Kidney length standardized to body length predicts outcome in infants with a solitary functioning kidney.

BACKGROUND: Infants with a solitary functioning kidney (SFK) are at risk for chronic kidney injury (CKI). Lack of compensatory kidney growth (CKG) is associated with CKI, but measuring CKG is challenging since it is typically reported relative to normal kidneys. This study aims to (1) standardize SFK growth in infants, (2) investigate the relationship between standardized kidney length and clinical outcomes, and (3) use these results to develop a risk-based prediction model and local clinical pathway for SFK care. METHODS: This was a quality improvement study of 166 infants with an SFK. Linear regression was used to assess kidney growth from 0 to 180 days of life. Univariate binary regression analysis was used to identify kidney length to body length thresholds associated with the development of CKI, defined as the composite outcome of chronic kidney disease (eGFR < 60 mL/min/1.73 m2), hypertension, or proteinuria. RESULTS: Kidneys grew in length from 0 to 180 days, and growth was constant when standardized to body length. Over follow-up, infants with a baseline kidney length to body length ≤ 0.088 were more likely to experience CKI than the rest of the cohort (27 vs. 8%, p = 0.04). Kidney length to body length ≤ 0.088 was also significantly associated with CKI development (OR 4.17, 95% CI 1.14-15.28, p = 0.04). CONCLUSIONS: In this study, kidney length to body length ratio was a stable CKG metric over 0-180 days, and a baseline ratio ≤ 0.088 was a risk factor for CKI. Results will aid in developing a practical, point-of-care risk assessment tool, and overarching risk-stratified clinical pathway for infants with an SFK. A higher resolution version of the Graphical abstract is available as Supplementary information.

Utility of adult-based ultrasound malignancy risk stratifications in pediatric thyroid nodules.

BACKGROUND: Individual ultrasound (US) features have limited ability to distinguish benign from malignant thyroid nodules. Adult-based systems have been developed to integrate the sonographic features in an effort to improve diagnostic accuracy. None, however, has been validated in children, in whom the likelihood of malignancy is 2-5 times higher than adults. OBJECTIVE: To assess the performance of two adult-based sonographic (US) stratification methods for assessment of thyroid nodules in children. MATERIALS AND METHODS: This retrospective study comprised 124 children who underwent thyroid US. Three radiologists reviewed the US data using the American Thyroid Association (ATA) and the Thyroid Image Reporting and Data System (TI-RADS). Radiologists' accuracy and agreement was assessed. The reference standard was histopathology/cytology or 2-year follow-up of clinical outcome for nonoperative cases. RESULTS: We assessed 71 benign and 52 malignant nodules and excluded 1 nodule. Using the ATA pattern descriptions, 80% of malignant nodules were classified as "high" 36/52 (69%) or "intermediate" 6/52 (11%) likelihood of malignancy. A total of 20/71 (28%) benign nodules were also classified within these two categories. Using the TI-RADS, malignant nodules were classified as 2, 3, 4a, 4b, 4c and 5, with rate of malignancy of 0%, 0%, 7/52 (13.5%), 7/52 (13.5%), 32/52 (61.5%) and 6/52 (11.5%), respectively. Benign nodules were also classified in the 4a (26/71; 36.6%), 4b (17/71; 24%), 4c (14/71; 19.7%) and 5 (1/71; 1.4%) categories. The positive and negative predictive values were 68.0% and 87.5% for ATA, and 71.7% and 80.0% for TI-RADS. CONCLUSION: We validated the use of ATA and TI-RADS methods in children and showed that they have test characteristics similar to those in adults, although neither is independently sufficient to discriminate nodules' likelihood of malignancy.