• 대한의용생체공학회:의공학회지
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• 제31권3호
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• pp.177-186
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• 2010

In 3D ultrasound color Doppler imaging (CDI), 8-16 pulse transmissions (ensembles) per each scanline are used for effective clutter rejection and flow estimation, but it yields a low volume acquisition rate. In this paper, we have evaluated three flow estimation methods: autoregression (AR), eigendecomposition (ED), and autocorrelation combined with adaptive clutter rejection (AC-ACR) for a small ensemble size (E=4). The performance of AR, ED and AC-ACR methods was compared using 2D and 3D in vivo data acquired under different clutter conditions (common carotid artery, kidney and liver). To evaluate the effectiveness of three methods, receiver operating characteristic (ROC) curves were generated. For 2D kidney in vivo data, the AC-ACR method outperforms the AR and ED methods in terms of the area under the ROC curve (AUC) (0.852 vs. 0.793 and 0.813, respectively). Similarly, the AC-ACR method shows higher AUC values for 2D liver in vivo data compared to the AR and ED methods (0.855 vs. 0.807 and 0.823, respectively). For the common carotid artery data, the AR provides higher AUC values, but it suffers from biased estimates. For 3D in vivo data acquired from a kidney transplant patient, the AC-ACR with E=4 provides an AUC value of 0.799. These in vivo experiment results indicate that the AC-ACR method can provide more robust flow estimates compared to the AR and ED methods with a small ensemble size.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권4호
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• pp.1738-1756
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• 2020

To improve the accuracy and realism of the virtual surgical simulation system, this paper proposes an optimized mass-spring model with shape restoration ability based on volume conservation to simulate soft tissue deformation. The proposed method constructs a soft tissue surface model that adopts a new flexion spring for resisting bending and incorporates it into the mass-spring model (MSM) to restore the original shape. Then, we employ the particle swarm optimization algorithm to achieve the optimal solution of the model parameters. Besides, the volume conservation constraint is applied to the position-based dynamics (PBD) approach to maintain the volume of the deformable object for constructing the soft tissue volumetric model base on tetrahedrons. Finally, we built a simulation system on the PHANTOM OMNI force tactile interaction device to realize the deformation simulation of the virtual liver. Experimental results show that the proposed model has a good shape restoration ability and incompressibility, which can enhance the deformation accuracy and interactive realism.

• Korean Journal of Radiology
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• 제24권2호
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• pp.86-94
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• 2023

Objective: To compare Octopus multipurpose (MP) electrodes, which are capable of saline instillation and direct tissue temperature measurement, and conventional electrodes for radiofrequency ablation (RFA) in porcine livers in vivo. Materials and Methods: Sixteen pigs were used in this study. In the first experiment, RFA was performed in the liver for 6 minutes using Octopus MP electrodes (n = 15 ablation zones) and conventional electrodes (n = 12 ablation zones) to investigate the effect of saline instillation. The ablation energy, electrical impedance, and ablation volume of the two electrodes were compared. In the second experiment, RFA was performed near the gallbladder (GB) and colon using Octopus MP electrodes (n = 12 ablation zones for each) with direct tissue temperature monitoring and conventional electrodes (n = 11 ablation zones for each). RFA was discontinued when the temperature increased to > 60℃ in the Octopus MP electrode group, whereas RFA was performed for a total of 6 minutes in the conventional electrode group. Thermal injury was assessed and compared between the two groups by pathological examination. Results: In the first experiment, the ablation volume and total energy delivered in the Octopus MP electrode group were significantly larger than those in the conventional electrode group (15.7 ± 4.26 cm³ vs. 12.5 ± 2.14 cm³, p = 0.027; 5.48 ± 0.49 Kcal vs. 5.04 ± 0.49 Kcal, p = 0.029). In the second experiment, thermal injury to the GB and colon was less frequently noted in the Octopus MP electrode group than that in the conventional electrode group (16.7% [2/12] vs. 90.9% [10/11] for GB and 8.3% [1/12] vs. 90.9% [10/11] for colon, p < 0.001 for all). The total energy delivered around the GB (2.65 ± 1.07 Kcal vs. 5.04 ± 0.66 Kcal) and colon (2.58 ± 0.57 Kcal vs. 5.17 ± 0.90 Kcal) were significantly lower in the Octopus MP electrode group than that in the conventional electrode group (p < 0.001 for all). Conclusion: RFA using the Octopus MP electrodes induced a larger ablation volume and resulted in less thermal injury to the adjacent organs compared with conventional electrodes.

