Simple Microcontact Printing Technique to Obtain Cell Patterns by Lithography Using Grayscale, Photopolymer Flexographic Mold, and PDMS.

Microcontact printing using PDMS embossing tools and its variations have aroused the interest of a wide spectrum of research fields, hence the feasibility of defining micro and nanoscale patterns. In this work, we have proposed and demonstrated a novel lithography method based on grayscale patterns printed in a flexographic photopolymer mold and transferred to epoxy resin and a single PDMS stamp to obtain different microprint pattern structures. The geometry of the patterns can be modified by adjusting the layout and grayscale of the stamp patterns. The functionality of this contact printing methodology was validated by generating human induced pluripotent stem cells (hiPSC) patterns. These specific micropatterns can be very useful for achieving complex differentiation in cell lines such as hiPSC. Microfabrication through the new technique provides a promising alternative to conventional lithography for constructing complex aligned surfaces; these structures could be used as components of biological patterns or microfluidic devices.

Grayscale, subjective color Doppler, combined grayscale with subjective color Doppler in predicting thyroid carcinoma: a retrospective analysis / Escala de cinza, doppler colorido subjetivo, combinação de escala de cinza com doppler colorido subjetivo na previsão de carcinoma da tireoide: uma análise retrospectiva

Abstract Introduction: Fine needle aspiration cytology is preferred for thyroid nodules preoperatively, but has disadvantages of false-negative and false-positive results. Objective: To compare the diagnostic performance of grayscale ultrasound, subjective color Doppler ultrasound, and combined features of grayscale ultrasound and subjective color Doppler ultrasound in predicting thyroid carcinoma, using results of the fine needle aspiration cytology as the reference standard. Methods: Data from gray-scale ultrasound images, subjective color Doppler ultrasound images, and the fine needle aspiration cytology of 325 nodules of 250 patients (age ≥ 18 years) were collected and analyzed. Hypo-echogenicity than adjacent strap muscle, micro-lobulated or irregular margins, micro- or mixed calcifications, and taller-than-wide shapes were considered as a suspicious malignant nodule in grayscale ultrasound. Marked vascularity was considered as a suspicious malignant nodule in color Doppler ultrasound. The Bethesda system for classification of thyroid nodules was used for cytopathology. Results: With respect to the results of fine-needle aspiration cytology for detecting suspicious malignant nodules, for grayscale ultrasound, subjective color Doppler ultrasound, and combined gray-scale with subjective color Doppler ultrasound, sensitivities were 0.564, 0.600 and 0.691, respectively and accuracies were 0.926, 0.919 and 0.959, respectively. Suspicious malignant nodules detectability for grayscale ultrasound, subjective color Doppler ultrasound, and combined gray-scale with subjective color Doppler ultrasound were 0.09-0.56 diagnostic confidence, 0.08-0.61 diagnostic confidence, and 0.063-0.7 diagnostic confidence, respectively. Conclusion: The combined gray-scale with subjective color Doppler ultrasound-guided fine-needle aspiration biopsies are recommended for the diagnosis of thyroid carcinoma. Level of Evidence: III.

Resumo Introdução: A citologia da punção aspirativa com agulha fina é preferida para nódulos tireoidianos no pré-operatório, mas apresenta desvantagens de resultados falso-negativos e falso-positivos. Objetivo: Comparar o desempenho diagnóstico da ultrassonografia em escala de cinza, do doppler colorido subjetivo e da combinação dos recursos da ultrassonografia em escala de cinza e do doppler colorido subjetivo na previsão do carcinoma da tireoide com os resultados da citologia da punção aspirativa com agulha fina como padrão de referência. Método: Dados de imagens de ultrassonografia em escala de cinza, imagens subjetivas da ultrassonografia com doppler colorido e citologia da punção aspirativa com agulha fina de 325 nódulos de 250 pacientes (idade ≥ 18 anos) foram coletados e analisados. A hipoecogenicidade da musculatura adjacente, as margens microlobuladas ou irregulares, as microcalcificações ou calcificações mistas e os formatos mais altos do que largos foram considerados como um nódulo maligno suspeito na ultrassonografia em escala de cinza. A vascularização acentuada foi considerada um nódulo maligno suspeito na ultrassonografia com doppler colorido. O sistema Bethesda para classificação de nódulos tireoidianos foi usado para a citopatologia. Resultados: Com relação aos resultados da citologia por punção aspirativa com agulha fina para detecção de nódulos malignos suspeitos, as sensibilidades foram de 0,564, 0,600 e 0,691 para a ultrassonografia em escala de cinza, ultrassonografia com doppler colorido subjetivo e escala de cinza combinada com ultrassonografia com doppler colorido subjetivo, respectivamente, e as acurácias foram 0,926, 0,919 e 0,959, respectivamente. A detectabilidade de nódulos suspeitos malignos para ultrassonografia em escala de cinza, ultrassonografia com doppler colorido subjetivo e escala de cinza combinada com ultrassonografia com doppler colorido subjetivo foram de 0,09-0,56, 0,08-0,61 e 0,063-0,7 de confiança diagnóstica, respectivamente. Conclusões: A ultrassonografia em escala de cinza combinada com o doppler colorido subjetivo e biópsias por punção aspirativa com agulha fina guiadas por ultrassonografia são recomendados para o diagnóstico de carcinoma da tireoide. Nível de evidência: III.

