The Impact of Noise and Brightness on Object Detection Methods.

The application of deep learning to image and video processing has become increasingly popular nowadays. Employing well-known pre-trained neural networks for detecting and classifying objects in images is beneficial in a wide range of application fields. However, diverse impediments may degrade the performance achieved by those neural networks. Particularly, Gaussian noise and brightness, among others, may be presented on images as sensor noise due to the limitations of image acquisition devices. In this work, we study the effect of the most representative noise types and brightness alterations on images in the performance of several state-of-the-art object detectors, such as YOLO or Faster-RCNN. Different experiments have been carried out and the results demonstrate how these adversities deteriorate their performance. Moreover, it is found that the size of objects to be detected is a factor that, together with noise and brightness factors, has a considerable impact on their performance.

Prevalence and grade of malignancy differences with respect to the area of involvement in multiparametric resonance imaging of the prostate in the diagnosis of prostate cancer using the PI-RADS version 2 classification.

PURPOSE: The peripheral zone is histologically different from the transitional zone. The aim of this study is to analyze the differences between the prevalence and grade of malignancy of mpMRI-targeted biopsies that involve the TZ with respect to the PZ. METHODS: A cross-sectional study of 597 men evaluated for PC screening between February 2016 and October 2022 was conducted. Exclusion criteria were prior BPH surgery, radiotherapy, 5-alpha-reductase inhibitors treatment, UTI, mixed involvement of PZ-TZ or doubts, and central-zone involvement. Hypothesis contrast test was used to study differences proportions of malignancy (ISUP > 0) and significant (ISUP > 1) and high-grade tumor (ISUP > 3) in PI-RADSv2 > 2-targeted biopsies in PZ with respect to TZ, and logistic regression and hypothesis contrast tests were used to study the influence of the area of exposure as an effect-modifying factor in the diagnosis of malignancy with respect to the PI-RADSv2 classification. RESULTS: 473 patients were selected and 573 lesions biopsied (127 PI-RADS3, 346 PI-RADS4 and 100 PI-RADS5). A significant increase was described in the proportion of malignancy and significant and high-grade tumor in PZ compared to TZ (22.6%, 21.3%, and 8.7%, respectively). Significant increase in proportions and malignancy were described in cores targeted to PZ with respect to TZ, highlight the differences between PZ and TZ for ST (37.3%vs23.7% for PI-RADS4, 69.2%vs27.3% for PI-RADS5, respectively). Statistically significant linear trend was described increasing for malignancy, significant and high-grade tumors with respect to the PI-RADSv2 scores (change > 10%). CONCLUSION: Although the prevalence and grade of malignancy in the TZ is lower than in the PZ, PI-RADS4 and 5-targeted biopsies should not be omitted in this location, but PI-RADS3 could be.

Diagnostic evaluation and incorporation of PSA density and the prostate imaging and data reporting system (PIRADS) version 2 classification in risk-nomograms for prostate cancer.

PURPOSE: The diagnostic approach for prostate cancer still depends on PSA and DRE. OBJECTIVES: to evaluate the diagnostic validity of PSA-Density and PIRADSv2 as diagnostic tests regarding biopsy results, and to design nomograms that include all diagnostic variables for malignancy, significant tumor (ST) and high-grade tumor. METHODS: Cross-sectional study which included men with PSA ≥ 4 ng/ml and/or suspicious DRE, PIRADSv2 ≥ 3 lesions on multiparametric MRI and prostate biopsy. The gold standard test was the maximum ISUP of the targeted biopsy per patient (malignancy: ISUP ≥ 1, ST: ISUP ≥ 2, high-grade tumor: ISUP ≥ 4). Association and logistic regression tests were used and diagnostic validity parameters using PSA-Density and PIRADSv2 classification was analyzed. Nomograms were designed for malignancy, ST, and high-grade tumor using the best model selection procedure from all possible equations. RESULTS: 336 men with median age, PSA and PSA-Density of 67.7 years (IQR:12.6), 6.3 ng/ml (IQR:3.3) and 0.12 ng/ml/cc (IQR:0.10), respectively; 63 index lesions were PIRADS3, 204 PIRADS4, and 69 PIRADS5. 65.8% and 37.8% were malignant and ST, respectively. The significant positive association highlighted between malignancy and ST with age, DRE, PSA-Density and PIRADSv2. PSA-Density and PIRADSv2 ≥ 3 presented the highest sensitivity to detect malignancy, and their combination showed sensitivity nearly 95% (AUC:0.803). Nomograms for malignancy and ST included the variables age, DRE, PSA-Density, and PIRADSv2 with a sensitivity closely 91% (AUC:0.833), and a specificity of almost 85% for ST, exposing risk < 5% for ST when PSA-Density is < 0.15, not suspicious DRE and PIRADS3. CONCLUSION: PSA-Density and PIRADSv2 classification in risk nomograms can provide highly relevant information to increase the accuracy in the diagnosis of PC and ST.

