Kidney Stones

Diagnosis

Diagnosis of renal stone disease is based on the symptoms, physical examination, laboratory evaluation, and imaging tests. Blood and urine tests help detect any abnormal substance that might promote stone formation. Imaging tests can give detailed information about the size of the stone and its location. These include ultrasound, IVP (intravenous pyelogram), retrograde pyelogram and CT (computed tomography) scan. The results of all these tests help to determine the proper treatment.

Ultrasound Scan : A procedure uses high-frequency sound waves (ultrasound) to produce pictures of internal tissues or organs. But this method may miss small stones which are located outside the kidney.

Intravenous Pyelogram (IVP) - In this method, a contract dye is injected into a vein and a series of x-rays is taken as the dye moves through the kidneys, ureters and bladder. IVP can determine the location of stones in the urinary system and can define the degree of blockage caused by a stone. It may produce allergic reaction in susceptable individuals.

Retrograde Pyelogram - The most reliable method for detecting kidney stones but generally used only when other imaging methods are unsuccessful. This test may require anesthesia and there is no risk of an allergic reaction. In Retrograde Pyelogram a cystoscopy is performed. It is the method of examining bladder and urethra using cystoscope, which is a thin, narrow tube with a light and a camera on the end. Cystoscope is inserted into the bladder through the urethra. The contrast agent (dye) is injected directly into this opening and an x-ray is taken to locate the kidney stone.

CT (computed tomography) scan - This gives a 3-dimensional view of the urinary system and can be done with or without contrast dye. If any stones are found, a plain abdominal x-ray is also taken to determine their size, shape, and orientation. CT scan may have difficulty detecting small stones located near the bladder.