The Diaphragmatic Crura and Retrocrural Space Normal Imaging Appearance, Variants, and Pathologic Conditions,Guo Xiaochao 2010.7.22,RadioGraphics 2008;28:1289-1305,The retrocrural space (RCS) is a small triangular region within the most inferior posterior mediastinum bordered by the two diaphragmatic crura. Multiplanar imaging modalities allow evaluation of the RCS as part of routine examinations. Normal structures within the retrocrural region include the aorta, nerves, the azygos and hemiazygos veins, the cisterna chyli with the thoracic duct, fat, and lymph nodes.,Anatomic Considerations,Diaphragm and Diaphragmatic Crura Lymph Nodes, Cisterna Chyli, and Thoracic Duct 52% at lymphangiography; 1.7% at CT; 15%96% at MR Aorta Azygos and Hemiazygos Veins Paravertebral Venous Plexus valveless Sympathetic Trunk and Splanchnic Nerves,Cisterna Chyli & Thoracic Duct,Paravertebral Venous Plexus,Congenital diaphragmatic hernia Bochdalek hernia(95%) Morgagnis hernia(2%) Partial duplication of the diaphragm Discontinuity of the diaphragm Congenital Anomalies of the IVC,Anatomic Variants and Anomalies,Abnormalities of the Crura,Lymphadenopathy Neoplasms Foregut Malformations Vascular Disorders Infammatory Conditions Infections Other Abnormalities,Abnormalities of the RCS,Lymphadenopathy (6mm),Neoplasms,These can be categorized according to their cell of origin into neurogenic, mesenchymal, germ cell, and lymphoid tumors.,Vascular Disorders,Infammatory Conditions,Retroperitoneal fbrosis Steroid-induced retrocrural lipomatosis Spondylosis deformans Pancreatic pseudocysts,Infections,Diabetes, immunosuppression, intravenous drug abuse, anemia, and urinary tract infections,Conclusions,Despite the small area that encompasses the RCS, there is a wide variety of pathologic conditions within this region, which is located at the posterior confnes of the inferior thorax and upper abdomen. An understanding of the anatomy, the normal variants, and the multiple pathologic conditions affecting the diaphragmatic crura and retrocrural structures facilitates the diagnosis of disease.,