The use of radio contrast medium enhances the image quality of CT scans. However, contrast CT is avoided in patients with CKD for fear of contrast-induced nephropathy. The current standard of care for these patients is CT without contrast. Taking advantage of fast scanning capabilities of modern CT scanners (64-Multi-Detector CT), the current investigators have developed a method to use low volume iso-osmolar non-ionic radio contrast medium (30 cc) which can be used in a selected group of adult patients with mild to moderate stable CKD (eGFR 16-60 ml/min/m\^2 for at least 12 months), who require thoracic CT imaging for diagnostic purposes. Up to 100 patients who meet the inclusion/exclusion criteria will be randomized to standard care (no-contrast, 50 controls) or low volume contrast CT (50 intervention group). The peak increase of serum creatinine levels within 72 hours after the CT procedure will be measured as an outcome variable for comparison between the two groups, as well as a safety monitoring variable in the intervention group (25% increase is the upper threshold).
