• Journal of the Korean Society of Radiology
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• v.8 no.3
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• pp.117-121
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• 2014

The understanding of medical knowledge regarding cardiac shape and cardiovascular system is essentially required for a medical personnel as well as a medical technician. Correct acquisition of medical knowledge through cardiac miniature model is very critical because it is directly related to a patient life. therefore replica model is necessary for the education regarding cardiac and cardiovascular system. In this study anatomical cardiovascular system on fluoroscopy can be shown by cardiac and cardiovascular fluoroscopy replica model. Also, it helps to understand a cardiovascular radiograph. Consequentially medical personnel and medical technician are able to take advantage of this equipment to understand cardiovascular fluoroscopy system.

• Proceedings of the KTCVS Conference
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• 1998.10a
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• pp.24-24
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• 1998

• Journal of the Korean Society of Radiology
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• v.12 no.7
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• pp.845-852
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• 2018

This study aimed to investigate the difference of X-ray exposure by comparing and analyzing absorbed dose according to changes in the number of frames in coronary angiography, also depending whether the zoom mode is FOV enlargement or Zoom Live. Moreover, for appropriate frame selection measures for examination, including the effect of frame change on the image quality, were sought by measuring the noise strength expressed by the standard deviation (SD), the signal to noise ratio (SNR) and contrast to noise ratio (CNR). The study was conducted with an anthropomorphic phantom on an angio-system. The linear relationship between the frame rate and the radiation dose was evident. On the contrary, the indices of image quality (SD, SNR, and CNR) were almost constant irrespective of the number of frames. The difference depending on the zoom mode was not statistically significant for DAP, air kerma, and SD (p > 0.05). However, SNR and CNR were statistically different between FOV enlargement and Zoom Live. In conclusion, since the image quality was not degraded significantly with the decreasing frame rate from 30, 15, to 7.5 f/s and the radiation dose evidently decreases in almost exactly linear proportion to the decreasing frame rate, the number of frames per second needs to be maintained as low as reasonably achievable. As for the dependence on the zooming mode, the Live Zoom mode showed statistically significant improvement in the image quality indices of SNR and CNR and it justifies active use of the Live Zoom mode which enables real-time image enlargment without additional radiation dose.

• Journal of Chest Surgery
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• v.30 no.1
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• pp.1-10
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• 1997

The successful cardiac transplantation depends partly on the donor heart preservation by a solution that will ensure recovery of myocardial function. The purpose of this study was to perform the evaluation of various preservation solutions and to accumulate the data on the requisites for ideal preservation solution. The experimental setup was the constant pressure Langendorffs perfusion system. Isolated rabbit hearts were perfused for 20minutes with unarm Krebs-Henseleit solution, stored for 4 hours in cold preservation solution after cardioplegia, and then were reperfused for 20minutes. The 4 experimental groups were prepared Hartmann's solution group (group 1, control), modified Euro-collins solution group(group II. MEC), modified University of Wisconsin group (group n, MUW), and CK solution(made by the author) group (group W, CK). The parameters for assessing the preservation ability were levels of enzymes in freezed myocardial tissues (lactate, creatine kinase-MB and adenosine deaminase), coronary flow. left ventricular developing pressure and dpldt. In conclusion, the ability of preservation for isolated rabbit heart was excellent in CK solution and modified University of Wisconsin solution, and poor in modified Euro-collins solution, compared with Hartmann solution. CK solution has low potassium concentrations(34.2mEq/L) and includes various substrates to be salutary on myocardial preservation. This fact may indicates the necessity of further refinements in selection or composition of electrolytes and substrates.

• Journal of Chest Surgery
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• v.34 no.3
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• pp.212-223
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• 2001

