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Scientific and professional journals must clearly define their editorial line and their guidelines for action regarding the process of review and acceptance of the manuscripts they receive. The role of the Editor-in-Chief is very important in these aspects. This paper will review the actions taken in this regard in the journal Insights into Imaging that placed the journal in the first quartile by impact factor of journals in the area of imaging and radiology. This narrative emphasizes the importance of critical thinking focused on improving editorial processes, guaranteeing the veracity and authorship of the works, equity, plagiarism control, time adjustment from the receipt to the final decision, simplification of the editorial process, and commitment to foster disruptive articles maintaining a structure focused on the best available evidence. All these measures aim to promote the perceived quality of the journal and the immediate impact of publications.

Background and objectives: In hemophiliac patients, recurrent intra-articular bleeding leads to progressive arthropathy. Magnetic resonance imaging (MRI) is the gold-standard technique for joint assessment. The development of ultrasound protocols and standardized scales such as “Hemophilia Early Arthropathy Detection with Ultrasound” (HEAD-US) and “Point-of-care Ultrasonography” (POC-US) allow patient monitoring. Our main objective is to establish the diagnostic accuracy of ultrasound in the early detection of hemophilic arthropathy, with MRI as the gold standard. The interobserver variability in the ultrasound and MRI scales, the association between the POC-US and HEAD-US protocol, and the ability of ultrasound to detect haemosiderotic remnants will also be established. Patients and Methods: 45 hemophiliac patients were included. 180 joints (knees and ankles) were evaluated with MRI (Denver scale) and Ultrasound (HEAD-US and POC-US scale). Results: There is a high and statistically significant association between the ultrasound and MRI scales. Only for the ankle effusion variable the association was medium. The specificity of HEAD-US was ≥90% in both joints. Sensitivity in the knee did not exceed 82% in any assessed aspect, being high in the ankle for the cartilage and bone alterations (97%) but low for effusions (55%). In general, the predictive values ​​were high, with the exception of the negative predictive value of joint leak in knee and ankle (close to 70%). Ultrasound did not detect haemosiderotic remnants in any case. Statistically significant interobserver agreement was obtained for HEAD-US and Denver-MRI assessment. The level of association between the HEAD-US scale and the POC-US protocol was medium. Conclusions: Ultrasound is a technique with high diagnostic accuracy and reproducibility to detect and quantify the early signs of hemophilic arthropathy. Ultrasound is insensitive to detect haemosiderin in synovial hypertrophy.

Magnetic resonance (MR) identification and grading of subjects with liver fibrosis and inflammation represents a clinical challenge. MR elastography plays a well-defined role in fibrosis estimation, but its use is not widely available in clinical settings. Given that liver MR is becoming the reference standard for fat and iron quantitation, there is a need to clarify whether there is any role for MR imaging in the concomitant evaluation of fibrosis and inflammation in this setting. This review summarizes the diagnostic estimations of different MR imaging parameters obtained from conventional non-contrast-enhanced multiple b values diffusion-weighted acquisitions, variable flip angles T1 relaxation maps and STIR images. Although some derived parameters have shown a significant correlation to histological scores, a small magnitude of effect with wide overlap across severity grades is the rule. Contrary to fat and iron quantification, the low precision and reproducibility of MR imaging metrics limits its clinical relevance in fibrosis and inflammation assessment. In a sequential clinical approach combining different methodologies, MR imaging has no applicability for ruling-out and low accuracy for ruling-in advanced fibrosis. Thereby, MR elastography remains as the only image method with high diagnostic accuracy for the detection of advanced fibrosis. Until date, inflammation remains in a gray zone where biopsy cannot be replaced, and further investigations are needed. The present review offers an in-depth discuss of the MR imaging diagnostic performance for the evaluation of liver fibrosis and inflammation, highlighting the need for scientific improvements.

The association of non-alcoholic fatty liver disease (NAFLD) with insulin resistance (IR) is well established, yet little is known of their possible relationship with intrahepatic iron and serum tumour necrosis factor (TNF)-α concentrations in adults without diabetes. Thus, this study looked at the relationship of intrahepatic iron and serum TNF-α with intrahepatic triglycerides and IR in non-diabetic adults.In this cross-sectional study of 104 healthy non-diabetic Caucasians, a quantitative magnetic resonance (MR) imaging T2 gradient-echo technique was used to measure hepatic iron, with 1H-MR spectroscopy used to measure hepatic triglycerides. HOMA-IR was calculated to determine IR.The prevalence of hepatic iron overload (HIOL) was 26.6% in individuals with NAFLD vs. 0% in those without. IR was present in 87.5% of subjects with both NAFLD and HIOL, in 45.4% of those with NAFLD but not HIOL, and in 4.5% of those with neither. HOMA-IR was positively correlated with hepatic triglycerides (r = 0.56, P 0.001) and hepatic iron (r = 0.52, P 0.001), whereas serum TNF-α concentrations correlated with intrahepatic triglyceride levels (r = 0.28, P 0.04), but not with intrahepatic iron. Hepatic triglycerides, serum TNF-α and age were the only significant determinants of IR in regression analyses.IR is closely associated with intrahepatic triglycerides and, to a lesser extent, intrahepatic iron, with some interplay between them. High serum TNF-α concentrations may contribute to the association between NAFLD and IR, while increased hepatic triglycerides appear to be a determinant of the development of HIOL in non-diabetic subjects without haemochromatosis.

