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Resumen Objetivo Comparar la esteatosis pancreatica y hepatica mediante la determinacion de la fraccion de grasa por densidad protonica (FGDP) por resonancia magnetica (RM) en pacientes con enfermedad hepatica cronica. Material y metodos Estudio transversal de 46 pacientes adultos con biopsia hepatica por hepatitis viral cronica (n = 19) o por enfermedad hepatica cronica no alcoholica (EHNA) (n = 27). La biopsia de higado se utilizo como referencia para la gradacion de la esteatosis hepatica. Todos los pacientes se sometieron a valoracion clinica y estudio de RM con una secuencia eco de gradiente codificado por desplazamiento quimico con multiples ecos (MECSE) para la cuantificacion de la FGDP en higado y pancreas. Se utilizo el coeficiente de correlacion de Spearman para calcular el grado de asociacion entre la FGDP hepatica y los grados de esteatosis por biopsia, y entre la FGDP pancreatica y la afectacion hepatica (grados de esteatosis y FGDP). El T-test se realizo para comparar variables continuas/ordinales en los grupos de hepatitis viral cronica y EHNA. Las variables categoricas se evaluaron mediante la prueba de χ. Resultados Se observo una correlacion significativa entre la FGDP hepatica y los grados de esteatosis (Rs = 0,875, p Conclusion El deposito de grasa pancreatica se correlaciona con la esteatosis hepatica en pacientes con EHNA cronica. Esta relacion se pierde en los pacientes con hepatitis viral cronica.

Resumen Objetivos: Desarrollar modelos de prediccion de pronostico para pacientes con COVID-19 que acuden a urgencias, basados en la radiografia de torax inicial (RXT), parametros demograficos, clinicos y de laboratorio. Metodos: Se reclutaron todos los pacientes sintomaticos con COVID-19 confirmada, que ingresaron en urgencias de nuestro hospital entre el 24 de febrero y el 24 de abril de 2020. Los parametros de la RXT, las variables clinicas y de laboratorio y los indices de hallazgos en RXT extraidos por una herramienta diagnostica de inteligencia artificial en esta primera visita se consideraron potenciales predictores. El desenlace individual mas grave definio los tres niveles de gravedad: 0) alta domiciliaria u hospitalizacion de 3 dias o inferior, 1) hospitalizacion mas de 3 dias y 2) necesidad de cuidados intensivos o muerte. Se desarrollaron y validaron internamente modelos de prediccion multivariable de gravedad y mortalidad hospitalaria. El indice de Youden se utilizo para la seleccion del umbral optimo del modelo de clasificacion. Resultados: Se registraron 440 pacientes (mediana de 64 anos; 55,9% hombres); el 13,6% de los pacientes fueron dados de alta, el 64% hospitalizo mas de 3 dias, el 6,6% requirio cuidados intensivos y un 15,7% fallecio. El modelo de prediccion de gravedad incluyo saturacion de oxigeno/fraccion de oxigeno inspirado (SatO2/FiO2), edad, proteina C reactiva (PCR), linfocitos, puntuacion de la extension de la afectacion pulmonar en la RXT (ExtScoreRXT), lactato deshidrogenasa (LDH), dimero D y plaquetas, con AUC-ROC = 0,94 y AUC-PRC = 0,88. El modelo de prediccion de mortalidad incluyo edad, SatO2/FiO2, PCR, LDH, ExtScoreRXT, linfocitos y dimero D, con AUC-ROC = 0,97 y AUC-PRC = 0,78. La adicion de indices radiologicos obtenidos por inteligencia artificial no mejoro significativamente las metricas predictivas. Conclusion: Los modelos de prediccion de pronostico desarrollados podrian ser utiles para clasificar en urgencias a los pacientes con COVID-19 u otras infecciones viricas con comportamiento similar.

Nowadays, the images and information generated in imaging tests, as well as the reports that are issued, are digital and represent a reliable source of data. Reports can be classified according to their content and to the type of information they include into three main types: organized (free text in natural language), predefined (with templates and guidelines elaborated with previously determined natural language like that used in BI-RADS and PI-RADS), or structured (with drop-down menus displaying questions with various possible answers that have been agreed on with the rest of the multidisciplinary team, which use standardized lexicons and are structured in the form of a database with data that can be traced and exploited with statistical tools and data mining). The structured report, compatible with Management of Radiology Report Templates (MRRT), makes it possible to incorporate quantitative information related with the digital analysis of the data from the acquired images to accurately and precisely describe the properties and behavior of tissues by means of radiomics (characteristics and parameters). In conclusion, structured digital information (images, text, measurements, radiomic features, and imaging biomarkers) should be integrated into computerized reports so that they can be indexed in large repositories. Radiologic databanks are fundamental for exploiting health information, phenotyping lesions and diseases, and extracting conclusions in personalized medicine.

