Vortex imaging method by the site selective NMR is explained by self-consistently solving the Bogoliubov--de Gennes equation for both s-wave and d-wave pairings. We analyze the temperature dependence of the relation time T₁ using the resonance frequency at the intensity maximum, namely the saddle point T₁ experiments. The site selective T₁ data are shown to yield valuable information on low-lying electronic excitations around a vortex core.

PACS numbers: 76.60.Pc, 74.60.Ec, 74.25.Jb