SVM classifier of cervical histopathology images based on texture and morphological features.

BACKGROUND: Cervical histopathology image classification is a crucial indicator in cervical biopsy results. OBJECTIVE: The objective of this study is to identify histopathology images of cervical cancer at an early stage by extracting texture and morphological features for the Support Vector Machine (SVM) classifier. METHODS: We extract three different texture features and one morphological feature of cervical histopathology images: first-order histogram, K-means clustering, Gray Level Co-occurrence Matrix (GLCM) and nucleus feature. The original dataset used in our experiment is obtained from 20 patients diagnosed with cervical cancer, including 135 whole slide images (WSIs). Given an entire WSI, the patches on its tissue region are extracted randomly. RESULTS: We finally obtain 3,000 patches, including 1,000 normal, 1,000 hysteromyoma and 1,000 cancer images. Among them, 80% of the entire data set is randomly selected as training set and the remaining 20% as test set. The accuracy of SVM classification using first-order histogram, K-means clustering, GLAM and nucleus feature for extracting features are respectively 87.4%, 90.6%, 91.6% and 93.5%. CONCLUSIONS: The classification accuracy of the SVM combining the four features is 96.8%, and the proposed nucleus feature plays a key role in the SVM classification of cervical histopathology images.

Effects of different-intensity laser acupuncture at two adjacent same-meridian acupoints on nitric oxide and soluble guanylate cyclase releases in human.

OBJECTIVES: The aim of this study was to detect the influences of LA at nonacupoint and two adjacent acupoints of pericardium meridian on the releases of NO and sGC in 20 healthy subjects. METHODS: Different intensities (12, 24, 48 mW) of infrared laser were used for irradiating Jianshi (PC5), Ximen (PC4) acupoints and nonacupoint for 20, 40 minutes, respectively. Semi-circular tubes were taped to the skin surface and filled with NO-scavenging compound for 20 minutes to capture NO and sGC, which were measured using spectrophotometry in a blinded fashion. RESULTS: As the increase in the intensity of LA stimulation, the levels of NO releases over acupoints all were significantly increased, NO releases in nonacupoints following the same treatment only changed slightly, sGC amounts were observably enhanced over acupoints, but did not any change in nonacupoint area. Different intensities of LA treatments can sensitively affect the NO and sGC releases over acupoints. This indicated that LA-induced releases of the NO and sGC were specific to acupoints. CONCLUSIONS: This is the first evidence reporting that LA induced significant elevations of NO-sGC releases over acupoints, and the enhanced signal molecules contribute to local circulation, which improves the beneficial effects of the therapy.

Effects of titanium dioxide nanoparticles coupled with diode laser on optical properties of in vitro normal and cancerous human lung tissues studied with optical coherence tomography and diffuse reflectance spectra.

The objective is to investigate the effects of two different sized (60 and 100 nm) titanium dioxide (TiO2) nanoparticles (NPs) penetration and accumulation in in vitro human normal lung (NL) tissue, lung squamous cell carcinoma (LSCC) tissue, and 650-nm diode laser-pretreated tissue on their optical properties studied with optical coherence tomography monitoring and diffuse reflectance (DR) spectra measurement. As with TiO2 NPs penetrating into the tissues, the intensities of DR of the samples increase, and then the enhancements of DR and the attenuation coefficients of the tissues were quantitatively calculated. The results suggest that 650-nm diode laser pretreatment increased the amounts of TiO2 NPs penetration and accumulation in NL and LSCC tissues, and the tissue optical properties were significantly influenced by accumulation of TiO2 NPs.

Influence of nanoparticles accumulation on optical properties of human normal and cancerous liver tissue in vitro estimated by OCT.

In this work, the potential use of nanoparticles as contrast agents by using spectral domain optical coherence tomography (SD-OCT) in liver tissue was demonstrated. Gold nanoparticles (average size of 25 and 70 nm), were studied in human normal and cancerous liver tissues in vitro, respectively. Each sample was monitored with SD-OCT functional imaging for 240 min. Continuous OCT monitoring showed that, after application of gold nanoparticles, the OCT signal intensities of normal liver and cancerous liver tissue both increase with time, and the larger nanoparticles tend to produce a greater signal enhancement in the same type of tissue. The results show that the values of attenuation coefficients have significant differences between normal liver tissue and cancerous liver tissue. In addition, 25 nm gold nanoparticles allow higher penetration depth than 70 nm gold nanoparticles in liver tissues.

