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doi: 10.1016/S0033-8338(04)77952-7
Surcando el espacio-kpara mejorar la imagen por resonancia magnética
Exploring k-Space for Improved MR Imaging
David Moratal-Péreza, José Millet-Roiga, Francisco Castellsa, Luis Martí-Bonmatíb,, Marijn E. Brummerc
a Departamento de Ingeniería Electrónica. Universitat Politècnica de València. Valencia.
b Servicio de Radiología. Clínica Quirón. Valencia. España.
c Radiology Department. Emory University School of Medicine. Atlanta. EE.UU.
Recibido 12 junio 2003, Aceptado 05 diciembre 2003
Resumen

Lo que marca la diferencia entre la resonancia magnética (RM) y otras modalidades de imagen médica es que el usuario tiene completo control sobre la forma de adquirir los datos y cómo éstos pueden manipularse para mostrar la imagen final. El radiólogo puede modificar la resolución, el tamaño del campo de visión, el contraste, la velocidad de la adquisición, la influencia de los artefactos y tantos otros muchos parámetros que contribuyen a formar la imagen final. El artífice de este control se conoce como espacio-k, y no es más que la matriz de datos sin procesar obtenida a la salida del equipo de RM antes de la aplicación de la transformada de Fourier, la cual proveerá de la imagen final reconstruida.

Este control que proporciona el espacio-kforzará la necesidad por parte del usuario de comprender los conceptos y los mecanismos ligados a éste. Sólo de esta forma le podrá sacar el máximo rendimiento a la resolución espacial, resolución temporal y calidad final de la imagen.

El principal problema radica en que el espacio-kes un concepto abstracto. Aunque su contenido se puede visualizar, sus datos tienen poco sentido y no poseen una relación aparente con la imagen de RM. Por otra parte, la construcción matemática que lo describe con detalle es sofisticada y complicada y no da a entender, de una forma intuitiva, de lo que se trata. Este artículo analizará este concepto poco conocido, aunque ampliamente utilizado en RM.

Resumen

What marks the difference between magnetic resonance (MR) and other medical imaging techniques is that the user has complete control over both the way in which data is acquired and how it can be manipulated in presenting the final image. The radiologist can modify resolution, field size, contrast, acquisition speed, artifact influence, and many other parameters which contribute in producing the final image.

The vehicle of this control is known as k-space, and is nothing more than a matrix of unprocessed output data from the MR unit before applying Fourier transformation, which will in turn provide a final reconstructed image. The user would necessarily be required to understand those concepts and mechanisms related to k-space. Only then could optimum results be yielded in regard to spatial resolution, temporal resolution and image quality.

The principal problem lies in the fact that k-space is an abstract concept. Although its content can be visualized, the data of which it is comprised makes little sense and suggests no apparent relation to MR imaging. On the other hand, the mathematical construction used to describe it in detail is sophisticated and complicated, and does not easily lend itself to an intuitive understanding of precisely what it is that k-space entails. This article analyzes this little known yet widely used concept in MR imaging.

Palabras clave
Espacio-k, Resonancia magnética, Técnicas de imagen
Key Word
k-Space, Magnetic Resonance, Imaging Techniques
El Texto completo solo esta disponible en PDF
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LUIS MARTÍ-BONMATÍ. Sección de RM y TAC. Servicio de Radiología. Hospital Universitario Doctor Peset. Avda. Gaspar Aguilar, 90. 46017 Valencia. España.
Copyright © 2004. Sociedad Española de Radiología Médica (SERAM) and Elsevier España, S.L.