Comparative study between 1.5 and 3 Tesla multiparametric MRI systems using the PIRADS version 2 classification in the diagnosis of prostate cancer.

INTRODUCTION: The 3-Tesla multiparametric MRI (mpMRI) system represents a diagnostic advance for prostate cancer. Our aim is to demonstrate that the results in 1.5-Tesla mpMRI are not inferior compared to the 3-Tesla for the correct diagnosis of prostate cancer. MATERIAL AND METHODS: Non-inferiority comparative cross-sectional study between fusion-guided prostate biopsy results. 344 patients with clinical suspicion of prostate cancer (elevated PSA and/or suspicious DRE) and mpMRI interpreted and verified by the same radiologists in all cases, 270 in 1.5-Tesla and 74 in 3-Tesla, with at least one lesion PIRADSv2≥ 3. Exclusion criteria were positive biopsy or previous prostate treatment. We consider malignancy as ISUP≥ 1 and significant tumor as ISUP≥ 2. We used Wilcoxon and t-student test (central tendency measures), diagnostic test (gold standard: ISUP of targeted biopsy), Chi2 test and Z-test (comparison of prevalences and 95%CI malignancy and significant tumor according to mpMRI). RESULTS: Median prostate volume 50cc(IQR:33.5) and PSA 6.11ng/ml(IQR:3.39). Mean age 67.4±8.1years. Number of suspi-cious lesions/patient: mpMRI 1.3 (1.5-Tesla) and 1.5 (3-Tesla). No differences were found between mpMRI (homogeneous and comparable samples). 57% (1.5-Tesla) vs 66% (3-Tesla) of targeted biopsies were malignant, and 34%vs38% were significant tumor, with no significant differences. Se, Sp, PPV and NPV for malignancy (1.5-Tesla vs 3-Tesla) were 96%vs90%, 38%vs44%, 67%vs76%, and 86%vs69%, with no significant differences. CONCLUSIONS: There are no significant differences between 1.5-Tesla vs 3-Tesla mpMRI regarding targeted biopsy results. Not to have 3-Tesla mpMRI may not be a limitation to use 1.5-Tesla as a diagnostic test for the better diagnosis of prostate cancer.

A real use case of semi-supervised learning for mammogram classification in a local clinic of Costa Rica.

The implementation of deep learning-based computer-aided diagnosis systems for the classification of mammogram images can help in improving the accuracy, reliability, and cost of diagnosing patients. However, training a deep learning model requires a considerable amount of labelled images, which can be expensive to obtain as time and effort from clinical practitioners are required. To address this, a number of publicly available datasets have been built with data from different hospitals and clinics, which can be used to pre-train the model. However, using models trained on these datasets for later transfer learning and model fine-tuning with images sampled from a different hospital or clinic might result in lower performance. This is due to the distribution mismatch of the datasets, which include different patient populations and image acquisition protocols. In this work, a real-world scenario is evaluated where a novel target dataset sampled from a private Costa Rican clinic is used, with few labels and heavily imbalanced data. The use of two popular and publicly available datasets (INbreast and CBIS-DDSM) as source data, to train and test the models on the novel target dataset, is evaluated. A common approach to further improve the model's performance under such small labelled target dataset setting is data augmentation. However, often cheaper unlabelled data is available from the target clinic. Therefore, semi-supervised deep learning, which leverages both labelled and unlabelled data, can be used in such conditions. In this work, we evaluate the semi-supervised deep learning approach known as MixMatch, to take advantage of unlabelled data from the target dataset, for whole mammogram image classification. We compare the usage of semi-supervised learning on its own, and combined with transfer learning (from a source mammogram dataset) with data augmentation, as also against regular supervised learning with transfer learning and data augmentation from source datasets. It is shown that the use of a semi-supervised deep learning combined with transfer learning and data augmentation can provide a meaningful advantage when using scarce labelled observations. Also, we found a strong influence of the source dataset, which suggests a more data-centric approach needed to tackle the challenge of scarcely labelled data. We used several different metrics to assess the performance gain of using semi-supervised learning, when dealing with very imbalanced test datasets (such as the G-mean and the F2-score), as mammogram datasets are often very imbalanced. Graphical Abstract Description of the test-bed implemented in this work. Two different source data distributions were used to fine-tune the different models tested in this work. The target dataset is the in-house CR-Chavarria-2020 dataset.