Resumen Antecedentes y objetivo Existe una carencia de metricas cuantitativas de la calidad del hueso trabecular alveolar, factor determinante en implantologia. El objetivo de este estudio es desarrollar una metodologia con tomografia computarizada multidetector para objetivar la calidad del hueso trabecular y establecer diferencias entre los distintos tipos y el estado de las piezas dentarias mediante procesado de imagenes y analisis estructural. Materiales y metodos Se analizan 20 pacientes con exploracion de tomografia computarizada multidetector dental para la valoracion del hueso mandibular y posiciones dentales. El analisis de las imagenes incluyo la segmentacion automatica de la mandibula, obtencion de secciones perpendiculares a la arcada dentaria y analisis estructural del hueso trabecular de cada seccion. Se obtuvieron la ratio entre volumen de hueso y volumen total de la seccion, el grosor, la separacion y el numero trabecular, y la atenuacion promedio en unidades Hounsfield. Se analizaron diferencias entre tipos de diente (incisivos, caninos, premolares y molares) y entre estados de las piezas dentarias (ausente o presente). Resultados Se obtuvieron diferencias estadisticamente significativas entre los tipos y estados de las piezas. Por tipo, los incisivos mostraron mayor ratio de hueso trabecular, con disminucion progresiva para caninos, premolares y molares. Por estado, las secciones pertenecientes a dientes ausentes presentaron mayor ratio de hueso que con el diente presente. Conclusiones La metodologia desarrollada permite cuantificar las propiedades estructurales del hueso alveolar a partir de imagenes de tomografia computarizada multidetector. Los resultados obtenidos objetivan el estado del sustrato oseo de cara a la planificacion y seguimiento de la colocacion de implantes dentales.

[EN] Purpose: To determine if preoperative vascular heterogeneity of glioblastoma is predictive of overall survival of patients undergoing standard-of-care treatment by using an unsupervised multiparametric perfusion-based habitat-discovery algorithm. Materials and Methods: Preoperative magnetic resonance (MR) imaging including dynamic susceptibility-weighted contrast material-enhanced perfusion studies in 50 consecutive patients with glioblastoma were retrieved. Perfusion parameters of glioblastoma were analyzed and used to automatically draw four reproducible habitats that describe the tumor vascular heterogeneity: high-angiogenic and low-angiogenic regions of the enhancing tumor, potentially tumor-infiltrated peripheral edema, and vasogenic edema. Kaplan-Meier and Cox proportional hazard analyses were conducted to assess the prognostic potential of the hemodynamic tissue signature to predict patient survival. Results: Cox regression analysis yielded a significant correlation between patients' survival and maximum relative cerebral blood volume (rCBV(max)) and maximum relative cerebral blood flow (rCBF(max)) in high-angiogenic and low-angiogenic habitats (P < .01, false discovery rate-corrected P < .05). Moreover, rCBF(max) in the potentially tumor-infiltrated peripheral edema habitat was also significantly correlated (P < .05, false discovery rate-corrected P < .05). Kaplan-Meier analysis demonstrated significant differences between the observed survival of populations divided according to the median of the rCBV(max) or rCBF(max) at the high-angiogenic and low-angiogenic habitats (log-rank test P < .05, false discovery rate-corrected P < .05), with an average survival increase of 230 days. Conclusion: Preoperative perfusion heterogeneity contains relevant information about overall survival in patients who undergo standard-of-care treatment. The hemodynamic tissue signature method automatically describes this heterogeneity, providing a set of vascular habitats with high prognostic capabilities., Study supported by H2020 European Institute of Innovation and Technology (POC-2016.SPAIN-07) and Universitat Politecnica de Valencia (PAID-10-14). J.J.A., E.F.G., and J.M.G.G. supported by Secretaria de Estado de Investigacion, Desarrollo e Innovacion (DPI2016-80054-R, TIN2013-43457-R). E.F.G. supported by CaixaImpulse program from Fundacio Bancaria "la Caixa" (LCF/TR/CI16/10010016). E.F.G and A.A.B. supported by the Universitat Politecnica de Valencia Instituto Investigacion Sanitaria de La Fe (C05).

