Rational arrangement of measuring shear wave speed in the liver

BACKGROUND Shear wave speed has been widely applied to quantify a degree of liver fibrosis. However, there is no standardized procedure, which makes it difficult to utilize the speed universally. AIM To provide procedural standardization of shear wave speed measurement. METHODS Point shear wave elastography (pSWE) was measured in 781 patients, and twodimensional shear wave elastography (2dSWE) was measured on the same day in 18 cases. Regions-of-interest were placed at 12 sites, and the median and robust coefficient-of-variation (CVR) were calculated. A residual sum-of-square (Σdi2) was computed for bootstrap values of 1000 iterations in 18 cases with each assumption of 1 to 12 measurements. The proportion of the Σdi2 (%Σdi2) was calculated as the ratio of Σdi2 to pSWE after converting it based on the correlation between pSWE and 2dSWE. RESULTS The CVR showed a significantly broader distribution in the left lobe (P < 0.0001),and the smallest CVR in the right anterior segment that covered 95% cases was 40.4%. pSWE was significantly higher in the left lobe than in the right lobe (1.63 ± 0.78 m/s vs 1.61 ± 0.78 m/s, P = 0.0004), and the difference between the lobes became further discrete when the subjects were limited to the cases with a CVR less than 40.4% in any segment (1.76 ± 0.80 m/s vs 1.70 ± 0.82 m/s, P < 0.0001). The highest values of the CVR in every 0.1 m/s interval were plotted in convex upward along pSWE and peaked at 1.93 m/s. pSWE and 2dSWE were significantly correlated (P < 0.0001, r = 0.95). In 216000 resamples from 18 cases, the %Σdi2 of 12 sites was 8.0% and gradually increased as the acquisition sites decreased to reach a significant difference with a %Σdi2 of 7 sites (P = 0.027). CONCLUSION These data suggest that shear wave speed should be measured at 8 or more sites of spreading in both lobes.

Gravity assistance enables liver stiffness measurements to detect liver fibrosis under congestive circumstances

BACKGROUND As survival has been prolonged owing to surgical and medical improvements,liver failure has become a prognostic determinant in patients with congestive heart diseases.Congestive hepatopathy,an abnormal state of the liver as a result of congestion,insidiously proceed toward end-stage liver disease without effective biomarkers evaluating pathological progression.Regular measurements of shear wave elastography cannot qualify liver fibrosis,which is a prognosticator in any type of chronic liver disease,in cases of congestion because congestion makes the liver stiff without fibrosis.We hypothesized that the effects of congestion and fibrosis on liver stiffness can be dissociated by inducing architectural deformation of the liver to expose structural rigidity.To establish a strategy measuring liver stiffness as a reflection of architectural rigidity under congestion.METHODS Two-dimensional shear wave elastography(2dSWE)was measured in the supine(Sp)and left decubitus(Ld)positions in 298 consecutive cases as they were subjected to an ultrasound study for various liver diseases.Regions of interest were placed at twelve sites,and the median and robust coefficient of variation were calculated.Numerical data were compared using the Mann-Whitney U or Kruskal-Wallis test followed by Dunn's post-hoc multiple comparisons.The inferior vena cava(IVC)diameters at different body positions were compared using the Wilcoxon matched pairs signed rank test.The number of cases with cardiothoracic ratios greater than or not greater than 50%was compared using Fisher’s exact test.A correlation of 2dSWE between different body positions was evaluated by calculating Spearman correlation coefficients.RESULTS The IVC diameter was significantly reduced in Ld in subjects with higher 2dSWE values in Ld(LdSWE)than in Sp(SpSWE)(P=0.007,(average±SD)13.9±3.6 vs 13.1±3.4 mm)but not in those with lower LdSWE values(P=0.32,13.3±3.5 vs 13.0±3.5 mm).In 81 subjects,SpSWE was increased or decreased in Ld beyond the magnitude of robust coefficient of variation,which suggests that body postural changes induced an alteration of liver stiffness significantly larger than the technical dispersion.Among these subjects,all 37 with normal SpSWE had a higher LdSWE than SpSWE(Normal-to-Hard,SpSWE-LdSWE(Δ2dSWE):(minimum-maximum)-0.74--0.08 m/sec),whereas in 44 residual subjects with abnormal SpSWE,LdSWE was higher in 27 subjects(Hard-to-Hard,-0.74--0.05 m/sec)and lower in 17 subjects(Hard-to-Soft,0.04-0.52 m/sec)than SpSWE.SpSWE was significantly correlated withΔ2dSWE only in Hard-to-Soft(P<0.0001).Δ2dSWE was larger in each lobe than in the entire liver.When Hard-to-Hard and Hard-to-Soft values were examined for each lobe,fibrosis-4 or platelet counts were significantly higher or lower only for Hard-to-Soft vs Normal-to-Hard cases.CONCLUSION Gravity alters the hepatic architecture during body postural changes,causing outflow blockage in hepatic veins.A rigid liver is resistant to structural deformation.Stiff-liver softening in the Ld position suggests a fibrous liver.

Pyloric-gland metaplasia may be an origin of cancer and intestinal metaplasia with possible CDX2 expression

Introduction The majority of cases of gastric cancer are thought to develop due to chronic inflammation from Helicobacter pylori(H.pylori)infection leading to intestinal metaplasia,termed the intestinal metaplasia–dysplasia–cancer sequence[1].Chronic inflammation from H.pylori infection causes mucin core protein 6-positive(MUC6t)pyloric-gland metaplasia;however,its origin is controversial.This MUC6t pyloric-gland metaplasia is similar to spasmolytic polypeptide-expressing metaplasia in mouse studies[2–4].