GRAY-SCALE SONOGRAPHIC CHARACTERIZATION OF AMINOGLYCOSIDE-INDUCED NEPHROTOXICOSIS IN A CANINE MODEL

RATIONALE AND OBJECTIVES. The diagnostic usefulness of gray-scale sono graphy was evaluated in a canine model of aminoglycoside-induced nephr otoxicosis. METHODS. Sonography was performed before and during the on set and progression of nephrotoxicosis induced by administration of a toxic dosage of gentamicin. Subjective visualization of increased rena l cortex echogenicity (IRCE) was objectified with digital image analys is methods, Results of both subjective and objective evaluation were c orrelated with clinicopathologic tests and renal cortex biopsy obtaine d concurrently. RESULTS. Subjective visualization of IRCE was associat ed with significant nephrotoxicosis and was superior to serum creatini ne elevation in nephrotoxicity detection, Objective detection of IRCE improved nephrotoxicity detection sensitivity to that of increased uri ne enzymuria. CONCLUSIONS. Based on the above results, subjective visu alization of IRCE in patients with aminoglycoside-induced nephrotoxici ty may occur before azotemia and is suggestive of significant renal dy sfunction; application of digital image analysis methods may lead to e arlier sonographic recognition of nephrotoxicity.