Radiological imaging devices such as ultrasound, CT or Mammography is a screening, diagnostic and monitoring tool in providing visual assistance and guidance to the radiologists/physicians in identifying abnormalities such as breast cancer. Evaluation of the clinical performance of such devices often involves the reader’s interpretation. In this talk, a typical study called multi-reader multi-case (MRMC) study is discussed from a regulatory reviewer’s perspective. Common issues in study design and analysis encountered when reviewing such devices will be summarized and presented.