To Accomplish Their Primary Goal of Diagnosing and Treating Illnesses, Radiologists Perform Many Tasks. We Analyzed Several Job Listings to Identify These Core Radiologist Duties and Responsibilities.Evaluate Patients Medical Historiesbefore Performing a Diagnostic Procedure On a Patient, a Radiologist Must Evaluate the Patient s Medical History to Ensure Tests Will Not Cause Harm. Some Patients, for Instance, Maybe Allergic to An Agent Used to Perform a Test. in that Case, a Radiologist Would Suggest Alternative Diagnostic Techniques.perform Diagnostic Imaging Proceduresradiologists Perform or Direct Radiology Staff to Perform a Variety of Diagnostic Procedures, such as X-rays, Mris, Ct Scans and Ultrasounds, to Diagnose Illnesses and Injuries. in the Case of a Sports-related Injury, for Instance, a Doctor May Order An X-ray to Determine Whether a Bone is Broken.