파킨슨씨병 환자에서 편측 담창구파괴술의 효과

조우진,이경진,지철,박성찬,박해관,조정기,조경근,나형균,강준기,최창락,Cho, Woo Jin,Lee, Kyung Jin,Ji, Cheul,Park, Sung Chan,Park, Hea Kwan,Jo, Jung Ki,Cho, Kyung Keun,Rha, Hyung Kyun,Kang, Joon Ki,Choi, Chang Rak 대한신경외과학회 2001 Journal of Korean neurosurgical society Vol.30 No.8

Objectives : For Parkinsonian patients who had not reacted favorably on drug therapy are good candidate for ventroposterolateral pallidotomy, although not curative. We studied these patients after unilateral pallidotomy, to confirm the effectiveness and safety of this procedure. Methods : We evaluated the 17 patients with idiopathic Parkinson's diesease who had undergone unilateral posteroventral pallidotomy. All patients responded to levodopa initially. Mean age was 55 years(38-75years), and mean duration of disease was 9.8 years(3-20years). Pre-and postoperative evaluation at 3 month intervals included Unified Parkinson's Disease Rating scale(UPDRS) scoring, Hoehn and Yahr(H & Y) staging, and neuropsychological examinations. Results : Pallidotomy significantly improved parkinsonian symptom(tremor, rigidity, bradykinesia, dyskinesia, sensory symptom). Nine of 10 patients who showed dyskinesia preoperatively significant improvement. The mean dose of levodopa in 9 patients was lowered. The mean H & Y score and UPDRS score were improved in on and/or off time in 15 patients. Among patients who were not improved, one patient worsened, and the others showed no change. The mean overall UPDRS off score changed from 76 preoperatively to 44(33%) at 6 months and from 70 to 52(25%) at 1 year. Transient surgical morbidity was showen in four patients and included dysarthria, hypotonia and confusion. Conclusion : We conclude that pallidotomy is safe and effective in patients who have levodopa-reponsive parkinsonism with severe symptom fluctuation. Unilateral pallidotomy also considered helpful to ipsilateral symptom. Unilateral pallidotomy can improve all of parkinsonian's symptom and allow to reduce the levodopa medication. Most of patients show satisfactory results.

가정 부문에서의 에너지 소비 실측과 절약 행위에 따른 전기에너지 절감 효과 분석

최창락(Chang Rak, Choi),이영준(Young Jun, Lee),이중호(Jung Ho, Lee),김준혁(Jun Hyeok, Kim),윤종호(Jong Ho, Yoon) 한국생태환경건축학회 2019 한국생태환경건축학회 학술발표대회 논문집 Vol.19 No.2

중성자 보안검색 장치를 위한 신경망 기반의 γ-스펙트럼 분류 방법

최창락(Chang-Rak Choi),김지수(Ji-Soo Kim),김수형(Soo-Hyung Kim),심철무(Cheul-Muu Sim) 한국정보과학회 2007 한국정보과학회 학술발표논문집 Vol.34 No.2C

본 논문은 한국 원자력 연구소 중성자 스펙트럼 패턴을 분류하는 시스템에 신경망(Neural Networks)을 적용하였다. 중성자 스펙트럼 분석시 3개의 신경망을 하나로 결합하여 각 신경망의 인식률을 확인하였다. 신경망1은 폭발물 판별을, 신경망2는 폭발물의 종류를, 신경망3은 비 폭발물 종류를 구별하도록 시스템을 설계하였다. 중성자 스펙트럼을 통해 실험한 결과 신경망1은 83.48%를, 신경망2는 84.6%를, 신경망3은 91.67%의 인식률을 얻어 본 논문에서 제안한 시스템의 우수성을 입증하였다.