Resumen Objetivo Nuestro objetivo fue analizar el rendimiento de la biopsia selectiva del ganglio centinela valorando la deteccion gammagrafica tras la administracion intratumoral del radiofarmaco en pacientes con cancer de mama que recibieron quimioterapia neoadyuvante. Material y metodos Sesenta pacientes con diagnostico de carcinoma infiltrante de mama, estadios T1-T3, que recibieron tratamiento con quimioterapia neoadyuvante fueron sometidas posteriormente a cirugia mamaria y biopsia del ganglio centinela mediante administracion intratumoral del radiofarmaco. Resultados Se consiguio la deteccion gammagrafica de algun ganglio centinela en 55/60 pacientes (91,6%). Cuando se excluyeron los casos con reinyeccion periareolar del radiofarmaco por falta de migracion, la deteccion fue del 70% (42/60). Cuando se comparo la deteccion o no del ganglio centinela en estas 42 pacientes, no se encontraron diferencias en funcion de la edad, lateralidad-localizacion de la lesion, tamano pre y posquimioterapia, grado histologico del tumor o perfil inmunohistoquimico. Si existieron diferencias significativas al comparar los grupos segun el grado de respuesta patologica del tumor, valorado tanto con el sistema de Miller-Payne (no deteccion 44,4%-deteccion 16,7%, p = 0,003) como con el sistema residual cancer burden (72,2%-28,6%, p Conclusiones La deteccion gammagrafica del ganglio centinela tras administracion intratumoral del radiofarmaco en pacientes con cancer de mama que recibieron quimioterapia neoadyuvante estuvo por debajo del valor optimo, siendo necesaria en ocasiones la reinyeccion periareolar, lo que podria estar en relacion con una alteracion de las vias de drenaje linfatico. Existio una significativa relacion inversa entre deteccion del ganglio centinela y el grado de respuesta patologica tumoral.

espanolObjetivos Comparar los resultados de la dosimetria individual en pacientes de cancer diferenciado de tiroides tratados con 131I en nuestro centro con los limites dosimetricos establecidos y con resultados obtenidos en estudios publicados. Analizar el numero optimo de medidas a realizar para reducir el impacto de la dosimetria en el bienestar del paciente y, en segundo termino, en la carga de trabajo del personal sanitario. Material y metodos Se realiza la dosimetria a 29 pacientes del Servicio de Medicina Nuclear del Hospital Universitario y Politecnico La Fe, afectados de cancer diferenciado de tiroides y tratados con actividades de entre 1,02 y 5,51 GBq (promedio de 2,68 GBq) de 131I. Para ello se utiliza el protocolo de la Sociedad Espanola de Fisica Medica (SEFM) basado en medidas de tasa de dosis externa ajustadas a una curva biexponencial, de acuerdo con un modelo de dos compartimentos. Para cada paciente se realizan distintas dosimetrias tomando diferentes selecciones de las medidas disponibles a fin de buscar el numero optimo. Resultados Los resultados estan muy por debajo de los limites dosimetricos y son coherentes con los obtenidos en otros centros. El numero de medidas puede reducirse de 5, como propone el protocolo de la SEFM, a 4 sin perdida de precision significativa. Una mayor reduccion de medidas puede justificarse en casos particulares. Conclusiones Los valores obtenidos para las magnitudes dosimetricas quedan muy por debajo de los limites establecidos. Se puede asumir la reduccion de medidas a costa de un aumento de la incertidumbre moderado beneficiando del paciente. EnglishObjectives To compare the results of individual dosimetry in differentiated thyroid cancer patients treated with 131I at our centre with the established limits and dosimetry results of published studies. Analysis of the optimal number of measurements necessary to reduce the impact of dosimetry for the comfort of the patient and, secondly, on the workload of health workers. Material and methods Dosimetry was performed in the Nuclear Medicine Department of the University and Polytechnic Hospital La Fe, on 29 patients suffering from differentiated thyroid cancer and treated with activities between 1.02 and 5.51 GBq (mean 2.68 GBq) of 131I. The Spanish Society of Medical Physics (SEFM) protocol was used, based on measurements of external dose rate adjusted to a bi-exponential curve according to a two compartment model. Different dosimetries were performed on each patient, taking different selections of the available measurements in order to find the optimal number. Results Results are well below the dosimetry limits, and are consistent with those obtained in other centres. The number of measurements can be reduced from 5, as proposed in the SEFM protocol, to 4 without significant loss of accuracy. Further reducing measures may be justified in individual cases. Conclusions The values obtained for the dosimetry quantities are significantly below the established limits. A reduction in measurements can be assumed at the cost of a moderate increase in uncertainty, benefiting the patient.

There is a lack of quantitative measures of the quality of alveolar trabecular bone, an important factor in implantology. This study aimed to develop a method of objectively assessing the quality of trabecular bone by means of image processing and structural analysis of multidetector computed tomography images and to establish differences between tooth types and tooth presence/absence.We analyzed 20 patients who underwent multidetector computed tomography to evaluate mandibular bone and tooth positioning. Image analysis included automatic segmentation of the mandible, obtainment of sections perpendicular to the dental arch, and structural analysis of the trabecular bone in each section. We calculated the ratio between the volume of bone and the total volume of the section, the thickness, the trabecular number, and the mean attenuation in Hounsfield units. We analyzed the differences among different tooth types (incisors, canines, premolars, and molars) and between present and absent teeth.We found statistically significant differences between different tooth types and between sections in which teeth were present or absent. Incisors had a greater ratio of trabecular bone; the ratio of trabecular bone progressively decreased from the incisors to the canines, premolars, and molars. The ratio of trabecular bone was greater in sections in which teeth were absent than in those in which teeth were present.The method allows to quantify the structural properties of alveolar bone from multidetector computed tomography images. Our results provide an objective picture of the bone substrate that can be useful for planning and following up dental implant procedures.

