[Tissue characterization with T1, T2 and proton density: dream and reality]

A survey of the measurement values T1 and T2 based on radiological studies of the last two years shows a high degree of variation in these measurement values with regard to normal and pathological tissues of different organs and regions of the body. T1, which is dependent on field strength, is not suitable for interinstitutional comparison. At present the methods used for T2 measurements are so different from one another that the potential comparability of T2 cannot be realised. The combinations of T1 and T2--as presented in various radiological studies -show signs of tissue characterisation. The expected high degree of selectivity caused by using different measurement methods has not yet been confirmed. The measurement of T1 and T2 in lesions under drug and radiotherapeutic treatment seems to be informative in respect of prognosis.