Pediatric Rib Fracture Etiology: blunt thoracic traumaImaging: spectrum from subtle cortical irregularity of rib contour to frank displacement of fracture fragments, look for underlying pneumothorax / lung parenchymal injury / liver + spleen injury Radiology Cases of Rib Fracture CXR AP shows cortical irregularities of the right 6th and 7th ribs and no evidence of lung injury. Axial CT of the chest shows a large amount of airspace disease in the right lower lobe and a very small amount of free air anteriorly in the right hemithorax. CXR AP shows a widened mediastinum and a small right-sided pneumothorax. Axial CT with contrast of the chest with lung (above) and bone (below) windows shows air in the pleural space anterior to the right lung and fluid in the pleural space posterior to the right lung as well as airspace disease in the right lower lobe and a cortical disruption through one of the right ribs posteriorly. CXR AP shows poorly expanded but grossly clear lungs bilaterally. There is dense periosteal reaction / callus formation around the posterior aspect of the left 8th and 9th ribs. CXR AP shows lucent lines without surrounding periosteal reaction through the right 6th-8th and left 6th-11th ribs posteriorly. 3D CT reconstruction with contrast of the chest shows callus formation around the right 4th-8th ribs and left 4th-9th ribs anteriorly. CXR AP (above) from initial skeletal survey was unremarkable. Repeat CXR AP (below) from follow-up skeletal survey 2 weeks later shows interval development of periosteal reaction around the left 8th-9th ribs posteriorly. CXR AP shows lucent lines without surrounding periosteal reaction through the left 5th-7th ribs posteriorly. CXR AP shows clear lungs and an area of callus surrounding the right 7th rib posteriorly. AP and lateral radiographs of the right femur (above) show a linear lucency through the diaphysis of the right femur with no associated periosteal reaction. CXR AP shows callus formation around the lateral aspect of the right 5th-6th ribs. AP radiograph of the right femur shows a lucency through the diaphysis of the right femur with no associated periosteal reaction. CXR AP shows callus formation around the right 7th and 9th ribs laterally, the right 7th-9th ribs posteriorly, the left 3rd-7th ribs laterally and the left 8th rib posteriorly. CXR AP (left) shows the lungs to be poorly expanded and clear but there are dense areas of callus along the lateral aspect of the right 3rd-5th ribs. Centralization of the loops of bowel were also incidentally noted and confirmed on a subsequent AXR AP (right). Gross Pathology Cases of Rib Fracture CXR (above) and complete skeletal survey showed no evidence of rib fractures. Gross pathological image (below) shows callus formation along the posterior aspect of the left 4th-8th ribs.