Advances in radiological anatomy of the kidney.

While using cortical nephrotomography to show the architecture and thickness of the cortical septa we have observed, in 76 out of 176 kidneys, the presence of 2 distinct parenchymal elements for which we suggest the term "renunculus". In such cases the upper renunculus is posterior relative to the lower. It lies rather obliquely, running downwards and laterally, while the lower renunculus lies more or less vertically and in front of the upper. The hilum of the upper renunculus as seen on CT is directed anteriorly relative to the corneal plane: the hilum of the lower renunculus is directly more medially. These anatomical observations make it easier to understand the topography and the pathogenesis of some lesions and help the surgeon to plan partial nephrectomy.