중성자 보안검색 장치를 위한 신경망 분류기 비교 연구

최창락 ( Chang-rak Choi ),김지수 ( Ji-soo Kim ),김수형 ( Soo-hyung Kim ),심철무 ( Cheul-muu Sim ) 한국정보처리학회 2007 한국정보처리학회 학술대회논문집 Vol.14 No.2

현재 우리나라는 원자력 발전에 대한 의존도가 매우 높고 그 기술 또한 우수하다. 그러나 중성자 스펙트럼을 사용하여 폭발물 탐지를 위한 시스템 개발 기술은 미흡한 실정이다. 본 논문은 신경망(Neural Networks)을 한국 원자력 연구소 중성자 스펙트럼 패턴을 분류하는 시스템에 적용하였다. 데이터 획득 방법을 달리하여 두 개의 신경망을 구현하였고 그 결과를 분석하여 보았다. 먼저 폭발물에 다량 포함되어 있는 C(Carbon), N(Nitrogen), O(Oxygen) 3개의 물질을 중심으로 중성자 스펙트럼을 분석하였다. 다른 하나는 중성자 스펙트럼을 전체 영역으로 획득한 데이터를 바탕으로 신경망을 구현하여 인식률을 확인하였다. 실험결과 전자의 경우 62.5%의 인식률을, 후자의 경우 신경망은 83.48%의 인식률을 나타내었다.

구리배플을 이용한 수소액화기의 Cold-Box 단열성능에 관한 실험적 연구

김태현(Tae Hyun Kim),최창락(Chang Rak Choi),이정민(Jung Min Lee),한동원(DongWon Han),김서영(Seo Young Kim) 대한설비공학회 2021 대한설비공학회 학술발표대회논문집 Vol.2021 No.6

실험관 및 생체내에서 U-87 교모세포종 세포주의 광역학 치료 효과에 대한 연구

조우진,조경근,지철,박성찬,박해관,강준기,최창락,Cho, Woo Jin,Cho, Kyung-Keun,Ji, Cheol,Park, Sung Chan,Park, Hea Kwan,Kang, Joon Ki,Choi, Chang Rak 대한신경외과학회 2001 Journal of Korean neurosurgical society Vol.30 No.5

Objective : The objective of this study was to determine the photodynamic therapeutic response of U-87 human glioma cell in vitro as well as in the nude rat xenograft model using photofrin as photosensitizer. Material and Method : U-87 cells were cultured on 96-well culture plates, photofrin(Quadralogic Technologies Inc., Vancouver, Canada) was added into the cell culture medium at concentration of $1{\mu}g/ml$, $2.5{\mu}g/ml$, $5{\mu}g/ml$, $10{\mu}g/ml$ and $20{\mu}g/ml$. 24 hour after drug treatment, cells were treated with optical(632nm) irradiation of $100mJ/cm^2$, $200mJ/cm^2$ and $400mJ/cm^2$. Photofrin(12.5mg/kg, i.p.) was administered to 28 nude rats containing intracerebral U-87 human glioma as well as 26 normal nude rats. 48 hours after administration, animals were treated with optical irradiation(632nm) of $35J/cm^2$, $140J/cm^2$ and $280J/cm^2$ to exposed tumor and normal brain. The photofrin concentration was measured in tumor and normal brain in a separate population of animals. Results : By MTT assay, there was 100% cytotoxicity at any dose of photofrin with optical irradiation of $200mJ/cm^2$ and $400mJ/cm^2$. But at the optical irradiation of $100mJ/cm^2$ cells were killed in dose dependent manner 28.5%, 49.1%, 54.4%, 78.2%, and 84.6% at concentration of $1{\mu}g/ml$, $2.5{\mu}g/ml$, $5{\mu}g/ml$, $10{\mu}g/ml$ and $20{\mu}g/ml$, respectively. Dose dependent PDT lesions in both tumor and normal brain were observed. In the tumor lesion, only superficial tissue damage was found with optical irradiation of $35J/cm^2$. However, in the optical irradiation group of $140J/cm^2$ and $280J/cm^2$ the volume of lesions was measured of $7.2mm^3$ and $14.0mm^3$ for treatment at $140J/cm^2$ and $280J/cm^2$, respectively. The U-87 bearing rats showed a photofrin concentration in tumor tissue of $6.53{\pm}2.16{\mu}g/g$, 23 times higher than that found in the contralateral hemisphere of $0.28{\pm}0.15{\mu}g/g$. Conclusion : Our data indicate that the U-87 human glioma in vitro and in the xenografted rats is responsive to PDT. At these doses, a reproducible injury can be delivered to human glioma in this model. Strategies to spare the normal brain collateral damage are being studied.

