Magnetic resonance imaging (MRI) signal enhancement is reported using a coating grown by layer-by-layer assembly. A macromolecular conjugate of hyaluronan with Gd-coordinated diethylenetriaminepentaacetic acid is used with chitosan to coat polymeric interventional tools. The MRI visibility of such Gd-loaded coatings can be easily tailored by varying the number of layers (see Figure).