• Journal of Biomedical Engineering Research
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• v.36 no.1
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• pp.16-21
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• 2015

Indocyanine green(ICG) and 5-aminolevulinic acid(5-ALA) have been widely used to mark blood vessels or tumors. However, fluorescent dye detection systems were designed to use one type of dyes only. In this study, we proposed a detection system capable of detecting Indocyanine green and 5-aminolevulinic acid. Multiple filters and light sources are integrated into a single system. In this study, we performed analysis of fluorescent dyes and configured a detection system. During the analysis, it was found that Indocyanine green and 5-aminolevulinic acid have the maximum intensity at $40{\mu}M$. We designed light source for fluorescent dyes and conducted compatibility test using a commercial surgical microscope. The fluorescent dye detection system was configured based on the experimental results. The developed system successfully detects Indocyanine green and 5-aminolevulinic acid. Therefore, more efficient surgical operations can be achieved using both fluorescent dyes at the same time. We expect that the developed system can increase the survival rate of patients.

• Journal of Korean Neurosurgical Society
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• v.65 no.4
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• pp.572-581
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• 2022

Objective : Compared to microscopes, exoscopes have advantages in field-depth, ergonomics, and educational value. Exoscopes are especially well-poised for adaptation into fluorescence-guided surgery (FGS) due to their excitation source, light path, and image processing capabilities. We evaluated the feasibility of near-infrared FGS using a 3-dimensional (3D), 4 K exoscope with near-infrared fluorescence imaging capability. We then compared it to the most sensitive, commercially-available near-infrared exoscope system (3D and 960 p). In-vitro and intraoperative comparisons were performed. Methods : Serial dilutions of indocyanine-green (1-2000 ㎍/mL) were imaged with the 3D, 4 K Olympus Orbeye (system 1) and the 3D, 960 p VisionSense Iridium (system 2). Near-infrared sensitivity was calculated using signal-to-background ratios (SBRs). In addition, three patients with brain tumors were administered indocyanine-green and imaged with system 1, with two also imaged with system 2 for comparison. Results : Systems 1 and 2 detected near-infrared fluorescence from indocyanine green concentrations of >250 ㎍/L and >31.3 ㎍/L, respectively. Intraoperatively, system 1 visualized strong near-infrared fluorescence from two, strongly gadolinium-enhancing meningiomas (SBR=2.4, 1.7). The high-resolution, bright images were sufficient for the surgeon to appreciate the underlying anatomy in the near-infrared mode. However, system 1 was not able to visualize fluorescence from a weakly-enhancing intraparenchymal metastasis. In contrast, system 2 successfully visualized both the meningioma and the metastasis but lacked high resolution stereopsis. Conclusion : Three-dimensional exoscope systems provide an alternative visualization platform for both standard microsurgery and near-infrared fluorescent guided surgery. However, when tumor fluorescence is weak (i.e., low fluorophore uptake, deep tumors), highly sensitive near-infrared visualization systems may be required.

• Journal of Korea Multimedia Society
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• v.22 no.12
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• pp.1339-1346
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• 2019

In the characteristic of the brain malignant, the blood vessels and tumors have the same color and shape, and the boundary distinction is not clear, Therefore, it is difficult to observe the naked eye. Because of the high invasiveness, the risk of recurrence is high. Therefore, complete resection of the tumor is essential. The method for distinguishing the boundary between blood vessels and tumors is a fluorescence contrast method using indocyanine green (ICG), a fluorescence contrast agent. In ICG, the concentration range analysis is very important because the fluorescence expression state varies depending on the concentration. However, since the analysis result of the fluorescence expression condition is insufficient according to the current concentration, this paper proposes by analyzing the initial protocol of the concentration range. 780 nm infrared light was irradiated to the ICG sample to observe the fluorescence expression through a near infrared (NIR) camera. The wavelength is measured by using a spectrum instrument (ocean view) to observe the fluorescence expression wavelength of 811nm. As a result of analyzing the mol concentration according to each sample, the fluorescence expression range was found to be 16.15-0.16M and the optimum fluorescence concentration on the brightest part was found to be 3.23-0.81M.

