Intravitreal Triamcinolone Reinjection for Refractory Diabetic Macular Edema

( Alireza Ramezani ),( Hamid Ahmadieh ),( Homa Tabatabaei ) 대한안과학회 2006 Korean Journal of Ophthalmology Vol.20 No.3

Purpose: To evaluate the effect of intravitreal triamcinolone acetonide (IVT) reinjection on clinical and optical coherence tomographic features in refractory diabetic macular edema. Methods: In a prospective interventional case series, all IVT treated patients enrolled in a previous clinical trial were recalled to have a new ophthalmologic examination and optical coherence tomography (OCT) performed. Eyes found suitable for reinjection received 4 mg IVT. Complete clinical examination and OCT were repeated at 2 and 4 months post-injection. The changes were statistically analyzed using a paired t test and were compared to the results of the first injections. Results: Of all returning patients, 12 cases with complete records were considered candidates for reinjection. Visual acuity (VA) changes were not significant after the first and second interventions, although there was a relative improvement (0.14 logMAR) 2 months after the first injection. Reductions of central macular thickness (CMT) were 43±69 μm, and 40±69 μm after the first injection and 27±48 μm, 49±58 μm after the reinjection at 2 & 4 months, respectively. None of the mentioned changes was significant. After the second injection, however, intraocular pressure was elevated at both 2 & 4 months (3.6 & 2.4 mmHg respectively, P<0.05). Two months after the first administration, intraocular pressure was found to be raised significantly (5.58 mmHg, P=0.001). Conclusions: The transient beneficial effects of IVT on diabetic macular edema are not repeated with second injections. However, IVT-related ocular hypertension is more persistent after reinjection. Purpose: To evaluate the effect of intravitreal triamcinolone acetonide (IVT) reinjection on clinical and optical coherence tomographic features in refractory diabetic macular edema. Methods: In a prospective interventional case series, all IVT treated patients enrolled in a previous clinical trial were recalled to have a new ophthalmologic examination and optical coherence tomography (OCT) performed. Eyes found suitable for reinjection received 4 mg IVT. Complete clinical examination and OCT were repeated at 2 and 4 months post-injection. The changes were statistically analyzed using a paired t test and were compared to the results of the first injections. Results: Of all returning patients, 12 cases with complete records were considered candidates for reinjection. Visual acuity (VA) changes were not significant after the first and second interventions, although there was a relative improvement (0.14 logMAR) 2 months after the first injection. Reductions of central macular thickness (CMT) were 43±69 μm, and 40±69 μm after the first injection and 27±48 μm, 49±58 μm after the reinjection at 2 & 4 months, respectively. None of the mentioned changes was significant. After the second injection, however, intraocular pressure was elevated at both 2 & 4 months (3.6 & 2.4 mmHg respectively, P<0.05). Two months after the first administration, intraocular pressure was found to be raised significantly (5.58 mmHg, P=0.001). Conclusions: The transient beneficial effects of IVT on diabetic macular edema are not repeated with second injections. However, IVT-related ocular hypertension is more persistent after reinjection.

급성심근경색환자의 심근생존능 평가에 있어서 T1-201 재분포영상과 24시간 재주사영상의 역할

윤석남,배문선,박찬희,윤명호,최병일 ( Seok Nam Yoon,Moon Sun Pai,Chan H Park,Myung Ho Yoon,Byung Il William Choi ) 대한핵의학회 1998 핵의학 분자영상 Vol.32 No.4

Purpose: We evaluated the importance of redistribution and 24 hour reinjection images in Tl-201 SPECT assessment of myocardial viability after acute myocardial infarction (AMI). Materials and Methods: We performed dipyridamole stress-4 hour redistribution-24 hour reinjection Tl-201 SPECT in 43 patients with recent AMI (4-16 days). The myocardium was divided into 16 segments and perfusion grade was measured visually with 4 point score from 0 to 3 (absent uptake to normal uptake). A perfusion defect with stress score 2 was considered moderate. A defect was considered severe if the stress score was 0 or l (absent uptake or severe perfusion decrease). Moderate defect on stress image were considered viable and segments with severe defect were considered viable if they showed improvement of 1 score or more on redistribution or reinjection images. We compared the results of viability assess-ment in stress-redistribution and stress-reinjection images. Results: On visual analysis, 344 of 688 segments (50%) had abnormal perfusion. Fifty two (15%) had moderate perfusion defects and 292 (85%) had severe perfusion defects on stress image. Of 292 severe stress defects, 53 were irreversible on redistribution and reversible on reinjection images, and 15 were reversible on redistribution and irreversible on reinjection images. Two hundred twenty four of 292 segments (76.7%) showed concordant results on stress-redistribution and stress- reinjection images. Therefore 24 hour reinjection image changed viability status from necrotic to viable in 53 segments of 292 severe stress defect (18%). However, myocardial viability was underestimated in only 5% (15/292) of severe defects by 24 hour reinjection. Conclusion: The 24 hour reinjection imaging is useful in the assessment of rnyocardial viability. It is more sensitive than 4 hour redistribution imaging. However, both redistribution and reinjection images are needed since they complement each other. (Korean J Nucl Med 1998;32:325-31)

