic properties similar to tissue. Recently, we proposed using glycerol dispersion to further tune the acoustic properties of the phantom. Chromophores can be added to tune optical absorption, while additives such as intralipid and TiO ₂ can be incorporated to tune optical scattering. Most additives used to tune optical properties of phantoms are hydrophilic; therefore, not soluble in mineral oil and SEBS molten gel. To overcome this limitation, in this study we propose using the glycerol dispersion technique to incorporate hydrophilic additives to the phantom. Therefore, the influence of adding glycerol on the acoustic, mechanical and optical properties of SEBS gel was evaluated. We also evaluated the viability of using this material as phantoms for photoacoustic imaging. SEBS/glycerol gel was prepared using 10% w/w of polymer SEBS in mineral oil and glycerol was added in a fraction of 15% of the oil mass. The material's speed of sound; acoustic attenuation and Young's modulus were assessed. We prepared two phantoms of SEBS/glycerol gel, with TiO ₂ as optical scatterer, containing cylindrical inclusions with India ink and methylene blue as optical absorbers. Photoacoustic spectroscopy had a peak between 680-690 nm for the methylene blue inclusion; for the India ink case a flat PA signal magnitude in the range of 680-950 nm was obtained. In both cases, the PA spectroscopy was consistent with the absorption spectra. Finally, we observed that the strategy of mixing the chromofores with glycerol prevented them to diffuse to the background material.

Acoustic attenuation

10.1109/ultsym.2017.8092278

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Citations (9)