Biomedical Engineering Reference
In-Depth Information
the  optical principles behind white-light and autofluorescence bronchos-
copy (AFB), as well as the role of AFB in early diagnosis of lung cancer and
the overall managements of patients are discussed. Other newest develop-
ments such as Raman spectroscopy were also highlighted. According to the
information presented in the article, AFB is the most successfully developed
technique and has significantly improved the detection sensitivity of early
lung cancer [44].
The research of K. Yano et al. was about direct measurement of human lung
cancerous and non-cancerous tissues by FTIR microscopy, in order to answer
the question of whether this technique can be used as a clinical tool or not.
The corrected peak heights (H1045 and H1467) obtained from the bands at
1045 cm −1 and 1465 cm −1 , which are due to glycogen and cholesterol, were
chosen for a quantitative evaluation of the malignancy. It was concluded that
these peaks are an exceptionally useful factor for discrimination of the can-
cerous tissues from the non-cancerous ones. If the H1045/H1467 ratio from
measured spectrum is larger than 1.4, it could be said with confidence that
the tissue contains squamous cell carcinoma (SCC) or adenocarcinoma at
least partially. Furthermore, they carried out the microscopic mapping of the
tissues containing both cancerous and non-cancerous sections, demonstrat-
ing that the colour map reflects small changes in the spatial distribution of
cancer cells in the tissues [66].
Y. Yang et al. reported on tumour cell invasion by FTIR microspectroscopy.
In this study, a three-dimensional artificial membrane using collagen
type I, one of the main components of basal membranes of the lung tis-
sue, was established in order to investigate tumour cell invasion of lung
cancer. The mapping images obtained with FTIR Microspectroscopy were
validated with standard histological section analysis. The FTIR image
produced using a single wave number at 1080 cm −1 , corresponding to PO 2
groups in DNA from cells, correlated well with the histological section,
which clearly revealed a cell layer and invading cells within the membrane.
Furthermore, the peaks corresponding to amid A, I, and II in the spectra of
the invading cells shifted compared to the non-invading cells, which may
relate to the changes in conformation and/or heterogeneity in the pheno-
type of the cells. The data presented in this study demonstrate that FTIR
Microspectroscopy can be a fast and reliable technique to assess tumour
invasion in vitro [67].
Y. K. Min et al. reported on near-infrared 1064-nm multichannel Raman
spectroscopy of fresh human lung tissues. Excitation at 785 nm failed to
detect any Raman bands because of an extremely high fluorescence back-
bone. As a result, it was confirmed that 1064-nm excitation was a requisite
for the Raman study of the fresh lung tissue. The observed Raman spectra
of lung tissues made a clear distinction between the normal and cancerous
states. It was demonstrated that 1064-nm near-infrared multichannel Raman
spectroscopy is a feasible tool for in vivo, noninvasive and molecular-level
clinical diagnosis of diseases including cancer [68].
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