Improving Uncertainty Estimation With Semi-Supervised Deep Learning for COVID-19 Detection Using Chest X-Ray Images.

In this work we implement a COVID-19 infection detection system based on chest X-ray images with uncertainty estimation. Uncertainty estimation is vital for safe usage of computer aided diagnosis tools in medical applications. Model estimations with high uncertainty should be carefully analyzed by a trained radiologist. We aim to improve uncertainty estimations using unlabelled data through the MixMatch semi-supervised framework. We test popular uncertainty estimation approaches, comprising Softmax scores, Monte-Carlo dropout and deterministic uncertainty quantification. To compare the reliability of the uncertainty estimates, we propose the usage of the Jensen-Shannon distance between the uncertainty distributions of correct and incorrect estimations. This metric is statistically relevant, unlike most previously used metrics, which often ignore the distribution of the uncertainty estimations. Our test results show a significant improvement in uncertainty estimates when using unlabelled data. The best results are obtained with the use of the Monte Carlo dropout method.

Inventario de Sexismo Ambivalente (ISA) en adolescentes chilenos: estructura factorial, fiabilidad, validez e invarianza por sexo / Ambivalent Sexism Inventory (ASI) in Chilean adolescents: Factor structure, reliability, validity and sex invariance

El sexismo ambivalente es un constructo multidimensional compuesto por creencias y actitudes hostiles y benévolas que se legitiman entre sí parajustificar el poder masculino estructural. Los estudios sobre sexismo en adolescentes cobran relevancia al ser una etapa evolutiva fundamental paraasentar creencias acerca de las relaciones de género. Sin embargo, los instrumentos para medir representaciones sexistas en este grupo son escasos.Este estudio evaluó las propiedades psicométricas del Inventario de Sexismo Ambivalente (ISA) en adolescentes chilenos, concretamente se analizóla estructura factorial y su fiabilidad, validez e invarianza factorial por sexo. La muestra estuvo conformada por 546 estudiantes entre 15 y 18 años(M=15.52; DT=.66), de los cuales el 58.8% fueron mujeres. Los métodos que se utilizaron fueron Análisis Factorial Exploratorio y Análisis FactorialConfirmatorio. El resultado del análisis exploratorio sugirió retener los 20 ítems de la escala original agrupados en dos factores. Los resultados delanálisis confirmatorio corroboraron la estructura original de la escala y precisaron un modelo de dos factores correlacionados, Sexismo Hostil y SexismoBenévolo (χ2(166) = 302.34; CFI = .99; TLI = .98, RMSEA = .05, SRMR = .07), que considera al Sexismo Benévolo como un factor de segundo ordencon tres subcomponentes (Paternalismo Protector, Intimidad Heterosexual y Diferenciación de Género). El modelo seleccionado coincidió con la pro-puesta teórica y explicó el 56% de la varianza. El análisis de fiabilidad indicó un alfa ordinal total de 0.93 y el análisis correlacional demostró evidencia devalidez discriminante. El análisis de invarianza factorial evidenció que el grado de equivalencia del instrumento por sexo es plausible a un nivel estricto.Se concluyó que el ISA presenta adecuadas propiedades psicométricas para su uso en adolescentes de Chile.(AU)

Ambivalent sexism is a multi-dimensional construct conformed by hostile and benevolent beliefs and attitudes that tend to legitimize each other justifying male structural power.Sexism studies in adolescent population become relevant as it is a fundamental evolutive stage for settle gender relations beliefs. However, thetools that measures sexist representations in adolescents are scarce. The main goal was to evaluate the psychometric properties of the AmbivalentSexism Inventory (ASI) in Chilean adolescents, and analyze invariance by sex. Sample was composed of 546 students between 15–18 years (M=15.52; SD=.66), of which 58.8% were women. Exploratory factor analyses and confirmatory factor analyses were the method of the study. Theresults of the exploratory factor analyses suggested to hold back the 20 items from the original structure grouped in two factors. Confirmatory factoranalyses results showed suitability of the two factors theoretical proposal, hostile sexism and benevolent sexism (χ2(166) = 302.34; CFI = .99; TLI= .98; RMSEA = .05; SRMR = .07), which includes benevolent sexism as a second-order factor conformed by three subcomponents (protectivepaternalism, complementary gender differentiation, and heterosexual intimacy). The factorial structure of the selected model explained 56% of thetotal variance. The reliability of the ASI reached a satisfactory levels of ordinal alpha (αordinal = .93) for the complete instrument and the correlationanalyses provide evidences of discriminant validity. The Invariance factorial analyses showed that the equivalence level of the ASI is plausible in thestrict level. It is concluded that the ASI presents adequate psychometric properties for its use in Chilean adolescent population.(AU)

Correcting data imbalance for semi-supervised COVID-19 detection using X-ray chest images.

