Situs Inversus Etiology: congenitalImaging: discordance between position of cardiac apex and stomach Radiology Cases of Situs Inversus AXR AP shows a left lower extremity PICC and a right femoral venous catheter both of whose tips project over a left-sided inferior vena cava. An umbilical venous catheter tip projects over the ductus venosus. An umbilical arterial catheter tip projects at the level of T9. Nasogastric tube tip projects over the stomach in the right upper quadrant. Feeding tube tip projects transpylorically over the duodenal bulb. The cardiac apex is in the right chest. CXR AP shows situs inversus with the cardiac apex in the right hemithorax, the stomach bubble in the right abdomen and mild thickening of the airways centrally. Axial CT with contrast of the heart (above), obtained in a venous phase, shows discontinuity of the ascending and descending aorta while the sagittal image (below right) shows a dilated patent ductus arteriosus reconstituting the descending aorta and the coronal image (below left) shows dextrocardia.