Radiofrequency Ablation of Rabbit Liver In Vivo: Effect of the Pringle Maneuver on Pathologic Changes in Liver Surrounding the Ablation Zone

Seung Kwon Kim,임효근,류정아,최동일,이원재,Ji Yeon Lee,Ju Hyun Lee,성연미,조은윤,홍승모,Jong-Sung Kim 대한영상의학회 2004 Korean Journal of Radiology Vol.5 No.4

Objective: We wished to evaluate the effect of the Pringle maneuver (occlusion of both the hepatic artery and portal vein) on the pathologic changes in the hepatic vessels, bile ducts and liver parenchyma surrounding the ablation zone in rabbit livers. Materials and Methods: Radiofrequency (RF) ablation zones were created in the livers of 24 rabbits in vivo by using a 50-W, 480-kHz monopolar RF generator and a 15-gauge expandable electrode with four sharp prongs for 7 mins. The tips of the electrodes were placed in the liver parenchyma near the porta hepatis with the distal 1 cm of their prongs deployed. Radiofrequency ablation was performed in the groups with (n=12 rabbits) and without (n=12 rabbits) the Pringle maneuver. Three animals of each group were sacrificed immediately, three days (the acute phase), seven days (the early subacute phase) and two weeks (the late subacute phase) after RF ablation. The ablation zones were excised and serial pathologic changes in the hepatic vessels, bile ducts and liver parenchyma surrounding the ablation zone were evaluated. Results: With the Pringle maneuver, portal vein thrombosis was found in three cases (in the immediate [n=2] and acute phase [n=1]), bile duct dilatation adjacent to the ablation zone was found in one case (in the late subacute phase [n=1]), infarction adjacent to the ablation zone was found in three cases (in the early subacute [n=2] and late subacute [n=1] phases). None of the above changes was found in the livers ablated without the Pringle maneuver. On the microscopic findings, centrilobular congestion, sinusoidal congestion, sinusoidal platelet and neutrophilic adhesion, and hepatocyte vacuolar and ballooning changes in liver ablated with Pringle maneuver showed more significant changes than in those livers ablated without the Pringle maneuver (p < 0.05) Conclusion: Radiofrequency ablation with the Pringle maneuver created more severe pathologic changes in the portal vein, bile ducts and liver parenchyma surrounding the ablation zone compared with RF ablation without the Pringle maneuver. Therefore, we suggest that RF ablation with the Pringle maneuver should be performed with great caution in order to avoid unwanted thermal injury.

스쿼시 백핸드와 포핸드 스트로크의 운동학적 비교

김승권(SeungKwonKim),박종진(JongJinPark) 한국체육학회 2008 한국체육학회지 Vol.47 No.6

스쿼시의 백핸드와 포핸드 스트로크의 운동학적 변인들을 3차원 영상분석법으로 비교분석한 결론은 다음과 같다. 포핸드 스트로크 시의 라켓은 전후 수평 움직임이 백핸드 스트로크 시의 라켓은 상하 수직 움직임 양상이 더 크게 나타났다. 포핸드의 경우는 높은 Top에서 시작하여 낮은 Finish로 끝나고 백핸드의 경우는 낮은 Top으로 시작하여 높은 Finish로 끝나는 것으로 나타났다. 포핸드 스트로크 시는 백핸드 스트로크보다 견관절을 상하, 전후로 많이 회전시키는 것으로 나타났다. 주관절각은 포핸드 시 임팩트 전에 감소하였다가 임팩트 시 증가한 후 Finish까지 다시 감소하는 반면 백핸드 시는 Top에서부터 Finish까지 계속하여 증가하였다. 포핸드 스트로크 시 변인들은 임팩트 시점에서 많이 변화하였으나 백핸드 시는 임팩트 보다 0.2 내지 0.3초 이전에 많은 변화를 보였다. 포핸드의 경우는 임팩트 시 급격히 증가하는 주관절의 신전현상을 보인 반면, 백핸드의 경우는 처음부터 계속하여 관절각이 증가하는 주관절의 신전현상을 보였다. The following are the results of comparing and analyzing the kinematic variables of the squash forehand and backhand stroke through three dimensional cinematographic analysis. During the forehand stroke, the racket moved in a front-to-rear horizontal motion while the racket for the backhand stroke showed more of a top-to-bottom vertical movement. The forehand stroke started from a high top position and ended with a low finish position while the backhand stroke started from a low top and ended with a high finish. The forehand stroke showed more front-to-rear and top-to-bottom rotation at the shoulder joint compared to the backhand stroke. The angular displacement at the elbow joint for the forehand stroke was reduced before impact, increased during impact, and reduced again until finish while for the backhand stroke it was continuously increased from top position to finish. Most of the variables of the forehand stroke showed big change at the impact, while those of backhand stoke showed big change 0.2 to 0.3 seconds ahead of the impact. The elbow joint of the forehand stroke showed rapid extension at the impact, while that of backhand stroke showed steadily increasing extension from the start.

