[Computerized tomography in the diagnosis of nonalcoholic fatty liver--comparison with liver biopsy]

Abstract

The frequency of nonalcoholic fatty liver disease (NAFLD) is high, an estimated 10-25% of the population in different countries. Due to the lack of specific symptoms or irregularities in laboratory examinations the major role in diagnosis is played by, apart form liver biopsy, the imaging examinations.

Aim: The assessment of the correlation between intensity of fatty liver in computed tomography (CT) and in liver biopsy.

Investing group and method: The initial group comprised of 147 patients who had undergone CT of the abdomen. Within this group the range of attenuation coefficient in Hansfield units was measured in certain areas of liver and spleen. Density of the tissues being given (in Hansfield units) the increase of the fat content in the liver above the norm (tKT) was calculated, according to the formula: tKT = [(spleen density in OH units + 4 OH units) - liver density in OH units] x 0.8 = fat above norm in mg/l g of the liver tissue. Out of this group 12 patients (8 men and 4 women, average age 45.9 +/- 14.5 years) with clinical features of NAFLD on clinical indications for liver biopsy were selected.

Results: 3 patients the received value of tKT was found to be correct, that is tKT < 0. In these patients the estimated percentage of hepatocytes affected by steatosis (%TB) reached 5-20%. In the subgroup that comprised if the folio wing 6 patients %TB ranged from 30 to 70% and tKT--from 3.2 to 10. In the group of patients with the highest %TB, reaching 100%, the tKT value reached respectively 5, 10.8 and 13.6. The analysis of the relation between %TB and tKT showed a linear correlation of these two parameters. Following the increase of the intensity of the fatty liver in the biopsy the value of tKT rises. CT of the liver with the range of attenuation coefficient marked (in Hansfield units) is a useful tool for quantitative assessment of the fatty pulp.