Purpose: To examine the relationship between focal renal cortical retention (FRCR) and contrast-associated nephropathy (CAN).
Material and methods: We investigated the incidence of both phenomena in 105 patients. CAN was defined as an increase in the creatinine level > 0.3 mg/dl and > 20% on days 1, 3, or 7. We compared predisposing factors for FRCR and CAN. Serum creatinine and blood urea nitrogen (BUN) for renal function were determined on the morning of the day of the angiography. The BUN/creatinine ratio was used as an indicator of the degree of hydration.
Results: FRCR was demonstrated in 17 patients (16%) by delayed CT 24 h after angiography, and CAN was found in 16 patients (15%). No significant relationship between CAN and FRCR was found. We found a correlation between high total volumes of contrast and FRCR. Advanced age, high blood urea nitrogen, high creatinine, and dehydration were risk factors for CAN.
Conclusion: Delayed CT showed a higher incidence of injury to the renal parenchyma than previously detected by conventional radiography.