**3. Alcoholic-induced liver fibrosis evaluation by ultrasound-based elastography**

Because the presence of liver fibrosis and liver cirrhosis is the main predictor of survival in patients with ALD, liver stiffness (LS) assessment is very important in high-risk patients [7]. Liver fibrosis assessment can be performed by biological

*The Place of Liver Elastography in Diagnosis of Alcohol-Related Liver Disease DOI: http://dx.doi.org/10.5772/intechopen.105691*

**Figure 1.** *Classification of ultrasound-based elastography methods.*

and elastography methods in the detriment of liver biopsy. Direct comparison with serum markers showed a better performance of TE in patients with ALD [20] with an AUROCs >0.9 for F4 cirrhosis diagnosis. In this chapter, we will discuss only the ultrasound-based elastography methods.

Liver elastography methods became more and more reliable in the liver stiffness measurement (LSM), being supported by recently published guidelines [28, 31]. The methods are classified into shear wave elastography (SWE) and strain elastography (SE) (**Figure 1**). Both guidelines support that SWE is the best for clinical use in LSM.

## **4. Ultrasound-based elastography techniques**

Transient elastography (TE) (FibroScan, EchoSens, Paris, and France), the first elastography technique developed, is the most widely used method, and it is noninvasive, rapid, and reproducible, with lower sampling errors [9]. The most important published studies in ALD are listed in the table below, majority of them biopsy-proven (**Table 2**). These studies showed good performance in the diagnosis of liver cirrhosis with AUROCs from 0.87 [41] to 0.97 [40], but the cut-off values differ quite a bit, most likely due to the presence of inflammation in these patients, given by recent alcohol consumption and assessed by AST levels. Several studies performed by Mueller et al. [40, 45, 46] show that absolute alcohol withdrawal leads to a 13% reduction of LS after one week and even a reduction of 40% in alcohol consumption can lead to a 17% reduction of LS [24]. In another study, LS improved in almost 80% of patients admitted for alcohol detoxification due to the coexistence of inflammation seen by AST >100 U/ml [25]. Preliminary observational data on long-term abstinence, observed over a period of more than 5 years, show LS decreases by 50% and also LS again increases by 22% if alcohol consumption continues [46]. **Table 3** resumes the data on alcohol abstinence/ relapse and LS improvement.

TE is followed by other ultrasound-based methods, such as point Share Wave Elastography (pSWE), Two-Dimensional Share Wave Elastography (2D-SWE), or Time-Harmonic Elastography embedded in ultrasound systems [47–53]. There are few studies that show data on the performance of pSWE or 2D-SWE in ALD (**Table 4**), with a small number of included patients, and in some studies, data show a wide range of values.

An important aspect of liver elastography in alcohol-induced liver fibrosis, compared to the rest of liver fibrosis etiologies is the presence of inflammation given by the levels of AST. In alcoholic liver disease, AST levels are typically higher as compared to ALT [58]. Although in cirrhotic stages, liver transaminases normalize, if alcohol consumption is continued, AST may be continuously increased.


#### **Table 2.**

*Elastography in ALD patients performed by TE.*


#### **Table 3.**

*Alcohol abstinence/relapse and liver stiffness improvement.*

The presence of steatohepatitis with AST >100 U/ml will increase liver stiffness in patients with ALD, so it was proposed to assess the presence of advanced fibrosis when AST decreases below <100 U/ml [40]. For that, an algorithm was developed for inflammation-adapted cut-off values in ALD [42], based on a multicentric study that included over 2000 patients with biopsy-proven HCV and ALD. In the absence of inflammation given by elevated transaminases, cut-off values for ALD and HCV were similar. The cut-off values increased exponentially in relation to median AST. After the formula was applied there was an improved agreement of the AST cut-off values with the histological stage for both HCV and ALD, so using inflammation-adapted cut-off values avoid repetitive assessment of LS in ALD.

In a recent meta-analysis [43], it was proved that in addition to AST, bilirubin can have a significant effect on LS assessment in ALD. Bilirubin was independently *The Place of Liver Elastography in Diagnosis of Alcohol-Related Liver Disease DOI: http://dx.doi.org/10.5772/intechopen.105691*


**Table 4.**

*Elastography in ALD patients performed by 2D-SWE and pSWE.*

associated with the presence of asymptomatic and non-severe steatohepatitis on histological features.

From an economical perspective, lifetime health care costs associated with ALD in advanced stages are very high, so noninvasive elastography methods for the diagnosis of advanced alcohol liver fibrosis were proven to be cost-effective [17] and may be used also for screening.
