**5. Digital assessment of inflammation in liver biopsy**

The computer-aided assessment of necroinflammatory processes in chronic viral hepatitis has been tested. To perform this, immunohistochemical visualisation is necessary in order to high‐ light inflammatory cells. The application of immunohistochemistry increases the expenses. This drawback can be counterbalanced by gains of rapid measurement, resulting in rigorous results expressed in scalar numbers as well as by complete characteristics more exactly reflect‐ ing the status of the whole organ [16].

The assessment of hepatic fibrosis and the closely related architectural deformities as bridging fibrosis and liver cirrhosis have important role in the diagnostics, treatment and prognostic evaluation of chronic liver diseases [24]. The studies of liver fibrosis are facilitated by standard use of special stains for the routine evaluation of liver biopsies in case of diffuse liver disease. Masson's trichrome is an efficient method to highlight fibrosis [3]. The sharp contrast between blue collagen and red parenchyma allows visualisation of even small excess amounts of colla‐ gen [23]. Sirius red stain has also been employed [21, 40]; it has the benefit of selective staining of collagen but not proteoglycans [22]. Not surprisingly, comparatively many authors have ap‐ plied digital image analysis to quantify fibrosis in liver tissue [24]. Validation studies of com‐ puter-assisted morphometry have also been performed [21]. Besides the well-developed methodology including software, the application of computer analysis has resulted in exact numerical data allowing detection of interesting biological relationships. For instance, the cor‐ relation of fibrosis burden with end-stage liver disease score, serum total bilirubin and interna‐ tional standard ratio of prothrombin has been shown in hepatitis B-related decompensated cirrhosis. Thus, the correlation between the amount of connective tissue in cirrhotic liver and hepatic functional reserve was demonstrated [24]. The problem was insufficient accuracy of computer-assisted morphometry [21] manifesting as inter-observer differences. Poor correla‐ tion of the fibrosis area with Ishak staging score has been observed as well [21]. Other scientists have also found that analysis of early fibrosis necessities qualitative assessment despite the general correlation between amount of connective tissue and Ishak grade of fibrosis [20]. Tis‐ sue geometry differences in subsequent sections also can be more accurately classified by hu‐ man eye [22]. Full section digital analysis seems to be important [20].

Digital image analysis for the evaluation of fibrosis in chronic viral hepatitis C has been studied also as mentioned in references [41-42]. Automatic quantification of liver fibrosis in‐ cluding the validation of the method has been performed as described in reference [43]. Oth‐ er investigators have employed computerised image analysis for the evaluation of fibrosis as well [44-47]. In most investigations, correlation between digital and manual semiquantita‐ tive score has been shown [20, 44-47]. However, the digital data do not allow to differentiate between low stages of fibrosis [20, 45, 47].
