Fig 1.
Diagram of the study population selection process.
Patients who were examined by using FibroScan at a success rate of greater than 60% with 10 valid measurement and an interquartile range (IQR) of 30% or less than 30% of the median LSM value were analyzed for the study. Patients whose body mass index (BMI) was at the 90th percentile or higher and without underlying liver diseases were included in the obese group. Patients whose BMI was lower than the 90th percentile were divided into 2 groups: control group or liver disease group. The control group was defined as having normal serum liver enzyme levels, an aspartate aminotransferase (AST)-to-platelet ratio index (APRI) score below 0.5, a normal-appearing liver on abdominal ultrasonography, and no episodes of liver disease. The remaining patients were included in the liver disease group.
Fig 2.
Age distribution of the patients examined by using FibroScan.
A total of 214 children and adolescents (age, 1.3–17.6 years; 121 male) were examined by using FibroScan. A total of 201 patients (93.9%; median age, 11.5 years; range, 1.3–17.6 years) (black bars) were examined successfully; the evaluation was unsuccessful in the remaining 13 patients (6.1%; median age, 13.1 years; range, 2.0–17.2 years) (gray bars) due to excessive thickness of subcutaneous adipose tissue in 5 obese children (BMI percentile [mean ± 1 SD], 99.6 ± 2.2), poor cooperation in 4 young children (2.0, 3.7, 4.0, and 6.2 years), and no obvious reason in 4 non-obese and cooperative children.
Table 1.
Characteristics of the 199 patients in the study.
Fig 3.
Comparison of results from FibroScan, liver biopsy, and abdominal ultrasonography (AUS).
a and b. Liver stiffness measurement (LSM) and controlled attenuation parameter (CAP) values from FibroScan evaluations were compared with histologic fibrosis stage and steatosis grade. Liver biopsy was performed in 8 pediatric patients, in which the underlying disease was simple obesity in 4 patients, type C hepatitis in 2 patients, type B hepatitis associated with obesity in 1 patient, and liver transplantation for treatment of congenital biliary atresia in 1 patient. Among the 5 obese patients, four patients were diagnosed with NASH, and the remaining patient was diagnosed with simple steatosis. a. Correlation between LSM value and histologic fibrosis stage. LSM was highly correlated with fibrosis stage (Spearman’s ρ = 0.920). b. Correlation between CAP value and histologic steatosis grade. CAP value was highly correlated with steatosis grade (ρ = 0.792). c. Correlation between CAP and fatty liver infiltration score calculated according to AUS findings. CAP was highly correlated with AUS fatty liver infiltration score (ρ = 0.713).
Fig 4.
Comparison of CAP values among control, obese, and liver disease groups.
a. CAP was significantly higher in the obese group (mean ± 1 SD, 285 ± 60 dB/m) compared with both the control group (179 ± 41 dB/m; P < 0.001) and the liver disease group (202 ± 62 dB/m; P < 0.001). b. LSM was significantly higher in the obese group (5.5 ± 2.3 kPa) than in the control group (3.9 ± 0.9 kPa, P < 0.001) but did not differ between the liver disease group (5.4 ± 4.2 kPa) and either the obese or control group.
Fig 5.
Correlation between LSM and CAP values.
LSM was positively correlated with CAP in the obese group (Spearman’s ρ = 0.511) but not in the control (ρ = 0.129) or liver disease (ρ = 0.170) group.
Table 2.
Correlation of FibroScan results and biochemical values.