Total air kerma at the interventional reference point (Ka,r, in Gy) and air kerma area product (PKA, in Gycm2 ) are required to be reported on interventional x-ray systems since 2006. These are useful in the assessment of potential tissue adverse effects or long-term radiation sequelae, respectively, and it is reasonable to include them in the catheterization record at the conclusion of each procedure. Appendix 4D summarizes considerations for patient follow-up based on radiation dose during the 4.4. Contrast-Induced AKI: Recommendations Class I 1. Patients should be assessed for risk of contrast- induced AKI before PCI.270,271 (Level of Evidence: C) 2. Patients undergoing cardiac catheterization with contrast media should receive adequate preparatory hydration.272 275 (Level of Evidence: B) 3. In patients with CKD (creatinine clearance <60 mL/min), the volume of contrast media should be minimized.276 278 (Level of Evidence: B) Class III: NO BENEFIT 1. Administration of N-acetyl-L-cysteine is not useful for the prevention of contrast-induced AKI.279 283 (Level of Evidence: A) See Online Data Supplements 16 to 18 for additional data regarding contrast-induced AKI. Contrast-induced AKI or contrast nephropathy is one of the leading causes of hospital-acquired AKI. Major risk factors for contrast-induced AKI include advanced age, CKD, congestive heart failure, diabetes, and the volume of contrast administered. A risk-scoring system is available to predict the risk of contrast nephropathy using these risk factors and additional variables.270 Thus far, the only strategies clearly shown to reduce the risk of contrast-induced AKI are hydra- tion and minimizing the amount of contrast media. Other than saline hydration, measures that were believed to reduce the risk of contrast-induced AKI have been found to be neutral, to have deleterious effects, or to be characterized by heteroge- neous and conflicting data. 