Quantitation of the prominent medullary pyramid: a reappraisal.

ABSTRACT

We propose a revised objective measurement of the size of the renal medullary pyramid in the assessment of the prominent renal pyramid the medullary-renal ratio (MRR). (Formula see text). This is a more accurate assessment of the size of the renal pyramid relative to the size of the kidney than the previously proposed medullary pyramid index, which fails to take into account the varying morphology of otherwise normal kidneys.