Table 3.

Comparison between the methods of liver disease diagnosis/stratification.

Test	Pros	Cons
Liver biopsy (gold standard)	It represents a direct analysis of the histological status of the liver. This method is highly established, with the scoring system having been developed since 1980.	It is a surgical procedure that requires at least one day at the hospital, which means it can be expensive (it depends on national healthcare/health insurance). The procedure requires high expertise in sampling and interpreting results. The specimens represent only a minimal part of the entire liver, and often, they are unique. Results typically take about 2 weeks, depending on the laboratory efficiency. Standardization is largely dependent on manual processes. Patients are exposed to significant stress and substantial risks of pain, bleeding, and infections.
Imaging techniques	Usually, these refer to several techniques that allow the direct observation of the liver’s status and enable quantitative measures (CPA). These represent non-invasive, quick, and safe procedures. The standardization process for these techniques and imaging results is ongoing, and there is significant interest in using artificial intelligence algorithms for this purpose. Scores are based on the liver biopsy score system.	These procedures require high-cost instruments that are usually available only in specialized clinical settings. They are expensive for both the national healthcare system and for the patient. The failure rate and the effectiveness of the measures depend on the patient’s body characteristics, with higher failure rates in patients suffering from ascites and obesity. The expertise of the operators remains a key factor. Despite standardization efforts, measurements from different techniques are not comparable.
Serum biomarkers	Non-invasive, repeatable, cost-effective, safer, quick, and better-tolerated measurements. They enable early detection for at-risk patients and open the way to the development of new stratification and prognostication models. They rely on the detection of biomarkers that reflect the following: (I) changes in the ECM structure; (II) molecules derived from liver damage; (III) molecules related to liver function; (IV) molecules derived from the immune response after liver injury; (V) antibodies, antigens, nucleic acids of hepatotropic viruses; (VI) molecules impacting on liver metabolism; (VII) cytokines. Combining these biomarkers with imaging tests can positively impact results. These tests are usually well standardized, and the techniques are continually being developed.	Non-invasive tests are very promising but show high susceptibility to factors such as gender, age, sex, time of blood sampling, quality of blood sampling, and quality and modality of storage. Moreover, their specificity could be invalidated by non-liver inflammation. Single-marker measurements appear to be inefficient. The combination of different biomarkers or with imaging tests is instrumental in increasing accuracy. Importantly, this process can result in freely available formulas or proprietary (paid) algorithms Despite the general availability of routine laboratory tests, not all biomarkers are accessible in every facility, resulting in longer testing times. The more recent biomarkers require further study to be applied effectively and focused expertise to ensure the best result. Results should be carefully evaluated to understand their real meaning based on the stage of the disease.