Grayscale, subjective color Doppler, combined grayscale with subjective color Doppler in predicting thyroid carcinoma: a retrospective analysis.

INTRODUCTION: Fine needle aspiration cytology is preferred for thyroid nodules preoperatively, but has disadvantages of false-negative and false-positive results. OBJECTIVE: To compare the diagnostic performance of grayscale ultrasound, subjective color Doppler ultrasound, and combined features of grayscale ultrasound and subjective color Doppler ultrasound in predicting thyroid carcinoma, using results of the fine needle aspiration cytology as the reference standard. METHODS: Data from gray-scale ultrasound images, subjective color Doppler ultrasound images, and the fine needle aspiration cytology of 325 nodules of 250 patients (age ≥ 18 years) were collected and analyzed. Hypo-echogenicity than adjacent strap muscle, micro-lobulated or irregular margins, micro- or mixed calcifications, and taller-than-wide shapes were considered as a suspicious malignant nodule in grayscale ultrasound. Marked vascularity was considered as a suspicious malignant nodule in color Doppler ultrasound. The Bethesda system for classification of thyroid nodules was used for cytopathology. RESULTS: With respect to the results of fine-needle aspiration cytology for detecting suspicious malignant nodules, for grayscale ultrasound, subjective color Doppler ultrasound, and combined gray-scale with subjective color Doppler ultrasound, sensitivities were 0.564, 0.600 and 0.691, respectively and accuracies were 0.926, 0.919 and 0.959, respectively. Suspicious malignant nodules detectability for grayscale ultrasound, subjective color Doppler ultrasound, and combined gray-scale with subjective color Doppler ultrasound were 0.09-0.56 diagnostic confidence, 0.08-0.61 diagnostic confidence, and 0.063-0.7 diagnostic confidence, respectively. CONCLUSIONS: The combined gray-scale with subjective color Doppler ultrasound-guided fine-needle aspiration biopsies are recommended for the diagnosis of thyroid carcinoma. LEVEL OF EVIDENCE: III.

Extraction of navigation line based on improved grayscale factor in corn field / Obtenção de linhas de tráfego em lavoura de milho baseada no fator de escala de cinza melhorado

Focusing on the problem that corn plant in different growth periods is grayed out by known methods, the gray scale difference of different part is large or the soil discrimination degree is not high, the navigation path is low in accuracy and speed. This paper proposed a new method for extracting cornfield navigation baselines, which is used to control walking of agricultural robots. Design method included image segmentation, navigation point extraction, and navigation path fitting. Image segmentation is based on a new grayscale factor combined with median filtering, OSTU method and morphological operations to achieve the separation of crops and soil. The extraction of the navigation point is based on the binary image vertical projection map to obtain the region of interest, and the navigation point coordinates are determined by calculating the relative center point of the white pixel points of the sampling line in the region of interest. The Hough transform is used to fit the navigation point obtained by the vertical projection map to determine the navigation path, and then the control parameters are obtained. The gray scale factor that is improved in this paper combined with the vertical projection map can extract the target ridge with an accuracy rate of 92%, and the accuracy of extracting the navigation line is more than 90%. When conducting navigation tracking experiments in corn field, the maximum error is 5cm.(AU)

