"Nanoscale" by this definition is anything smaller than 100 nm.
IBM's Magnetic Resonance Force Microscopy equipment can resolve objects as small as 90 nm in 2D. For comparison, the best MRI microscopy is limited to about 3,000 nm. Specialized magnetic tips on the microscope manipulate and detect weak magnetism of atomic nuclei to image as few as 1,000 atoms as opposed to the 100 million-atom resolution of conventional MRI. "Our ultimate goal is 3D imaging of complex structures such as molecules with atomic resolution," says Dan Rugar, manager, Nanoscale Studies, IBM Research.