ABSTRACT
In this chapter, concepts of quantitative magnetic resonance imaging (qMRI) are introduced. The traditions of measurement science and MRI meet in qMRI. MRI has undergone a paradigm shift, as a sophisticated device for visualisation within the brain also offers the option for high-quality measurement, giving access to biological and physiological information, often at the microstructural level. qMRI can measure the effects of disease and the response to treatment. In clinical trials, it is often used as an objective and early indicator of treatment efficacy. The long tradition of scientific measurement is followed to the invention of MRI. The ‘longitude problem’ in the 1700s posed a similar scientific challenge to that of qMRI – how to develop a technology that would have a dramatic impact on human well-being. Principles of good study design are laid out; attention to measurement error (the instrumental standard deviation) can enormously reduce the size and cost of a study. A table of recommended MRI books is given in this chapter.