Depois de usar o método conhecido como escala de cinza para plantas de milho, a diferença de escala de cinza entre diferentes partes da planta é grande ou a diferenciação do solo não é alta, a precisão do trajeto de navegação é baixa e a velocidade é lenta. Neste trabalho foi proposto um novo método de extração da linha de referência de navegação para campos de milho, que é usado para controlar a caminhada de robôs agrícolas. Os métodos de projeto incluem: segmentação de imagem, extração de ponto de navegação e encaixe de linha de navegação. A segmentação por imagem é baseada na separação de culturas e solos com base no novo fator de escala de cinza combinado com a filtragem mediana, método de Otsu e operação morfológica. A extração de pontos de navegação é baseada em um mapa de projeção vertical de imagem de dois valores para obter a área de interesse, e as coordenadas do ponto de navegação são determinadas por cálculo do ponto central relativo no pixel branco da linha amostral na área de interesse. O fator de escala de cinza melhorado nesta pesquisa irá extrair o centro da entre linha de plantio alvo com uma taxa de precisão de 92%. A precisão de extração da linha de navegação é mais de 90%. O erro máximo foi de 5cm quando o experimento de rastreamento de navegação em tempo foi é realizado em campos de milho.(AU)

Extraction of navigation line based on improved grayscale factor in corn field / Obtenção de linhas de tráfego em lavoura de milho baseada no fator de escala de cinza melhorado

ABSTRACT: Focusing on the problem that corn plant in different growth periods is grayed out by known methods, the gray scale difference of different part is large or the soil discrimination degree is not high, the navigation path is low in accuracy and speed. This paper proposed a new method for extracting cornfield navigation baselines, which is used to control walking of agricultural robots. Design method included image segmentation, navigation point extraction, and navigation path fitting. Image segmentation is based on a new grayscale factor combined with median filtering, OSTU method and morphological operations to achieve the separation of crops and soil. The extraction of the navigation point is based on the binary image vertical projection map to obtain the region of interest, and the navigation point coordinates are determined by calculating the relative center point of the white pixel points of the sampling line in the region of interest. The Hough transform is used to fit the navigation point obtained by the vertical projection map to determine the navigation path, and then the control parameters are obtained. The gray scale factor that is improved in this paper combined with the vertical projection map can extract the target ridge with an accuracy rate of 92%, and the accuracy of extracting the navigation line is more than 90%. When conducting navigation tracking experiments in corn field, the maximum error is 5cm.

RESUMO: Depois de usar o método conhecido como escala de cinza para plantas de milho, a diferença de escala de cinza entre diferentes partes da planta é grande ou a diferenciação do solo não é alta, a precisão do trajeto de navegação é baixa e a velocidade é lenta. Neste trabalho foi proposto um novo método de extração da linha de referência de navegação para campos de milho, que é usado para controlar a caminhada de robôs agrícolas. Os métodos de projeto incluem: segmentação de imagem, extração de ponto de navegação e encaixe de linha de navegação. A segmentação por imagem é baseada na separação de culturas e solos com base no novo fator de escala de cinza combinado com a filtragem mediana, método de Otsu e operação morfológica. A extração de pontos de navegação é baseada em um mapa de projeção vertical de imagem de dois valores para obter a área de interesse, e as coordenadas do ponto de navegação são determinadas por cálculo do ponto central relativo no pixel branco da linha amostral na área de interesse. O fator de escala de cinza melhorado nesta pesquisa irá extrair o centro da entre linha de plantio alvo com uma taxa de precisão de 92%. A precisão de extração da linha de navegação é mais de 90%. O erro máximo foi de 5cm quando o experimento de rastreamento de navegação em tempo foi é realizado em campos de milho.

Effect of the location and size of thyroid nodules on the diagnostic performance of ultrasound elastography: A retrospective analysis

OBJECTIVES: Ultrasound-guided fine-needle aspiration biopsies are recommended for the detection of suspicious thyroid nodules. However, the best approach regarding suspicious ultrasound features for thyroid nodules is still unclear. This study aimed to evaluate the effect of location and size of thyroid nodules on the diagnostic performance of strain ultrasound elastography. In addition, this study evaluated whether ultrasound elastography predicts malignancy in thyroid nodules. METHODS: Data regarding the size, depth, and distance from the carotid artery of nodules, the elasticity contrast index, and the nature of nodules were analyzed. RESULTS: There was no significant difference in the depth (p=0.092) and the distance from the carotid artery (p=0.061) between benign and suspicious nodules. Suspicious nodules were smaller than benign nodules (p<0.0001, q=23.84) and had a higher elasticity contrast index (p<0.0001, q=21.05). The depth of nodules and the size of the nodule were not associated with the correct value of the elasticity contrast index (p>0.05 for both). The diagnostic performance of ultrasound elastography was not affected by the distance of the nodules from the carotid artery if they were located ≥15 mm from the carotid artery (p=0.5960). However, if the suspicious nodules were located <15 mm from the carotid artery, the diagnostic accuracy was hampered (p=0.006). CONCLUSIONS: The strain ultrasound elastography should be carefully evaluated when small thyroid nodules are located near the carotid artery.

