[Quality control in magnetic resonance for clinical use].

This chapter summarizes requirements, rationale and main steps in the recent evolution of protocols adopted at international level for quality controls in clinical magnetic resonance imaging (MRI) and spectroscopy (MRS). An accurate assessment of instrumental performance in MRI and MRS is essential for enhancing the clinical value of these methodologies, both in terms of anatomical and physio-pathological information. In the field of MRI, a series of Concerted Actions, carried out in the frame of the medical and health research programmes of the European Economic Communities (EEC), led to the definition of standardized methodologies and to the construction of five test objects for assessing the quality of fourteen instrumental parameters, inherent to: signal uniformity and linearity; geometry; slice position and thickness; spatial resolution; signal-to-noise and contrast-to-noise ratios; T1 and T2 precision and accuracy. The first part of this paper devotes particular attention to the protocols adopted by the EEC Concerted Actions and by the National Electrical Manufacturers Association (NEMA, US), for assessing signal uniformity, geometric distortion and signal-to-noise ratio in MRI. A brief description is also given of the rationale and protocols for measuring other MRI parameters. The second part is devoted to describe eleven parameters of instrumental performance, two test objects and the measuring protocols recently proposed by the EEC Concerted Actions for quality control in single-volume localized MRS, following their validation in a series of experimental multi-centre trials.