파킨슨환자의 자기공명영상과 미세전극기록을 이용한 담창구 파괴술

이경진,손형선,박성찬,조경근,박해관,최창락,Lee, Kyung Jin,Son, Hyung Sun,Park, Sung Chan,Cho, Kyung Keun,Park, Hae Kwan,Choi, Chang Rak 대한신경외과학회 2001 Journal of Korean neurosurgical society Vol.30 No.1

Objective : The exact position of the lesion during the pallidotomy is critical to obtain the clinical improvement of parkinson's disease without damage to surrounding structure. Ventriculogrphy, CT(computed tomograpy) or MRI(magnetic resonance imaging) have been used to determine the initial coordinates of stereotactic target for pallidotomy. The goal of this study was to determine whether microelectrode recording significantly improves the neurophysiologic localization of the target obtained from MRI. Methods : Twenty patients were studied. They underwent a unilateral pallidotomy. Leksell frame was applied and T1 axial images parallel to the AC-PC(anterior commissure-posterior commissure) plane using a 1.5 Tesla MRI with 3mm slice thickness were obtained. Anteroposterior coordinate of target was chosen at 2mm in front of the midcommissural point and lateral coordinate between 19 and 22mm from the midline. The vertical coordinate was calculated on coronal slice using a fast spin echo inversion recovery sequence(FSEIR) related to the position of the choroidal fissure and ranged over 4-5mm below the AC-PC plane. Confirmation of the anatomical target was done on axial slices using the same FSEIR sequence . Microrecording was done at the pallidum contralateral to the symptomatic side using an electrode with a tip diameter of $1{{\mu}m}$ diameter tip and 1.1-1.4 mOhm impedance at 1000Hz. Electrophysiologic localization of the target was also confirmed intraoperatively by macrostimulation. Results : Microrecording techniques were reliable to define the transition from the base of the pallidum which was characterized by the disappearance of spike activity and by the change of the audible background activity. Signals from high amplitude neurons firing at 200-400Hz were recorded in the pallidal base. X, Y and Z coordinates of target obtained from the MRI were within 1mm from the X, Y, Z coordinates obtained with microrecording in 16 patients (80%), 15 patients(75%), 10 patients(50%) respectively. The difference of Y coordinate between on MRI and on microrecording was 4mm in only one patient. Conclusion : The MRI was accurate to localize the target within 1mm of the error from microrecording target in 70% of the patients. 4mm discrepancy was observed only once. We conclude that MRI alone can be used to determine the target for pallidotomy in most patients. However, microrecording technique can still be extremely valuable in patents with aberrant anatomy or unusual MRI coordinates. We also consider physiologic confirmation of the target using macrostimulation to be mandatory in all cases.

경막하 수종으로 오인된 중두개와 지주막 낭종을 동반한 대뇌궁륭부 지주막 낭종 - 증 례 보 고 -

김성림,박해관,박성찬,나형균,강준기,최창락,Kim, Seong-Rim,Park, Hae Kwan,Park, Sung Chan,Rha, Hyung Kyun,Kang, Joon Ki,Choi, Chang Rak 대한신경외과학회 2001 Journal of Korean neurosurgical society Vol.30 No.2

Arachnoid cysts are defined as duplicated arachnoids and their splitting with congenital, intra-arachnoid, and leptomeningeal malformations. They are most commonly located in the middle cranial fossa followed by suprasellar and quadrigeminal cisterns, posterior fossa, and very rare in cerebral convexities. They are often ruptured by trauma or spontaneously and cause subdural hygroma or subdural hematoma. Authors report a case of a 32-year-old woman with a convexity arachnoid cyst mimicking subdural hygroma associated with a separate middle fossa arachnoid cyst. Preoperatively, the convexity arachnoid cyst was misinterpreted as subdural hygroma resulted from a ruptured middle fossa cyst. The patient underwent craniotomy and cyst fenestration into the basal cistern. Two separate arachnoid cysts were found in the cerebral convexity and middle cranial fossa during the operation. Finally, cysts were resolved and she was discharged without any complication.