• 핵의학기술
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• 제14권1호
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• pp.115-121
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• 2010

방사성핵종과 방사능을 측정하는 dose calibrator의 서로 다른 두개의 기기에서 F-18 FDG을 각각 측정하고, 이 측정값에 의한 인체 내 SUV (Standard Uptake Value)에 미치는 영향은 없는지에 대하여 알아보고자 하였다. 이 연구에서 두개의 다른 dose calibrator는 CRC-15 Dual PET, CRC-15R을 사용하였다. 각 dose calibrator에서 F-18 FDG를 2 mL 주사기 3개에 볼륨 1 mL, 2 mL, 3 mL를 만들어 각각 초기 radio activity를 측정한 후 4시간 30분(270분)까지 30분 간격으로 radio activity를 각각 측정하고 기록한다. 초기 radio activity 값을 기준으로 방사선붕괴 공식으로 산출된 값(decay factor)과 dose calibrator로 측정된 값 간의 직선성을 단순선형을 통하여 분석하였다. CRC-15 Dual PET에서 가장 이상적인 값에 가까운 측정값을 볼륨을 기준으로 하여, CRC-15R에서 측정된 값을 최적화하기 위한 선형회귀식을 회귀분석을 통하여 구한다. 선형회귀식의 산출값을 적용하여 PET/CT 검사를 시행한 50명을 대상으로 lung, liver, region 부위에 ROI을 그려 SUV를 구한다. CRC-15 Dual PET, CRC-15R에서 측정한 radio activity와 그 값을 이용한 SUV를 paired t-test로 통계적으로 유의한 차이가 있는지 알아보았다. CRC-15 Dual PET과 CRC-15R에서 측정한 radio activity의 상관분석결과 1 mL의 경우 상관성을 보여주는 r값은 r=0.999이었으며, 회귀분석에 위한 선형식은 y=1.0345x+ 0.2601이었다. 2 mL의 경우 r=0.999이며, 선형회귀식은 y=1.0226x+0.1669이었다. 3 mL의 경우 r=0.999이며, 선형회귀식은 y=1.0094x+0.1577이었다. 각 세 가지 볼륨에서 얻어진 선형회귀식의 산출 값을 이용하여 구한 lung, liver, region 부위에 ROI의 SUV에서의 차이는 1 mL의 경우, lung, liver, region은 (p<0.0001)로 t-test 결과 모두 유의한 차이가 있었다. 2mL의 경우, lung (p<0.002), liver, region은 ROI의 SUV에서 유의한 차이(p<0.0001)를 보였다. 또한 3 mL의 경우, lung(p<0.044), liver, region의 유의한 차이(p<0.0001)가 있었다. F-18 FDG 검사에서 사용되는 두 개의 dose calibrator CRC-15 Dual PET, CRC-15R의 radioactivity에 대한 측정치에서는 상관관계의 차이가 없다는 것을 알 수 있었다. 그러나 이 두 값을 통해 SUV는 인체 내의 uptake 정도에 있어서는 유의한 차이를 보인다는 것을 알 수 있었다. 따라서 이 두개의 dose calibrator를 사용함에 있어서, 이 두 값이 인체 내 SUV의 차이를 고려하여 사용하여야 할 필요성이 요구된다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권21호
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• pp.9143-9146
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• 2014