There is a need for early identification of patients with chronic liver diseases due to their increasing prevalence and morbidity-mortality. The degree of liver fibrosis determines the prognosis and therapeutic options in this population. Liver biopsy represents the reference standard for fibrosis staging. However, given its limitations and complications, different non-invasive methods have been developed recently for the in vivo quantification of fibrosis. Due to their precision and reliability, biomarkers' measurements derived from Ultrasound and Magnetic Resonance stand out. This article reviews the different acquisition techniques and image processing methods currently used in the evaluation of liver fibrosis, focusing on their diagnostic performance, applicability and clinical value. In order to properly interpret their results in the appropriate clinical context, it seems necessary to understand the techniques and their quality parameters, the standardization and validation of the measurement units and the quality control of the methodological problems.

Several pathological conditions carry high risk of bone fracture which is associated to high economic and healthy costs. In order to improve understanding the bone microarchitecture, this work aims to evaluate the accuracy of the bone analysis methodology and compare it to the reference standard under different imaging modalities. The results indicate that there is a good relation between the analysis of the bone analysis methodology obtained from the MDCT and MR scans and these modalities can be used for bone quality assessment in clinical practice.

The Spanish Agency for Drugs and Healthcare Products (AEMPS), based on the recommendations of the European Committee for Risk Assessment in Pharmacovigilance, established on 13 March 2017 that linear gadolinium-based MR contrast media, such as MultiHance, Omniscan, Magnevist (currently not marketed) and Optimark (no longer marketed in Spain), the clinical benefits do not outweigh the potential risks derived from their use. AEMPS recommends to suspend its marketing for general use based on the retention of these compounds in the brain. On the other hand, the AEMPS justifies the maintenance of Primovist and MultiHance for liver studies, and Magnevist of intra-articular administration (not commercialized in Spain), and justified the almost exclusive use of macrocyclic structure contrasts (Gadovist, ProHance and Dotarem). However, this retention is known to be different for each of the contrast media. All existing gadolinium contrasts agents have a distribution phase with tissue retention, due to a very slow exchange, in the interstitium of bone, skin, kidney, brain and other organs. The existence of histological effects or clinical symptoms associated with the accumulation of these trace amounts of gadolinium has not been demonstrated. The major toxicological concern with these contrast agents is related to nephrogenic systemic fibrosis (NSF). Since the safety profiles are mainly related to the interstitial retention space in the tissues, it does not seem justified to actually exclude contrast media that do not have cases related to the NSF. Based on all of this, we disagree with the latest AEMPS recommendation suggesting the marketing stoppage of linear agents without considering the individual retention profiles. This recommendation is not based neither on the data nor existing knowledge about the retention, relaxivity and clinical efficiency of the Gd compounds. It is therefore necessary to carry out prospective studies on the histological and clinical relevance of these organic Gd deposits.

Resumen Objetivos Estudiar si los histogramas de los parametros cuantitativos de perfusion por RM obtenidos a partir de los volumenes tumoral y peritumoral permiten clasificar in vivo el grado de los astrocitomas. Material y metodos Se incluyen 61 pacientes diagnosticados histologicamente de astrocitoma grado II, III o IV, estudiados mediante RM de perfusion T2* con contraste intravenoso, seleccionando manualmente los volumenes tumoral y peritumoral, cuantificandose voxel a voxel diferentes parametros de perfusion: volumen sanguineo (VS), flujo sanguineo (FS), tiempo de transito medio (TTM), constante de transferencia (K trans ), coeficiente de lavado, volumen intersticial y volumen vascular. Para cada volumen se obtuvo el histograma correspondiente con su media, desviacion tipica y curtosis, estas ultimas como medidas de heterogeneidad, comparandose las diferencias por parametro y grado tumoral. Tambien se calcularon la media y desviacion del 10% de los valores maximos. Finalmente se realizo un analisis discriminante multiparametrico para mejorar la clasificacion. Resultados En el volumen tumoral se obtuvieron diferencias estadisticamente significativas entre los 3 grados tumorales para la media y la desviacion de VS, FS y K trans , tanto para la distribucion completa, como para el 10% maximo. En la region peritumoral no se obtuvieron diferencias significativas para ningun parametro. El analisis discriminante mejoro ligeramente la clasificacion. Conclusiones La cuantificacion de parametros del volumen total de la region tumoral con VS, FS y K trans es util para establecer el grado de los astrocitomas. La heterogeneidad, representada por la desviacion tipica del FS, es el parametro con mayor fiabilidad diagnostica para separar los tumores de bajo y alto grado.

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).