Evaluation of ultrasound and glucose synergy effect on the optical clearing and light penetration for human colon tissue using SD-OCT.

Topical application optical clearing agents (OCAs) can effectively enhance the tissue optical clearing on the human colon tissue, which has been demonstrated in our previous studies. Nevertheless, the strong light scattering still limits the diffusion rate of OCAs and penetration depth of light into the tissue. In this study, in order to further increase the diffusion of the OCA of glucose into tissue, we employ a method to improve the glucose permeability and light penetration with ultrasound (sonophoretic delivery, SP) and glucose (G) synergy on human normal and cancerous colon tissues in vitro, which was measured and quantified with spectral-domain optical coherence tomography (SD-OCT) technology. To evaluate the effect of ultrasound mediation, the percentages of OCT signal enhancement (PSE) and 1/e light-penetration depth were calculated for G alone and ultrasound-G treatments. The PSE was calculated at approximately 313 µm from the sample tissue surface. For normal and cancerous colon tissues the PSE were about 91.1 ± 10.6% and 65.3% ± 12.3% with 30% G/SP, but for the 30% G alone treatment it was about 78.6 ± 11.2% and 54.5% ± 9.3%, respectively. The max value of 1/e light-penetration depth for normal colon tissue was 0.47 ± 0.02 mm with 30% G alone and 0.60 ± 0.05 mm (p < 0.05)with 30% G/SP synergy. However, for the cancerous colon tissue the max value was 0.45 ± 0.01 mm and 0.57 ± 0.03 mm (p < 0.05), respectively. The obtained permeability coefficients showed a significant enhancement with ultrasound mediation. The mean permeability coefficients of 30% G/SP in normal and cancerous colon tissues were (6.3 ± 0.16) × 10(-6) cm/s and (12.1 ± 0.34) × 10(-6) cm/s (p < 0.05), respectively. These preliminary experiments showed that ultrasound can effectively enhance the tissue optical clearing and glucose diffusion rate as well as increase the light-penetration depth into biotissues.

Ex vivo determination of glucose permeability and optical attenuation coefficient in normal and adenomatous human colon tissues using spectral domain optical coherence tomography.

Recent reports have suggested that spectral domain optical coherence tomography (SD-OCT) is a useful tool for quantifying the permeability of hyperosmotic agents in various tissues. We report our preliminary results on quantification of glucose diffusion and assessment of the optical attenuation change due to the diffusion of glucose in normal and adenomatous human colon tissues in vitro by using a SD-OCT and then calculated the permeability coefficients (PC) and optical attenuation coefficients (AC). The PC of a 30% aqueous solution of glucose was 3.37±0.23×10⁻6 cm/s in normal tissue and 5.65±0.16×10⁻6 cm/s in cancerous colon tissue. Optical AC in a normal colon ranged from 3.48±0.37 to 2.68±0.82 mm⁻¹ and was significantly lower than those seen in the cancerous tissue (8.48±0.95 to 3.16±0.69 mm⁻¹, p<0.05). The results suggest that quantitative measurements of using PC and AC from OCT images could be a potentially powerful method for colon cancer detection.

Synergistic effect of hyperosmotic agents and sonophoresis on breast tissue optical properties and permeability studied with spectral domain optical coherence tomography.