Resumen Objetivo En este trabajo se analizan en un modelo animal la reproducibilidad y la exactitud de ciertos biomarcadores de imagen de calidad osea utilizando como patron de referencia la microtomografia computarizada (μTC). Material y metodos Se estudiaron con RM y μTC 5 metafisis tibiales de oveja. Las imagenes de RM (3 Tesla) se adquirieron con una secuencia eco de gradiente potenciada en T1 y una resolucion espacial isotropica de 180 μm. Las imagenes de μTC se adquirieron en un escaner con una resolucion espacial de 7,5 μm en voxeles isotropicos. En la preparacion de las imagenes se aplicaron algoritmos de ecualizacion, interpolacion y umbralizacion. En el analisis cuantitativo se calculo el porcentaje de volumen de hueso (BV/TV), el grosor trabecular (Tb.Th), la separacion trabecular (Tb.Sp), el indice trabecular (Tb.N), la dimension fractal en 2 D (D 2D ) y 3 D (D 3D ) y el modulo elastico en las 3 direcciones del espacio (Ex, Ey y Ez). Resultados La cuantificacion morfometrica y mecanica del hueso esponjoso con la RM fue muy reproducible, con porcentajes de variacion por debajo del 9% para todos los parametros. Su exactitud con respecto a la μTC fue alta, con errores inferiores al 15% para BV/TV, D 2D , D 3D y E app x, E app y y E app z. Conclusiones Los resultados experimentales en animales confirman que los parametros de BV/TV, D 2D , D 3D y E app x, E app y y E app z obtenidos a partir de RM tienen una excelente reproducibilidad y precision, y pueden emplearse como biomarcadores de imagen de la calidad del hueso trabecular.

Imaging biomarkers describe objective characteristics that are related to normal biological processes, diseases, or the response to treatment. They enable radiologists to incorporate into their reports data about structure, function, and tissue components. With the aim of taking maximum advantage of the quantification of medical images, we present a procedure to integrate imaging biomarkers into radiological reports, bringing the new paradigm of personal medicine closer to radiological workflow. In this manner, the results of quantification can complement traditional radiological diagnosis, improving accuracy and the evaluation of the efficacy of treatments. A more personalized, standardized, structured radiological report should include quantitative analyses to complement conventional qualitative reporting in selected cases.

MRI is a powerful diagnostic imaging tool and its use has increased significantly in hospitals all over the world. Due to the technical particularities of MRI, all staff members dealing with the scanner need to have adequate knowledge of how it works and of aspects related to safety. The European parliament and council's directive on minimum health and safety requirements for workers dealing with electromagnetic fields (EMF) 2004/40/CE represents a threat to the clinical development and healthcare use of MRI. The efforts of the Alliance for MRI led to a postponement of the European parliament's decision, first until April 2012 and finally until October 2013. The purpose of this article is to define and propose a set of practical rules to ensure the protection of workers involved with MRI scanners. It also aims to define our position with respect to UE directive (2004/40/CE).

Imaging biomarkers define objective characteristics extracted from medical images that are related to normal biological processes, diseases, or the response to treatment. To develop an imaging biomarker, it is necessary to carry out a series of steps to validate its relation with the reality studied and to check its clinical and technical validity. This process includes defining tests for the concepts and mechanisms; obtaining standardized and optimized anatomic, functional, and molecular images; analyzing the data with computer models; displaying data appropriately; obtaining the appropriate statistic measures; and conducting tests on the principle, efficacy, and effectiveness. In this article, we aim to explain the steps that must be established to enable biomarkers to be correctly applied, from their theoretical conception to their clinical implementation. To this end, we use the evaluation of angiogenesis in articular cartilage as an example.