Reinjection of cooled water into sandstone geothermal reservoirs in China: a review

Yujuan Su,Fengtian Yang,Bing Wang,Zhi Jia,Zhongfeng Duan 한국지질과학협의회 2018 Geosciences Journal Vol.22 No.1

Low injectivity of sandstone geothermal reservoirs during reinjection of geothermal waste water is a problem generally encountered in China, and has become a main obstacle for sustainable development of the geothermal resources. Over the last few decades, researchers have made much efforts to solve it based on the studies of reinjection schemes, hydrogeology of the reservoirs, well completion, reinjection water disposal techniques, and water-rock interactions focused on precipitation/dissolution reactions during reinjection. These studies have been very helpful in improving the injectivity. However, there are still many problems remaining for further investigations, among which characterization of the complete process of water-rock interactions during reinjection with the change in redox conditions, CO2 partial pressure, non-isothermal transport process of the reinjection water, and the mechanism of release, transport and sedimentation of colloidal particles on reservoir permeability being taken into account are considered to be the most necessary. This paper gives a brief review of the history and state of the art of the research works on reinjection of cooled water into sandstone geothermal reservoirs, and outlooks the research demands in water-rock interactions during reinjection in the future.

탈륨 재주사영상법에서 휴식기재분포영상의 의의

김지열(Ji Yeul Kim),범희승(Hee Seung Bom),정명호(Myung Ho Jeong),강정채(Jung Chaee Kang),송호천(Ho Chun Song) 대한핵의학회 1993 핵의학 분자영상 Vol.27 No.2

N/A Apparent washout of T1-201 may occur between redistribution and reinjection images. To examine the frequency of it, we prospectively compared 4-hour redistribution and reinjection images in 63 consequent patients. Al1 patients underwent pharmacological stress test using 0.56 mg/kg dipyridamole. Immediately after the 4-hour redistribution images, 1mCi T1-201 was injected at rest, and images were reacquired 10 minutes after reinjection. The stress, redistribution, and reinjection images were then analyzed semiquantitatively (0=no uptake, l=faint uptake, 2=mildly diminished uptake, 3=normal uptake). Of the 100 abnormal myocardial regions on the stress images, 54 showed either complete or partial reversibility on 4-hour redistribution images. After reinjection 11(21, 2%) of these regions demonstrated apparent T1-201 washout due to low differential uptake of the tracer, Such lesions would appear irreversible if redistribution imaging is not performed before reinjection. Thus 4-hour redistribution imaging should be performed for assessment of myocardial ischemia and viability.

급성심근경색 환자에서 역재분포를 보인 심근의 Thallium 재주사에 의한 생존능의 평가

윤석남(Seok Nam Yoon),배문선(Moon Sun Pai),박찬희(Chan H Park) 대한핵의학회 1998 핵의학 분자영상 Vol.32 No.6

N/A Purpose: The aim of this study was to evaluate whether T1-201 reinjection distinguishes viable from non-viable myocardium in patients with reverse redistribution after acute myocardial infarction. Materials and Methods: We studied 42 patients with acute myocardial infarction (age, 55±12 years). Eighteen (43%) out of 42 showed reverse redistribution on dipyridamole stress-4 hour redistribution T1-201 single photon emission computed tomography (SPECT). T1-201 reinjection was performed at 24 hours. Reverse redistribution was defined as worsening of perfusion defect at 4 hour delayed scan. All patients underwent follow-up echocardiography in 4 months to assess regional wall motion improvement. T1-201 uptake on reinjection images were analyzed for the prediction of myocardial wall motion improvement. Results: Of 36 segments with reverse redistribution, 17 segments showed normal wall motion on echocardiography, while 19 segments showed all motion abnormalities. Of 19 the segments with reverse redistribution, 11 (58%) showed enhanced uptake after 24 hour reinjection. Myocardial wall motion was improved in 10 of 11 segments (90%) with enhanced uptake on reinjection. Wall motion improvement was not seen in 5 of 8 segments (63%) without enhanced thallium uptake. When myocardial viability was assessed by the uptake on reinjection image, nine of 10 segments (90%) with normal or mildly decreased uptake showed improved wall motion. Wall motion was not improved in 5 of 9 segments (56%) with severely decreased uptake. Conclusion: In patients with acute myocardial ifarction, T1-201 reinjection imaging on myocardial segments with reverse redistribution has a high positive predictive value in the assessment of myocardial viability

점성토 지반에 설치된 압력재주입 그라우팅 보강재의 인발특성

서중원(Seo, Jungwon),김나라(Kim, Nara),이봉직(Lee, Bongjik) 한국지반환경공학회 2012 한국지반환경공학회논문집 Vol.13 No.9