Hyperosmotic agents have shown great potential in tissue optical clearing. However, the low efficiency of the permeation in biological tissues seriously restricts its application in reality. The synergy of sonophoresis as a penetration enhancer and hyperosmotic agents, 20% glucose (G) and 20% mannitol (M), in optical clearing has been investigated by analyzing the variation of the attenuation coefficients and the permeability coefficients. In the sonophoresis experiments, ultrasound (US) was applied for 10 min before applying hyperosmotic agents. Along with the administration of hyperosmotic agents, the samples were monitored with optical coherence tomography (OCT) functional imaging for the next 2 h. The attenuation coefficients of each group were obtained from the 2-D OCT images based on Beer's Law. The original attenuation coefficient is 12.38 ± 0.73 cm-1 in normal breast tissue. After 45 min treatment, it changes to be 5.91 ± 0.82 cm-1 and 4.14 ± 0.67 cm-1 for 20% G and 20% G/US, respectively. The attenuation coefficient of breast cancer tissue is 18.17 ± 1.45 cm-1 at the beginning, and it becomes 8.70 ± 0.87 cm-1 for 20% G and 6.80 ± 0.92 cm-1 for 20% G/US after 30 min. Meanwhile, the permeability coefficients of hyperosmotic agents were much enlarged by the treatment of ultrasound in both breast normal tissue and breast cancer tissue. A significant difference in permeability coefficients between health tissue and tumor tissue was also observed in the experiment (p<0.01).

Assessment of the effects of ultrasound-mediated glucose on permeability of normal, benign, and cancerous human lung tissues with the Fourier-domain optical coherence tomography.

The objective of this study was to evaluate the effects of ultrasound-mediated analyte diffusion on permeability of normal, benign, and cancerous human lung tissue in vitro and to find more effective sonophoretic (SP) delivery in combination with the optical clearing agents (OCAs) method to distinguish normal and diseased lung tissues. The permeability coefficients of SP in combination with OCAs diffusion in lung tissue were measured with Fourier-domain optical coherence tomography (FD-OCT). 30% glucose and SP with a frequency of 1 MHz and an intensity of 0.80 W/cm2 over a 3 cm probe was simultaneously applied for 15 min. Experimental results show that the mean permeability coefficients of 30% glucose/SP were found to be (2.01±0.21)×10(-5) cm/s from normal lung (NL) tissue, (2.75±0.28)×10(-5) cm/s from lung benign granulomatosis (LBG) tissue, (4.53±0.49)×10(-5) cm/s from lung adenocarcinoma tumor (LAT) tissue, and (5.81±0.62)×10(-5) cm/s from lung squamous cell carcinoma (LSCC) tissue, respectively. The permeability coefficients of 30% glucose/SP increase approximately 36.8%, 125.4%, and 189.1% for the LBG, LAT, and LSCC tissue compared with that for the NL tissue, respectively. There were statistically significant differences in permeability coefficients of 30% glucose/SP between LBG and NL tissue (p<0.05), between LAT and NL tissue (p<0.05), and between LSCC and NL tissue (p<0.05). The results suggest that the OCT functional imaging technique to combine an ultrasound-OCAs combination method could become a powerful tool in early diagnosis and monitoring of changed microstructure of pathologic human lung tissue.

Investigation of the permeability and optical clearing ability of different analytes in human normal and cancerous breast tissues by spectral domain OCT.

The potential of OCT applied for early breast cancer detection attracted significant efforts. The permeability coefficients and the percentages of OCT signal enhancement for normal and cancerous breast tissues have been investigated from the experiments of 20% glucose, 40% glucose, and 20% mannitol in vitro. Obtained results indicate that the permeability coefficient in breast cancer tissue is prominently larger than that in normal breast tissue, while the optical clearing effect is just the reverse to that for each agent. The results suggest that OCT has the ability to distinguish cancer tissue from different aspect.

Quantification of glucose diffusion in human lung tissues by using Fourier domain optical coherence tomography.

