Q: I have been asked to take the Isotope GFR test as my right kidney was found to be slightly smaller in length (Length :8.2 cms; Breadth: 4.3cms; thickness: 4.8 cms; CMD ratio well maintained with normal echogenecity). Left kidney is normal. Hence, as a precaution I was asked to take the Isotope GFR test(99 Tm DTPA dynamic renal studies). The test results read as : Both kidneys showed normal perfusion, concentration and clearance of the tracer. GFR: Right kidney 29ml, Left kidney 31 ml with a total of 60 ml/min. Backward activity slightly high. I was then asked to take a 24 hr urine analysis, which read: pH 6, SG 1.030, albumin - nil, sugar - nil, total Protein 48 mg/day, occasional RBC, pus cells-2-4/hpf, blood and nitrite - Nil. Please advice based on the above tests and the subsequent GFR results. Does isotope GFR result alone give a reliable and accurate diagnosis; is there a possibility for erroneous results. Clinicaly I have no problem and only occasionally after being aware of this I feel some pin prick sensation on my penis and am deeply worried. In case of a problem can my father donate his kidney? He is 62 years old and healthy. Kindly give a positive result since I am newly married and will I go into acute renal failure?

A:This person need not worry on account of these reports at all. GFR is not a very accurate determinant of kidney function. Moreover, there is nothing grossly wrong with his reports and do not suggest kidney disorder or an impending renal failure and his recent symptoms are anxiety related. What he needs to do are the following things: 1) 24 hour urinary creatinine clearance 2) Serial serum creatinine value estimation (once in three months, two or three times and if normal, then once a year) 3) Repeat ultrasound for kidney size after six months.