A key factor in the fight against viral diseases such as the coronavirus (COVID-19) is the identification of virus carriers as early and quickly as possible, in a cheap and efficient manner. The application of deep learning for image classification of chest X-ray images of COVID-19 patients could become a useful pre-diagnostic detection methodology. However, deep learning architectures require large labelled datasets. This is often a limitation when the subject of research is relatively new as in the case of the virus outbreak, where dealing with small labelled datasets is a challenge. Moreover, in such context, the datasets are also highly imbalanced, with few observations from positive cases of the new disease. In this work we evaluate the performance of the semi-supervised deep learning architecture known as MixMatch with a very limited number of labelled observations and highly imbalanced labelled datasets. We demonstrate the critical impact of data imbalance to the model's accuracy. Therefore, we propose a simple approach for correcting data imbalance, by re-weighting each observation in the loss function, giving a higher weight to the observations corresponding to the under-represented class. For unlabelled observations, we use the pseudo and augmented labels calculated by MixMatch to choose the appropriate weight. The proposed method improved classification accuracy by up to 18%, with respect to the non balanced MixMatch algorithm. We tested our proposed approach with several available datasets using 10, 15 and 20 labelled observations, for binary classification (COVID-19 positive and normal cases). For multi-class classification (COVID-19 positive, pneumonia and normal cases), we tested 30, 50, 70 and 90 labelled observations. Additionally, a new dataset is included among the tested datasets, composed of chest X-ray images of Costa Rican adult patients.

Biodiesel production using microbial lipids derived from food waste discarded by catering services.

Biodiesel production using microbial oil derived from food waste discarded by the hospilatity sector could provide a sustainable replacement for diesel fuel. Discarded potato peels were used in solid-state fermentations of Aspergillus awamori for the production of glucoamylase (30 U/g) and protease (50 U/g). Hospitality food waste hydrolysis led to 98% (w/w) starch to glucose conversion yields. Crude hydrolyzates were used in shake flask fermentations with the oleaginous yeast Rhodosporidium toruloides Y-27012 leading to 32.9 g/L total dry weight (TDW) with 36.4% (w/w) intracellular lipid content. Fed-bath bioreactor cultures resulted in TDW of 53.9 g/L and lipid concentration of 26.7 g/L. Principal component analysis showed a fatty acid profile similar to soybean oil and solid food waste oil. Microbial oil was transesterified into biodiesel with satisfactory performance considering the European standard EN 14214. This work demonstrated that valorization of food waste for biodiesel production is feasible.

A rare case of penile metastases from small cell prostate cancer / Un caso inusual de metástasis peneanas en el carcinoma prostático de células pequeñas

We present a case of an 83-year-old-male with painless penile nodules several months after he was diagnosed with pure prostatic small cell carcinoma. Penile doppler ultrasound and magnetic resonance imaging demonstrated solid nodules in both corpora cavernosa. Fine-needle aspiration of the nodules with immunohistochemical examination confirmed prostatic small cell carcinoma origin of metastases. Small cell carcinoma of the prostate is a rare disorder accounting for less than 1% of all prostate cancers, the penis being an uncommon site for metastasis. An extremely low number of cases of penile metastases from prostatic small cell carcinoma has been reported to date in the literature

Presentamos un caso de un varón de 83 años con nódulos peneanos indoloros, tras ser diagnosticado meses atrás de carcinoma prostático de células pequeñas puro. La eco-doppler e imagen de resonancia magnética de pene reflejaron nódulos sólidos en ambos cuerpos cavernosos. La aspiración con aguja fina de los nódulos con prueba inmunohistoquímica confirmó el origen metastásico del carcinoma de células pequeñas. El carcinoma prostático de células pequeñas es un trastorno inusual que representa menos del 1% de todos los cánceres prostáticos, siendo el pene un sitio infrecuente de metástasis. Hasta la fecha se ha reportado en la literatura un número de casos extremadamente bajo de metástasis peneanas en el carcinoma de próstata de células pequeñas

Evaluación de la Escala de Identidad Étnica en adolescentes mapuche de Chile / Evaluation of the ethnic identity scale among Mapuche adolescents in Chile / Avaliação da escala de identidade étnica nos adolescentes mapuche no Chile

Resumen (analítico) Los estudios evidencian que la identidad étnica es un factor protector para sociedades con relaciones interétnicas e interculturales desiguales. Sin embargo, los instrumentos para su medición presentan escasas validaciones psicométricas en contextos indígenas chilenos y latinoamericanos. El estudio evaluó las propiedades psicométricas de la Escala de Identidad Étnica en una muestra de 501 adolescentes indígenas mapuche con una edad promedio de 15.63 años. Los análisis factoriales exploratorios y confirmatorios evidenciaron una estructura factorial coincidente con la propuesta teórica de tres factores (exploración, resolución y afirmación), la cual explicó el 76 % de la varianza. El análisis de fiabilidad indicó un alfa ordinal de .90 para la escala total y el análisis correlacional demostró validez externa. Se concluyó que la escala presenta evidencia psicométrica para su uso en población adolescente mapuche.