In this study, we report permeability coefficients of 30% glucose diffusion by the optical coherence tomography signal slope (OCTSS) method in four kinds of human lung tissue in vitro: normal lung tissue, benign granulomatosis lung tissue, squamous cell carcinoma and adenocarcinoma tumor. To quantify the permeability coefficient of the agent, the monitored region was 80 µm thickness at a tissue depth of ca 230 µm from the surface. The permeability coefficients of 30% glucose from 10 independent experiments were averaged and found to be (1.35 ± 0.13) × 10(-5) cm s(-1) from the normal lung tissue, (1.78 ± 0.21) × 10(-5) cm s(-1) from the benign granulomatosis lung tissue, (2.88 ± 0.19) × 10(-5) cm s(-1) from the adenocarcinoma tumor and (3.53 ± 0.25) × 10(-5) cm s(-1) from the squamous cell carcinoma, respectively. It could be clearly seen that the permeability coefficients of 30% glucose increase ca 32%, 113% and 162% in the benign granulomatosis, adenocarcinoma tumor and squamous cell carcinoma of human lung tissue compared with that from the normal lung tissue, respectively. Therefore, we inferred from this pilot study that the OCT imaging is a feasible method to distinguish normal and cancer lung tissue.

[Gastric cancer detection using kubelka-Munk spectral function of DNA and protein absorption bands].

Differential diagnosis for epithelial tissues of normal human gastric, undifferentiation gastric adenocarcinoma, gastric squamous cell carcinomas, and poorly differentiated gastric adenocarcinoma were studied using the Kubelka-Munk spectral function of the DNA and protein absorption bands at 260 and 280 nm in vitro. Diffuse reflectance spectra of tissue were measured using a spectrophotometer with an integrating sphere attachment. The results of measurement showed that for the spectral range from 250 to 650 nm, pathological changes of gastric epithelial tissues induced that there were significant differences in the averaged value of the Kubelka-Munk function f(r infinity) and logarithmic Kubelka-Munk function log[f(r infinity)] of the DNA absorption bands at 260 nm between epithelial tissues of normal human stomach and human undifferentiation gastric cancer, between epithelial tissues of normal human stomach and human gastric squamous cell carcinomas, and between epithelial tissues of normal human stomach and human poorly differentiated cancer. Their differences were 68.5% (p < 0.05), 146.5% (p < 0.05), 282.4% (p < 0.05), 32.4% (p < 0.05), 56.00 (p < 0.05) and 83.0% (p < 0.05) respectively. And pathological changes of gastric epithelial tissues induced that there were significant differences in the averaged value of the Kubelka-Munk function f(r infinity) and logarithmic Kubelka-Munk function log[f(r infinity)] of the protein absorption bands at 280 nm between epithelial tissues of normal human stomach and human undifferentiation gastric cancer, between epithelial tissues of normal human stomach and human gastric squamous cell carcinomas, and between epithelial tissues of normal human stomach and human poorly differentiated cancer. Their differences were 86.8% (p < 0.05), 262.9% (p < 0.05), 660.1% (p < 0.05) and 34% (p < 0.05), 72. 2% (p < 0.05), 113.5% (p < 0.05) respectively. And pathological changes of gastric epithelial tissues induced that there were significant differences in the averaged value of the Kubelka-Munk function f(r infinity) and logarithmic Kubelka-Munk function log[f(r infinity)] of the carotene absorption bands at 480 nm between epithelial tissues of normal human stomach and human undifferentiation gastric cancer, between epithelial tissues of normal human stomach and human gastric squamous cell carcinomas, and between epithelial tissues of normal human stomach and human poorly differentiated cancer. Their differences were 59.5% (p < 0.05), 73% (p < 0.05), 258.9% (p < 0.05), 118.7% (p < 0.05), 139.2% (p < 0.05), and 324. 6% (p < 0.05) respectively. It is obvious that pathological changes of gastric epithelial tissues induced that there were significant changes in the contents of the DNA, protein and beta-carotene of gastric epithelial tissues. The conclusion can be applied to rapid, low-cost and noninvasive the optical biopsy for gastric cancer and provides a useful reference.

[Colon adenoma detection using Kubelka-Munk spectral function of DNA and protein bands].

