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

<div><p>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.</p></div

Molecular and morphological variability of Mesalina watsonana and Ophisops elegans (Squamata: Lacertidae) in the Middle East

<p>Immunohistochemistry shows that no obvious ICAM-1 staining (200×, 400×) is seen in the liver samples of the SO group (A, B); and ICAM-1 has a high expression in periportal endothelial cells (arrow), liver sinusoidal endothelial cells (arrow), and some hepatocytes (arrow) in the I/R group, with significantly deep staining and expanded area (200×, 400×) (C, D).</p

Comparison of the peak intensity (PI) of the nanobubbles (mean ± standard deviation).

<p>Comparison of the peak intensity (PI) of the nanobubbles (mean ± standard deviation).</p

Transmission electronic microscopy reveals that the hepatocytes in the SO group have a clear and complete structure, nuclei are placed in the middle, nucleolus and nuclear membrane are clear, and cytoplasm mitochondria and rough endoplasmic reticulum are well arranged with a normal shape and structure.

<p>The ridges are clear (8000×) (A). Hepatocytes in the SO group have a tight junction and normal cholangiole microvilli can be seen (25,000×) (B). The I/R group is shown to have irregular nucleus and karyopyknosis, expanded perinuclear space, chromatin margination and condensation (arrow), lost tight junctions, and breaking and dropping off of microvilli (7000×) (C). Significantly swollen mitochondria (arrow); vacuoles; blurred, disappearing, or decreasing crest; expanded rough endoplasmic reticulum; and large particle lipid droplets (25,000×) are also seen in the IR group (D).</p

Transmission electronic microscopy shows that nanobubbles (arrow) have equal sizes and are well distributed (120, 000×).

<p>Transmission electronic microscopy shows that nanobubbles (arrow) have equal sizes and are well distributed (120, 000×).</p

Comparison of the time to peak of the nanobubble (mean ± standard deviation).

<p>Comparison of the time to peak of the nanobubble (mean ± standard deviation).</p