SummaryBackground: Radiology reports are commonly written on free-text using voice recognition devices. Structured reports (SR) have a high potential but they are usually considered more difficult to fill-in so their adoption in clinical practice leads to a lower efficiency. However, some studies have demonstrated that in some cases, producing SRs may require shorter time than plain-text ones. This work focuses on the definition and demonstration of a methodology to evaluate the productivity of software tools for producing radiology reports. A set of SRs for breast cancer diagnosis based on BI-RADS have been developed using this method. An analysis of their efficiency with respect to free-text reports has been performed.Material and Methods: The methodology proposed compares the Elapsed Time (ET) on a set of radiological reports. Free-text reports are produced with the speech recognition devices used in the clinical practice. Structured reports are generated using a web application generated with TRENCADIS framework. A team of six radiologists with three different levels of experience in the breast cancer diagnosis was recruited. These radiologists performed the evaluation, each one introducing 50 reports for mammography, 50 for ultrasound scan and 50 for MRI using both approaches. Also, the Relative Efficiency (REF) was computed for each report, dividing the ET of both methods. We applied the T-Student (T-S) test to compare the ETs and the ANOVA test to compare the REFs. Both tests were computed using the SPSS software.Results: The study produced three DICOM- SR templates for Breast Cancer Diagnosis on mammography, ultrasound and MRI, using RADLEX terms based on BIRADs 5th edition. The T-S test on radiologists with high or intermediate profile, showed that the difference between the ET was only statistically significant for mammography and ultrasound. The ANOVA test performed grouping the REF by modalities, indicated that there were no significant differences between mammograms and ultrasound scans, but both have significant statistical differences with MRI. The ANOVA test of the REF for each modality, indicated that there were only significant differences in Mammography (ANOVA p = 0.024) and Ultrasound (ANOVA p = 0.008). The ANOVA test for each radiologist profile, indicated that there were significant differences on the high profile (ANOVA p = 0.028) and medium (ANOVA p=0.045).Conclusions: In this work, we have defined and demonstrated a methodology to evaluate the productivity of software tools for producing radiology reports in Breast Cancer. We have evaluated that adopting Structured Reporting in mammography and ultrasound studies in breast cancer diagnosis improves the performance in producing reports.

Purpose: Our objective was to analyse the accuracy of the sentinel node biopsy, taking into consideration the scintigraphy detection rate after the intratumoural administration of the radiopharmaceutical in patients with breast cancer who received neoadjuvant chemotherapy. Materials and methods: The study included 60 patients with a diagnosis of invasive breast carcinoma, stage T1-T3, who received treatment with neoadjuvant chemotherapy, and were subsequently subjected to breast surgery and sentinel node biopsy after intra-tumour administration of the radiopharmaceutical. Results: Scintigraphic detection of some sentinel node was achieved in 55/60 patients (91.6%). When those cases that received a second injection of the radiopharmaceutical, performed peri-areolarly due to a lack of tracer migration, were excluded, the detection rate dropped to 70% (42/60). When the detection of sentinel node, or its absence, was compared in those 42 patients, no differences were found with age, laterality-location of the lesion, size pre- and post-neoadjuvant chemotherapy, histological grade, or immunohistochemical profile. There were significant differences when comparing the groups according to the degree of pathological tumour response, both with the Miller-Payne system (non-detection 44.4%-detection 16.7%, p = 0.003) as well as the residual cancer burden (72.2%-28.6%, p

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.

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.

Brain connectivity is a key concept for understanding brain function. Current methods to detect and quantify different types of connectivity with neuroimaging techniques are fundamental for understanding the pathophysiology of many neurologic and psychiatric disorders. This article aims to present a critical review of the magnetic resonance imaging techniques used to measure brain connectivity within the context of the Human Connectome Project. We review techniques used to measure: a) structural connectivity b) functional connectivity (main component analysis, independent component analysis, seed voxel, meta-analysis), and c) effective connectivity (psychophysiological interactions, causal dynamic models, multivariate autoregressive models, and structural equation models). These three approaches make it possible to combine and use different statistical techniques to elaborate mathematical models in the attempt to understand the functioning of the brain. The findings obtained with these techniques must be validated by other techniques for analyzing structural and functional connectivity. This information is integrated in the Human Connectome Project where all these approaches converge to provide a representation of all the different models of connectivity.

Objectives. To classify the tumor areas in patients with grade IV astrocytoma by calculating and statistically analyzing quantitative MRI perfusion parameters. Material and methods. We applied two models of MRI perfusion, the unicompartmental and the pharmacokinetic models, in 15 patients diagnosed with grade IV astrocytoma. In the unicompartmental model, we quantified cerebral blood volume (CBV), mean transit time (MTT), and cerebral blood flow (CBF). In the pharmacokinetic model, we measured the permeability constant (Ktrans), the extraction coefficient (kep), the fraction of the volume in the interstitial space (ve), the fraction of the volume in the vessels (vp), the permeability in the first pass (Kfp), and the vascular volume in the first pass (vpfp). For each parameter, histograms were obtained for the total tumor area, for the peritumoral area, and for the healthy tissue. The statistical analysis included an analysis of variance for each parameter and a discriminant analysis. Results. The most significant differences between the regions were obtained with CBV, CBF, Ktrans, and vpfp; of these, CBV had the best results. The best classificatory function on the discriminant analysis was the combination of Ktrans and CBV. The analysis of the shape of the histogram showed statistically significant differences for the kurtosis of Ktrans and kep, as well as for the skewness of CBV, CBF, Ktrans, and vpfp. Conclusion. When parameters are considered individually, CBV is the one that best enables differentiation between tumor, peritumoral, and healthy tissue. The classificatory function generated from CBV and Ktrans results in improved classification by areas.

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.

Objectives To study the viability of longitudinal relaxation time ( T1 ) of patellar cartilage as a biomarker of the degree of degeneration. Material and methods 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. Results 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. Conclusion In this preliminary study, calculating the T1 of the cartilage enabled regions with different degrees of degeneration to be differentiated.

