There is an adage that applies equally to all multipulse NMR experiments which states it is easier to induce spin ethos than not. Rather than ignore or suppress these additional ethos in NMR imaging experiments (I) we wish to communicate techniques which glean added information from them. In particular we exploit the unique properties of the stimulated echo as first identified by Hahn (2) and further quantified by Woessner (3). Although new to NMR imaging, stimulated ethos have been successfully applied by Tanner to the measurement of translational selfdiffusion coefficients (4), by Lausch and Spiess to study infrequent jumps of complex molecules (5, 6), and more recently to analyze slow rotational motions of molecular solids by Sullivan et al. (7). This communication will outline the methodology involved in the execution of stimulated echo NMR imaging. A subsequent communication (8) will present specific applications, and is henceforth referred to as Part II. Consider a spin system in thermal equilibrium with its surroundings subjected to the rf pulse and magnetic field gradient pulse experiment depicted in Fig. 1. We bring the net magnetization into the transverse plane with the transmission (TX) of a 7r/2 rf pulse. Unless stated to the contrary, the rf pulse is of frequency wp and width t,, such that t,, is small compared to Ti and T2, and excites the entire chemical shift frequency bandwidth equally. If, for example, the pulse has phase A equal to 0” (i.e., along the positive y direction), the transverse magnetization will initially be aligned with the positive x direction in the rotating frame. Free precession of all isochromats occurs during the time interval 7,. During this time span we apply pulsed magnetic field gradients as in the conventional Fourier imaging technique (9). The preparatory readout gradient is embodied in the effective x gradient (G,), whereas GY and G , are employed for phase encoding. Obviously z-direction discrimination could also be achieved with a selective 7r/2 rf pulse applied in the presence of G , (10). A second 7r/2 rf pulse is applied at the end of the 71 interval. Thus far the rf pulse sequence described is simply Hahn’s original spin echo experiment (2). Hence