Safety of Low Dose IV Contrast CT Scanning in Chronic Kidney Disease

Inclusion Criteria: * Subjects with documented stable Chronic Kidney Disease (CKD) defined as a stable eGFR 16-60 ml/min/m\^2 for ≥ 12 months; and * Referred to CT scanning procedure to evaluate pulmonary embolism, pulmonary malignancy, acute aortic syndromes, or renal artery stenosis. Exclusion Criteria: * CKD Stages 1, 2 and 5 * Stage 3-4 congestive heart failure (CHF) * Irregular supraventricular tachycardia * Allergic to iodinated Radio Contrast Medium (RCM) * Allergic to Mucomyst * Pregnancy * Evidence of acute renal failure (ARF) * Serum bicarbonate either less than 20 meq/L or greater than 35 meq/L * Hydration with a bicarbonate solution is contraindicated or considered unsafe by the subject's caring physicians