Resumen Objetivo Estimar las relaciones dinamicas entre los fluidos craneoespinales (liquido cefalorraquideo [LCR] y sangre) en el espacio ventricular, subaracnoideo cerebral y subaracnoideo espinal mediante la cuantificacion de imagenes de resonancia magnetica (RM) en contraste de fase. Material y metodos Se analizaron 15 sujetos voluntarios sanos en la misma franja horaria y bajo la misma intensidad de campo (3 T). Para cada estudio se realizaron 4 exploraciones en contraste de fase: 2 secuencias para el calculo de LCR (acueducto de Silvio y espacio perimedular C2-C3) y 2 para el calculo del flujo sanguineo (arterias carotidas internas y vertebrales, seno sagital superior y recto). En todos los sujetos se calcularon los parametros de amplitud (volumen sistolico, flujo promedio, indices de pulsatibilidad y distensibilidad, amplitud del gradiente de presion absoluta y relacion de volumen de fluido de LCR por ciclo) y temporales (retrasos frente a la entrada de flujo arterial). Resultados Respecto a la entrada de sangre arterial, el desplazamiento de sangre venosa (al 22 y 38% del ciclo cardiaco en los senos recto y sagital superior, respectivamente) y del LCR (al 12 y 25% de ciclo cardiaco en el espacio perimedular C2-C3 y el acueducto de Silvio, respectivamente) describen la distribucion de la pulsatibilidad de los fluidos intracraneales. Se obtienen indices de distensibilidad para los compartimientos encefalico y medular en una poblacion normal. Conclusiones Mediante los mapas de velocidad de flujo obtenidos con RM es posible describir de manera cuantitativa las relaciones dinamicas de los fluidos intracraneales e inferir el comportamiento elastico encefalico y medular.

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.

This article reviews the regulations in force about the exposure of workers to the electromagnetic fields generated by magnetic resonance imaging (MRI) and evaluates the impact of European Directive 2004/40/EC on the daily use of MRI. We provide a detailed review of the safety criteria stipulated in the International Commission on Non-Ionizing Radiation Protection, in Spanish Royal Decree 1066/2001, and in European Directive 2004/40/EC about exposure to electromagnetic fields. In the case of European Directive 2004/40/EC, the European Union (EU) has introduced a law without adequately evaluating its repercussions. In response to alarms sounded by the radiological and general medical communities, the EU has decided to delay implementation of the Directive. Although the implementation of Directive 2004/40/ EC has been postponed until April 30, 2012, it remains in force. There remains the hope that the Directive will be reconsidered during this interval and that MRI workers will be exempt.

Resumen Objetivo Establecer valores de normalidad de los diferentes parametros que caracterizan la dinamica del liquido cefalorraquideo (LCR) en el acueducto de Silvio (velocidad, flujo, volumen por ciclo y produccion), obtenidos de las imagenes de resonancia magnetica (RM) por contraste de fase empleando un metodo de posproceso fiable y reproducible. El metodo semiautomatico optimizado presenta una variabilidad nula de los resultados interobservador y corrige los errores debidos a los movimientos de baja amplitud, al submuestreo (aliasing) y al efecto del volumen parcial. Material y metodos Se analizo a 42 sujetos sanos sin alteraciones neurologicas, hidrocefalia ni enfermedades cerebrovasculares. Las imagenes se adquirieron en un equipo de RM de 1,5 T con una secuencia de contraste de fase. Todas las exploraciones se adquirieron en la misma franja horaria (de 14:00 a 18:00 h) para evitar influencias circadianas. Resultados Se obtuvieron valores de normalidad para cada uno de los parametros que caracterizan la dinamica del LCR en el acueducto de Silvio (velocidades maximas diastolica y sistolica, velocidad promedio, flujos maximos diastolico y sistolico, flujo promedio, produccion de LCR y volumen por ciclo). Aunque hubo una tendencia, ni el sexo ni la edad ( 51 anos) influyeron estadisticamente en los parametros calculados. Conclusiones Aunque las mediciones de los parametros de la dinamica del flujo de LCR son sensibles a multiples factores (resolucion temporal y espacial de la secuencia RM, ritmo circadiano, edad y sexo, y fabricante del equipo de RM), un metodo optimizado de posproceso permite establecer valores y rangos de normalidad precisos y reproducibles.

The tough [correction of turf] battles with other specialties that tend to take control of the radiological practice and some of our areas of interest are one of the most important problems that Radiology must face at the present time. Interventional Radiology is the last one and the more recent example of this phenomenon that spreads world-wide. Far from defeatist attitudes, we must learn from our past mistakes to turn this scenario into an opportunity to evolve towards a more competitive and updated specialty according to our time. The authors review the present situation of the tough [correction of turf] batlles of Radiology with other specialties, pointing to their possible causes and proposing the resolution strategies.