배경: 이식폐의 보존 및 재관류 동안 cyclic adenosine monophosphate(cAMP)와 nitric oxide(NO)는 폐혈관 내 순환조절을 유지하는데 있어 중심적인 역할을 한다. 그러나 내치세포내의 cAMP와 NO 모두 허혈-재관류 과정 동안에 현저하게 감소한다. 이에 저자는 low potassium dextran(LPD) 폐조본액에 cAMP의 유사체인 dibutyry1 cAMP(db-cAMP)와 NO의 공여물질인 nitroglycerin(NTG)을 첨가하여 이들의 폐보존 효과를 알아보고, 이들은 첨가한 폐보존액 들의 효과를 비교하였다. 대상 및 방법: 토끼 폐장 분리관류 모형에 실험군은 각각 6마리씩 4개군으로 단순 LPD 페보존액만 사용한 경우(I군), LPD 용액에 NTG 만 참가한 경우(II군), cAMP 만 첨가한 겨우(III군) 그리고 두가지 모두를 첨가한 경우는 IV군으로 분류하였으며, 폐보존액이 주입된 심폐블록은 영상 1$0^{\circ}C$에서 24시간 동안 보관한 다음 100% 산소농도에서 기계호흡을 하면서 신선 정맥혈로 30분 동안 재관류를 시행하였다. 재관류폐의 평가를 위해 폐기능 및 폐부종 정도를 정량 측정하였으며, 유출로 혈액으로부터 tumor necrosis factor $\alpha$(TNF-$\alpha$)와 간접적인 NO의 총량을 알기 위해 nitrite/nitrate의 양을 측정하였다. 또한 재관류가 끝난 후 광학 및 전자현미경학적 소견을 관찰하였다. 결과: 모든 실험군 중 제 IV군 의 폐보존 능력이 가장 우수하였으나, 제 II, III, IV군 사이는 통RP적으로 유의한 차이가 없었다. 제 I군은 제 II, III, IV군들에 비해 유의하게 폐기능이 가장 나쁘고 폐부종 정도가 가장 심했다(p<0.05). 제 II군은 제 III군에 비해 더 좋은 폐기능을 보였고, 폐부종 정도가 덜 하였으나 통계적은 유의성은 없었다. TNF-$\alpha$ 는 제 IV 군이 Irns에 비해 유의하게 분비량이 적었다. (p<0.05). 총 NO의 양은 제 II군과 IV 군이 제 I 군과 III군보다 유의하게 높았으나(p<0.001), 제 II군과 IV군, 제 I군과 III군 사이 비교에서 유의한 차이는 없었다. 또한 제 I 군과 III군에서는 시간이 지남에 따라 유의하게 NO의 양이 점차 감소하였다. (p<0.05). 광학 및 전자현민경 소견상 폐포 및 폐혈관 구조가 제 II, III, IV 군이 I 군에 비해 더 잘 보존되어있었다. 결론: LPD 폐보존액에 db-cAMP 및 NTG의 첨가는 폐보존 효과가 모두 우수함을 확인하였고 이들의 폐보존 효과 차이는 거의 없음을 알수 있었다. 그렇지만 이들의 병합사용이 폐혈관 항상성을 더 잘 유지시킬 수 있고 허혈-재관류 손상을 줄여 폐보존 효과를 높일 수 있을 것이라고 기대된다.

• Journal of Chest Surgery
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• v.30 no.6
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• pp.573-579
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• 1997

During the last 30 years, major organ transplantation has become popular, even in Korea, such as kidney, liver, etc. After the successful clinical cardiac transplantation in Korea, many cases of cardiac transplantation are being performed in some centers. But lung transplantation has a lot of obstacles, especially'donor shortage and decreased tolerability of the lung to ischemia-reperfusion injury. Usually it was considered that the maximum safety margin of ischemic time in lung transplantation was about 4 to 6 hours. So, many investigators have tried to develop better preservation methods and experimental model for evaluation of effectiveness in those various methods. But most of those methods had several drawbacks in clinical and experimental settings. So we developed an easily-controllable, reliable, and inexpensive experimental model of isolated rabbit lung block. Using these model, we evaluated its effectiveness and reliability for the experiment of ischemia-reperfusion injury in lung transplantation.

• Journal of Chest Surgery
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• v.33 no.7
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• pp.541-546
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• 2000

Background; Pericardial adhesion poses a major problem during re-operative cardiac surgery. The purpose of this study was to determine the effect of sodium carboxymethol cellulose on experimental pericardial adhesions. Material and Method; Twenty-four rabbits were divided into 2 groups of 12 rabbits each and pericardial mesothelial injury was induced by abrasion. Group A included rabbits receiving intrapericardial injection of Ringer's solution, and Group B included rabbits receiving intrapericardial injection of 3% sodium carboxymethoyl cellulose solution. Three weeks after the surgery, the incidence of adhesions in Group A was compared with that in Group B. Result; Pericardial adhesions were evaluated by tenacity and type scores. Tenacity scores of 3 or greater were considered clinically significant adhesion. Pericardial adhesion was found in 100% of rabbits in group A. However 25% of the rabbits in Group B had pericardial adhesions(p<0.0001). Type scores were also considered clinically significant between 2 groups. Conclusion; Our findings demonstrated that intrapericardial injection of 3% sodium carboxymethyl cellulose solution reduced the incidence of pericardial adhesions in an animal models.

