Disclosed herein is an article and thermoplastic composition comprising a polysiloxane-polycarbonate, optionally, a polycarbonate, and an X-ray contrast agent comprising X-ray scattering atoms having an atomic number of greater than or equal to 22, wherein a 3.2 mm thick article molded from the thermoplastic composition has a notched Izod impact strength of greater than or equal to about 620 J/m, when measured at a temperature of 0° C. according to ASTM D256-04, and has an Equivalent Al Thickness of greater than 0.51 mm, when irradiated with 50 kV X-ray radiation, and wherein melt volume rates determined under a load of 1.2 kg at 300° C. (ASTM D1238-04), a melt volume rate measured at a dwell time of 18 minutes increases relative to that measured at 6 minutes by less than or equal to 31%. A method of improving contrast in a polycarbonate composition, and specific articles are also disclosed.