Echo intensity reliability between two rectus femoris probe sites.

INTRODUCTION: The ultrasound technique has been extensively used to measure echo intensity, with the goal of measuring muscle quality, muscle damage, or to detect neuromuscular disorders. However, it is not clear how reliable the technique is when comparing different days, raters, and analysts, or if the reliability is affected by the muscle site where the image is obtained from. The goal of this study was to compare the intra-rater, inter-rater, and inter-analyst reliability of ultrasound measurements obtained from two different sites at the rectus femoris muscle. METHODS: Muscle echo intensity was quantified from ultrasound images acquired at 50% [RF50] and at 70% [RF70] of the thigh length in 32 healthy subjects. RESULTS: Echo intensity values were higher (p = 0.0001) at RF50 (61.08 ± 12.04) compared to RF70 (57.32 ± 12.58). Reliability was high in both RF50 and RF70 for all comparisons: intra-rater (ICC = 0.89 and 0.94), inter-rater (ICC = 0.89 and 0.89), and inter-analyst (ICC = 0.98 and 0.99), respectively. However, there were differences (p < 0.05) between raters and analysts when obtaining/analyzing echo intensity values in both rectus femoris sites. CONCLUSIONS: The differences in echo intensity values between positions suggest that rectus femoris's structure is not homogeneous, and therefore measurements from different muscle regions should not be used interchangeably. Both sites showed a high reliability, meaning that the measure is accurate if performed by the same experienced rater in different days, if performed by different experienced raters in the same day, and if analyzed by different well-trained analysts, regardless of the evaluated muscle site.

Grayscale histogram analysis to study the echogenicity and echotexture of the walls of the common carotid arteries of horses and mules / Análise por histograma em escala de cinza para estudo da ecogenicidade e ecotextura das paredes das artérias carótidas comuns de equinos e muares

Visual inspection of ultrasound examination for assessment of echogenicity and echotexture of blood vessel tissues is a technique routinely used in medical practice in humans. However, simple visual inspection can lead to poor quality diagnoses and errors. The use of grayscale histogram (GSH) analysis has proved to be an efficient technique to quantify the region of interest, allowing minimization of image interpretation errors. This study aimed to evaluate and compare the echogenicity and echotexture of the walls of the common carotid arteries of healthy female horses and mules using the GSH technique and correlate them with age, body mass, and vessel diameters. B-mode ultrasound examinations were performed in the left and right common carotid arteries in three regions (cranial, middle, and caudal) in 11 horses and 11 healthy mules. The GSH of the animals showed heterogeneous walls, but did not differentiate statistically between female horses and mules. The Mean variable of the middle right, middle left and caudal right sides showed differences, more significant in the mules. On the middle right side, the Min variable was different, higher in the mules. On the middle and caudal left side, the variables Max and Mode showed higher values in the mules. For the mules, the age factor presented negative correlation with the Mean, Mode,, Mode(Count), and Mode(Count)/Count(%) variables, and the body mass factor presented negative correlation with the Mode, Mean and Max variables. For the female horses, the body mass factor showed positive correlation with the Mean and Mode variables. Echogenicity of the carotid artery walls differed between female horses and mules, whereas echotexture was heterogeneous and statistically similar among the animals. The age and body mass factors inversely influenced the echogenicity of the mules, but were not significant in the female horses, in which only the body mass factor positively influenced echogenicity.(AU)