Objetivos. Estudiar la viabilidad del tiempo de relajacion longitudinal (T1) en RM del cartilago patelar como biomarcador del grado de degeneracion. Material y metodos. Se incluyeron 15 sujetos clasificados mediante criterios clinicos (dolor, limitacion funcional y duracion de la sintomatologia) y de imagen como normales (3 hombres, 2 mujeres, 30±14 anos), con degeneracion inicial del cartilago patelar (3 hombres, 2 mujeres, 30±6 anos) y con degeneracion avanzada (3 hombres, 2 mujeres, 57±10 anos). A todos se les realizo un estudio de RM con secuencias especiales eco de gradiente para segmentar el cartilago y calcular los mapas de T1. Se selecciono el cartilago completo y las regiones de interes clasificadas en base a criterios clinico-radiologicos como normalidad, degeneracion inicial y degeneracion avanzada. Los valores de T1 del cartilago se obtuvieron pixel a pixel y se calcularon como la media para todo el cartilago o por subregiones (normal, inicial, avanzada). Las diferencias entre grupos para el cartilago completo y las regiones se analizaron mediante ANOVA Student-Newman-Keuls. La reproducibilidad se estudio mediante el coeficiente de varianza. Resultados. El analisis global del cartilago no presento diferencias estadisticamente significativas entre los 3 grupos (normal: 1.003±172ms; inicial: 1.064±124ms; avanzada: 1.041±308ms, p=0,665). En cambio, en el analisis por regiones se obtuvieron diferencias significativas (normal: 908±53ms; degeneracion inicial: 1.057±157 ms; degeneracion avanzada: 1.133±116 ms; p=0,029). El estudio de reproducibilidad ofrecio variaciones del 1,3% para el calculo global, del 3,7% para el regional, y del 8,2% para la adquisicion. Conclusion. En este estudio preliminar, el calculo del T1 del cartilago permite diferenciar regiones con diferente grado de degeneracion.

Resumen Objetivo Valorar el efecto del tratamiento con cabergolina en el sindrome de hiperestimulacion ovarica (SHO) mediante la aplicacion de modelos mono y bicompartimentales en resonancia magnetica (RM). Material y metodos Se estudiaron 20 mujeres donantes de ovulos con riesgo de desarrollar SHO, divididas en 2 grupos (placebo y tratamiento). Se realizaron 2 estudios de RM de perfusion, antes y tras el inicio del tratamiento. Se comparo el modelo monocompartimental, con parametros de permeabilidad vascular (Ktrans), ratio de extraccion (kep) y fraccion de espacio extravascular extracelular (ve), y el bicompartimental, que anade la fraccion de espacio intravascular (vp). El analisis de las diferencias entre grupos (placebo frente a tratamiento) para los 2 estudios de RM y para cada modelo farmacocinetico se realizo con una prueba t para muestras independientes. El coeficiente de correlacion intraclase (CCI) analizo la variabilidad de las medidas. Resultados En el grupo placebo se observo un incremento significativo de Ktrans para ambos modelos (p=0,021 para un compartimiento, y p 0,95 para todos los parametros, excepto vp (CCI=0,89). Conclusiones La permeabilidad capilar calculada empleando modelos farmacocineticos bicompartimentales tras la administracion de un contraste en RM es un biomarcador del efecto del tratamiento en pacientes con SHO.

