Yin and Yang: acute kidney injury and chronic kidney disease.

establish ultrasonographic criteria in patients who have unknown genotype and are at risk for ADPKD. Moreover, the results demonstrate that the diagnostic criteria currently in use for PKD1 may be inaccurate when applied to PKD2 because of higher risks for false-negative results yielding a reduced sensitivity for individuals aged 15 to 59. In summary, the authors propose new ultrasound diagnostic criteria for screening patients for ADPKD from families of unknown genotype. Because the majority of patients seen in clinical practice have unknown genotype, the proposed diagnostic criteria will be useful in screening patients who are at risk for ADPKD in the clinical setting in which the genotype is seldom known. According to the Ravine criteria for patients with PKD1, 6 the finding of fewer than two cysts in each kidney is enough for disease exclusion in at-risk individuals aged Ն 30 yr. In contrast, the study by Pei et al. 7 of both patients with PKD1 and with PKD2 suggests the utility of ultrasound may be limited for at-risk individuals who are younger than 30 yr and have a negative or indeterminate scan and unknown genotype. For these individuals , repeat ultrasound scanning or even magnetic resonance imaging scanning 4 may be useful to detect new cysts. According to the new unified criteria presented by Pei et al., 7 the presence of fewer than two renal cysts has a negative predictive value of 100% and is enough to exclude the disease in at-risk individuals who are aged Ն40 yr.