A técnica de avaliação da ecogenicidade e ecotextura dos tecidos dos vasos sanguíneos por inspeção visual do exame de ultrassonografia, já é uma prática da rotina médica em humanos. No entanto, a simples visualização manual pode induzir à erros e diagnósticos de pouca qualidade. O uso de análise por histograma em escala de cinza (HEC) tem se demostrado uma eficiente técnica para quantificar a região avaliada, permitindo minimizar erros de interpretação. O objetivo deste trabalho foi avaliar e comparar a ecogenicidade e ecotextura das paredes das artérias carótidas comuns das fêmeas equina e muares hígidos usando a técnica de HEC, e correlacioná-las com a idade, massa corpórea e diâmetros dos vasos. Exames de ultrassonografia modo-B foram realizados nas artérias carótidas comuns esquerda e direita em três regiões (cranial, médio e caudal) em 11 fêmeas equina e 11 muares hígidos. O HEC dos animais apresentou paredes heterogêneas, mas não diferenciaram estatisticamente entre fêmeas equinas e muares. A variável Mean do lado direito médio, esquerdo médio e caudal apresentou diferenças, sendo maiores nos muares. No lado direito médio, o Min foi diferente, sendo superior nos muares. Já para o lado esquerdo médio e caudal, as variáveis Max e Mode apresentaram valores maiores nos muares. Para os muares, o fator idade apresentou correlação negativa com Mean, Mode, Mode (Count) e Mode(Count)/Count (%) e o fator massa corpórea apresentou correlação negativa com Mode, Mean e Max. Para as fêmeas equinas o fator massa corpórea apresentou correlação positiva com Mean e Mode. A ecogenicidade das paredes das artérias carótidas diferiram entre fêmeas equina e muares, já a ecotextura foi heterogênea e semelhante estatisticamente entre os animais. A idade e a massa corpórea influenciaram inversamente na ecogenicidade dos muares, enquanto que nas fêmeas equina a idade não foi significativa, apenas a massa corpórea influenciou positivamente com a ecogenicidade.(AU)

Grayscale histogram analysis to study the echogenicity and echotexture of the walls of the common carotid arteries of horses and mules / Análise por histograma em escala de cinza para estudo da ecogenicidade e ecotextura das paredes das artérias carótidas comuns de equinos e muares

Visual inspection of ultrasound examination for assessment of echogenicity and echotexture of blood vessel tissues is a technique routinely used in medical practice in humans. However, simple visual inspection can lead to poor quality diagnoses and errors. The use of grayscale histogram (GSH) analysis has proved to be an efficient technique to quantify the region of interest, allowing minimization of image interpretation errors. This study aimed to evaluate and compare the echogenicity and echotexture of the walls of the common carotid arteries of healthy female horses and mules using the GSH technique and correlate them with age, body mass, and vessel diameters. B-mode ultrasound examinations were performed in the left and right common carotid arteries in three regions (cranial, middle, and caudal) in 11 horses and 11 healthy mules. The GSH of the animals showed heterogeneous walls, but did not differentiate statistically between female horses and mules. The Mean variable of the middle right, middle left and caudal right sides showed differences, more significant in the mules. On the middle right side, the Min variable was different, higher in the mules. On the middle and caudal left side, the variables Max and Mode showed higher values in the mules. For the mules, the age factor presented negative correlation with the Mean, Mode,, Mode(Count), and Mode(Count)/Count(%) variables, and the body mass factor presented negative correlation with the Mode, Mean and Max variables. For the female horses, the body mass factor showed positive correlation with the Mean and Mode variables. Echogenicity of the carotid artery walls differed between female horses and mules, whereas echotexture was heterogeneous and statistically similar among the animals. The age and body mass factors inversely influenced the echogenicity of the mules, but were not significant in the female horses, in which only the body mass factor positively influenced echogenicity.(AU)