La imagen basada en la genomica y la proteomica va a permitir seleccionar a poblaciones e individuos «con riesgo» de padecer una determinada enfermedad antes de que aparezcan los sintomas clinicos, identificando la existencia, localizacion y extension de las bases de la enfermedad, estratificando el riesgo y posibilitando la realizacion y el control de tratamientos disenados para cada paciente. Estas tecnicas de imagen molecular deben generar, para ser eficaces, informacion tanto funcional como estructural. La utilizacion de sondas de imagen junto a equipamientos avanzados permite ver numerosos complejos moleculares y estructuras celulares. La imagen molecular permite, directa o indirectamente, recoger y seguir la distribucion espacio- temporal de los procesos moleculares o celulares con aplicaciones no solo clinicas (diagnosticas y terapeuticas), sino tambien basicas (bioquimicas y fisiologicas). En la parte clinica, la Medicina Nuclear y la Radiologia estan necesariamente obligadas a trabajar conjuntamente para liderar el desarrollo, la implantacion y la evaluacion tecnologica de la imagen molecular. Desde esta perspectiva, las tecnicas de hibridacion molecular deben progresar hacia la coordinacion de esfuerzos, tanto de formacion y utilizacion, como de investigacion, que permitan desarrollarnos plenamente como profesionales de la imagen medica al servicio de la sanidad. La imagen molecular dota a los medicos relacionados con la imagen medica de la posibilidad de avanzar sustancialmente en el diagnostico precoz, la estratificacion del riesgo y el pronostico, y la monitorizacion del tratamiento de numerosos procesos biologicos y celulares relacionados con la enfermedad.

To compare the results of individual dosimetry in differentiated thyroid cancer patients treated with (131)I at our centre with the established limits and dosimetry results of published studies. Analysis of the optimal number of measurements necessary to reduce the impact of dosimetry for the comfort of the patient and, secondly, on the workload of health workers.Dosimetry was performed in the Nuclear Medicine Department of the University and Polytechnic Hospital La Fe, on 29 patients suffering from differentiated thyroid cancer and treated with activities between 1.02 and 5.51 GBq (mean 2.68 GBq) of (131)I. The Spanish Society of Medical Physics (SEFM) protocol was used, based on measurements of external dose rate adjusted to a bi-exponential curve according to a two compartment model. Different dosimetries were performed on each patient, taking different selections of the available measurements in order to find the optimal number.Results are well below the dosimetry limits, and are consistent with those obtained in other centres. The number of measurements can be reduced from 5, as proposed in the SEFM protocol, to 4 without significant loss of accuracy. Further reducing measures may be justified in individual cases.The values obtained for the dosimetry quantities are significantly below the established limits. A reduction in measurements can be assumed at the cost of a moderate increase in uncertainty, benefiting the patient.

Object: Automatic accurate measurement techniques are needed to increase reproducibility in the quantification of cervical cord area (CCA) with magnetic resonance (MR) imaging in the assessment of central nervous system (CNS) atrophy in multiple sclerosis (MS) patients. Materials and methods: Two segmentation methods were implemented: (1) spatial mean brightness level estimation (SMBLE), and (2) partial-volume modeling (PVM). These were evaluated with the inclusion of spinal cord inclination and/or partial-volume-effect corrections. An averaged manually segmented set was considered as reference. Thirty MR studies were used to compare the different methods. A set of 15 MS patients and 15 control subjects within a two-year longitudinal study were used to evaluate cord atrophy with the best method. Statistical evaluation was made by using an intraclass correlation coefficient and Bland–Altman comparisons. Results: Partial-volume modeling with spinal cord inclination correction and partial-volume spinal-cord contour contribution estimation was the most accurate method. The longitudinal test showed a 4% decrease in CCA in MS patients with no significant reduction in control subjects. Conclusion: The automatic PVM cord-segmentation approach, taking into consideration the spinal-cord inclination and partial-volume treatment, provides reproducibility and increased accuracy in the evaluation of cord atrophy, allowing the monitoring of changes in MS patients.

Objetivo Analizar la distinta contribucion de las categorias jerarquicas en los articulos publicados por radiologos de hospitales pertenecientes a la Comunidad Valenciana en el periodo 1994-2001, asi como su distribucion en las revistas. Material y metodo Para la recuperacion de la muestra de articulos hemos disenado perfiles de busqueda especificos para las bases de datos IME y Medline. Se identifico la categoria jerarquica de los autores mediante entrevistas personales. Resultados Hemos analizado 417 trabajos, con 1.321 firmas distribuidas de la siguiente forma: jefe de servicio: 8,8%; jefe de seccion: 12,4%; adjunto: 50,7%, y residente: 28%. Las agrupaciones jerarquicas con participacion de residentes fueron las que firmaron de manera mas estable trabajos en todas las anualidades (1994-2001). El mayor porcentaje de firmas (21%) correspondio a la agrupacion «residentes + adjuntos». Radiologia fue la revista mas productiva (42% de los trabajos). Todos los resultados fueron estadisticamente significativos (p Conclusion Los residentes en radiodiagnostico de los hospitales de la Comunidad Valenciana mostraron una participacion activa en los articulos e investigacion publicados en el periodo 1994-2001, en colaboracion con el resto de las categorias jerarquicas, mas frecuentemente con adjuntos. La figura del adjunto aporto el mayor numero de firmas. El jefe de seccion y el jefe de servicio suponen, conjuntamente, la quinta parte de las firmas.

