Comparative study on chronic hepatitis B liver fibrosis and inflammation degrees between ultrasound diagnosis and pathology in patients with chronic hepatitis B
Comparative study on chronic hepatitis B liver fibrosis and inflammation degrees between ultrasound diagnosis and pathology Deng Kaishang, Department of Infection Medicine, Affiliated Hospital of Guizhou Medical University
Deng Kaishang1 Tian Xiulan2 Wang Jun2 Li Jun2 Wang Yan2 Wan Hua2 Xu Xiaoyuan2＊ Cheng Mingliang1＊
[[Keywords] Hepatitis B; hepatic fibrosis; pathology; ultrasound diagnosis.
[Key words] Hepatitis B; Liver fibrosis; Pathology; Ultrasound diagnosis;
Ultrasound is widely used in clinical practice as a reproducible and non-invasive examination method. Previously, the assessment of liver fibrosis by ultrasound seldom considered the effect of inflammation on the sonogram, while the changes in the patient’s sonogram were a combination of inflammatory necrosis and fibrosis. In this paper, five ultrasound indices reflecting the combined manifestation of inflammation and fibrosis sonograms were observed and integrated according to ultrasound imaging principles, and analyzed against liver pathology diagnosis to explore the application value of ultrasound in the diagnosis of liver fibrosis and inflammation degree in chronic hepatitis.
Materials and methods
1Case selection
There were 106 patients with chronic hepatitis B who underwent liver puncture and were inpatients of the First Hospital of Peking University from February 2006 to November 2007, and the diagnostic criteria were in accordance with the prevention and treatment program for chronic hepatitis B established in 2000 [2], 74 males and 32 females, aged 19 to 70 years, with an average age of 36.9 years.
2 Instruments and methods.
2.1 The ultrasound diagnostic instrument was a SIEMEN G50 color Doppler ultrasound diagnostic instrument with a convex array probe frequency of 3.5
~Patients underwent ultrasound examination within 2 days before liver puncture, fasting for 8-12 hours before the examination and examined by two experienced physicians at rest, with all measurements, ultrasound descriptions and images stored in the ultrasound workstation.
2.2 Ultrasound measurement of spleen thickness and diameter, multi-sectional observation of liver parenchymal echogenicity [3], according to the ultrasound characteristics of the smoothness of the liver peritoneum, the strength of backscatter in the section, the thickness of the liver real echogenicity, the uniformity of the distribution of echogenic light points and the intrahepatic vascular pathways were observed and given corresponding scores according to different sonographic performances, as shown in Table 1.
Table 1 Liver sonographic scoring scheme
1 point
2 points
3 points
Peritoneum of liver
Smooth
water ripples
jagged
backscatter
Isoechoic
Weak Echo
High Echo
Substantial Echo
Normal
Dense
Thickened
Distribution of light spots
homogeneous
Local unevenness
Uneven
Vessel alignment
Clear
Blurred
unclear
3 Liver pathological examination.
Percutaneous liver puncture was performed with a G14 needle, and liver tissue specimens of 1-2 cm in length were routinely paraffin sectioned and stained for HE, Masson and reticulocyte fibers. Pathological diagnosis was made according to the criteria of the 2000 viral hepatitis control program [2], and the degree of liver fibrosis was divided into five stages S0~S4: S0 for no fibrosis; S1 for enlargement of the confluent area with fibrous hyperplasia; S2 for fibrosis around the confluent area with preservation of lobular structures; S3 for fibrous interval with disorganized lobular structures and no cirrhosis; and S4 for severe fibrosis or definite cirrhosis. Inflammatory activity was classified into four grades from G1 to G4: G1 was inflammation in the confluent area with degeneration and few foci of point and focal necrosis in the lobules, G2 was mild PN in the confluent area, G3 was moderate PN in the confluent area with intralobular cellular fusion necrosis or BN seen, and G4 was severe PN in the confluent area with extensive intralobular BN and multilobular necrosis.
4 Statistical analysis.
All data were statistically processed with the SPSS 13.0 statistical package. One-way ANOVA was used for correlation between ultrasound score and liver inflammation and liver fibrosis, LSD method was used for multiple comparisons (Dunnett, s T3 method when variance was not equal), x2 test was used for multiple group comparison of count data, t-test was used for comparison of two groups, and p<0.05 was considered statistically significant.
Results
1 Pathological examination results.
1.1 ① Inflammation classification: G1 44 cases; G2 47 cases; G3 15 cases; G4 0 cases. ②Fibrosis staging: S0 46 cases; S1 20 cases; S2 22 cases; S3 18 cases, S4 0 cases, see Table 2.
