[How are the hypothesis and the objectives established in a Radiology research project?]. / ¿Cómo establecer la hipótesis y los objetivos de un proyecto de investigación en Radiología?

Research is a systematic process designed to answer a question. This is the starting point of the whole project and specifically formulates a problem observed in the analysis of the reality. The answer to this attempts to clarify an uncertainty in our knowledge. The conceptual hypothesis is the theoretical answer to the question set out. The operational hypothesis is the particular form that which sets out to demonstrate the conceptual hypothesis. The objectives are the justification for conducting the research. They help to define what it attempts to obtain, and what answers it will give to the formulated questions. It must show a clear and consistent relationship with the description of the problem and, specifically, with the questions and/or hypothesis that are to be resolved.

[Quantification of liver iron concentration using 1-Tesla MRI]. / Cuantificación de la concentración de hierro en hígado mediante RM de 1 Tesla.

OBJECTIVE: To evaluate the quantification of liver iron concentration using 1-Tesla magnetic resonance imaging (MRI) and its ability to diagnose or rule out hemochromatosis. To evaluate the role of 1.5-Tesla MRI in inconclusive cases. MATERIAL AND METHOD: Between 2002 and 2006, we used 1-Tesla MRI (Gandon method) and liver biopsy to quantify the liver iron concentration in 31 patients. Moreover, we used 1.5-Tesla MRI (according to Alústiza's model) and liver biopsy to determine the liver iron concentration in 10 additional patients and to check the results of 10 patients in whom 1-Tesla MRI detected iron overload. RESULTS: In the first group of 31 patients, liver biopsy classified the liver iron concentration as normal (<36 micromol.Fe/g) in 11 patients, as hemosiderosis (36-80 micromol.Fe/g) in 15, and as hemochromatosis (>80 micromol.Fe/g) in 5. The correlation with the values calculated at MRI was 100% in the 5 cases with hemochromatosis; in the 15 patients with hemosiderosis, 5 were correctly classified and the liver iron concentration was overestimated in 10; of the 11 patients with normal liver iron concentration, 6 were correctly classified and 5 were overestimated. Quantification >80 at MRI has a sensitivity and negative predictive value of 100% and specificity of 50% for the diagnosis of hemochromatosis. Quantification <36 at MRI has a positive predictive value and specificity of 100% to identify the absence of iron overload. In the 10 patients with liver biopsy that underwent 1.5-Tesla MRI, there was a high correlation between the two techniques. CONCLUSION: The reliability of the evaluation of liver iron concentration using 1-Tesla MRI is useful for ruling out hemochromatosis and identifying patients without iron overload. We observed a tendency to overestimate liver iron concentration in both patients with overload and in those without, and this limits the reliability of the technique. 1.5-Tesla MRI is a good alternative for quantifying liver iron concentration more precisely.

[Diagnosis and quantification of iron overload in the liver using MRI]. / Diagnóstico y cuantificación de la sobrecarga férrica en el hígado mediante resonancia magnética.

Hereditary hemochromatosis is the most common cause of iron overload. The diagnosis of hereditary hemochromatosis has improved since Feder et al. isolated the HFE gene in 1996 and discovered the mutations related with this disease. Nevertheless, in many cases genetic tests for hereditary hemochromatosis are negative. These cases require diagnostic confirmation by quantifying the concentration of iron in the liver (LIC); this has traditionally been accomplished by liver biopsy. Many studies have shown that it is possible to quantify LIC using MRI. However, a consensus has yet to be reached about the most appropriate technique or whether it is possible to reproduce the same methods of calculation on different MRI units. This article reviews the current state of these questions and points to possible lines to standardize this noninvasive method of quantifying LIC in the future.

¿Cómo establecer la hipótesis y los objetivos de un proyecto de investigación en Radiología? / How are the hypothesis and the objectives established in a Radiology research project?

La investigación es un proceso sistemático destinado a responder a una pregunta. Ésta constituye el punto de partida de todo proyecto, y formula de manera concreta un problema observado en el análisis dela realidad. La respuesta pretende aclarar una incertidumbre de nuestro conocimiento. La hipótesis conceptual es la respuesta teórica a la pregunta planteada. La forma concreta por la que se pretende demostrar lahipótesis conceptual es lahipótesis operativa. Los objetivos son la razón de ser y hacer enlainvestigación. Ayudan a definir qué es lo que se pretende obtener, qué respuestas va a dar a las preguntas formuladas. Deben mostrar una relación clara y consistente con la descripción del problema y, específicamente, con las preguntas y/o hipótesis que se quieren resolver (AU)

Research is a systematic process designed to answer a question. This is the starting point of the whole project and specifically formulates a problem observed in the analysis of the reality. The answer to this attempts to clarify an uncertainty in our knowledge. The conceptual hypothesis is the theoretical answer to the question set out. The operational hypothesis is the particular form that which sets out to demonstrate the conceptual hypothesis. The objectives are the justification for conducting the research. They help to define what it attempts to obtain, and what answers it will give to the formulated questions. It must show a clear and consistent relationship with the description of the problem and, specifically, with the questions and/or hypothesis that are to be resolved (AU)

Diagnóstico y cuantificación de la sobrecarga férrica en el hígado mediante resonancia magnética / Diagnosis and quantification of iron overload in the liver using MRI

La hemocromatosis hereditaria es la modalidad más frecuente de sobrecarga férrica. El diagnóstico de la misma ha mejorado desde que en 1996 Feder et al aislaron el gen HFE descubriendo las mutaciones relacionadas con la enfermedad. Sin embargo, son muchos los pacientes con estudios genéticos negativos, y que por tanto requieren una confirmación diagnóstica mediante la cuantificación de la concentración de hierro en hígado (CHH) que tradicionalmente se ha realizado mediante biopsia hepática. Muchos estudios han demostrado la posibilidad de cuantificar la CHH mediante resonancia magnética. Sin embargo, todavía no existe un consenso en cuanto a la técnica más idónea ni en cuanto a la posibilidad o no de reproducir el mismo método de cálculo en diferentes máquinas. Este artículo revisa la realidad de estas cuestiones y señala posibles líneas de futuro para estandarizar este método no invasivo de cuantificación de la CHH

Hereditary hemochromatosis is the most common cause of iron overload. The diagnosis of hereditary hemochromatosis has improved since Feder et al. isolated the HFE gene in 1996 and discovered the mutations related with this disease. Nevertheless, in many cases genetic tests for hereditary hemochromatosis are negative. These cases require diagnostic confirmation by quantifying the concentration of iron in the liver (LIC); this has traditionally been accomplished by liver biopsy. Many studies have shown that it is possible to quantify LIC using MRI. However, a consensus has yet to be reached about the most appropriate technique or whether it is possible to reproduce the same methods of calculation on different MRI units. This article reviews the current state of these questions and points to possible lines to standardize this noninvasive method of quantifying LIC in the future

Hepatitis tóxica tras tratamiento con flutamida / Toxic hepatitis after flutamide treatment

No disponible

Enfermedad celíaca y déficit selectivo de inmunoglobulina A / Celiac disease and selective IgA deficit

No disponible

Ageusia e hiposmia reversibles inducidas por tratamiento con interferón en un paciente con hepatitis crónica C / Reversible ageusia and hyposmia induced by interferon in a patient with chronic hepatitis C

No disponible