Novel Assessment of Acute Lung Injury by In VivoNear-Infrared Spectroscopy

Abstract

We investigated the feasibility and validity of near-infrared (NIR) spectroscopy for evaluation of acute lung injury (ALI). In an in vitro model simulating the spectrophotometric characteristics of the lung, NIR spectroscopy could precisely detect changes in water volume, suggesting its ability to assess the extent of pulmonary edema caused by ALI. The different grades of ALI were induced in rats by administering oleic acid and varying the pulmonary ventilation conditions, and NIR spectroscopy was employed to determine lung water content and hemoglobin (Hb) oxygenation of the lungs. NIR spectroscopy detected increased water content even in histologically mild ALI. The changes in lung water content measured by NIR spectroscopy were significantly correlated with gravimetric lung water content (r = 0.877, p < 0.0001). Deoxy-Hb measured by NIR spectroscopy consistently reflected the histological changes in the lungs, and the deoxy-Hb levels correlated with changes in SaO2 (r = -0.798, p < 0.0001). These findings demonstrate that NIR spectroscopy can evaluate lung water content and Hb oxygenation quantitatively, and may be a useful tool for assessing pathological status in ALI.

In vivo documentation of cutaneous inflammation using spectral imaging

“…[5][6][7][8]21 In contrast to erythema, there are very few reports where spectroscopy was used to document the edema reaction. 16 All these methods are limited to the fact that the area measured is defined by the size of the probe. Furthermore, these methods require for the probe to come in contact with the skin, so that care must be taken to avoid cross-contamination of the measured skin areas.…”

“…The light absorption properties of water in the near IR ͑NIR͒ can be used to estimate the severity of the edema reaction. 16,17 Similar to the case of erythema, spectral imaging provides the means to localize and quantify the cutaneous edema reaction. 15 In this paper, we present the potential of spectral imaging as a noninvasive method for quantitative documentation of skin inflammation.…”

Intrahepatic triglyceride measurement and estimation of viability in rat fatty livers by near‐infrared spectroscopy

“…Because the absorption intensity of NIR light depends on the level of hemoglobin (Hb) oxygenation, the redox state of cytochrome aa 3 (Cyt. aa 3 ) and biological content, NIR spectroscopy is currently being applied in the medical field to evaluate oxygen availability and oxygen consumption relationships within living tissues such as brain, muscle, lung and liver . We previously reported that in vivo NIR spectroscopy non‐invasively measured the tissue Hb oxygenation, the redox state of Cyt.…”

“…aa3) and biological content, NIR spectroscopy is currently being applied in the medical field to evaluate oxygen availability and oxygen consumption relationships within living tissues such as brain, muscle, lung and liver. [17][18][19][20][21][22][23][24][25] We previously reported that in vivo NIR spectroscopy non-invasively measured the tissue Hb oxygenation, the redox state of Cyt. aa3 and water content, and could additionally evaluate the viability of grafts damaged by warm ischemia in the living rat liver and lung.…”

Detection and visualization of intracutaneous allergic type‐specific elements using long‐wavelength near‐infrared hyperspectral imaging

“…Detection and quantification of the water contained in an object using near-infrared spectroscopy is a conventional technique, as infrared and nearinfrared reflectance spectra are normally strongly affected by the spectral absorption properties of the hydroxyl group. Therefore, there are many reports on the estimation of water content in vivo and the applications thereof, including the evaluation of lung edema, detection of interactions between atopic skin and pharmaceutical additives, assessment of the nasal mucosa for swelling, and measurement of the water content in the stratum corneum (9)(10)(11)(12)(13)(14). For the assessment of allergic dermatitis, Stamatas et al proposed a method for evaluating erythema and edema in which oxyhemoglobin and water content distributions were visualized by visible and near-infrared spectral imaging (15)(16)(17).…”