Objetivo El analisis morfologico de la estructura trabecular de la epifisis distal del radio y su representacion 3D evalua adecuadamente la calidad del hueso. Nuestro objetivo es presentar un analisis de la morfologia trabecular osea y su modelizacion 3D con resonancia magnetica (RM) de alto campo para detectar aquellos parametros que proporcionan informacion relevante sobre el estado del hueso. Material y metodos Todas las adquisiciones se realizaron con una secuencia 3D eco de gradiente potenciada en T1 en un equipo de RM de 3 Teslas. Se desarrollaron sobre PC en entorno Matlab los algoritmos matematicos necesarios para estudiar la estructura trabecular osea. Se analizaron 16 sujetos sanos (10 mujeres y 6 hombres) en un rango de edades de 23 a 54 anos, siendo la edad media de 36 anos ± 10 (desviacion estandar). No hubo diferencias significativas (p = 0,285) entre mujeres (edad media de 39 anos ± 12; rango: 23-54) y hombres (edad media de 33 anos ± 6; rango: 25-42). Los casos analizados se corresponden con sujetos normales a los que se les realizaba la adquisicion para valoracion ligamentosa de la muneca. Los parametros morfologicos analizados se corresponden con el volumen trabecular, el grosor trabecular medio, la separacion trabecular media y el indice trabecular. Resultados Los parametros morfologicos relevantes para evaluar la calidad del hueso son el volumen trabecular (mujeres: 23,22 ± 1,78%; hombres: 27,49 ± 1,30%), el espesor trabecular (mujeres: 0,1901 ± 0,0014 mm; hombres: 0,1935 ± 0,0014 mm), la separacion trabecular (mujeres: 0,8332 ± 0,0440 mm; hombres: 0,7697 ± 0,0258 mm) y el numero trabecular (mujeres: 1,2215 ± 0,0920 mm −1 ; hombres: 1,4207 ± 0,0640 mm −1 ). Todos los parametros analizados fueron estadisticamente diferentes entre mujeres y hombres, no existiendo diferencias significativas con la edad en esta serie. Conclusiones En este estudio se evidencia que la RM de alta resolucion permite la caracterizacion morfologica de la estructura trabecular osea y supone un avance en la deteccion de biomarcadores de la enfermedad.

We used an animal model to analyze the reproducibility and accuracy of certain biomarkers of bone image quality in comparison to a gold standard of computed microtomography (μCT).We used magnetic resonance (MR) imaging and μCT to study the metaphyses of 5 sheep tibiae. The MR images (3 Teslas) were acquired with a T1-weighted gradient echo sequence and an isotropic spatial resolution of 180μm. The μCT images were acquired using a scanner with a spatial resolution of 7.5μm isotropic voxels. In the preparation of the images, we applied equalization, interpolation, and thresholding algorithms. In the quantitative analysis, we calculated the percentage of bone volume (BV/TV), the trabecular thickness (Tb.Th), the trabecular separation (Tb.Sp), the trabecular index (Tb.N), the 2D fractal dimension (D(2D)), the 3D fractal dimension (D(3D)), and the elastic module in the three spatial directions (Ex, Ey and Ez).The morphometric and mechanical quantification of trabecular bone by MR was very reproducible, with percentages of variation below 9% for all the parameters. Its accuracy compared to the gold standard (μCT) was high, with errors less than 15% for BV/TV, D(2D), D(3D), and E(app)x, E(app)y and E(app)z.Our experimental results in animals confirm that the parameters of BV/TV, D(2D), D(3D), and E(app)x, E(app)y and E(app)z obtained by MR have excellent reproducibility and accuracy and can be used as imaging biomarkers for the quality of trabecular bone.

Imaging biomarkers describe objective characteristics that are related to normal biological processes, diseases, or the response to treatment. They enable radiologists to incorporate into their reports data about structure, function, and tissue components. With the aim of taking maximum advantage of the quantification of medical images, we present a procedure to integrate imaging biomarkers into radiological reports, bringing the new paradigm of personal medicine closer to radiological workflow. In this manner, the results of quantification can complement traditional radiological diagnosis, improving accuracy and the evaluation of the efficacy of treatments. A more personalized, standardized, structured radiological report should include quantitative analyses to complement conventional qualitative reporting in selected cases.

Imaging biomarkers define objective characteristics extracted from medical images that are related to normal biological processes, diseases, or the response to treatment. To develop an imaging biomarker, it is necessary to carry out a series of steps to validate its relation with the reality studied and to check its clinical and technical validity. This process includes defining tests for the concepts and mechanisms; obtaining standardized and optimized anatomic, functional, and molecular images; analyzing the data with computer models; displaying data appropriately; obtaining the appropriate statistic measures; and conducting tests on the principle, efficacy, and effectiveness. In this article, we aim to explain the steps that must be established to enable biomarkers to be correctly applied, from their theoretical conception to their clinical implementation. To this end, we use the evaluation of angiogenesis in articular cartilage as an example.