Overlapping Ablation Using a Coaxial Radiofrequency Electrode and Multiple Cannulae System: Experimental Study in ex-Vivo Bovine Liver

DongilChoi,SeungKwonKim,HyoK.Lim,MinJuKim,JongmeeLee,EungYeopKim,SooahKim,SeongHyunKim 대한영상의학회 2003 Korean Journal of Radiology Vol.4 No.2

상업스포츠시설의 서비스품질이 고객의 감정, 만족, 태도, 관계지속의도에 미치는 영향

박찬규(ChanKyuPark),김승권(SeungKwonKim),장창현(ChangHyunJang) 한국체육학회 2009 한국체육학회지 Vol.48 No.3

상업스포츠시설의 서비스품질이 고객의 감정, 만족, 태도, 관계지속의도에 미치는 영향을 규명하기 위해 상업스포츠시설 이용객을 대상으로 편의표본추출법을 이용하여 자료를 수집하였다. 자료 분석 방법으로는 빈도분석, 탐색적 요인분석, 상관분석, 신뢰도분석, 확인적 요인분석과 구조방정식 모형분석 등을 사용하였으며 그 결과는 다음과 같다. 첫째, 서비스품질은 긍정적 감정에 통계적으로 유의한 정(+)의 영향을 미치는 것으로 나타났으며, 부정적 감정에 부(-)의 영향을 미치는 것으로 나타났다. 둘째, 긍정적 감정은 고객만족에 통계적으로 유의한 정(+)의 영향을 미치는 것으로 나타났으며, 부정적 감정은 부(-)의 영향을 미치는 것으로 나타났다. 셋째, 긍정적 감정은 고객태도에 통계적으로 유의한 영향을 미치지 않는 것으로 나타났지만, 부정적 감정은 부(-)의 영향을 미치는 것으로 나타났다. 넷째, 고객만족은 고객태도에 통계적으로 유의한 정(+)의 영향을 미치는 것으로 나타났다. 다섯째, 고객태도는 관계지속의도에 통계적으로 유의한 정(+)의 영향을 미치는 것으로 나타났다. A convenience sampling method was used for the commercial sports facility customers to analyze the effects of the service quality of commercial sports facilities on a customer's emotion, satisfaction, attitude, and intention for relationship continuance. Data was analyzed through frequency analysis, exploratory factor analysis, correlation analysis, reliability analysis, confirmatory factor analysis, and structure equation modeling, and the results were as follows. First, service quality showed statistically significant positive effects on positive emotions, while showing negative effects on negative emotions. Second, positive emotions showed statistically significant positive effects on customer satisfaction, while negative emotions showed statistically significant negative effects on customer satisfaction. Third, positive emotions did not show statistically significant effects on a customer's attitude, while negative emotions showed statistically significant negative effects on a customer's attitude. Fourth, customer satisfaction showed statistically significant positive effects on a customer's attitude. Fifth, a customer's attitude showed statistically significant positive effects on the customer's intention to continue the relationship.

