Monday, February, 13, 2012

Kidney Stones - Risk Factors

Table of Contents

  • Gallstones
  • Diverticulitis (infection or irritation of abnormal pouches in the intestines)
  • Intestinal blockage
  • Blood clots
  • Irritable bowel syndrome
  • Appendicitis
  • Peptic ulcers
  • Pancreatitis (inflammation of the pancreas)
  • Hepatitis
  • Pelvic inflammatory disease
  • Inflammatory bowel disease (Crohn's and colitis)
  • Heart attack

Imaging Techniques

Various imaging techniques are helpful in determining the presence of kidney stones. The best approach uses spiral (or helical) computed tomography (CT) scans. If these scans are not available, the patient will need ultrasound or standard x-rays. If no stones show up, but the patient has severe pain that suggests the presence of kidney stones, the next step is an intravenous pyelogram (IVP).

X-Rays. A standard x-ray of the kidneys, ureters, and bladder may be a good first step for identifying stones, because many stones are visible on x-rays. Calcium stones can be identified on x-rays by their white color. Cystine crystals can also show up on x-rays.

Spiral (or Helical) Computed Tomography. A type of CT scan called a spiral or helical CT scan is currently the best method for diagnosing stones in either the kidneys or the ureters. This test is fast, noninvasive, and it provides detailed, accurate images of even very small stones. If stones are not present, a spiral CT scan can often identify other causes of pain in the kidney area. It is better than x-rays, ultrasound, and IVP for detecting kidney stones. Experts hope spiral CT will eventually be able to identify the chemicals present in a stone.

Ultrasound. Ultrasound can detect clear uric acid stones and obstruction in the urinary tract. It is not useful for finding very small stones, but some research indicates that it may be an effective first diagnostic step in the emergency room to help identify whether a patient has a stone. Ultrasound is also effective in children.

Intravenous Pyelogram (IVP). With IVP, the doctor injects a special dye into the patient. A technician then takes x-rays as the dye enters the kidneys and travels down the urinary tract. IVP is invasive but, until recently, it was the most cost-effective method for detecting stones. Where it is available, spiral CT is now preferred, since it gives a faster diagnosis and is more accurate, safer, and similar in cost.

IVP should not be used on patients with kidney failure. There is also a risk for an allergic reaction to standard dyes, although newer, less allergenic dyes are becoming available.

Intravenous pyelogram (IVP)
In the procedure intravenous pyelogram (IVP), the patient is injected with dye. X-rays are taken as the dye travels through the urinary tract. This procedure is done to confirm the presence of kidney stones, although some stones may be too small to see.

Review Date: 06/08/2010
Reviewed By: Reviewed by: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)