7 Comment No clear beneﬁt Deleterious in PVD No clear beneﬁt May be intrarenal at higher doses No clear beneﬁt No clear beneﬁt May be beneﬁcial May be beneﬁcial No beneﬁt No beneﬁt May be beneﬁcial Table 5: List of agents assessed for prevention of CIN and the literature available on each. Mechanism Renal vasodilatation Selective dopa 1 receptor agonist Adenosine receptor antagonist Relieve vasoconstriction Vasodilatation Antioxidant Vasodilatation Removal of oﬀending agent Continuous Cardiology Research and Practice Agent Dopamine [93–95] Fenoldopam [96–98] Theophylline [95, 99–101] Calcium Channel Blockers [102–104] Prostaglandin E [105] Ascorbic Acid [106] ANP [107] Hemodialysis [108, 109] Hemoﬁltration [110, 111] Table 6: Studies assessing incidence of CIN in patients with exposure of gadolinium as contrast. Study Sample design Contrast dose Renal status CIN deﬁnition Renal outcome Erley (2004) 21-Prospective, [113] randomized study Spinosa (2000) [112] Briguori (2006) [114] 35-Randomized 57-Retrospective study 0.29 mmol/kg (0.13– 0.40 mmol/kg) Gadolinium; 51 mL (33–80 mL) nonionic contrast 0.57 ± 0.17 mmol/kg Gadolinium; 0.60 ± 0.271 mmol/kg Iohexol 0.6 ± 0.3 mmol/kg Gadolinium based; 122 ± 58 mL Iodixanol Cr > 1.5 mg/dL Cr > 1.5 mg/dL or GFR < 50 mL/min Cr > 2 mg/dL or CrCL < 40 mL/min ih>no0[u.5Crsmr]g/wdiLthiinncr4e8ase (5nG6oa%/nd1i5o(o)1lni/nei2xci0upc)mooesn;xet4pdr0oat%ssoted to 50% (5/10) exposed to >50% decrease in Gadolinium and 45% GFR (5/11) exposed to Iohexol iddh>naio0ay[u.l5sCyrssmrios]grww/dniitLethheiidinnncf5o4re8rase iia62Gool.8oa5dd%d%niinnoe(aal(7itt2nee//idd23u52ccm))oonneepxxttlrruppaaososssstteeaddnttdoo 151 ± 79 mL Gadolinium (with Reed (2007) 169-Retrospective Iodinated contrast [115] Study dilution); 136 ± 72 mL iodinated contrast 3 comparative groups receiving 76 ± 40 mL Kane [38] 163-Retrospective Gadolinium; 55 ± 35 (2008) Study Gadolinium (with 37 ± 37 Iodinated contrast); 102 ± 50 Iodinated contrast CrCl < 60 mL/min/1.73 m2, a serum Cr level >1.5 mL/dL, and not on hemodialysis. 16% (14/90) of those ≥in0[.C5rm] gw/ditLhiinnc5redaasyes (eG1xa1pd/o7os9lei)ndoitufomIdoidalnuindtead1te4d% contrast Cr ≥ 2 mg/dL 5.3% (3/57) in Gadolinium only; 10.5% (4/38) in ≥0.5 mg/dL increase Gadolinium + in [Cr] within 7 days Iodinated Contrast; 20.6% (14/68) in Iodinated contrast alone Preventive treatment used Volume administration Volume administration Normal saline plus N- acetylcysteine N- acetylcysteine plus Volume administration N- acetylcysteine plus Volume administration CrCL: Creatinine Clearance; Cr: Serum Creatinine GFR: Glomerular Filtration Rate. nephrogenic systemic ﬁbrosis (NSF) through administration of Gadolinium in patients already renally compromised must be emphasized [117]. NSF seems to be associated with administration of higher than usual doses of Gadolinium, according to one study [118]. Hence, till further evidence becomes available, administration of Gadolinium to decrease CIN incidence appears questionable, especially in the light of its particular adverse eﬀects. 10. Conclusion CIN is an iatrogenic disorder with high morbidity and mortality and a high incidence in elderly, diabetics, and patients with pre existing renal failure. Despite uncertainty regarding the degree of nephrotoxicity produced by vari- ous contrast agents, nonionic low-osmolar or iso-osmolar contrast media remains the preferred choice. Limiting the