• Journal of Veterinary Clinics
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• v.4 no.2
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• pp.473-481
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• 1987

This experiment was performed in order to establish a proper method to determine the half life of indocyanine green(ICG T$\frac{1}{2}$) and its fractional clearance rate(KICG) and investigate the applicability of indocyanine green ( ICG ) excretion test in hepatotoxicity experiment in Korean black goats. The results were as follows : 1. Maximum absorbance of ICG in plasma was at 810 nm in this experiment. 2. The coefficient of correlation between the results obtained by standard method and potassium cyanide method was 0.99 and the regression equation between two methods was y=0.9996 x＋0.0065. 3. As the disappearance curve of ICG plotted in semi-log graph revealed linear pattern at least for 6 minutes after injection, the postinjection blood samples were decided to collect at 2 and 6 minutes after ICG injection. 4. ICG T$\frac{1}{2}$ and KICG values were not affected by dose level of ICG. 5. When 0.25 mg of ICG per kg body weight was administered the normal data of ICG T$\frac{1}{2}$ and KICG in Korean black goa were 1.468${\pm}$0.197 minutes(mean${\pm}$SD) and 0.482${\pm}$0.076/minutes respectively. 6. After administration of carbon tetracholride. the ICG T$\frac{1}{2}$ started to increase acutely from day 1, revealed the peak at day 3, and then returned almostly but not completely to preinjection level at day 14. The ICG T$\frac{1}{2}$ value was suggested to be a sensitive indicator of hepatic injury in Korean black goats.

• Korean Journal of Veterinary Research
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• v.32 no.4
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• pp.677-681
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• 1992

This experiment was carried out to establish a proper method of indocyanine green(ICG) excrection test for a applicable liver function test in three Korean native cattle average weighing about 450kg and dairy cattle parity of 3~5. The results obtained the half life($T^1/_2$), fractional clearance rate(KICG), retention rate and plasma enzyme activities before or after injection of ICG were as follows. 1. The maximum absorbance of ICG in plasma was at 805nm. 2. Average half life and fractional clearance rate following the injection of ICG 0.25mg/kg body weight were $5.53{\pm}1.27$ minute and $0.131{\pm}0.031$/minute in Korean native cattle, $4.55{\pm}0.68$ minute and $0.156{\pm}0.031$/minute in dairy cattle, respectively. The ICG removal rate was exponentially liner for the first 15 minutes after injection both of Korean native cattle and dairy cattle. 3. Average plasma retention rate when 10, 15, 30 minutes after injection was $35.7{\pm}13.9$, $23.2{\pm}7.1$, $10.8{\pm}3.5%$ in Korean native cattle, $26.8{\pm}3.3$, $14.2{\pm}1.2$, $5.5{\pm}2.2%$ in dairy cattle, respectively. 4. Plasma enzyme activities(AST, ALT, r-GTP) were no variation among the before, during and after injection of ICG. From these results, ICG excretion test to cattle is applicable to evaluation of liver funtion in both clinical and research, and adopted the 15 minutes plasma sample as the sample taken at the ideal time for comparative purposes.

• Current Optics and Photonics
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• v.5 no.5
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• pp.554-561
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• 2021

Indocyanine green (ICG) is a cyanine dye that has been used in medical diagnostics based on fluorescence imaging, and in medical therapy based on the photothermal effect. It is important to systematically understand the photothermal effect and fluorescence characteristics of ICG simultaneously. By varying a number of conditions such as laser power density, laser irradiation wavelength, concentration of ICG solution, and exposure time of laser irradiation, the intensity properties of fluorescence and the temperature change induced by the photothermal effect are measured simultaneously using a charge-coupled-device camera and a thermal-imaging camera. The optimal conditions for maximizing the photothermal effect are determined, while maintaining a relatively long lifetime and high efficiency of the fluorescence for fluorescence imaging. When the concentration of ICG is approximately 50 ㎍/ml and the laser power density exceeds 1.5 W/cm², the fluorescence lifetime is the longest and the temperature induced by the photothermal effect rapidly increases, exceeding the critical temperature sufficient to damage human cells and tissues. The findings provide useful insight into the realization of effective photothermal therapy, while also specifying the site to be treated and enabling real-time treatment monitoring.

