[Nuclear magnetic resonance tomography in the study of the liver and its diseases]

Nuclear Magnetic Resonance (NMR) tomography has already attained a position in clinical use beside the established techniques ultrasound (US) und computerized tomography (CT) for the examination of the liver and its related diseases. In assessing its methodical significance one has to differentiate between focal liver lesions and damages of the liver parenchyma. Focal lesions may be identified with NMR just as safely as with US and CT. However, NMR produces additional information, especially in the echo-dense lesions in US, where both NMR and angio-CT can differentiate between echo-dense metastases, haemangiomas and fatty tumours. In damages of the liver parenchyma NMR seems to become the method of choice. Quantitative tissue differentiation is possible by determining the relaxation times. In fatty degeneration of the liver focal fatty infiltration and circumscribed cirrhotic changes can be discerned. It is possible to identify cirrhoses directly and not merely by indirect criteria as is the case with US and CT. NMR can also differentiate between aethylic (prolonged T1) and primary-biliary cirrhosis (shortened T1). Haemochromatosis may be identified with CT, the accompanying secondary cirrhotic change, however, can only be detected by NMR. In liver cell carcinoma, e.g. secondary to cirrhosis, cancer nodes and cirrhotic regeneration nodes may be differentiated. Whole body NMR spectroscopy is still under research. Once it is perfected for clinical use it will change the entire laboratory medicine.