Abstract (analytical) Recent studies evidence that ethnic identity is a protective factor for interethnic and intercultural societies with unequal relations. The tools that measure ethnic identity have limited psychometric validations for indigenous Chilean and Latin American populations. This study evaluated the psychometric properties of the ethnic identity scale with a sample of Mapuche indigenous adolescents consisting of 501 students with an average age of 15.63, through which exploratory and confirmatory factorial analyses were performed. The factorial assessment results showed strong internal reliability. The suitability of the three factors included in the theoretical proposal (exploration, resolution and affirmation) explained 76% of the variance. The reliability measures indicated a .90 value for the ordinal alpha and the correlations demonstrated external validity. It is concluded that the EIS presents sufficient psychometric evidence for use in the Mapuche adolescent population.

Resumo (analítico) Estudos mostram que a identidade étnica é um fator de proteção para sociedades com relações interétnicas e interculturais desiguais. No entanto, os instrumentos para a sua medição apresentam pouca validação psicométrica nos contextos indígenas chilenos e latino-americanos. O estudo avaliou as propriedades psicométricas da escala de identidade étnica numa amostra de 501 adolescentes Mapuche indígenas com uma idade média de 15.63 anos. As análises exploratórias e confirmatórias dos fatores mostraram uma estrutura de fatorial que coincidia com a proposta teórica de três fatores (exploração, resolução e afirmação), o que explicava 76% da variância. A análise de fiabilidade indicou um alfa ordinal de .90 para a escala total e a análise correlacional demonstrou a validade externa. Concluiu-se que a EIE apresenta provas psicométricas para uso na população adolescente Mapuche.

A rare case of penile metastases from small cell prostate cancer.

We present a case of an 83-year-old-male with painless penile nodules several months after he was diagnosed with pure prostatic small cell carcinoma. Penile doppler ultrasound and magnetic resonance imaging demonstrated solid nodules in both corpora cavernosa. Fine-needle aspiration of the nodules with immunohistochemical examination confirmed prostatic small cell carcinoma origin of metastases. Small cell carcinoma of the prostate is a rare disorder accounting for less than 1% of all prostate cancers, the penis being an uncommon site for metastasis. An extremely low number of cases of penile metastases from prostatic small cell carcinoma has been reported to date in the literature.

Auxiliary energy-assisted biodiesel production data from solid food waste oil.

A number of samples from solid food waste oil (SFWO) from different restaurants have been collected. Data regarding fatty acid profile, acid value, water content and kinematic viscosity were used for characterization purposes. Response surface methodology data has been used to carry out conventional transesterification optimization. The quality of the final product has been checked following the European biodiesel standard EN14214. To compare conventional and ultrasound-assisted transesterification results, energy consumption and reaction time data have been gathered. More information and result interpretation may be found in "Optimization of solid food waste oil biodiesel by ultrasound assisted transesterification" [1].

Design of coils for lateralized TMS on mice.

OBJECTIVE: Translational studies on animals play a vital role in the advancement of transcranial magnetic stimulation (TMS) as clinical technique. Nonetheless the relevance of these procedures is frequently limited by the lack of TMS systems specifically designed for small animals capable of producing comparable stimulation conditions to those found in human TMS. In this work, we propose to take advantage of the versatility of recently introduced TMS coil design methods to produce optimal rodent-specific TMS stimulators. APPROACH: A stream function inverse boundary element method (IBEM) has been used for producing three small sized mice-specific TMS coils of different geometries. They have been created for unilateral hemispheric stimulation of the rodent brain, and several constraints have been considered in the design process to satisfy essential performance requirements, such as minimum stored magnetic energy, minimum power dissipation, optimised maximum current density or minimization of the undesired electric field induced in non-target regions. In order to validate the presented strategy, three prototype coils have been built. The performance of each prototype has also been numerically investigated, where the electric field induced in a mouse model has been found by using an existing computational forward technique. MAIN RESULTS: Stream function IBEM represents an ideally suited approach for designing specific TMS coils for small animals, capable of fulfilling many essential functional and technical requirements. The prototypes produced in this work focally stimulate the right hemisphere of the mouse brain, and so they can be successfully used in lateralized TMS experiments. SIGNIFICANCE: The design scheme proposed here can be used to produce efficient TMS stimulators for small animals, which can overcome some of the existing limitations found when producing more reliable translational experiments.