Background: The aim of this study was to investigate the general characteristics of patients with deep vein thrombosis (DVT) and pancreatic cancer as well as evaluate the relationship between mean platelet volume (MPV), DVT and survival. Materials and Methods: Seventy-seven patients with pancreatic cancer, who were admitted to Cukurova University Medical Faculty, Department of Medical Oncology, were enrolled in the study Results: The mean age was $59{\pm}20$. Forty-nine (63.6%) were men and 28 women (36.4%). Sixty-eight (88.3%) patients had adenocarcinoma and 9 (11.7%) had a malignant epithelial tumor. Thirty-six (46.7%) had liver metastasis at diagnosis. Twenty-six (33.8%) patients were alive, 20 (26%) were dead and in 31 (40.2%) the status was unknown. Only 14 (18.1%) patients had DVT. In 42 (54.5%) patients MPV values were normal, in 28 (36.4%) patients they were above normal, and in 7 (9.1%) patients they were below normal. There was no statistically significant difference between gender, tumour localization, chemotherapy and survival rates (p:0.56, p:0.11, p:0.21). There was no significant difference between DVT, gender, localisation, histological subtype, the presence of metastasis, stage and if the patient had been treated with chemotherapy (p:0.5, p:0.6, p:0.2, p:0.32, p:0.1, p:0.84). There was also no significant difference between MPV and DVT (p:0.57) but there was a significant difference between liver metastasis and DVT (p:0.02). Age, stage, the presence of metastasis and DVT were prognostic in pancreatic cancer patients. Conclusions: Cases of pancreatic cancer with liver metastasis should be studied more carefully as thrombosis is more common in these patients.

• Journal of Nutrition and Health
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• 제7권2호
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• pp.37-51
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• 1974

This Study was carried out to observe the effect of nutritional condition on the change of protein metabolism in the animal body by feeding on imbalanced protein diet. A total 242 growing male albino rats, weighing $115{\sim}120$ gm, were used for the experimental animals. The rats were fed on the standard diet(st), protein flee diet(pf) and imbalanced protein diet(ib) for twelve weeks respectively. Hemoglobin, packed cell volume in blood, and total nitrogen, amino acid nitrogen, urea-nitrogen, creatinine, transaminases(GPT, GOT) in liver and serum, and total nitrogen in small intestine, and total nitrogen, urea-nitrogen In small intestine, and total nitrogen, urea-nitrogen, creatinine, urea-nitrogen/creatinine ratio in urine were measured. The results obtained are as follows; 1. The gained body weight were lower in pf group and ib group than those of st group. The gained body weight fed for 12 weeks, were 80% lower in pf group than those of st group, and the body weight of pf group for $50{\sim}75$ days feeding were $40{\sim}60%$ decreased, compared with the stating weight, and then all of them died. 2. The change of the brain, liver, kidney, spleen and small intestine by feeding on imbalanced diet for 12 weeks were no remarkable difference with the starting weight, but those of protein free diet group were half or more decrease and those were significantly lower in spleen and small intestine especially than the other organ 3. The contents of hemoglobin in pf group for 8 weeks feeding, and the packed cell volume in pf group for 8 weeks feeding and in ib group for 12 weeks feeding were decreased. but those of the other feeding group were almost same value. 4. The total nitrogen in the liver, small intestine and serum of each diet group were no remarkable difference respectively. The contents of amino acid nitrogen in pf group for 2 and 6 weeks feeding were increased. 5. On transaminases: a) The cycle of increase and decrease of GPT activities were come periodically and the interval of cycle were fast in the early stage of feeding and slow there-after. b) The GPT activities were decreased gradually in pf group after feeding and those were increased in ib group for 6 weeks feeding but decreased there-after. The frequency of cycle were more GPT than GOT and specially those of GPT in early stage of feeding were two or three times while GOT was one. c) The interval of increase and decrease in GOT and amino acid nitrogen cycle were similar tendency. 6. The contents of total nitrogen, creatinine and urea-nitrogen of pf group in urine were decreased very sharply from sharting feeding to one week but increased dully from six weeks to eight weeks feeding. The contents of urea-nitrogen of ib group were increased dully by feeding on ten weeks but decreased by feeding on twelve weeks. From the above results, it is concluded that the trend of the metabolic change is maintained equally by homeostatic mechanism using the endogenous protein source during a certain period by imbalanced protein diet feeding. The homeostatic mechanism is come peridically, very fast in early stage of feeing and than slow there-after.

