A method of generating a map or distribution of parameters that are a function of proton transverse relaxation time (T.sub.2) constant in a target subject to localised movement (such as in abdominal tissue) by using nuclear magnetic resonance imaging. The method compensates for localised movement, (e.g. breathing artefacts) in the imaging by spatial neighboring averaging of image intensities over a region of interest subject to the localised movement. A map or distribution of T.sub.2 parameters is then calculated over the entire region of interest. To ensure accuracy and position of the T.sub.2 values, the effects of signal level off set, instrumental drift, and noise level is incorporated into the calculations.