Henrich WL, Clark RL, Kelly JP, Buckalew VM, Fenves A, Finn WF, Shapiro JI, Kimmel PL, Eggers P, Agodoa LE, Porter GA, Shapiro S, Toto R, Anderson T, Cupples LA, Kaufman DW. Non-contrasted computerized tomography and analgesic-related kidney disease: Report of the National Analgesic Nephropathy Study. J Am Soc Nephrol 2006;17:1472-1480.