When Drug-Related Materials (DRM) are extracted from tissue homogenates for LC-MS/MS analysis, any information about compartmental distribution is lost. Moreover, quantified DRM is presumed to be an average value, equally distributed throughout the tissue, missing potentially toxic amounts of compound that may be localized to very small compartments.
MALDI targeted imaging reveals not only compartmentalized distributions of DRM, but also can provide quantitative measures of compounds within each compartment that is not possible with LC-MS/MS.

MALDI targeted imaging reveals compund localization not detectable with LC-MS/MS