Motion Induced Artifact Mimicking Cervical Dens Fracture on the CT Scan: A Case Report

The diagnostic performance of helical computed tomography (CT) is excellent. However, some artifacts have been reported, such as motion, beam hardening and scatter artifacts. We herein report a case of motion-induced artifact mimicking cervical dens fracture. A 60-year-old man was involved in a motorcycle accident that resulted in cervical spinal cord injury and quadri plegia. Reconstructed CT images of the cervical spine showed a dens fracture. We assessed axial CT in detail, and motion artifact was detected.

Pooling System for Multiple-Choice Questions for the National Examination for Medical Practitioners. Results of a Field Study in Japan / 医学教育

The Ministry of Health and Welfare of Japan is planning a pooling system for multiple-choice questions (MCQs) for the national examination for medical practitioners. To clarify possible problems of such a system, a field study was performed by 10 medical schools in Japan using 90 MCQs from previous examinations. Nine hundred twenty-four 6th-year students participated in the field test. For each MCQ, the correct-response rates at the originating school and those obtained in the field test were significantly correlated. Thus, the correct-response rates to questions on the field test could be predicted from the rates at the originating schools. However, for each question the correct-response rate was significantly higher for students of the originating school than for students of other schools. In the national examination, care should be taken to prevent differences in scores on the basis of question sources.