Figure 1 A 40-year-old male patient, admitted to the Thoracic Surgery Department after a traffic accident, was found to have a type I rib fracture. (A, B) Schematic diagram of type I fracture in the inflammatory stage and the callus-forming stage. (C) At 32 days after the trauma, the left seventh rib fracture with callus formation (arrow) was observed in the CT rescanning; oblique-axial plane. (D) Two days after the trauma, a cortical fracture of the left seventh rib (arrow) was observed in the initial CT. (E, F) Two days after the trauma, the corresponding rib fractures showed “sandwich” signs (arrow) on MRI T2-STIR and T2-SPAIR sequences with oblique-axial scanning.