The only real drawback for the administration of contrast media is renal insufficiency. It can be diagnosed measuring serum creatinine (increased) and calculating the glomerular filtration rate (eGFR). These are the only laboratory tests to perform. Patients with multiple myeloma or other plasmacellular diseases* (situation in which Bence-Jones proteinuria can be present) may have renal insufficiency, but not all these patients have reduced renal function. For this reason these diseases do not constitute a risk factor for contrast media induced nephropathy. Thus it is not necessary to perform specific tests to exclude plasmacellular diseases (serum protein electrophoresis, Bence-Jones protein analysis), moreover because none of these test is sufficient to exclude these diseases. * disorders characterized by plasmacellular proliferation.