Design of TMS coils with reduced Lorentz forces: application to concurrent TMS-fMRI.

OBJECTIVE: Interleaving TMS (transcranial magnetic stimulation) with fMRI (functional Magnetic Resonance Imaging) is a promising technique to study functional connectivity in the human brain, but its development is being restricted by technical limitations, such as that due to the interaction of the TMS current pulses with the magnetic fields of an MRI scanner. In this work, a TMS coil design method capable of controlling Lorentz forces experienced by the coil in the presence of static magnetic fields is presented. APPROACH: The suggested approach is based on an existing inverse boundary element method (IBEM) for TMS coil design, in which new electromagnetic computational models of the Lorentz forces have been included to be controlled in the design process. MAIN RESULTS: To demonstrate the validity of this technique, it has been used for the design and simulation of TMS coils wound on rectangular flat, spherical and hemispherical surfaces with improved mechanical stability. The obtained results confirm that TMS coils with reduced Lorentz forces inside the static main field of an MRI scanner can be produced, which is achieved to the detriment of other coil performance parameters. SIGNIFICANCE: The proposed approach provides an efficient tool to design TMS stimulators of a wide range of coil geometries with improved mechanical stability, which can be extremely useful to overcome current limitations for interleaved TMS-fMRI.

Evaluación del sistema PI-RADSv2 en una cohorte de pacientes sometidos a biopsia prostática por fusión / Evaluation of the PI-RADSv2 classification in a cohort of patients who underwent a prostate fusion biopsy

INTRODUCCIÓN: La biopsia prostática por fusión se describe como superior a la biopsia transrectal sistemática para identificar lesiones sospechosas de carcinoma de próstata. OBJETIVOS: Evaluar la clasificación PIRADS propuesto por la Sociedad Europea de Radiología Urogenital para la detección de cáncer de próstata mediante RNM en una cohorte consecutiva de pacientes con RNM y biopsia guiada por fusión. MATERIAL Y MÉTODOS: Estudio observacional transversal. 87 pacientes con sospecha de cáncer de próstata sometidos a biopsia de próstata transperineal y fusión con RNM en nuestro centro. Describimos tumor significativo como Gleason ≥ 7(3 + 4), y carcinoma de alto riesgo como Gleason ≥ 8. Utilizamos la prueba de Chi-cuadrado para analizar la relación entre cáncer de próstata y PIRADS, así como regresión logística y pruebas de tendencia lineal, comparando las proporciones con medidas de intensidad de asociación. Empleamos el sistema HITACHI Real-Time Virtual Sonography y el software STATA/IC v.14.2 para el análisis estadístico. RESULTADOS: 64,37% pacientes presentaron resultado positivo para malignidad. Media de edad 67,89 años (SD 7,42), de PSA total 9,15 ng/ml (SD 7,85), y de volumen prostático 54,05 cc (SD 22,92). Se biopsiaron 124 lesiones sospechosas en RNM (25% PIRADS III, 57,26% PIRADS IV y 17,74% PIRADS V). 5/31 lesiones PIRADS III, 47/71 PIRADS IV y 18/22 PIRADS V fueron positivas para malignidad, con relación lineal estadísticamente significativa entre PIRADS y malignidad (p < 0,001), razón de prevalencias (RP) 4,10 (IC95% 1,81-9,32) para PIRADS IV, y RP 5,07 (CI95% 2,2211,59) para PIRADS V respecto a PIRADS III. 3,23% lesiones PIRADS III, 32,39% PIRADS IV y 63,64% PIRADS V correspondieron a tumores significativos. Encontramos asociación estadísticamente significativa entre PIRADS y tumores significativos (p < 0,001), RP 10,04 (IC95% 1,42-71,09) para PIRADS IV y RP 19,73 (IC95% 2,80139,18) para PIRADS V respecto a PIRADS III. CONCLUSIÓN: Nuestros resultados muestran que la biopsia de próstata ecodirigida y por fusión utilizando RNM es una técnica segura con excelentes resultados para obtener un diagnóstico preciso de cáncer de próstata, y puede mejorar el diagnóstico de malignidad y de tumores significativos reduciendo el sobrediagnóstico

