Introduction:
Iodinated Contrast agents are used in Computed Tomography (CT) to increase the contrast between lesions and surrounding tissues with similar chemical characteristics. Contrast agent has the disadvantage that it produces kidney damage. Patients under chemo and radiotherapy are susceptible to kidney failure. Therefore, CT enhancement protocols must have certain restrictions. The aim of this study is to evaluate the performance of low kVp, CT protocols with reduced iodine usage in patients under chemo and radiotherapy. 
Materials and methods:
The patients, under chemo and radiotherapy in a university hospital, agreed to sign the consent form, were selected for this study. They were scanned by 16-MDCT GE system with routine (120 kVp and 1mlI/kg) and reduced kVp (80 kVp) with reduced contrast agent protocols respectively. CT protocols included neck and chest enhanced CT images. Renal function before and after CT scanning was used to evaluate the effect of contrast agent reduction on kidney function. Two expert radiologists with more than 5 years’ experience evaluated the CT images, qualitatively.
Results:
The results of this study, on 20 patients, showed that the quality of neck and chest CT images with 65% contrast agent reduction taken at 80 kVp were comparable to the similar CT images taken by routine protocol. The results of blood test showed that the reduced iodinated contrast protocol did not have impaired kidney function.
Conclusion:
The results of the present study support our hypothesis that low kVp CT protocol with iodine load reduction has the acceptable image quality and the kidney function is not altered due to this protocol.
Key words: x-ray Computed Tomography, kidney failure, contrast agent