Repeatability of the "flash-replenishment" method in contrast-enhanced ultrasound for the quantitative assessment of hepatic microvascular perfusion.

This study aimed to evaluate the feasibility and repeatability of the flash-replenishment method in contrast-enhanced ultrasound (CEUS) perfusion imaging and assess quantitatively microvascular perfusion in the liver. Twenty healthy New Zealand rabbits were submitted to CEUS perfusion imaging with continuous intravenous infusion. Using flash-replenishment kinetics, the dynamic process of depletion and refilling of microbubble contrast agent was recorded. The hepatic microvascular perfusion parameters were calculated, including region of interest, peak intensity (PI), area under the curve (AUC), and hepatic artery to vein transit time (HA-HVTT). A consistency test was performed for multiple measurements by the same operator and blind measurements by two different operators. The hepatic perfusion imaging of 3×108 bubbles/min had minimal error and the best imaging effect and repeatability. The variability of the perfusion parameter measured at 3 cm depth under the liver capsule was at a minimum with coefficient of variation of 3.9%. The interclass correlation coefficient (ICC) of measurements taken by the same operator was 0.985, (95% confidence interval, CI=0.927-0.998). Measurements taken by two operators had good consistency and reliability, with the ICC of 0.948 (95%CI=0.853-0.982). The PI and AUC of liver parenchyma after reperfusion were lower than before blocking; and HA-HVTT was significantly longer than before blocking (P<0.05). The flash-replenishment method in CEUS perfusion imaging showed good stability and repeatability, which provide a valuable experimental basis for the quantitative assessment of hepatic microvascular perfusion in clinical practice.

Repeatability of the "flash-replenishment" method in contrast-enhanced ultrasound for the quantitative assessment of hepatic microvascular perfusion

This study aimed to evaluate the feasibility and repeatability of the flash-replenishment method in contrast-enhanced ultrasound (CEUS) perfusion imaging and assess quantitatively microvascular perfusion in the liver. Twenty healthy New Zealand rabbits were submitted to CEUS perfusion imaging with continuous intravenous infusion. Using flash-replenishment kinetics, the dynamic process of depletion and refilling of microbubble contrast agent was recorded. The hepatic microvascular perfusion parameters were calculated, including region of interest, peak intensity (PI), area under the curve (AUC), and hepatic artery to vein transit time (HA-HVTT). A consistency test was performed for multiple measurements by the same operator and blind measurements by two different operators. The hepatic perfusion imaging of 3×108 bubbles/min had minimal error and the best imaging effect and repeatability. The variability of the perfusion parameter measured at 3 cm depth under the liver capsule was at a minimum with coefficient of variation of 3.9%. The interclass correlation coefficient (ICC) of measurements taken by the same operator was 0.985, (95% confidence interval, CI=0.927-0.998). Measurements taken by two operators had good consistency and reliability, with the ICC of 0.948 (95%CI=0.853-0.982). The PI and AUC of liver parenchyma after reperfusion were lower than before blocking; and HA-HVTT was significantly longer than before blocking (P<0.05). The flash-replenishment method in CEUS perfusion imaging showed good stability and repeatability, which provide a valuable experimental basis for the quantitative assessment of hepatic microvascular perfusion in clinical practice.

Effect of Mexican tea herb and pilular adina herb on concrescence of gastric mucosa in experimental gastric ulcer rats.

OBJECTIVE: To study the effect and mechanism of mexican tea herb and pilular adina herb (abbreviated to MP) on concrescence of gastric mucosa in experimental gastric ulcer rats by observing the changes of epidermal growth factor (EGF), nitrogen monoxidum (NO) and expression of epidermal growth factor receptor (EGFR). METHODS: The rat ulcer model was established by 100% glacial acetic injection into the subserosa. The ulcer index (UI) was measured by sliding caliper. The levels of NO and EGF in tissue and serum were measured by the nitrate reductase method and enzyme-linked immunosorbent assay, respectively. The expression of EGFR in the mucosa around the ulcer was detected by the immunohistochemical assay and microimage analysis system. RESULTS: (1) Compared with the model group, UI of MP groups (10, 15 and 20 mg.kg(-1).d(-1)) and ranitidine group was lower (P<0.05 or P<0.01), the levels of NO and EGF in the tissue and serum were higher (P<0.05), the thickness of regenerated mucous membrane increased, and the width loss of lamina muscularis mucosa decreased (all P<0.05). (2) The expression of EGFR is weakly positive in gastric mucosa cells in the normal group, mainly in the cytoplasm and cytomembrane. In the model group, the expression of EGFR was mainly in epithelial cells in cervical part and basilar part of gastric gland around the ulcer margin, and the number of cells with EGFR weakly positive expression was more than that in the normal group. Compared with that in the normal and model groups, the number of cells with EGFR positive in MP groups and ranitidine group increased (all P<0.05), with weakly positive expression. CONCLUSION: MP can protect gastric mucosa, cure gastric ulcer, restrain the secretion of gastric acid, and boost multiplication, differentiation, migration and repair of the endothelial cell by promoting the secretion of NO and EGF, and increasing the expression of EGFR of gastric mucosa epithelial cells.