1.2 Pathological changes: G1 cells were cloudy and swollen, a few points and focal necrosis, lymphocytes and plasma cells infiltration; G2 hepatocytes were cloudy and swollen, focal necrosis, mild debris necrosis, lymphocytes and plasma cells infiltration in the confluent area; G3 hepatocytes were cloudy and swollen, eosinophilic change, boundary plate destruction, moderate debris necrosis partly with bridging necrosis; S0 stage did not see fibrosis, S1 stage confluent area enlargement with fibroplasia S2 was fibrosis around the confluent area with preserved lobular structure; S3 had incomplete lobular structure with fibrous septum formation and hyperplasia of small bile ducts.
Table 2 Pathological findings of liver puncture in 106 patients with chronic hepatitis B (cases)
S0
S1
S2
S3
Total
G1
28
9
6
1
44
G2
17
11
11
8
47
G3
1
0
5
9
15
Total
46
20
22
18
106
2 Ultrasound score and pathology.
2.1 Ultrasound integral G3>G2>G1 , by ANOVA, F=48.48, p<0.01. In the grouping of liver fibrosis, S3 was statistically significant (p<0.01) compared with S0, S1, and S2, but S1 was not statistically significant (p>0.05) compared with S2. S0 was statistically significant (p<0.01) compared with S1, S2, and S3. The ultrasound product cut-off for fibrosis was ≥9.85±2.11.
Spleen thickness and pathology: In this group of cases, only G3 and S3 groups had greater than normal spleen thickness, 4.05±0.72(cm) and 4.50±0.89(cm), respectively, while the spleen thickness of other groups fluctuated within the normal range.
4 Ultrasound indexes and pathology: unsmooth liver surface, backscattered hyperechogenicity, thickened parenchymal echogenicity, uneven distribution of light spots, and unclear vascular alignment were significantly different in each pathology group, with the most significant performance in G3 and S3 (P<0.01), and no weak echogenicity was demonstrated in this group of cases, see Table 4
DISCUSSION
Ultrasound imaging is based on the reflection and refraction of ultrasound waves in the acoustic interface of human tissues; in tissues with high protein content, the reflection is strong and shows high echogenicity, and in tissues with high water content, the reflection is weak and shows low echogenicity; in pathological changes, tissue inflammatory edema acoustic interface disorder shows dense, and fibrous tissue hyperplasia structural disorder shows thickened light spots [4]. The pathology of chronic hepatitis liver is characterized by different degrees of inflammation and fibrous tissue proliferation, which causes changes in the acoustic interface and acoustic impedance of the liver, providing an objective basis for the diagnosis of liver fibrosis and inflammation by ultrasound [5]. The pathological findings of our cases showed that there were different stages of fibrosis in the same inflammatory grade and different grades of inflammatory changes in the same fibrotic stage, and the changes in the liver sonogram of the patients were a combination of inflammatory necrosis and fibrosis. There are many two-dimensional ultrasound indices to evaluate liver fibrosis, and the focus of measurement varies among researchers. Zheng Rongqin et al [6] examined 44 ultrasound indices in 225 cases of chronic hepatitis and 51 normal subjects, and the results showed that liver peritoneal and parenchymal echoes and gallbladder wall thickness were independent discriminators of liver fibrosis. The total ultrasound score derived from five parameters including liver surface, liver echogenicity, hepatic veins, liver margins, and spleen area by Chen Yu et al [7] showed good correlation for liver fibrosis, but still had difficulties for S1-S3 staging.
In this study, from the characteristics of ultrasound two-dimensional imaging, five sonographic parameters that can reflect the internal structural changes of the liver, such as smoothness of the liver tegument, strength of backscatter, thickness of parenchymal echo, uniformity of light point distribution and clarity of vascular alignment, were selected as indicators for observation, and the results showed that the ultrasound scores of the selected indicators can sensitively distinguish the degree of inflammation in the liver (p < 0.01 for the comparison of G1, G2 and G3 ultrasound scores ), and the more severe the inflammation, the higher the ultrasound score. This index can also better distinguish the presence or absence of liver fibrosis and the difference between mild, moderate and severe liver fibrosis (S0 vs S1, S2, S3 and S3 vs S2, S1 ultrasound scores p < 0.01), and the cut-off value of liver fibrosis ultrasound score was ≥ 9.85 ± 2.11.
