In vivovalidation of a bimodal technique combining time-resolved fluorescence spectroscopy and ultrasonic backscatter microscopy for diagnosis of oral carcinoma

Abstract

Tissue diagnostic features generated by a bimodal technique integrating scanning time-resolved fluorescence spectroscopy (TRFS) and ultrasonic backscatter microscopy (UBM) are investigated in an in vivo hamster oral carcinoma model. Tissue fluorescence is excited by a pulsed nitrogen laser and spectrally and temporally resolved using a set of filters/dichroic mirrors and a fast digitizer, respectively. A 41-MHz focused transducer (37-μm axial, 65-μm lateral resolution) is used for UBM scanning. Representative lesions of the different stages of carcinogenesis show that fluorescence characteristics complement ultrasonic features, and both correlate with histological findings. These results demonstrate that TRFS-UBM provide a wealth of co-registered, complementary data concerning tissue composition and structure as it relates to disease status. The direct co-registration of the TRFS data (sensitive to surface molecular changes) with the UBM data (sensitive to cross-sectional structural changes and depth of tumor invasion) is expected to play an important role in pre-operative diagnosis and intra-operative determination of tumor margins.

Fluorescence lifetime imaging and reflectance confocal microscopy for multiscale imaging of oral precancer

“…All the FLIM results are summarized in Table 1 and are consistent with similar systems reported in Ref. 38.…”

Endoscopic Fluorescence Lifetime Imaging for In Vivo Intraoperative Diagnosis of Oral Carcinoma

“…Further system improvements are continuing, including the use of a fiber laser at 355 nm at 1 MHz repetition rate to replace the nitrogen laser. This is expected to significantly reduce the time of data acquisition to less than 20 s. An alternative scanning FLIM approach our group recently reported (Sun et al, 2011 a , 2011 b , 2012) also has the potential to offset such limitation. Online display of FLIM images will require further integration of data/image analysis algorithms in the FLIM system prototype.…”

Handheld multispectral fluorescence lifetime imaging system for in vivo applications

“…4(e) was diagnosed as dysplasia as most of the biopsy. The increase in lifetime in Region 1 can be attributed to poryphirin, the presence of which is known to increase with progression of precancer [14]. …”