At NYU Langone, hepatologists, or liver specialists, and infectious disease specialists use blood tests to diagnose hepatitis A, B, and C. These viral infections cause inflammation of the liver.
If the results of a blood test confirm a diagnosis of viral hepatitis, your doctor may recommend imaging tests or a liver biopsy to determine the extent of liver disease.
A doctor performs a physical exam to look for signs and symptoms of viral hepatitis. He or she presses gently against your abdomen to assess whether the liver is swollen or tender and examines your eyes and skin to see whether jaundice has caused a yellow hue to develop.
As part of a physical exam, your doctor also asks questions about your current and past health, including whether you have noticed increasing fatigue, muscle weakness, or a loss of appetite.
Blood tests are used to look for signs that a viral infection is present and to evaluate liver function. Your doctor draws a small amount of blood from a vein in your arm and sends it to a laboratory for testing.
The results of a blood test can confirm the type of viral hepatitis, the severity of the infection, whether an infection is active or dormant, and whether a person is currently contagious. A blood test can also confirm whether a virus is acute, meaning short term, or chronic, meaning long term.
NYU Langone doctors may recommend different blood tests throughout the diagnostic process. For example, many blood tests look for antibodies, which are substances that the body produces in response to viruses or bacteria. If the results of a blood test indicate the presence of hepatitis antibodies in the bloodstream, the same blood sample is tested to evaluate whether the virus is still present—and if so how much is present—in the bloodstream. Your doctor may also recommend a blood test to determine how significantly the virus has affected the liver.
The results of blood tests are available in one or two days, and your doctor can discuss the results with you to explain how they affect your health and whether they indicate the need for further testing or treatment.
If the results of blood tests confirm a diagnosis of hepatitis A, B, or C, your doctor may recommend one or more imaging tests of the liver to assess liver damage.
A doctor may recommend an ultrasound to see whether the liver is inflamed. An ultrasound image may also reveal large areas of scar tissue within the liver, which may suggest cirrhosis.
Ultrasound uses high-frequency sound waves to create images of structures inside the body. A specialist places a handheld probe called a transducer against your abdomen, and the transducer sends an image of the liver to a computer monitor, where it can be analyzed. This is a painless test often performed in a doctor’s office.
Doctors at NYU Langone are among the first in New York City to use transient elastography, an advanced imaging test, to measure how hard or soft the tissue of the liver is.
Stiffness in the liver suggests the presence of fibrosis, or scar tissue, generated in response to injury. The extent of stiffness indicates the extent of liver disease caused by viral hepatitis.
Transient elastography is very similar to ultrasound. Using a device called the FibroScan®, your doctor places a handheld probe against your abdomen, and the probe sends a painless vibration through the body and into the liver. A transducer on the end of the probe measures how long it takes for the vibration to travel through the liver. The faster the vibration passes through, the stiffer the liver is.
This quick and accurate test can take place in a doctor’s office, and often eliminates the need for a liver biopsy.
If the results of blood tests or ultrasound indicate you may be at risk for liver cancer, or if you have a family history of liver cancer and therefore are at increased risk, your doctor may recommend a CT scan or MRI scan to examine the liver in more detail. These imaging tests use computers to create two- or three-dimensional images of structures inside of the body.
Rarely, the results of imaging studies are not detailed enough to show the extent of liver damage, and a doctor may recommend a liver biopsy. A biopsy can determine the extent of scarring, or fibrosis, in a liver affected by viral hepatitis. Information provided by a biopsy can be used to guide treatment.
The doctor injects a local anesthetic into the skin to numb it, and then inserts a needle through the skin and into the liver, removing a tiny sample of liver tissue. Often, doctors use imaging, such as ultrasound or CT scanning, to guide the position of the needle. This tissue sample is sent to a laboratory for testing, and results are usually available in one week.
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