DTI is the official term used in all research articles concerning this topic. You shouldnt be inventing new "wikipedia" terms if other terms are already in use by the scientific community. If, as you correctly pointed out, DTI is an established misnomer in the MRI world, Wikipedia will use the same misnomer. 

 Moreover, you are wrong in your assumption, that "The latter is about measuring diffusion using MR, while the former is representation/analysis of these measurements".  
 * Diffusion MRI is only sensitive to diffusion in general (one shot, one direction), irrespective of its direction and its main clinical value rests in the detection of acute ischemic stroke. 
 * Diffusion tensor imaging is an extension of the Diffusion MRI technique - magnetic gradients are switched on in at least 6 different directions in order to obtain a map of main diffusion directions. These data can be used to measure structural organisation of the white matter, or to reconstruct white matter tracts.  The main clinical use of DTI lays in preoperative planning for brain tumor surgery -  and DTI reconstructions of the pyramid fiber tract (corticospinal) are now widely used in neuronavigation during the surgery. 

  
 Ackoz, not logged in.