Reflux Nephropathy - How is reflux nephropathy diagnosed?
How is reflux nephropathy diagnosed?
Even if a doctor might suspect reflux nephropathy very strongly, for example if someone has multiple urine infections and there are a number of proven cases in the family, tests must be performed before the diagnosis can be proven.
The tests that might be performed are listed. Not all of these are needed, and someone’s own specialist will need to decide what is necessary.
Urine tests will be performed to look for infection in the urine, and also to test for blood or protein in the urine. In some cases, a 24 hour collection of urine may be performed to measure the exact amount of protein in the urine (click here for more details about protein in the urine).
Blood tests will be performed to measure the level of kidney function, and to look for other possible causes of kidney disease if the diagnosis is not certain.
This is a scan using sound waves (the sound waves are too high pitched for us to hear). A probe is pressed gently on the skin, with some jelly on the skin to make a good contact. Ultrasound is painless and harmless, and can easily be performed on babies as well as older people. An ultrasound can show the size and shape of the kidneys, and sometimes can show enlarged ureters (tubes from kidney to bladder). It can also show whether the bladder empties fully. Unfortunately, though, it cannot prove whether reflux is actually occurring. Therefore further tests may be necessary.
‘IVU’ or ‘IVP’
Pictures of the kidneys and ureters can be obtained by a series of X-ray pictures after an injection of an X-ray dye into the arm. This is called an ‘IVU’ or ‘IVP’. It is not, however, 100% reliable at showing reflux.
‘Micturating’ is a medical term which means passing urine. Cystogram means picture of the bladder. A catheter is passed into the bladder and X ray contrast injected into the bladder. Pictures are taken while urine is being passed. This gives the best pictures of reflux and can assess the need for surgery (click here for more details of who might need surgery), but is not pleasant, and carries a small risk of causing urine infection. In children, a micturating cystogram may need to be carried out using a short anaesthetic to put your child to sleep.
A number of other tests are sometimes advised. Surgeons may inspect the inside of the bladder using a tube called a cystoscope. This examination may be performed while you are awake, using a local anaesthetic, or sometimes while someone is asleep (for example in children). Using the cystoscope, a doctor may be able to see abnormal ureters, or take X-ray pictures in the operating theatre which show reflux. A ‘micturating radio-isotope scan’ is a type of scan performed by putting slightly radio-active fluid into the bladder though a tube. When urine is being passed, pictures are taken to measure any reflux of urine. This is a specialist technique, but is very successful in some hospitals. The radio-isotope is radioactive, but the exposure of the subject to radiation is equal to, or less than, a micturating cystogram.
Tests in babies
Performing medical tests in children and young babies is not always easy. Unfortunately, simple urine tests and ultrasound are not always enough to diagnose reflux nephropathy (and other conditions of the kidneys) with certainty. The specialist may then advise other tests, which are less pleasant. Sometimes it is possible for these to be performed under an anaesthetic, although of course there are slight risks associated with a general anaesthetic. If a slightly unpleasant test reduces the chances of a baby developing kidney failure in adult life, it may be worth having, even if it causes some worry to the parents. The details of each case need to be discussed with a specialist.
The National Kidney Federation cannot accept responsibility for information provided. The above is for guidance only. Patients are advised to seek further information from their own doctor.