INTRODUCTION: Prostate Fusion biopsy (MRI + prostate ultrasound) is described in literature as superior to classic random transrectal biopsy in order to identify suspicious lesion. OBJECTIVES: To evaluate the Prostate Imaging Reporting and Data System (PI-RADS) proposed by the European Society of Urogenital Radiology (ESUR) for detection of prostate cancer by multiparametric MRI in a consecutive cohort of patients with MRI and transrectal ultrasound prostate fusion-guided biopsy. MATERIAL AND METHODS: 87 patients with suspected Prostatic Cancer on prostate MRI underwent fusion transperineal prostate biopsy in our Department. 37 patients had at least one prior negative classic prostatic transrectal biopsy. Clinically significant tumor was described as Gleason 7(3+4) or higher. The Chi-square test was used to analyze the relationship between prostate cancer and the different PIRADS stages, as well as logistic regression and linear trend tests, comparing the proportions using measures of association intensity. We use the HITACHI Real-Time Virtual Sonography (HI-RVS) system, and the STATA/IC v.14.2 software for statistical analysis. RESULTS: 64.37% patients had tested positive for malignancy. Median age 67.89 years old. Median PSA 9.15 ng/ml, and average prostate volume was 54.05 cc. 124 suspicious lesions were described in prostate MRI (25% PIRADS III, 57% PIRADS IV and 17% PIRADS V). 5/31 lesions PIRADS III, 47/71 PIRADS IV and 18/22 PIRADS V were positive for malignancy, with a statistically significant linear relationship between PIRADS and malignancy (p < 0.001) - HR 4.10 (CI 95% 1.81 to 9.32) for PIRADS IV and HR 5.07 (CI95% 2.22 to 11.59) for PIRADS V vs. PIRADS III. 3.23% lesions PIRADS III, 32.39% PIRADS IV and 63.64% PIRADS V corresponded to significant tumors. A statistically significant association between PIRADS and significant tumors (p < 0.001) - HR 10.04 (CI95% 1.42 to 71.09) for PIRADS IV and HR 19.73 (CI95% 2.80 to 139.18) for PIRADS V vs PIRADS III was observed -. CONCLUSION: Our results show that transperineal targeted prostate biopsy using multiparametric MRI and transrectal ultrasound fusion is a safe procedure with excellent outcomes to obtain an accurate diagnosis of prostate cancer. Fusion biopsy has the potential to improve the diagnosis of malignancy and clinically significant tumors while reducing overdiagnosis

[Evaluation of the PI-RADSv2 classification in a cohort of patients who underwent a prostate fusion biopsy.] / Evaluación del sistema PI-RADSv2 en una cohorte de pacientes sometidos a biopsia prostática por fusión.

INTRODUCTION: Prostate Fusion biopsy (MRI + prostate ultrasound) is described in literature as superior to classic random transrectal biopsy in order to identify suspicious lesion. OBJECTIVES: To evaluate the Prostate Imaging Reporting and Data System (PI-RADS) proposed by the European Society of Urogenital Radiology (ESUR) for detection of prostate cancer by multiparametric MRI in a consecutive cohort of patients with MRI and transrectal ultrasound prostate fusion-guided biopsy. MATERIAL AND METHODS: 87 patients with suspected Prostatic Cancer on prostate MRI underwent fusion transperineal prostate biopsy in our Department. 37 patients had at least one prior negative classic prostatic transrectal biopsy. Clinically significant tumor was described as Gleason 7(3+4) or higher. The Chi-square test was used to analyze the relationship between prostate cancer and the different PIRADS stages, as well as logistic regression and linear trend tests, comparing the proportions using measures of association intensity. We use the HITACHI Real-Time Virtual Sonography (HI-RVS) system, and the STATA/IC v.14.2 software for statistical analysis. RESULTS: 64.37% patients had tested positive for malignancy. Median age 67.89 years old. Median PSA 9.15 ng/ml, and average prostate volume was 54.05 cc. 124 suspicious lesions were described in prostate MRI (25% PIRADS III, 57% PIRADS IV and 17% PIRADS V). 5/31 lesions PIRADS III, 47/71 PIRADS IV and 18/22 PIRADS V were positive for malignancy, with a statistically significant linear relationship between PIRADS and malignancy (p<0.001) - HR 4.10 (CI 95% 1.81 to 9.32) for PIRADS IV and HR 5.07 (CI95% 2.22 to 11.59) for PIRADS V vs. PIRADS III. 3.23% lesions PIRADS III, 32.39% PIRADS IV and 63.64% PIRADS V corresponded to significant tumors. A statistically significant association between PIRADS and significant tumors (p<0.001) - HR 10.04 (CI95% 1.42 to 71.09) for PIRADS IV and HR 19.73 (CI95% 2.80 to 139.18) for PIRADS V vs PIRADS III was observed -. CONCLUSION: Our results show that transperineal targeted prostate biopsy using multiparametric MRI and transrectal ultrasound fusion is a safe procedure with excellent outcomes to obtain an accurate diagnosis of prostate cancer. Fusion biopsy has the potential to improve the diagnosis of malignancy and clinically significant tumors while reducing overdiagnosis.

