question about numbers

I got a eGFR of 57,  2 weeks ago.  today I had a ultra sound of both kidneys,  the tech. said there were alot of bright patches and calcifications,  but it needs to be read by an radioligist.  On my way out I asked the receptionist if the blood test came back. She said they had,  and I asked her if she could tell me the egfr number . She said it said  it's within normal range.  I have been really been good about following a kidney diet since I was told about the problem 2 weeks ago.  Could this number change be due to my good eating habits?  I don't go back for all the results, ultra sound, blood tests, and 24 hr urine until July 3.  I was just wondering if you hand any info on this.
Thank You
Tami
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[Dr_Aparna]

Hi,
The glomerular filtration rate (GFR) is an estimate of the filtering capacity of the kidneys. It is usually expressed as milliliters (mL) per minute (min) and adjusted to a “standard” body size with a surface area of 1.73 meters2. The normal GFR ranges between 95 -120 mL/min/1.73m2 but it varies depending on age, gender and body size.
Patients at risk for kidney disease or have signs of kidney damage (i.e. blood or protein in the urine) should have their kidney function assessed.
Currently the best method is to do estimate the GFR by measuring the amount of creatinine in the blood (i.e. serum creatinine) and then using a specific mathematical formula (i.e. MDRD equation) to adjust for the person’s age, gender, race, and body size.
If the person is at risk and the GFR is less than 60 (or 60 mL/min/1.73m2), then the doctor should act.
If the GFR is above 60, there aren’t other signs of kidney damage or dysfunction and the person is not at a high risk for developing severe kidney failure, it may prudent to monitor the situation instead of starting treatment or sending them to the kidney doctor. In these cases, it is recommended that the person’s medications be adjusted, substances known to be toxic to the kidney avoided, and the GFR be checked more frequently. If the GFR is or starts to rapidly drop without explanation (i.e. more than 30% within 4 months), then it is appropriate to start treatment or refer to a nephrologist.
ref:http://kidneydiseases.about.com/od/diagnostictests/a/Article0051.htm

[shannonkim]

Hi Tami, do you know what the formula is for figuring out the MDRD eGFR? thanks,
Kim

[kelleyblair]

Thanks for any information.
Kelley

[Rairigh]

I am a 63 yr. old woman.  I recently had my annual bloodwork done.  All great numbers except for the GRF.  Several months ago, I had it checked because my identical twin sister's GFR was 53.  At that particular time, mine was <60.  Now mine is also 53.  Her doctor had her wait three months and do the test over.  Hers was then <60, but the next three months, it went back to 53.  We are a concerned because we read that this is supposedly Stage III of Chronic Kidney Failure.  We are healthy and are not overweight. There was no protein in my urine sample, creatine was 1.1, and the BUN was 25. We've both taken diurectics for many years due to hormonal changes causing fluid retention. This has been going on since we were young.  Should we be concerned about this?  Thank you, Dona