• Journal of Chest Surgery
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• v.32 no.5
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• pp.428-432
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• 1999

Background: It has been shown that low-grade electrical stimulus can transform fatigue resistant muscles which then can be used to protect the heart. The bulky and cumbersome power sources of the artificial heart or implantable ventricular assist devices are still in need of solution; however, on the other hand, the implantable ventricular assist devices using the resistant muscles as the power source have the advantages of using its own muscle contractions. The purpose of this study was to determine the possibility of a clinical application of the skeletal muscle ventricle. Material and Method: Latissimus dorsi muscles (LDM) of 8 canines were used for skeletal muscle ventricle. A latex chamber was wrapped one and a half times with LDM. The chamber was attached to a pressure transducer via Tygon tube. An electrode stimulator was placed around the thoracodorsal nerve and LDM was stimulated in cyclic bursts of 0.31 sec on time and 6.0 sec off time using 3.0 volt Itrel stimulator. The preload volume was added to the system in 25cc increments. Ejection volumes, pressures, and peak power outputs were measured. Result: Ejection volume was 76.3cc with 0cc of preload. Ejection volumes were less than 70ml with increments of preload over 75cc Pressures were more than 107 mmHg when the preloads were less than 75cc and less than 100 mmHg when the preloads were more than 100cc. Peak power output of 16.6 W/kg was observed at 50cc preload. Conclusion: Depending on the changes of preload, the volumes ejected from skeletal muscle ventricle and pressures from the skeletal muscle contraction surpassed those of the normal heart. These data suggest that there are clinical applications for skeletal muscle ventricular assist system.

• Journal of Chest Surgery
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• v.42 no.5
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• pp.610-614
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• 2009

Background: Several trials have reported on whether adjuvant chemotherapy for resected stage IB non-small cell lung cancer is needed. The aim of our study was to investigate prognostic factors for recurrence to help identify patients who should receive adjuvant chemotherapy. Material and Method: We reviewed the cases of 48 stage IB non-small cell lung cancer patients between 1997 and 2006. Disease-free survival and overall survival rates were calculated by the Kaplan-Meier method. Univariate analysis was performed with the log rank test and multivariate analysis was done using Cox's proportional hazard model. Result: The median follow-up time was 48 months. The overall survival rate was 55.9%, and the disease-free survival rate was 48.6%. Of 8 variables, two factors, visceral pleural invasion and Iymphovascular invasion, were prognostic factors of disease-free survival (univariate analysis). Visceral pleural invasion was a significant prognostic factor in multivariate analysis, and overall survival in com-pared one or more variable such as visceral pleural invasion or, and lymphovascular invasion with the other variables. Conclusion: Visceral pleural invasion was identified as a poor prognostic factor and it may help select which patients will benefit from adjuvant chemotherapy in addition to more comprehensive follow-up.

• Journal of Chest Surgery
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• v.24 no.5
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• pp.429-437
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• 1991

Beta hydroxytrimethylammonium butyrate[L-carnitine] is highly concentrated in myocardium and it is essential substance for transfer of fatty acids into the mitochondria. We respect that L-carnitine has protective action to myocardium during ischemia. I studied coronary flow and CK - MB isoenzyme of coronary effluent of Langendorff`s isolated rat heart model. As a control group 5 Sprague-Dowley species rat hearts were connected to Langendorff`s isolated rat heart model and perfused for 30 minutes with Kreb-Henseleit buffer solution. After cessation of perfusion for 30 minutes they were reperfused for 30 minutes. In experimental group 10 Sprague-Dowley species rat hearts were perfused with 10mmole /L of L-carnitine contained in Kleb-Henseleit buffer solution. In equilibrium state, coronary flow was 1.7 times greater in experimental group. During reperfusion, both group showed equally decreased flow amount of about 60% of that of equilibrium state. CK-MB isoenzyme level of perfused coronary fluid showed no significant difference in equilibrium state. In reperfusion. CK-MB isoenzyme levels of control group were 17.61$\pm$8. 68U/L at 25 minutes, 23.32$\pm$4.15U /L at 30 minutes; and in experimental group, 13.63$\pm$6. 08U/L at 15 minutes and 13.6$\pm$8.41U /L at 30 minutes respectively. Those values in both states showed significantly lower CK-MB level in experimental group. In conclusion, L-carnitine prevent ischemic myocardial damage during ischemic and reperfusion state of Langendorff`s isolated rat hearts and also I suggest the L-carnitine act potent coronary vasodilator during preischemic and postischemic states of rat hearts.