INTRODUCCIÓN: La biopsia prostática por fusión se describe como superior a la biopsia transrectal sistemática para identificar lesiones sospechosas de carcinoma de próstata.OBJETIVOS: Evaluar la clasificación PIRADS propuesto por la Sociedad Europea de Radiología Urogenital para la detección de cáncer de próstata mediante RNM en una cohorte consecutiva de pacientes con RNM y biopsia guiada por fusión.MATERIAL Y MÉTODOS: Estudio observacional transversal. 87 pacientes con sospecha de cáncer de próstata sometidos a biopsia de próstata transperineal y fusión con RNM en nuestro centro. Describimos tumor significativo como Gleason ≥7(3+4), y carcinoma de alto riesgo como Gleason ≥8. Utilizamos la prueba de Chi-cuadrado para analizar la relación entre cáncer de próstata y PIRADS, así como regresión logística y pruebas de tendencia lineal, comparando las proporciones con medidas de intensidad de asociación. Empleamos el sistema HITACHI Real-Time Virtual Sonography y el software STATA/IC v.14.2 para el análisis estadístico.RESULTADOS: 64,37% pacientes presentaron resultado positivo para malignidad. Media de edad 67,89 años (SD7,42), de PSA total 9,15 ng/ml (SD7,85), y de volumen prostático 54,05 cc (SD22,92). Se biopsiaron 124 lesiones sospechosas en RNM (25% PIRADS III, 57,26% PIRADS IV y 17,74% PIRADS V). 5/31 lesiones PIRADS III, 47/71 PIRADS IV y 18/22 PIRADS V fueron positivas para malignidad, con relación lineal estadísticamente significativa entre PIRADS y malignidad (p<0,001), razón de prevalencias (RP) 4,10 (IC95% 1,81-9,32) para PIRADS IV, y RP 5,07 (CI95% 2,2211,59) para PIRADS V respecto a PIRADS III. 3,23% lesiones PIRADS III, 32,39% PIRADS IV y 63,64% PIRADS V correspondieron a tumores significativos. Encontramos asociación estadísticamente significativa entre PIRADS y tumores significativos (p<0,001), RP 10,04 (IC95% 1,42-71,09) para PIRADS IV y RP 19,73 (IC95% 2,80139,18) para PIRADS V respecto a PIRADS III.CONCLUSIÓN: Nuestros resultados muestran que la biopsia de próstata ecodirigida y por fusión utilizando RNM es una técnica segura con excelentes resultados para obtener un diagnóstico preciso de cáncer de próstata, y puede mejorar el diagnóstico de malignidad y de tumores significativos reduciendo el sobrediagnóstico.

Extracellular Electrophysiology in the Prostate Cancer Cell Model PC-3.

Although prostate cancer is one of the most common cancers in the male population, its basic biological function at a cellular level remains to be fully understood. This lack of in depth understanding of its physiology significantly hinders the development of new, targeted and more effective treatment strategies. Whilst electrophysiological studies can provide in depth analysis, the possibility of recording electrical activity in large populations of non-neuronal cells remains a significant challenge, even harder to address in the picoAmpere-range, which is typical of cellular level electrical activities. In this paper, we present the measurement and characterization of electrical activity of populations of prostate cancer cells PC-3, demonstrating for the first time a meaningful electrical pattern. The low noise system used comprises a multi-electrode array (MEA) with circular gold electrodes on silicon oxide substrates. The extracellular capacitive currents present two standard patterns: an asynchronous sporadic pattern and a synchronous quasi-periodic biphasic spike pattern. An amplitude of ±150 pA, a width between 50⁻300 ms and an inter-spike interval around 0.5 Hz characterize the quasi-periodic spikes. Our experiments using treatment of cells with Gd³âº, known as an inhibitor for the Ca²âº exchanges, suggest that the quasi-periodic signals originate from Ca²âº channels. After adding the Gd³âº to a population of living PC-3 cells, their electrical activity considerably decreased; once the culture was washed, thus eliminating the Gd³âº containing medium and addition of fresh cellular growth medium, the PC-3 cells recovered their normal electrical activity. Cellular viability plots have been carried out, demonstrating that the PC-3 cells remain viable after the use of Gd³âº, on the timescale of this experiment. Hence, this experimental work suggests that Ca²âº is significantly affecting the electrophysiological communication pattern among PC-3 cell populations. Our measuring platform opens up new avenues for real time and highly sensitive investigations of prostate cancer signalling pathways.