Differential diagnosis of human colon adenoma was studied using the Kubelka-Munk spectral function of the DNA and protein absorption bands at 260 and 280 nm in vitro. Diffuse reflectance spectra of tissue were measured using a spectrophotometer with an integrating sphere attachment. The results of measurement showed that for the spectral range from 590 to 1 064 nm pathological changes of colon epithelial tissues were induced so that there were significant differences in the averaged values of the Kubelka-Munk function f(r infinity) and logarithmic Kubelka-Munk function log [f(r infinity)] of the DNA absorption bands at 260 nm between normal and adenomatous colon epithelial tissues, and the differences were 218% (p < 0.05) and 68.5% (p < 0.05) respectively. Pathological changes of colon epithelial tissues were induced so that there were significant differences in the averaged values of the Kubelka-Munk function f(r infinity) and logarithmic Kubelka-Munk function log [f(r infinity)] of the protein absorption bands at 280 nm between normal and adenomatous colon epithelial tissues, and the differences were 208% (p < 0.05) and 59.0% (p < 0.05) respectively. Pathological changes of colon epithelial tissues were induced so that there were significant differences in the averaged values of the Kubelka-Munk function f(r infinity) and logarithmic Kubelka-Munk function log [f(r infinity)] of the beta-carotene absorption bands at 480 nm between normal and adenomatous colon epithelial tissues, and the differences were 41.7% (p < 0.05) and 32.9% (p < 0.05) respectively. Obviously, pathological changes of colon epithelial tissues were induced so that there were significant changes in the contents of the DNA, protein and beta-carotene of colon epithelial tissues. The conclusion can be applied to rapid, low-cost and noninvasive optical biopsy of colon adenoma, and provides a useful reference.

[Thermal coagulation of human benign prostatic hyperplasia tissues induced changes in the absorption and scattering properties in spectral range from 590 to 1 064 nm in vitro].

The optical properties and their differences of native and coagulated human benign prostatic hyperplasia (BPH) tissues were studied in the spectral range from 590 to 1 064 nm in vitro. The measurements were performed using a spectrophotometer with an integrating sphere attachment, and the absorption and scattering properties were assessed from these measurements using the inverse adding-doubling method. The results of measurement showed that the thermal coagulation of BPH tissues induced obviously the decrease in the absorption coefficients in the spectral range from 590 to 1 064 nm. The peaks in the absorption coefficients for native and coagulated BPH tissues were respectively 0.438 and 0.416 mm(-1) corresponding to the same wavelength of 990 nm, the maximum difference in the absorption coefficients of native and coagulated BPH tissues is 86.79% at 1 064 nm, and the minimum difference is 4.74% at 920 nm. The thermal coagulation of BPH tissues induced an increase in the reduced scattering coefficients in the spectral range from 600 to 1 064 nm obviously, and induced a decrease in the reduced scattering coefficients at 590 nm obviously. The peaks in the reduced scattering coefficients for native and coagulated BPH tissues were respectively 1.090 and 1. 449 mm(-1) corresponding to the same wavelength of 970 nm, and other peaks in the reduced scattering coefficients for native and coagulated BPH tissues were respectively 1.116 and 1.627 mm(-1) corresponding to the same wavelength of 1 050 nm, the maximum difference in the reduced scattering coefficients of native and coagulated BPH tissues is 47.73% at 1 064 nm, and the minimum difference is 4.86% at 600 nm.

Thermal coagulation-induced changes of the optical properties of normal and adenomatous human colon tissues in vitro in the spectral range 400-1,100 nm.

The absorption coefficients, the reduced scattering coefficients and the optical penetration depths for native and coagulated human normal and adenomatous colon tissues in vitro were determined over the range of 400-1,100 nm using a spectrophotometer with an internal integrating sphere system, and the inverse adding-doubling method was applied to calculate the tissue optical properties from diffuse reflectance and total transmittance measurements. The experimental results showed that in the range of 400-1,100 nm there were larger absorption coefficients (P < 0.01) and smaller reduced scattering coefficients (P < 0.01) for adenomatous colon tissues than for normal colon tissues, and there were smaller optical penetration depths for adenomatous colon tissues than for normal colon tissues, especially in the near-infrared wavelength. Thermal coagulation induced significant increase of the absorption coefficients and reduced scattering coefficients for the normal and adenomatous colon tissues, and significantly reduced decrease of the optical penetration depths for the normal and adenomatous colon tissues. The smaller optical penetration depth for coagulated adenomatous colon tissues is a disadvantage for laser-induced thermotherapy (LITT) and photodynamic therapy (PDT). It is necessary to adjust the application parameters of lasers to achieve optimal therapy.