• Radiation Oncology Journal
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• 제26권4호
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• pp.280-288
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• 2008

목 적: 토모테라피 영상유도장치인 MVCT (mega-voltage computed tomography) 영상을 이용하여 자유 호흡시 분할 치료 간 간조직의 위치변화 양상을 알아보고자 하였다. 대상 및 방법: 2006년 4월부터 2007년 8월까지 간종양에 토모테라피를 받은 환자 26 명을 대상으로 치료 시작 후 10회까지 매회 치료시의 MVCT 영상을 분석하였다. 1차적으로 골격 구조에 따라 셋업오차보정을 한 상태에서 2차원 직교좌표계 상에서 간조직 경계부위의 위치 변화를 치료계획 KVCT (Kilo-Voltage Computed Tomography)와 MVCT의 영상융합을 통해 비교하여 오차 정도를 파악하였다. 간종양의 위치 별 변화 양상을 보기 위하여 종양 위치를 Couinaud's proposal을 기준으로 1군(Segment 1), 2군(Segment 2, 3, 4), 3군(Segment 5, 6), 4군(Segment 7, 8)으로 나누어 각 군별 위치 변화 양상을 비교하였다. 결 과: MVCT를 통해 알아본 평균 셋업오차는 각각 $0.45{\pm}2.04\;mm$ (좌-우), $0.97{\pm}4.06\;mm$ (상-하), $8.38{\pm}4.67\;mm$ (전-후) 이었다. 2군에서 전방 바깥쪽으로 $2.80{\pm}1.73\;mm$, 좌방 안쪽으로 $2.23{\pm}1.37\;mm$ 이동하였고 4군에서는 전, 후, 좌, 우 각 방향으로 $-0.15{\pm}3.93\;mm$, $-3.15{\pm}6.58\;mm$, $-0.60{\pm}3.58\;mm$, $-4.50{\pm}5.35\;mm$ 이동하였다. 1, 2, 3군에서 후방으로의 위치 변화는 평균 1 mm 이내였다(각각 $0.07{\pm}0.9 \;mm$, $-0.07{\pm}1.38\;mm$, $0.50{\pm}0.47\;mm$). MVCT 값들의 적용 시 보이는 2군에서의 종양체적 감소는 위 독성을 증가시킬 것으로 생각되었다. 결 론: 분할치료 간 간조직의 위치 변화 양상은 각 군마다 편차가 있는 가운데 어느 정도 규칙적이었다. 호흡에 의한 간조직의 기하학적 변형은 segment 2, 3, 4에서 좌방 표적 체적의 감소를 가져오는 반면 segment 5, 6에서는 호흡에도 불구하고 안정적인 양상을 나타내었다. 따라서 자유 호흡 상태에서 간 좌엽에 대한 방사선치료 시 위에 대한 독성을 줄이기 위해 보다 세심한 접근이 필요하다.

• Archives of Pharmacal Research
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• 제25권6호
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• pp.973-977
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• 2002

The pharmacokinetic of paclitaxel (1 mg/kg, i.v.) was investigated in rabbits with carbon tetrachloride-induced hepatic failure. The area under the plasma concentration-time curve (AUC) of paclitaxel was significantly (p<0.01) increased in severe carbon tetrachloride-induced hepatic failure rabbits ($1364.54{\pm}382.07$ ng/ml$\cdot$hr) compared to that of normal rabbits ($567.52{\pm}141.88$ ng/ml$\cdot$hr), but not significantly in moderate carbon tetrachloride-induced hepatic failure rabbits ($803.1{\pm}208.81$ ng/ml$\cdot$hr). The volume of distribution (Vd) (6.25$\pm$1.56 L) and the elimination rate constant($\beta$) ($0.09{\pm}0.025{\;}hr^{-1}$) of paclitaxel in severe carbon tetrachloride-induced hepatic failure rabbits were significantly (p<0.05) decreased compared to those of normal rabbits ($11.65<{\pm}2.91$L, $0.12{\pm}0.030{\;}hr^{-1}$), but not significantly in moderate carbon tetrachloride-induced hepatic failure rabbits ($9.46{\pm}2.37$ L, $0.10{\pm}0.026{\;}hr^{-1}$). Total body clearance ($CL_t$) of paclitaxel in severe carbon tetrachloride-induced hepatic failure rabbits ($0.733{\pm}0.183$ L/hr/kg) was significantly (p<0.01) decreased compared to that of normal rabbits ($1.762{\pm}0.440$ L/hr/kg), but not significantly in moderate carbon tetrachloride-induced hepatic failure rabbits ($1.245{\pm}0.311$ L/hr/kg). The half-life(t1/2) of paclitaxel in severe carbon tetrachloride-induced hepatic failure rabbits ($7.71{\pm}2.16$ hr) was significantly (p<0.05) increased compared to that of normal rabbits ($5.75{\pm}1.44$hr), but not significantly in moderate carbon tetrachloride-induced hepatic failure rabbits ($6.77{\pm}1.76$hr). This results could be due to inhibition of paclitaxel metabolism in liver disorder rabbits since paclitaxel is essentially metabolized in liver. The findings suggest that the dosage regimen of paclitaxel should be adjusted when the drug would be administered in patients with liver disorder in a clinical situation.

