The CT examination is illuminating. This demonstrates no overt pleuroparenchymal abnormality. There is elevation of the anterior aspect of the right liver lobe with a notched appearance to the lateral margin of the liver on the bottom left image. Also noted is that there is low attenuation along the vessels in the anterior segment of liver. This suggests that there is segmental mild biliary obstruction in this region, but not centrally in the porta hepatis. The remainder of the right posterior liver and left liver lobe are unremarkable. The right lateral margin of the liver in contact with the right lateral chest wall has lost its normal rounded configuration and has a squared off appearance.
These appearances are indicative of a right diaphragmatic traumatic injury with partial herniation of the liver through the diaphragmatic tear. This results in the notch in the lateral liver aspect as well as the segmental ductal obstruction of the herniating segments.
Diaphragmatic tearss are not uncommonly delayed presentations following trauma. In part this may because patients with trauma may be treated with positive pressure ventilation which may suppress a diaphragmatic injury. But also tears can enlarge with time becoming sympomatic. Diaphragmatic injuries are commoner on the left side and less so on the right side, thought to be due to the protective of the liver. Most commonly these are due to increased intra-abdominal pressure from blunt injury but can also of course occur with penetrating injuries. Delayed diagnosis results in increased morbidity and mortality, particularly as larger hernias can become more difficult to surgically repair.
CT is essential in confirming the diagnosis of diaphragmatic tears, particularly the coronal and sagittal reconstructions, although these are less helpful on the right side due to close approximation of the liver to the diaphragmatic fibres, frequently with no substantial interposing fat. This case was diagnosed based on the abnormal configuration of the right diaphragm with evidence of prior trauma (rib fractures), aided by the focal biliary tract obstruction. Such cases should be differentiated from diaphragmatic eventration which is due to an anteromedial weakness of the diaphragm. In this context the PA chest x-ray would demonstrate loss of the entirety of the right cardiac border near the elevated segment and there would be no evidence of biliary obstruction present.