[Absorption and scattering characteristics of human benign prostatic hyperplasia tissue with Ti: sapphire laser irradiation in vitro].

The optical properties and their differences of human benign prostatic hyperplasia (BPH) tissues removed using transurethral plasma kinetic resection of the prostate (PKRP) and transurethral vaporization of the prostate (TUVP) at 640, 660, 680, 700, 720, 740, 760, 780, 800, 820, 840, 860 and 880 nm of Ti: Sapphire laser were studied in vitro. The measurements were performed using a double-integrating-sphere setup, and the absorption and scattering properties were assessed using the inverse adding-doubling method. The results of measurement showed that the absorption coefficients and reduced scattering coefficients of BPH tissues removed using PKRP and TURP obviously decreased with the increase in the wavelength for thirteen different laser wavelengths. The absorption coefficient and reduced scattering coefficient of BPH tissues removed using PKRP at a certain laser wavelength were obviously smaller than that of BPH tissues removed using TUVP at the same laser wavelength. The maximum absorption coefficient and maximum reduced scattering coefficient of BPH tissues removed using PKRP and TURP were respectively (0. 885 +/- 0. 022) and (0.955 +/- 0.024)mm(-1), and (1.564 +/- 0.039) and (1.658 +/- 0.042)mm(-1) at 640 nm, their differences were respectively 7.91% and 6.01%, and the minimum absorption coefficient and minimum reduced scattering coefficient of BPH tissues removed using PKRP and TURP were respectively (0.443 +/- 0.011) and (0.455 +/- 0.011) mm(-1), and (1.117 +/- 0.028) and (1.197 +/- 0.030)mm(-1) at 640 nm, their differences were respectively 2.71% and 9.13%. The maximum difference in the absorption coefficients of BPH tissues removed using PKRP and TURP is 8.95% at 660 nm, and the minimum difference is 1.75% at 860 nm. The maximum difference in the reduced scattering coefficients of BPH tissues removed using PKRP and TURP is 9.13% at 800 nm, and the minimum difference is 6.01% at 640 nm.

[Superficial bladder cancer detection using diffuse reflectance spectral ratio R540/R575 of oxygenated hemoglobin bands].

A low-cost, fast, and noninvasive method for early diagnosis of malignant lesions of mucosa tissue based on diffuse reflectance spectra was applied in the study of the optical biopsy of superficial human bladder cancer. In the present paper, differential diagnosis of superficial human bladder cancer was studied using the diffuse reflectance spectral ratio (R540/R575) of the oxygenated hemoglobin absorption bands at 540 and 575 nm in vitro. Diffuse reflectance spectra for mucosa/submucosa tissues of normal bladder and superficial bladder cancer were measured using a spectrophotometer with an integrating sphere attachment. The results of measurement showed that there were three the diffuse reflectance spectral dips at 415, 542 and 577 nm respectively for mucosa/submucosa tissues of normal bladder and superficial bladder cancer in the spectral range from 400 to 600 nm. The mean diffuse reflectance spectral ratio (R540/R575) of normal bladder mucosa/submucosa tissue decreased slowly with time increase after surgical excision, and the mean diffuse reflectance spectral ratio (R540/R575) of superficial bladder cancer mucosa/ submucosa tissue also decreased slowly with time increasing after surgical excision. The mean diffuse reflectance spectral ratios (R540/R575) of normal bladder mucosa/submucosa tissue were 111%, 107%, 104% and 102% after 2, 3, 4 and 5 h after surgical excision respectively, and those of superficial bladder cancer mucosa/submucosa tissue were 98.4%, 95.5%, 93.1% and 91.6% after 2, 3, 4 and 5 h after surgical excision respectively. There were significant differences in mean diffuse reflectance spectral ratio (R540/R575) for mucosa/submucosa tissues between normal bladder and superficial bladder cancer after 2, 3, 4 and 5 h after surgical excision respectively (p < 0.05). Differences in mean diffuse reflectance spectral ratio (R540/R575) for mucosa/ submucosa tissues between normal bladder and superficial bladder cancer were 12.6%, 11.5%, 10.9% and 10.4% after 2, 3, 4 and 5 h after surgical excision respectively. It is obvious that pathological changes in bladder mucosa/submucosa tissues induced changes in the component and structure of the tissues, and especially quantitative changes in oxyhemoglobin and de-oxyhemoglobin of tissues obviously. Conclusion of the study provides a new method that can be applied to rapid, low-cost and noninvasive optical biopsy of superficial bladder cancer.

