What It Is
A renal biopsy, also known as a kidney biopsy, is a procedure in which a small sample of kidney tissue is removed for closer examination, helping assess the specific cause of kidney-related problems.
What It Checks
A kidney biopsy allows direct microscopic examination of kidney tissue, including the small filtering structures called glomeruli, which can reveal the specific pattern and extent of damage or disease affecting the kidney, often providing more detailed information than blood or urine tests alone.
Why It's Used
A kidney biopsy is commonly used to help identify the specific underlying cause of unexplained kidney function decline, significant protein or blood in the urine, or other kidney-related findings that need more detailed evaluation to guide appropriate treatment.
How It's Done
A kidney biopsy is most commonly performed using a thin needle inserted through the skin into the kidney, typically guided by ultrasound or CT imaging to help ensure accurate and safe placement, after numbing the area. A small sample of tissue is withdrawn through the needle and sent to a laboratory for detailed examination by a pathologist.
Background
Kidney biopsy techniques developed over the mid-20th century, growing alongside advances in understanding the many different specific patterns of kidney disease that couldn't be distinguished through blood and urine testing alone. The introduction of imaging guidance improved the safety and accuracy of the procedure considerably, and kidney biopsy remains an important diagnostic tool for identifying the specific underlying cause of many kidney conditions today.