OBJECTIVE: To reduce radiation dose and increase x-ray tube life in computed tomography. MATERIALS AND METHODS: Head, upper abdomen and chest scans were evaluated. We assessed the techniques employed and if these could be changed, suggested new protocols and compared the quality of the images, the radiation dose and the x-ray tube heating. RESULTS: A mAs reduction could be done without interfering with the diagnostic quality, allowing a decrease of up to 20% in the average dose for adults' head exams and up to 45% for 0 to 6 years old children; patients with less than 50 kg had a reduction of 37% on the upper abdomen radiation average dose; for chest routine scans the reduction was 54%. The decrease in the heating of the x-ray tube for head, upper abdomen and chest scans was approximately 13%, 23% and 41%, respectively. CONCLUSION: A change on the described protocols will produce a significant reduction on the radiation dose and an increasing in x-ray tube life without loss of diagnostic quality.

Keywords: X-ray computed tomography, Radiation exposure, Radiation dosage, Radiation protection