[Canceration and thermal coagulation of human liver induced changes in the absorption and scattering properties of liver-tissue at near infrared in vitro].

Canceration and thermal coagulation of human liver induced changes in the absorption and scattering properties of liver tissue at 710, 730, 750, 77, 790, 810, 830, 850, 870 and 890 nm of Ti: sapphire laser were studied in vitro. The measurements were performed using a double-integrating-sphere setup, and the absorption and scattering properties were assessed from these measurements using the inverse adding-doubling method. The results of measurement showed that canceration of liver induced significant decrease in the absorption coefficients of liver tissue, and the maximum change in the absorption coefficients is 86.12% at 850 nm, while the minimum change in the absorption coefficients is 82.65% at 750 nm. Thermal coagulation of normal liver induced obvious change in the absorption coefficients from 710 to 890 nm, and the maximum change in the absorption coefficients is 79.55% at 710 nm, while the minimum change in the absorption coefficients 0.72% at 790 nm. Thermal coagulation of carcinoma liver tissue induced significant increase in the absorption coefficients, the maximum change in the absorption coefficients of carcinoma liver tissue is 78.69% at 810 nm, in the minimum change in the absorption coefficients of carcinoma liver tissue 38.16% at 710 nm. Canceration of liver induced significant increase in the scattering coefficients of liver tissue, and the maximum change in the scattering coefficients is 158.37% at 710 nm, while the minimum change in the scattering coefficients is 136.03% at 890 nm. Thermal coagulation of normal liver induced significant increase in the scattering coefficients of liver tissue, and the maximum change in the scattering coefficients is 632.92% at 890 nm, while the minimum change for the scattering coefficients is 587.40% at 710 nm. Thermal coagulation of carcinoma liver tissue induced significant increase in the scattering coefficients, and the maximum change in the scattering coefficients of carcinoma liver tissue is 384. 25% at 810 nm, while the minimum change in the scattering coefficients of carcinoma liver tissue is 330. 86% at 710 nm. The change in the absorption and scattering properties also varies with the change of laser wavelength.

[Comparison of light attenuation characteristics and optical penetration depths between native and coagulated human liver tissues].

A double-integrating-spheres and IAD method were used to study the differences in the optical penetration depths (OPDs) and light attenuation (LA) native and coagulated human liver tumors and liver tissues at the wavelengths of 680, 720, 780, 810, 850 and 890 nm of Ti: Sapphire laser. The results of measurement showed that the OPDs for native and coagulated human liver tumors and liver tissues at six different wavelengths obviously increase with increasing laser wavelength, the OPDs of coagulated human liver tumors and liver tissues at six different wavelengths were significantly smaller than that of native human liver tumors and liver tissues at the same wavelength respectively (P<0.05), and the OPDs of native and coagulated human liver tumors at six different wavelengths were significantly bigger than that of native and coagulated human liver tissues at the same wavelength respectively (P<0.05). The LA for native and coagulated human liver tumors and liver tissues at six different wavelengths obviously decreases with increasing laser wavelength, and the LA for coagulated human liver tumors and liver tissues at six different wavelengths is significantly bigger than that for native human liver tumors and liver tissues at the same wavelength respectively (P<0.05). The LA for native and coagulated human liver tumors at six different wavelengths is significantly bigger than that for native and coagulated human liver tissue at the same wavelength respectively (P<0.05).

Differences in optical properties between healthy and pathological human colon tissues using a Ti:sapphire laser: an in vitro study using the Monte Carlo inversion technique.

