Endoscopic ultrasonography-guided fine-needle aspiration biopsy (EUS-FNB) enhances the diagnostic capabilities of EUS by providing additional pathological samples. However, detecting the target specimens within the collected samples can be challenging. This study determined the most appropriate wavelength for detecting target specimens within EUS-FNB samples in an animal experiment.
EUS-FNB pancreatic tissue samples were collected from a male beagle (weight, 10 kg). The samples were illuminated with monochromatic light of varying wavelengths at 5-nm intervals from 430 to 700 nm. Optimal wavelengths for distinguishing target specimens within samples were determined.
Transmitted monochromatic light at a wavelength of 605 nm effectively enhanced the contrast between target specimens and blood in EUS-FNB samples. The strengths of the target specimen and blood samples were quantified and analyzed using densitometry in images obtained by irradiating at each wavelength. The contrast between target specimens and blood samples peaked at 600–605 nm.
Microscopical observations using transmitted light at a wavelength of 605 nm effectively identified target tissues within EUS-FNB samples.