Post-mortem Studies of Fish Using Magnetic Resonance Imaging

Although being less sensitive than many other analytical methods, magnetic resonance imaging (MRI) does have significant advantages such as being non-invasive and non-destructive. Furthermore, no sample preparation is needed prior to analysis and the method is not hampered by limitations regarding signal penetration depth. However, due to the high investment costs, the sheer size of the instrument and the necessary related infrastructure, MRI cannot presently be considered as a standard analytical tool in aquaculture or fish processing industry. As a research tool, however, taking advantage of the unique features of the method, we can obtain basic insight into a number of issues related to anatomical studies, composition and structure of tissues, distribution maps of fat, water, and salt as well as temperature profiles (mapping). Moreover, theoretical transport models can in turn be used to interpret the images. For the aquaculture industry, MRI studies may for instance be helpful to study the effect of feed composition (fat) and different feeding regimes on fat contents and distribution in tissues. In fish processing, MRI can be used as a tool for the optimization of various unit operations such as salting, freezing, and thawing. For a more detailed treatment of various MRI applications, see review by Hills [1].