Because RI more closely reflects changes in renal blood flow than pelvic pressure, it can accurately diagnose acute obstruction but only after several hours. Diagnostic accuracy in chronic obstruction may be influenced by these physiologic relationships.

The histologic effect of unilateral torsion on the contralateral testicle in adult Noble rats was examined. Utilizing detorsion or orchiectomy at 3 hours and 24 hours after torsion, the effect of early and late treatment of these changes was reviewed. The histologic changes consisted of loss of tubular spermatozoa, clumping of chromatin within the spermatocytes, the presence of Sertoli-only cells, evacuolization of Sertoli cytoplasm and germinal epithelial sloughing. Depression of spermatogenesis and decrease in the mean seminiferous tubular size was seen in the "normal" testicle after unilateral torsion. This effect was negated by early treatment with either orchiectomy or detorsion. Late detorsion does not negate these effects and late orchiectomy only partially negates them. Despite the depressed tubular function, the presence of early spermatogenic elements seen in the majority of the tubules in the "normal" testicle implies the possible reversibility of these changes.