To study the viability of longitudinal relaxation time (T1) of patellar cartilage as a biomarker of the degree of degeneration.We included 15 subjects classified into three groups according to clinical criteria (pain, functional limitation, and duration of symptoms) and imaging criteria as follows: (a) normal (3 men, 2 women; age 30+/-14 years), (b) with initial degeneration of the patellar cartilage (3 men, 2 women; age 30+/-6 years), or (c) with advanced degeneration (3 men, 2 women; age 57+/-10 years). All underwent MRI examination using special echo-gradient sequences to segment the cartilage and calculate the T1 maps. We selected the entire cartilage and the regions of interest classified according to clinical and imaging criteria as normal, initial degeneration, and advanced degeneration. The T1 values of the cartilage were obtained pixel by pixel and were calculated as the mean for the entire cartilage or by subregions (normal, initial, advanced). Differences between groups for the entire cartilage and the regions were analyzed using Student-Newman-Keuls post-hoc ANOVA. Reproducibility was evaluated using the coefficient of variance.No significant differences in the overall analysis of the entire cartilage were found between the three groups (normal: 1003+/-172 ms, initial: 1064+/-124 ms, advanced: 1041+/-308 ms, p=0.665). However, the analysis by regions revealed significant differences (normal: 908+/-53 ms, initial degeneration: 1057+/-157 ms, advanced degeneration: 1133+/-116 ms, p=0.029). The reproducibility analysis found variations of 1.3% for the overall calculation, 3.7% for the regional calculation, and 8.2% for the acquisition.In this preliminary study, calculating the T1 of the cartilage enabled regions with different degrees of degeneration to be differentiated.

The morphological analysis of trabecular bone of the distal epiphysis of the radius and its three-dimensional representation allow an adequate evaluation of bone quality. We analyzed trabecular bone morphology and its three-dimensional modeling with high resolution magnetic resonance imaging (MRI) to determine the parameters that provide useful information about bone condition.All data were acquired using 3D T1-weighted gradient-echo sequences in a 3-Tesla MRI scanner. The mathematical algorithms required to study trabecular bone structure were developed in a Matlab environment on a personal computer. A total of 16 healthy subjects (10 women and 6 men; aged 23 to 54 years, mean 36+/-10 years) were studied. No significant differences were found between women (mean age 39+/-12, range: 23-54 years) and men (mean age 33+/-6, range: 25-42) (p = 0.285). Healthy subjects were recruited from among normal subjects studied to assess the ligaments of the wrist. The morphological parameters analyzed were trabecular volume, mean trabecular thickness, mean trabecular separation, and trabecular index.The morphological parameters that were useful in the evaluation of bone quality were trabecular volume (women: 23.22+/-1.78%; men: 27.49+/-1.30%), trabecular thickness (women: 0.1901+/-0.0014 mm; men: 0.1935+/-0.0014 mm), trabecular separation (women: 0.8332+/-0.0440 mm; men: 0.7697+/-0.0258 mm), and the number of trabeculae (women: 1.2215+/-0.0920 mm-1; men: 1.4207+/-0.0640 mm-1). Statistically significant differences between men and women were found for all the parameters analyzed; no significant differences were found in relation with age in this series.High resolution MRI enabled the morphological characterization of the trabecular bone structure; this represents an advance in the detection of biomarkers for disease.

To evaluate the response to treatment with cabergoline for ovarian hyperstimulation syndrome (OHS) using mono- and bi-compartmental MRI models.We studied 20 ovum donors with a high risk of developing OHS, divided in two groups (placebo vs. treatment). MRI perfusion studies were performed before and after the beginning of treatment. We compared the monocompartmental model, with the parameters vascular permeability (K(trans)), extraction ratio (k(ep)), and extravascular extracellular space fraction (v(e)), against the bicompartmental model, with the same parameters as in the monocompartmental model and the additional parameter vascular space fraction (v(p)). The differences between groups (placebo vs. treatment) on the two MRI studies and for each pharmacokinetic model were analyzed using t-tests for independent samples. The intraclass correlation coefficient (ICC) was used to assess the variability of the measurements.In the placebo group, a significant increase in K(trans) was observed with both models (p=0.021 for one compartment; and p0.001 for two compartments). In the treatment group, no statistically significant differences were found for any parameter in either model. Regarding differences between groups, in the bicompartmental model K(trans) increased 168.6%+/-151.9% in the placebo group versus 43.3%+/-54.5% in the treatment group, p=0.04). In the monocompartmental model, no differences were found between groups. In the variability analysis, the ICC was higher than 0.95 for all parameters except v(p) (ICC=0.89).Capillary permeability calculated with bicompartmental pharmacokinetic models after MRI contrast administration is a biomarker of the treatment effect in OHS patients.