지반 및 사면보강을 위해 국내에서 널리 사용되고 있는 공법으로 앵커, 쏘일네일 및 마이크로파일공법 등을 들 수 있다. 상기 공법들은 공통적으로 보강재를 설치한 후 그라우팅을 실시하는 공정을 포함한다. 압력재주입 그라우팅은 그라우트체의 직경확대와 그라우트체 주면의 응력 증가 및 불규칙한 표면을 조성함으로써 지지력을 증대시킬 수 있다. 그러나 국내에서는 시공장비와 적용실적의 부족 및 보강효과의 검증이 어려워 널리 적용되지 못하고 있는 실정이다. 이에 본 연구에서는 점성토 지반을 대상으로 그라우팅 방법에 따른 보강효과를 평가하기 위하여 실내 모형실험을 실시하였다. 실험결과, 인발력은 압력재주입 그라우팅 방식이 중력식 그라우팅에 비해 최소 1.22배에서 최대 2.61배까지 크게 발휘되는 것으로 나타났다. Anchor, soil nail and micropile have been widely used for slope reinforcement and foundation. These all methods need grouting work after placing reinforcing member. The pressure injection-grouting techniques helps to increase the bearing capacity of reinforcing member by enhancing larger effective pile diameter and increasing the radial stresses acting on the grout body and causing irregular surface. However, the pressure reinjection-grouting techniques is not commonly used because grouting equipment and practical application example are short and the verification of reinforcing effect is difficult. In this study, the laboratory test was performed to evaluate the reinforcing effect with variation of grouting methods in clay. As a result of the test, the pressure reinjection-grouting techniques showed that the pullout capacity of reinforcing member increased up to 1.22~2.61 times comparing to the gravity fill techniques.

화강풍화토 지반에 설치된 압력재주입 그라우팅 보강재의 인발특성

심용진(Shim, Yong-Jin),이종규(Lee, Jong-Kyu),이봉직(Lee, Bong-Jik) 한국지반환경공학회 2012 한국지반환경공학회논문집 Vol.13 No.11

지반보강을 위해 국내에서 널리 사용되고 있는 공법으로 앵커공법, 소일네일 공법 및 소구경말뚝 공법 등을 들 수 있다. 상기 공법의 경우 보강재의 시공은 용도에 따라 구분되지만 공통적으로 보강재를 삽입한 후에 그라우팅 작업을 실시하는 공정이 포함되어 있다. 지금까지는 국내 대부분의 경우 중력식 그라우팅으로 시공되고 있지만 중력에 의해 그라우팅을 실시하기 때문에 천공 시 발생하는 지반이완영역에 대한 복원이 명확지 않아 보강재의 구조적 결함을 유발할 우려가 있다. 반면에 압력재주입 그라우팅은 먼저 그라우트를 채운 후 소정의 시간이 지나고 미리 설치한 튜브를 통하여 추가적으로 재주입하는 방식으로 기존의 그라우팅 방식에서 발생할 수 있는 문제를 상당부분 해결할 수 있어 그라우팅의 품질을 향상할 수 있다. 본 연구에서는 그라우팅 방식에 따른 인발특성을 평가하기 위하여 화강풍화토 지반을 대상으로 모형실험을 실시하였으며, 그라우팅방법에 따른 인발력 변화와 압력 재주입그라우팅의 재주입시기와 재주입압에 따른 보강재 지지력 증대 특성을 평가하고자 하였다. 연구결과 압력재주입식 그라우팅 이 중력식그라우팅에 비해 최소 1.1배에서 1.3배까지 인발력이 크게 발휘되는 것을 확인하였으며, 압력재주입식 그라우팅의 적정물시멘트비, 주입압력 및 재주입시기에 대한 고찰결과를 제시하였다. Most widely methods for reinforcement of soil utilized in Korea are anchor method, soil nail method and micro pile method. These methods are classified by the intended use of the structure to be constructed, but the reinforcement of the ground is accomplished contains in common the process of grouting work after inserting the reinforcements. Domestically, gravity grouting has been used mostly so far, but there has always been the risk of insufficient restoration of the loose ground area from the drill holes because the grouting is conducted only by gravity. On the other hand, pressure reinjection grouting may enhance the grouting quality by solving the problem of the existing grouting method considerably since it additionally reinjects grouting through pre-installed tube a certain time after the first grouting. Accordingly, this study evaluated the pullout characteristics by the grouting methods by performing model test on decomposed granite soil, and investigated the support increasing characteristics of reinforcements depending on the curing time, reinjection pressure, and uplift force variation of the pressure reinjection grouting. The result of this research shows that the pressure reinjection grouting demonstrated 1.1~1.3 times of performance of the gravity grouting, and suggests some analysis on optimal water content, reinjection pressure and curing time of the pressure reinjection grouting.

급성심근경색환자의 심근생존능 평가에 있어서 24시간 재주사영상의 유용성과 제한성

윤석남,박찬희,신준한,윤명호,황경훈 대한순환기학회 2001 Korean Circulation Journal Vol.31 No.1

그라우팅방법에 따른 점토지반의 보강효과

서중원(Jung-Won Seo),이봉직(Bong-Jik Lee),이종규(Jong-Kyu Lee),김나라(Na-Ra Kim) 한국지반환경공학회 2011 한국지반환경공학회 학술발표회논문집 Vol.2011 No.9