The first peak of RCN occurrence is in early infancy and is associated with severe perinatal events or conditions. RCN in childhood usually is secondary to HUS or severe volume depletion. Occurrence also peaks in women of childbearing age due to obstetric causes. Serum electrolyte measurements and renal function tests are used to check for hyperkalemia, hypocalcemia, metabolic acidosis, and elevated creatinine. A CBC may reveal hemolytic anemia and thrombocytopenia.
Coagulation studies detect low fibrinogen levels and increased fibrin-degradation products.
Urinalysis detects hematuria, proteinuria, red blood cell casts, and granular casts. Thin cortical shells or tram lines caused by calcification are a radiologic hallmark, but they develop only 4-5 weeks after the initial insult. The sonogram initially shows enlarged kidneys with reduced blood flow. Cortical tissue becomes shrunken later in disease progression. Contrast-enhanced CT scans CT scans with contrast are the most sensitive imaging modality.