Selective angiography in renal and peri-renal inflammatory lesions: correlation with histopathology

We have correlated the angiographic and pathological findings in renal and peri-renal inflammatory disease in acute, sub-acute and chronic phases. In all stages of renal infection, the renal vasculature is attenuated. This corresponds in acute inflammation to vasospasm, acute vascular necrosis and post glomerular peritubular capillary congestion. In sub-acute inflammation, the reduction in vascularity is due to peri-vascular fibrosis and intimal and medial hyperplasia. In chronic infections, the renal vessels are completely destroyed and replaced by fibrotic tissue. In contrast to this, peri-renal inflammatory disease leads to vaso-dilatation and enlargement of the renal capsular arterial complex, and of retroperitoneal arteries. If both renal and peri-renal inflammation occurs simultaneously, a discordance between the renal cortical and capsular arterial filling results: this striking phenomenon is highly suggestive of inflammation, and extremely rare in tumours. Three types of inflammatory vascularity are described, two of which can be easily distinguished from tumour vascularity. An inflammatory blush, slow emptying of vessels and a mottled nephrogram with loss of cortical definition are highly suggestive signs of renal inflammation. It is concluded that angiography is a sensitive and accurate method for the early diagnoses of renal and peri-renal flammatory conditions.