Isosignal contours and signal gradients as an aid to choosing MR imaging techniques.

The signal strength of a magnetic resonance (MR) image depends on a variety of factors, including the tissue properties of proton density (p) and relaxation times (T1 and T2) and the scanning sequence. Given this complex interrelation of factors, a graphic method of displaying the image intensity for various tissue properties is needed. In this paper we use isosignal contour curves to display "topographically" the relationships of signal intensity to the tissue properties of p, T1, and T2 for a variety of operator settings in the techniques of saturation recovery, inversion recovery, and spin echo. We further demonstrate the utility of these curves in explaining image appearances and in choosing appropriate pulse sequences for imaging.