신경외과 영역에서의 미세혈관 문합술

나형균,이경진,조경근,박성찬,박해관,조정기,지철,최창락,Rha, Hyoung-Kyun,Lee, Kyung-Jin,Cho, Kyung-Keun,Park, Sung-Chan,Park, Hae-Kwan,Cho, Jung-Ki,Ji, Chul,Choi, Chang-Rak 대한미세수술학회 1999 Archives of reconstructive microsurgery Vol.8 No.2

Objective : Extracranial-intracranial(EC-IC) microvascular anastomosis was performed in 18 patients with hemodynamic cerebral ischemia and traumatic cerebral aneurysm, the aim of this retrospective study was to assess its value in neurosurgical field. Method : Of 18 cases, 17 case were hemodynamic cerebral ischemia and one was traumatic cerebral aneurysm. There were 14 superficial temporal artery(STA)-to-middle cerebral artery(MCA) anastomosis, 3 saphenous vein graft bypass(2 external carotid artery(ECA)-to-MCA, 1main trunk of the STA-to-MCA) and 1 radial artery bypass(ECA-to-MCA). Results : Bypass patency was confirmed by postoperative angiography in all cases except for two cases, postoperative cerebral blood flow of ischemic brain showed significant increased in all cases with good patency through bypass. Conclusion : Revascularization by EC-IC microvascular anastomosis to the ischemic brain eliminated ischemia and was associated with excellent good outcome and good patency rates.

국소재발된 두경부종양의 무고정틀 정위적 분할방사선치료

김인아(In Ah Kim),최일봉(Ihl Bhong Choi),장지영(Ji Young Jang),강기문(Ki Mun Kang),조승호(Seung Ho Jho),김형태(Hyung Tae Kim),이경진(Kyung Jin Lee),최창락(Chang Rak Choi) 대한두경부종양학회 1998 대한두경부 종양학회지 Vol.14 No.2

Background & Objectives: Frameless fractionated stereotactic radiotherapy(FFSRT) is a modification of stereotactic radiosurgery(SRS) with radiobiologic advantage of fractionation without losing mechanical accuracy of SRS. Local recurrence of head and neck cancer at or near skull base benefit from reirradiation. Main barrier to successful palliation is dose limitation secondary to normal tissue tolerance. We try to evaluate the efficacy and safety of FFSRT as a new modality of reirradaton in these challenging patients. Materials & Methods: Seven patients with recurrent head & neck cancer involving at or near skull base received FFSRT from September 1995 to November 1997. Six patients with nasopharyngeal cancer had received induction chemotherapy and curative radiation therapy. One patient with maxillary sinus cancer had received total maxillectomy and postoperative radiation therapy as a initial treatment. Follow-up ranged from 11 to 32 months with median of 24 months. Three of 7 patients received hyperfractionated radiation therapy(1.1-1.2Gy/fraction, bid, total 19.8-24Gy) just before FFSRT. All patients received FFSRT(3-5Gy/fraction, total 15-30Gy/5-10fractions). Chemotherapy(cis-platin 100mg/m(2)) were given concurrently with FFSRT in four patients. Second course of FFSRT were given in 4 patients with progression or recurrence after initial FFSRT. Because IF(irregularity factor; ratio of surface area of target to the surface area of sphere with same volume as a target) is too big to use conventional stereotactic RT using multiple arc method for protection of radiation damage to critical normal tissue, all patients received FFSRT with conformal method using irregular static ports. Results: Five of 7 patients showed complete remission in follow-up CT &/or MRI. Three of these five patients who developed marginal, in-field, and out-field recurrences, respectively. Another one of complete responders has been dead of G-I bleeding without evidence of local recurrence. One partial responder who showed progressive disease 15 months after initial FFSRT has received additional FFSRT, and then he is well-being with symptomatic improvement. One minmal responder who showed progression of locoregional disease 9 months after 1st FFSRT has received 2nd FFSRT, and then he is alive with stable disease. Five of 7 case had showed direct invasion to skull base and had complaint headache and various symptoms of cranial nerve involvement. Four of these five case showed improvement of neurologic symptoms after FFSRT. No significant neurologic complicaltion related to FFSRT was observed during follow-up periods. Tumor volumes were ranged from 3.9 to 50.7 cc and surface area ranged from 16.1 to 114.9cm(2). IF ranged from 1.21 to 1.74. The average ratio of volume of prescription isodose shell to target volume was 1.02 that indicated the improvement of target coverage and dose distribution with FFSRT with conformal method compared to target coverage with FFSRT with multiple arc method. Conclusion: Our initial experience suggests that FFSRT with conformal method was relatively effective and safe modality in the treatment of recurrent head and neck cancer involving at or near skull base. Treatment benefit included good palliation of symptoms and reasonable radiographic response. However, more experience and additional follow-up are needed to better assess its ultimate role in treating these challenging patients.