• Medical Lasers
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• v.10 no.3
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• pp.123-131
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• 2021

Optical imaging modalities with properties of real-time, non-invasive, in vivo, and high resolution for image-guided surgery have been widely studied. In this review, we introduce two optical imaging systems, that could be the core of image-guided surgery and introduce the system configuration, implementation, and operation methods. First, we introduce the optical coherence tomography (OCT) system implemented by our research group. This system is implemented based on a swept-source, and the system has an axial resolution of 11 ㎛ and a lateral resolution of 22 ㎛. Second, we introduce a fluorescence imaging system. The fluorescence imaging system was implemented based on the absorption and fluorescence wavelength of indocyanine green (ICG), with a light-emitting diode (LED) light source. To confirm the performance of the two imaging systems, human malignant melanoma cells were injected into BALB/c nude mice to create a xenograft model and using this, OCT images of cancer and pathological slide images were compared. In addition, in a mouse model, an intravenous injection of indocyanine green was used with a fluorescence imaging system to detect real-time images moving along blood vessels and to detect sentinel lymph nodes, which could be very important for cancer staging. Finally, polarization-sensitive OCT to find the boundaries of cancer in real-time and real-time image-guided surgery using a developed contrast agent and fluorescence imaging system were introduced.

• Journal of Veterinary Clinics
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• v.39 no.6
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• pp.395-399
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• 2022

A 6-year-old spayed, female golden retriever dog was presented with a skin mass on the dorsal region of the right carpus. The cytology result of the region revealed characteristics of mast cell tumors (MCTs). Short wave-infrared fluorescence-guided surgery using Indocyanine green (ICG) was performed to determine the surgical margin of the tumor. ICG was injected intravenously 24 hours before the surgery and the patient was hospitalized and carefully monitored. During the surgery, ICG fluorescence-based surgery was performed to identify the tumor and the surgical margin. The tumor was visible, and the skin mass was resected using NIR device for the guidance of the surgical margin of the tumor. Once the resection was complete, the surgical site was again inspected with SWIR fluorescence imaging to identify residual tumor cells. The resected tumor, using ICG navigation, was classified as low-grade cutaneous MCT and the margin was complete on the histopathological result. We report herein a case of resection of a cutaneous MCT in a dog using SWIR fluorescence imaging ICG which can be potentially used for the identification of tumors and evaluation of the surgical margin for complete resection.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.1
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• pp.21-30
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• 2021

The purpose of this study is to investigate the antibacterial effects of indocyanine green (ICG) and near-infrared diode lasers on multispecies biofilms. Multispecies biofilms of Streptococcus mutans, Lactobacillus casei and Candida albicans were treated with different irradiation time using photosensitizer ICG and 808 nm near-infrared diode laser. Colony forming unit (CFU) was measured, and qualitative evaluation of biofilm was performed with confocal laser scanning microscopy (CLSM). Temperature measurement was conducted to evaluate photothermal effect. In the groups using ICG and diode laser, reduction in CFU was statistically significant, but the difference in antibacterial effect on L. casei and C. albicans with irradiation time was not significant, and similar results were confirmed with CLSM. Groups with ICG and diode laser showed higher temperature elevation than groups without ICG, and results of measured temperature were similar to the range of hyperthermia. In conclusion, ICG and near-infrared diode laser showed antibacterial effects on multispecies biofilms, but studies on protocol are necessary for clinical application.

• Korean Journal of Clinical Pharmacy
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• v.3 no.2
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• pp.163-168
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• 1993

The influence of cimetidine pretreatment(100mg/kg, single i.p.) on the hepatic blood flow was investigated using pharmacokinetic parameters of indocyanine green(ICG) in the rat on the basis of hepacc perfusion-limited model. ICG(1mg/kg) was respectively administered via femoral and portal vein to the control and to the cimetidine-pretreated rats. The rate constant K12, K20 and the systemic clearance(CLt) of ICG were significantly(p<0.05) decreased ill the cimetidine-pretrea-to(B rats, but no significant diffirences were observed in hematocrit and liver weight. The biliary excretion rates of ICG were also decreased regardless of the route of administration in the cimetidine-pretreated rats. And also the hepatic blood flow in rats was decreased about $16\%$ by cimetidine. It may be concluded that the decreased hepatic blood flow with cimetidine mainly contributed to the decreased hepatic uptake and the decreased systemic clearance of ICG.