The diagnosis of the scars of chronic pvelonephritis.

The thesis put forward by Hodson (1959) from radiological evidence that renal scars due to ischaemia show a narrowed parenchyma associated with a normal calyceal pattern, whereas in focal pyelonephritic scars the narrowed parenchyma is associated with clubbing of the calyx in the affected area, has been investigated anatomically. The thesis finds considerable support and the importance of careful examination of the calyceal system in scarred kidneys is stressed. In only one of 23 examples in which all the circumstantial evidence of the case pointed to an ischaemic scar was there any deformation of the renal calyx. In 13 of 14 examples in which the evidence pointed to chronic pyelonephritis there was clubbing of the calyx associated with the scar.