• 대한한방내과학회지
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• 제29권2호
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• pp.299-310
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• 2008

Objectives : This study was performed to investigate the anti-fibrogenic effect of Salvia miltiorrhiza on rat hepatic stellate cells. Materials and Methods : Hepatic stellate cells(HSC-T6) were treated with various concentrations of Salvia miltiorrhiza extract for 24 hours. It was extracted either with distilled water or 50% EtOH. After the treatment, cell viability, proliferation, procollagen levels and the mRNA of the collagen type 1a2 and ASMA were measured Results : The viability and proliferation of the hepatic stellate cells were decreased as concentration increased. The mRNA expression decreased consistently with the volume of the secreted procollagen with the extraction made with distilled water. This indicates the herb has inhibitory effect on fibrogenesis of the liver by regulating one of the fibrosis associated genes in transcription. However it increased in 50% EtOH extraction, which shows that a more stable reaction is expected of the extraction made with distilled water than the extraction made with 50% EtOH. The production of procollagen was decreased by a low-concentration treatment with Salvia miltiorrhiza, but increased by a high concentration. It seemed that the cells were responding to Salvia miltiorrhiza in low- concentration, thus producing smaller amounts of collagen. When the drug was administered in high enough concentration to give direct toxicity to cells, an overproduction of collagen was observed. Conclusion : These results suggest that Salvia miltiorrhiza is a possible candidate for the treatment of cirrhotic patients as well as for patients with chronic hepatitis when extracted with water in the proper concentrations.

• Radiation Oncology Journal
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• 제33권3호
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• pp.233-241
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• 2015

Purpose: To compare volumetric modulated arc therapy of RapidArc with robotic stereotactic body radiation therapy (SBRT) of CyberKnife in the planning and delivery of SBRT for hepatocellular carcinoma (HCC) treatment by analyzing dosimetric parameters. Materials and Methods: Two radiation treatment plans were generated for 29 HCC patients, one using Eclipse for the RapidArc plan and the other using Multiplan for the CyberKnife plan. The prescription dose was 60 Gy in 3 fractions. The dosimetric parameters of planning target volume (PTV) coverage and normal tissue sparing in the RapidArc and the CyberKnife plans were analyzed. Results: The conformity index was $1.05{\pm}0.02$ for the CyberKnife plan, and $1.13{\pm}0.10$ for the RapidArc plan. The homogeneity index was $1.23{\pm}0.01$ for the CyberKnife plan, and $1.10{\pm}0.03$ for the RapidArc plan. For the normal liver, there were significant differences between the two plans in the low-dose regions of $V_1$ and $V_3$. The normalized volumes of $V_{60}$ for the normal liver in the RapidArc plan were drastically increased when the mean dose of the PTVs in RapidArc plan is equivalent to the mean dose of the PTVs in the CyberKnife plan. Conclusion: CyberKnife plans show greater dose conformity, especially in small-sized tumors, while RapidArc plans show good dosimetric distribution of low dose sparing in the normal liver and body.