Repeated inflammatory necrosis and repair of hepatocytes are the basis of liver fibrosis formation, and the inflammatory grade of liver tissue represents the current damage and inflammatory activity of the liver, while the liver fibrosis stage illustrates the cumulative damage of the liver. The pathological data of our group showed that there were different inflammatory activity for the same fibrosis stage, different fibrosis stages for the same inflammatory grade, and the degree of fibrosis increased with the increase of inflammation. Comparison of ultrasound scores of different fibrosis stages of the same inflammatory grade and different inflammatory grades of the same fibrosis stage revealed that: the ultrasound scores could better distinguish the presence or absence of fibrosis in mild inflammation (G1 level: p<0.05 for S0 compared with S1 and S2 ultrasound scores); it was more difficult to distinguish the stages of fibrosis in severe inflammation (G3 level: p>0.05 for S3 compared with S2 ultrasound scores). This indicates that the degree of inflammation influences the staging of fibrosis. Similarly, the comparison of ultrasound scores of different inflammatory grades at the same fibrosis stage revealed that as the degree of fibrosis increased, it became more difficult to distinguish the grade of inflammation (S0 stage: p<0.05 for G1 vs. G2; S2 stage: p<0.05 for G2 vs. G3; S3 stage: p>0.05 for G2 vs. G3), suggesting that the degree of fibrosis also influenced the grading of inflammation. In the sonogram, the dense echogenicity of tissue inflammatory edema and the thickened echogenicity of fibrosis are opposed, and the enhanced manifestation of one side diminishes the other, so inflammatory factors should be taken into account when assessing liver fibrosis with ultrasound.
In the analysis of the selected ultrasound indices, it was found that liver surface opacification, parenchymal hyperechogenicity, thickened dots, uneven distribution, and unclear vascularity became more pronounced with increasing fibrosis (p < 0.01), so these items can be used as diagnostic indices for liver fibrosis sonography. In contrast to the thickened spots, the dense changes of the spots were obvious as the degree of fibrosis decreased (p < 0.01), and there was a significant difference among G1, G2 and G3, with G3 being the lowest (p < 0.01), which might be accompanied by obvious fibrosis (thickening) and weakened the dense spots in G3 cases. In the pathological changes, all inflammation had cloudy and swollen hepatocytes, and the sonogram was dense. As the degree of inflammation increased, the necrosis gradually expanded from punctate, focal, fragmented, and bridging, and the repair process caused a high degree of proliferation of fibrous tissue, which led to a coarsening of the photopoints, which weakened the dense change of photopoints. Therefore, dense photodots are still a sensitive indicator of the sonographic manifestation of inflammation, but have an interaction with fibrosis.
The present data showed that splenic thickening was only seen in the G3 and S3 groups, the same as observed by Ge Huiyu et al [8], where splenic thickening was relatively lagging as an ultrasound indicator of fibrosis. Although the ultrasound score of this study has better distinguished S0 from S1, S2, S3 and S3 from S1 and S2, it still could not distinguish S1 from S2 either from the overall fibrosis ultrasound score comparison or the ultrasound score comparison of different fibrosis stages of the same inflammation grade, which is the same as Li Xiaoling et al [9] who used 5 liver envelope smoothness, liver parenchymal echogenicity, intrahepatic vascular alignment, gallbladder wall status, and spleen thickness The results were the same as those observed by using five indexes: liver pericardial smoothness, liver parenchymal echogenicity, intrahepatic vascular alignment, gallbladder wall status and spleen thickness. Meng Fankun et al [10] compared the ultrasound findings with pathological findings in 693 patients with liver disease using the double-severity method, and concluded that the deviation of ultrasound to discriminate the stage of liver fibrosis from pathology in chronic liver disease may be due to the failure of the current ultrasound instruments to achieve resolution. In S1 and S2 stages, the hyperplastic fibrous tissue was confined to the confluent area and surrounding areas, and the structure of liver lobules was intact, which could not be distinguished exactly even with higher probe frequency, which is a difficult point for ultrasound to discriminate the stage of liver fibrosis, and this was confirmed by the results of our study.
Ultrasonography is able to assess the degree of liver fibrosis and inflammatory inflammation in chronic hepatitis, but the mutual influence of inflammation and fibrosis should be considered comprehensively. The ultrasound observation indexes selected in this study meet the conventional requirements, and the integration method is easy to grasp, which has important clinical application value for the diagnosis of liver fibrosis and inflammation degree in chronic hepatitis B.
1 Kaisheng Deng, Department of Infection, Affiliated Hospital of Guiyang Medical College, Guiyang, China. (Postal Code 550004, Email: [email protected])
2 Tian Xiulan, Wang Jun, Li Jun, Wang Yan, Wan Hua, Xu Xiaoyuan, Department of Infection, Peking University First Hospital