An EMI shielding device is set in an electronic device. An ink jet recording medium comprising the dye fixing agent for water-color ink formed on a substrate. In cardiac perfusion imaging the preparations may advantageously be coadministered with vasodilator drugs such as adenosine in order to enhance the differences in return signal intensity from normal and hypoperfused myocardial tissue respectively. A plurality of optical devices such as color sensitive half-silvered mirrors or sets of prisms having color-sensitive coatings on their respective faces, are used to produce a coaxial set of laser beams. 5 microns, a texture density of about 104-107 pits per cm2, a texture size of about 0. T2* relaxation rates for GE and T2 relaxation rates for SE are calculated from the acquired NMR signals and are corrected for extravasation of contrast agent into surrounding tissues.