Noninvasive Testing For Cirrhosis Avoids Liver Biopsy

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Noninvasive

Testing For Cirrhosis Avoids Liver Biopsy

Article Date: 02 Oct 2007 - 7:00 PDT

Newer ultrasound and magnetic resonance (MR) imaging tests yield encouraging

initial results in diagnosing fibrosis (scarring) and cirrhosis of the liver, according

to three studies in the October issue of the journal Clinical Gastroenterology and Hepatology.

With further research, these and other non-invasive imaging techniques

may reduce the need for biopsies -- procedures done to obtain a tissue sample --

to determine the presence and severity of fibrosis and cirrhosis.

Two of the three new papers evaluated techniques of elastography

-- tests that evaluate reactions to ultrasound vibrations or energy waves as a

means of measuring the elasticity or stiffness of the liver tissue. Lower elasticity (or higher stiffness) corresponds to

increased fibrosis or scarring. When fibrosis becomes

severe, it signals the presence of cirrhosis.

Dr. Jayant A. Talwalkar

and colleagues of Mayo Clinic College of Medicine, Rochester, Minn., analyzed the current evidence on

ultrasound-based transient elastography -- the

approach that has received the most research attention to date. Based on data from 18 previous studies, the ultrasound

test was highly accurate in identifying patients with cirrhosis, defined as

severe (stage IV) fibrosis of the liver. About 90

percent of patients with cirrhosis were correctly identified by

ultrasound-based transient elastography. The test was somewhat less accurate in detecting

less-severe fibrosis.

Because the studies used differing cutoff points, the analysis could not

establish the true accuracy of this emerging technology. The

researchers highlight the need for additional high-quality studies including

patients with liver fibrosis ranging from mild to severe.

Dr. Meng Yin and colleagues, also of Mayo

Clinic College of Medicine, evaluated a different approach to measuring liver

elasticity/stiffness: MR elastography. Although the principle is the same as with the ultrasound

technique, MR elastography measures reactions to

mechanical shear waves, rather than ultrasound vibrations.

The researchers performed MR elastography in

50 patients with chronic liver disease and 35 normal volunteers. The test was nearly 100 percent accurate in identifying

patients with any degree of liver fibrosis, including those with mild fibrosis. With further study, Dr. Yin and colleagues believe MR elastography could be a useful initial test for fibrosis --

avoiding the discomfort and risks of liver biopsy for many patients, while

potentially increasing the reliability of diagnosis.

Dr. Chen-Hua Liu and colleagues of National Taiwan University Hospital, Taipei, evaluated a different ultrasound

technique for measuring fibrosis. Using widely

available duplex Doppler ultrasound equipment, they measured the

characteristics of blood flow in the vessels in and around the liver in

patients with chronic hepatitis C -- an increasingly important cause of

fibrosis and cirrhosis.

The results showed that a specific measure of blood flow in the spleen

-- the splenic artery pulsatility index (SAPI) -- was

highly accurate in identifying fibrosis and cirrhosis. The

authors believe that, with further study, the SAPI could also be a useful

indicator of fibrosis/cirrhosis in other groups of patients with kidney

disease.

Cirrhosis and related complications are responsible for over 40,000

deaths per year in the United States, with direct health care costs of more

than $1 billion. Several trends are likely to produce

further increases in death and disease from cirrhosis, including the aging of

the population; the epidemic of obesity, which leads to nonalcoholic fatty

liver diseases; and the emergence of liver disease among patients with chronic

hepatitis C.

Traditionally, liver biopsy has been the " gold standard "

technique for diagnosing fibrosis and cirrhosis. However,

in addition to pain and a risk of bleeding and other complications, liver

biopsy is a costly technique that is prone to sampling errors.

The new non-invasive imaging techniques may provide a useful new set of

tools not only for diagnosing liver fibrosis and cirrhosis, but also for

evaluating the effectiveness of new treatments for early-stage fibrosis.

" Application of current imaging modalities may help to define the

presence of cirrhosis and even fibrosis in patients with suspected liver

disease, " commented Dr. C. Mel Wilcox, Editor of CGH. " Using

Doppler ultrasound and MRI, these investigators found these modalities to be

accurate and reproducible in detecting fibrosis and cirrhosis.

Look for more studies using these non-invasive imaging studies, and

perhaps others in the future. "

With love, Barb in Texas - Together in the Fight, Whatever it Takes!

Son Ken (33) UC 91 - PSC 99 - Tx 6/21 & 6/30/07 @ Baylor in Dallas