A técnica de avaliação da ecogenicidade e ecotextura dos tecidos dos vasos sanguíneos por inspeção visual do exame de ultrassonografia, já é uma prática da rotina médica em humanos. No entanto, a simples visualização manual pode induzir à erros e diagnósticos de pouca qualidade. O uso de análise por histograma em escala de cinza (HEC) tem se demostrado uma eficiente técnica para quantificar a região avaliada, permitindo minimizar erros de interpretação. O objetivo deste trabalho foi avaliar e comparar a ecogenicidade e ecotextura das paredes das artérias carótidas comuns das fêmeas equina e muares hígidos usando a técnica de HEC, e correlacioná-las com a idade, massa corpórea e diâmetros dos vasos. Exames de ultrassonografia modo-B foram realizados nas artérias carótidas comuns esquerda e direita em três regiões (cranial, médio e caudal) em 11 fêmeas equina e 11 muares hígidos. O HEC dos animais apresentou paredes heterogêneas, mas não diferenciaram estatisticamente entre fêmeas equinas e muares. A variável Mean do lado direito médio, esquerdo médio e caudal apresentou diferenças, sendo maiores nos muares. No lado direito médio, o Min foi diferente, sendo superior nos muares. Já para o lado esquerdo médio e caudal, as variáveis Max e Mode apresentaram valores maiores nos muares. Para os muares, o fator idade apresentou correlação negativa com Mean, Mode, Mode (Count) e Mode(Count)/Count (%) e o fator massa corpórea apresentou correlação negativa com Mode, Mean e Max. Para as fêmeas equinas o fator massa corpórea apresentou correlação positiva com Mean e Mode. A ecogenicidade das paredes das artérias carótidas diferiram entre fêmeas equina e muares, já a ecotextura foi heterogênea e semelhante estatisticamente entre os animais. A idade e a massa corpórea influenciaram inversamente na ecogenicidade dos muares, enquanto que nas fêmeas equina a idade não foi significativa, apenas a massa corpórea influenciou positivamente com a ecogenicidade.(AU)

Ultrasound and its clinical use in rheumatoid arthritis: where do we stand?

High-resolution musculoskeletal ultrasound (MSUS) has been increasingly employed in daily rheumatological practice and in clinical research. In rheumatoid arthritis (RA), MSUS can be now considered a complement to physical examination. This method evaluates synovitis through gray-scale and power Doppler and it is also able to identify bone erosions. The utilization of MSUS as a marker of RA activity has received attention in recent literature. Current data account for good correlation of MSUS with classical measures of clinical activity; in some instances, MSUS appears to perform even better. Diagnosis of subclinical synovitis by MSUS might help the physician in RA management. With some variation, interobserver MSUS agreement seems excellent for erosion and good for synovitis. However, lack of MSUS score standardization is still an unmet need. In this review, we describe several MSUS scores, as well as their correlation with clinical RA activity and response to therapy. Finally, we look at the relationship of MSUS with synovial tissue inflammation and discuss future perspectives for a better interpretation and integration of this imaging method into clinical practice.

An alternative method for the analysis of melanin production in Cryptococcus neoformans sensu lato and Cryptococcus gattii sensu lato.

Melanin is an important virulence factor for several microorganisms, including Cryptococcus neoformans sensu lato and Cryptococcus gattii sensu lato, thus, the assessment of melanin production and its quantification may contribute to the understanding of microbial pathogenesis. The objective of this study was to standardise an alternative method for the production and indirect quantification of melanin in C. neoformans sensu lato and C. gattii sensu lato. Eight C. neoformans sensu lato and three C. gattii sensu lato, identified through URA5 methodology, Candida parapsilosis ATCC 22019 (negative control) and one Hortaea werneckii (positive control) were inoculated on minimal medium agar with or without L-DOPA, in duplicate, and incubated at 35°C, for 7 days. Pictures were taken from the third to the seventh day, under standardised conditions in a photographic chamber. Then, photographs were analysed using grayscale images. All Cryptococcus spp. strains produced melanin after growth on minimal medium agar containing L-DOPA. C. parapsilosis ATCC 22019 did not produce melanin on medium containing L-DOPA, while H. werneckii presented the strongest pigmentation. This new method allows the indirect analysis of melanin production through pixel quantification in grayscale images, enabling the study of substances that can modulate melanin production.

Comparison between a new computer program and the reference software for gray-scale median analysis of atherosclerotic carotid plaques.

PURPOSE: To compare a new dedicated software program and Adobe Photoshop for gray-scale median (GSM) analysis of B-mode images of carotid plaques. METHODS: A series of 42 carotid plaques generating ≥50% diameter stenosis was evaluated by a single observer. The best segment for visualization of internal carotid artery plaque was identified on a single longitudinal view and images were recorded in JPEG format. Plaque analysis was performed by both programs. After normalization of image intensity (blood = 0, adventitial layer = 190), histograms were obtained after manual delineation of plaque. Results were compared with nonparametric Wilcoxon signed rank test and Kendall tau-b correlation analysis. RESULTS: GSM ranged from 00 to 100 with Adobe Photoshop and from 00 to 96 with IMTPC, with a high grade of similarity between image pairs, and a highly significant correlation (R = 0.94, p < .0001). CONCLUSIONS: IMTPC software appears suitable for the GSM analysis of carotid plaques.