The purpose of the study is to analyze and compare differences in the optical properties between normal and adenomatous human colon tissues in vitro at 630-, 680-, 720-, 780-, 850-, and 890-nm wavelengths using a Ti:sapphire laser. The optical parameters of tissue samples are determined using a double integrating sphere setup at seven different laser wavelengths. The inverse Monte Carlo simulation is used to determine the optical properties from the measurements. The results of measurement show that the optical properties and their differences vary with a change of laser wavelength for normal and adenomatous colon mucosa/submucosa and normal and adenomatous colon muscle layer/chorion. The maximum absorption coefficients for normal and adenomatous human colon mucosa/submucosa are 680 nm, and the minimum absorption coefficients for both are 890 nm. The maximum difference of the absorption coefficients between both is 56.8% at 780 nm. The maximum scattering coefficients for normal and adenomatous colon mucosa/submucosa are 890 nm, and the minimum scattering coefficients for both are 780 nm. The maximum difference of the scattering coefficients between both is 10.6% at 780 nm. The maximum absorption coefficients for normal and adenomatous colon muscle layer/chorion are 680 nm, and the minimum absorption coefficients for both are 890 nm. The maximum difference of the absorption coefficients between both is 47.9% at 780 nm. The maximum scattering coefficients for normal and adenomatous colon muscle layer/chorion are 890 nm, and the minimum scattering coefficients for both are 680 nm. The maximum difference of the scattering coefficients between both is 9.61% at 850 nm. The differences in absorption coefficients between normal and adenomatous tissues are more significant than those in scattering coefficients.

Determination of optical properties of normal and adenomatous human colon tissues in vitro using integrating sphere techniques.

AIM: The purpose of the present study is to compare the optical properties of normal human colon mucosa/submucosa and muscle layer/chorion, and adenomatous human colon mucosa/submucosa and muscle layer/chorion in vitro at 476.5, 488, 496.5, 514.5 and 532 nm. We believe these differences in optical properties should help differential diagnosis of human colon tissues by using optical methods. METHODS: In vitro optical properties were investigated for four kinds of tissues: normal human colon mucosa/submucosa and muscle layer/chorion, and adenomatous human colon mucosa/submucosa and muscle layer/chorion. Tissue samples were taken from 13 human colons (13 adenomatous, 13 normal). From the normal human colons a total of 26 tissue samples, with a mean thickness of 0.40 mm, were used (13 from mucosa/submucosa and 13 from muscle layer/chorion), and from the adenomatous human bladders a total of 26 tissue samples, with a mean thickness of 0.40 mm, were used (13 from mucosa/submucosa and 13 from muscle layer/chorion). The measurements were performed using a double-integrating-sphere setup and the optical properties were assessed from these measurements using the adding-doubling method that was considered reliable. RESULTS: The results of measurement showed that there were significant differences in the absorption coefficients and scattering coefficients between normal and adenomatous human colon mucosa/submucosa at the same wavelength, and there were also significant differences in the two optical parameters between both colon muscle layer/chorion at the same wavelength. And there were large differences in the anisotropy factors between both colon mucosa/submucosa at the same wavelength, there were also large differences in the anisotropy factors between both colon muscle layer/chorion at the same wavelength. There were large differences in the value ranges of the absorption coefficients, scattering coefficients and anisotropy factors between both colon mucosa/submucosa, and there were also large differences in these value ranges between both colon muscle layer/chorion. There are the same orders of magnitude in the absorption coefficients for four kinds of colon tissues. The scattering coefficients of these tissues exceed the absorption coefficients by at least two orders of magnitude. CONCLUSION: There were large differences in the three optical parameters between normal and adenomatous human colon mucosa/submucosa at the same laser wavelength, and there were also large differences in these parameters between both colon muscle layer/chorion at the same laser wavelength. Large differences in optical parameters indicate that there were large differences in compositions and structures between both colon mucosa/submucosa, and between both colon muscle layer/chorion. Optical parameters for four kinds of colon tissues are wavelength dependent, and these differences would be useful and helpful in clinical applications of laser and tumors photodynamic therapy (PDT).