Definition: Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.
Input: Abstract: Records of 55 percutaneous renal biopsies performed in 53 children aged 5 days to two years were reviewed. Radiographic or ultrasound imaging techniques were not utilized during the biopsy procedure. Forty-nine of 55 biopsy attempts yielded sufficient tissue for histologic evaluation (89.1%). Transient gross hematuria not requiring intervention was the sole complication and was noted in 6 of 55 biopsy attempts (10.9%). Percutaneous renal biopsy can be performed safely in very young children and the success of the procedure is comparable to that in older children.

Kidney