자연과학편 : 배구 스파이크의 도움닫기와 발구름 동작이 도약높이에 미치는 영향

박홍균(HongKyunPark),김승권(SeungKwonKim) 한국체육학회 1995 한국체육학회지 Vol.34 No.3

A kinematic analysis of the approach and take-off motion in volleyball spike was done using three-dimensional high speed cinematography. Twelve high-class collegiate male volleyball players were involved in the data gathering process. Two cameras were utilized for filming three trials of each subject’s spike movements with the filming rate of 100 frames per second. Digitized raw data were smoothed using the digital filtering method with 8 Hz of cut-off frequency. DLT(Direct Linear Transformation) method were applied to convert the two-dimensional data to three-dimensional ones. An interpolation method of Cubic Spline Function was also used to synchronize the two separate two-dimensional data. The calculated kinematic variables of volleyball spike were descriptively analyzed. The correlation between those variables and jumping height and vertical velocity of the total body center of gravity(CG) were analyzed.Based on the results and discussion presented in the preceding chapter, the following conclusions were drawn :1) The stride before the take-off was found to be shorter than that in the high jump motion, and this is thought to be due to the ‘power flop’ action which is important in the vertical jump.2) The displacement of the CG during the volleyball spike was similar to that of the high jump.3) It is essential to practice concentric contraction training to maximize the efficiency of converting the horizontal running momentum to the vertical jumping velocity.4) The angular displacement of the left knee joint was continuously increased from touch down to take-off, while that of the right knee joint increased just before the take-off moment. This might indicate that the concentric contraction of the left leg more critically affects the jumping speed and the height.5) Since the contribution of the upper extremities to the vertical velocity is pretty high, the skill of controlling upper arms in the volleyball spike movement is very important.6) It is thought that the decrease in the horizontal velocity during the take-off is mainly due to the concentric contraction of the left leg.7) The short take-off time, and the smaller right foot angle and the angle of the knee joint in touch down seem to increase the jumping height.For the letter and sound results, the following factors are recommended to the further researches: more subjects, actual competing situation, kinetic data.

Optimal Pulse Sequence for Ferumoxides-Enhanced MR Imaging Used in the Detection of Hepatocellular Carcinoma: A Comparative Study Using Seven Pulse Sequences

SeungHoonKim,DongilChoi,JaeHoonLim,WonJaeLee,Hyun-JungJang,HyoKeunLim,SoonJinLee,JaeMinCho,SeungKwonKim,GabChulKim 대한영상의학회 2002 Korean Journal of Radiology Vol.3 No.2

Objective: To identify the optimal pulse sequence for ferumoxides-enhanced magnetic resonance (MR) imaging in the detection of hepatocelluar carcinomas (HCCs). Materials and Methods: Sixteen patients with 25 HCCs underwent MR imaging following intravenous infusion of ferumoxides. All MR studies were performed on a 1.5-T MR system, using a phased-array coil. Ferumoxides (Feridex IV) at a dose of 15 mol/Kg was slowly infused intravenously, and axial images of seven sequences were obtained 30 minutes after the end of infusion. The MR protocol included fast spin-echo (FSE) with two echo times (TR3333 8571/TE18 and 90-117), singleshot FSE (SSFSE) with two echo times (TR /TE39 and 98), T2*-weighted gradient-recalled acquisition in the steady state (GRASS) (TR216/TE20), T2*-weighted fast multiplanar GRASS (FMPGR) (TR130/TE8.4 9.5), and T2*-weighted fast multiplanar spoiled GRASS (FMPSPGR) (TR130/TE8.4 9.5). Contrast-to-noise ratios (CNRs) of HCCs determined during the imaging sequences formed the basis of quantitative analysis, and images were qualitatively assessed in terms of lesion conspicuity and image artifacts. The diagnostic accuracy of all sequences was assessed using receiver operating characteristic (ROC) analysis. Results: Quantitative analysis revealed that the CNRs of T2*-weighted FMPGR and T2*-weighted FMPSPGR were significantly higher than those of the other sequences, while qualitative analysis showed that image artifacts were prominent at T2*-weighted GRASS imaging. Lesion conspicuity was statistically significantly less clear at SSFSE imaging. In term of lesion detection, T2*-weighted FMPGR, T2*- weighted FMPSPGR, and proton density FSE imaging were statistically superior to the others. Conclusion: T2*-weighted FMPGR, T2*- weighted FMPSPGR, and proton density FSE appear to be the optimal pulse sequences for ferumoxidesenhanced MR imaging in the detection of HCCs.