Q: I am a 30 years old woman suffering from chronic kidney disease for the last 8 months. What is a kidney biopsy? How is it done? What are renal scan with diuretic and glomerular filtration rate (GFR) measurement and how are they performed?

A:Kidney biopsy is a safe procedure performed with ultrasound guidance using local anaesthetic agent to numb the area around the point of needle insertion overlying the scanned kidney. There is minimal risk of bleeding post-biopsy obvious in the form of blood in urine (haematuria), which subsides over a period of hours. One would advise bed rest post biopsy for at least 12 hours while avoid lifting heavy objects.

Renal Lasix scan is used to study the underlying functional abnormality of each kidney, assess each kidney's function (signified as glomerular filtration rate, GFR) and study the evidence of any obstruction in the filtering system. It involves injecting a radiotracer substance (deemed safe) followed by taking images of kidney’s filtering system. Lasix, a water pill is injected later to increase the amount of urine made thereby increasing the sensitivity of the test result. In your case with diagnosed chronic kidney disease, one would be interested in studying the focal functional abnormality in each kidney's parenchymal body substance. You would benefit from "Static renal scan" which involves using DMSA (99mTc- Dimercaptosuccinic acid), a safe and most commonly used radiotracer material.