Effects on confocal laser endomicroscopy image quality by different acriflavine concentrations

Abstract

BACKGROUND: Acriflavine is one of the commonly used staining agents in confocal laser endomicroscopy (CLE), a newly developed technique allows for real time histological observation of gastrointestinal mucosa, but the concentration is not unified. This study aimed to evaluate the effects of acriflavine with different concentrations on the CLE image quality and to find a sound concentration in clinical practice. METHODS: Twenty four consecutive patients who underwent upper gastrointestinal CLE were enrolled into this study. The patients randomly accepted acriflavine in four different concentrations which were the conventional 0.05% and 3 lower ones respectively: 0.02%, 0.01% and 0.005% spraying onto the same focal antrum mucosa during CLE procedures. Differences of Image quality were demonstrated by an objective score system. RESULTS: THERE WAS NO SIGNIFICANT DIFFERENCE ABOUT IMAGE QUALITY AMONG ACRIFLAVINE CONCENTRATIONS: 0.05%, 0.02% and 0.01%, but 0.005% decreased image quality significantly (P=0.012). And 0.005% was also the only one which decreased general assessment significantly (P=0.01). For the 3 diagnostic value assessment indices, there was no significant difference about nonspecific and even staining, while 0.02% showed significant better polar staining (P=0.03). CONCLUSIONS: Acriflavine concentration 0.02% is the best one applied in CLE with the best nuclei staining ability and preserved image quality.

Figure 1

Polarization of gastric epithelial cells. (A) Histopathology shows the nuclei of gastric epithelial cells were basally located. (B) CLE images show the nuclei of gastric epithelial cells as a single bright line in the base of cells near gastric pits.

Figure 2

Effect of acriflavine concentration on image quality. Acriflavine applied in 0.005% decreased image quality significantly, while there was no significant difference among the other 3 concentrations [*concentration decreases image quality significantly (P<0.05)].

Figure 3

Representative images for each group. (A) Acriflavine in 0.05%, tissue structure was clearly shown and nuclei of some epithelial cells were stained brightly with well polarization and some without. (B, C) Acriflavine in 0.02% and group 0.01% respectively, tissue structures were clearly shown and nuclei of most epithelial cells were stained and showed well polarization. (D) Acriflavine in 0.005%, tissue structure could not be clearly visible.