Resumen Objetivos Establecer las variables minimas para diagnosticar las lesiones de la boveda craneal con tomografia computarizada (TC) y comprobar la precision de la regresion logistica (RL) y las redes neuronales artificiales (RN) en su diagnostico. Material y Metodos Estudiamos 167 pacientes con lesiones de boveda craneal como unica manifestacion conocida de enfermedad. Los datos clinicos y de la TC se emplearon para los modelos de RL y RN, que se probaron con el metodo jacknife. Los resultados finales de cada modelo se compararon con el area bajo la curva ROC (A2). Resultados Las lesiones fueron en un 73,1 % benignas y 26,9% malignas. No hubo diferencia estadisticamente significativa entre la RL y la RN para diagnosticar las lesiones malignas. Para la caracterizacion de los diagnosticos histologicos, la RN fue estadisticamente superior a la RL. Las variables necesarias para el diagnostico de lesion maligna fueron la edad y la definicion de los bordes, y para los diagnosticos histologicos, matriz, esclerosis marginal y la edad. Conclusiones Se necesitan cuatro minimas variables para el diagnostico de estas lesiones, no siendo importante el tipo de sintomatologia. Las redes neuronales ofrecen grandes posibilidades sobre la estadistica para las lesiones de la boveda craneal ademas de un mejor rendimiento diagnostico.

Objetivo Valorar la prevalencia y describir los hallazgos de los quistes de Baker complicados observados en una serie larga de estudios de resonancia magnetica (RM) de rodilla. Material y metodos De una serie de 382 pacientes consecutivos con estudio de RM de rodilla se detectaron 145 (38%) quistes de Baker. Los quistes se clasificaron como simples (paredes lisas, contenido homogeneo, intensidad de senal semejante a la del liquido sinovial y sin alteraciones en los tejidos circundantes) o complicados (alteracion de las paredes, alteraciones de la intensidad de senal del contenido, presencia de cuerpos libres o alteraciones en los tejidos de alrededor). Se observaron complicaciones en 10 (6,9%) quistes, confirmadas mediante observacion directa (artroscopica o quirurgicamente, n = 9 casos) o por evidencia clinica con seguimiento (n = 1 caso). Resultados No se detectaron diferencias en la distribucion por sexos entre quistes simples y complicados (c2, p = 0,9), aunque si se evidencio una relacion estadisticamente significativa entre la existencia de complicaciones con una mayor edad del paciente (p = 0,003) y la presencia de lesiones meniscales (p = 0,019). En 5 pacientes se encontro rotura del quiste de Baker, en 4 cuerpos libres intraquisticos y en 1 caso se trataba de una sinovitis villonodular pigmentada con focos intraquisticos. De los 5 pacientes con rotura del quiste, solo 2 presentaron sintomas de tromboflebitis, siendo el resto de roturas asintomaticas. En 3 de los 4 pacientes con cuerpos libres intraquisticos, estos se consideraron secundarios a lesiones osteocondrales degenerativas, presentando el otro caso una condromatosis sinovial. Conclusion Los quistes de Baker son frecuentes y generalmente no presentan complicaciones asociadas. En nuestra serie se ha observado una prevalencia de un 6,8% de quistes complicados, bien por su contenido o por alteraciones en sus paredes. La complicacion mas frecuente es la rotura (50% de los quistes complicados), que puede ser asintomatica hasta en un 80% de los casos, seguida de cuerpos libres intraquisticos (40% de las complicaciones), usualmente de origen degenerativo. La complicacion se asocia estadisticamente a roturas meniscales y pacientes mayores.

There is no doubt that radiologists play an increasingly important role in the detection of focal liver lesions, and in the evaluation of persistent or recurrent malignant disease after treatment. The characterization of focal liver lesions depends on the clinical integration of the information generated by different radiologic techniques. Most often, MR imaging is quite effective in liver tumor characterization. Our purpose is to provide an overview of the MR characteristics of the most commonly encountered liver tumors and their differential diagnosis, with the most accepted reliable proof of the lesion type in a clinical environment. Radiologists must know the level of confidence they can reach in a given diagnosis, and the influence that this diagnosis has in the patient's management. With this knowledge, radiologists decide whether to leave or follow-up the lesion, perform tissue samples, or carry out therapeutic procedures.

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.

The aim of this study is to evaluate the use of phase-contrast MR imaging to diagnose normal pressure hydrocephalus (NPH) and differentiate it from other neurological disorders with similar clinical symptoms.The study included 108 subjects, of whom 61 were healthy controls and 47, patients; in the patient group, 19 had cerebrovascular disease (CVD) and 28 had NPH. All patients underwent a phase-contrast MRI study and several CSF flow and velocity parameters were measured at the aqueduct of Sylvius. Discriminant analyses were performed to evaluate the classification capacity of both individual parameters and the combination of different parameters.Maximum diastolic velocity, mean flow, and stroke volume showed statistically significant differences that could be used to distinguish between NPH and CVD patients (P.001). Stroke volume and mean flow showed no false positive results and successful classification rates of 86% and 79%, respectively. No other parameters or combination produced better results.Phase-contrast MR imaging is a useful tool for the early diagnosis of patients with NPH. CSF flow quantitative parameters, along with morphological features in a conventional MR study, enable us to differentiate between NPH and CVD patients.