A shield is placed on a patient's body over a secondary organ adjacent a target organ. The shield is partially transparent to x-ray radiation. A CT scan of the target organ is conducted according to conventional protocols and technical parameters. No artifacts are formed in the diagnostic portion of the CT image and there is no degradation of the diagnostic portion of the CT image. A reduction of between about 40% and about 60% in the radiation dose of the secondary organ as compared to the same CT scan made without the shield is achieved.