Vibration-controlled Transient Elastography

A Practical Approach to the Noninvasive Assessment of Liver Fibrosis

Elliot B. Tapper; Nezam H. Afdhal

Disclosures

Curr Opin Gastroenterol. 2015;31(3):192-198. 

In This Article

How Do I Use Vibration-controlled Transient Elastography?

The interpretation of LSM requires first an understanding of optimal test conditions and, second, the effect of known confounders. The ideal VCTE examination takes place with an experienced technician,[8,12] a patient who has fasted for 2–3 h (given the effects of postmeal absorption on portal circulation),[12,15] and a patient without central venous congestion.[16] The principle confounders of VCTE are inflammation, cholestasis and BMI. As above, BMI is best addressed with probe choice.[13,14] There are no explicit BMI limits for VCTE, though LSM success declines, especially above 35 kg/m2. In practice, if one cannot obtain a successful measurement with the 'M' probe, the 'XL' should be used.[17] Inflammation and cholestasis, reflected respectively by the alanine aminotransferase (ALT) and alkaline phosphatase level, are important, independent determinants of liver stiffness.[18–20] These values must be known at the time of VCTE and affect the positive predictive value (PPV) of a high LSM.

Once the LSM has been obtained, its value is determined by the patient's clinical context and the treatment decisions posed by their specific liver disease. In the remaining sections of this article, we will discuss specific treatment considerations in chronic HCV infection and NAFLD. The general approach supported by the available data is delineated in Fig. 2 and the LSM cutoffs discussed are summarized in Table 1 .

Figure 2.

How to use vibration-controlled transient elastography (VCTE). IQR, interquartile range; LSM, liver stiffness measurement.

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