• Proceedings of the Korean Information Science Society Conference
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• 1998.10c
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• pp.612-614
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• 1998

뇌정위 수술(Stereotactic Surgery)은 컴퓨터 단층영상과 자기공명 영상 같은 3차원 영상을 이용하여 뇌병변의 위치를 입체적으로 정확히 파악하여 정상 뇌에 대한 손상을 최소화하며 병변을 수술하는 기법이다. 본 논문에서는 수술 받을 환자의 컴퓨터 단층영상과 자기공명 영상 등 다양한 종류의 3차원 볼륨 데이터를 전처리한 다음 동일한 3차원 공간 내에서 정렬시켜 선택적 또는 동시적으로 3차원 영상을 가시화 하는 기법을 제안한다. 또한 3차원 영상에서 뇌정위 수술의 삽입점과 목표점을 지정할 수 있는 기능을 지원하며 수술 경로에 따른 가상 수술의 시뮬레이션을 통하여 수술 경로의 안전성을 검증할 수 있게 하였다.

• Progress in Medical Physics
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• v.15 no.4
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• pp.197-201
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• 2004

Stereotactic brain biopsy using stereotactic head frame such as CRW (Radionics, USA) has demonstrated a precise lesion localizing accuracy. In this study, we developed the target point calculation program for brain lesion biopsy using CRW stereotactic head frame and designed a phantom for verify the new developed program. The phantom was designed to have capability to simulate clinical stereotactic brain biopsy. The phantom has 10 vertical rods whose diameters are 6mm and tip of each rods are 2mm. Each rod has different length, 150 mm x 4 ea, 130 mm x 4 ea, 110 mm x 2 ea. CT images were acquired with Simens CT scanner as continuous transverse slice, 1 mm thickness in a 25 cm field of view and stored in a dicom file as a 256 x 256 matrix. As a result, the developed new target localization program will be useful for planning and training in complicated 3 dimensional stereotactic brain biopsy.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.3
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• pp.192-200
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• 2008

To evaluate the hemodynamic changes and the predictive factors of the clinical outcome in pediatric patients with moyamoya disease, we analyzed pre/post basal/acetazolamide stress brain perfusion SPECT with automated volume of interest (VOIs) method. Methods: Total fifty six (M:F = 33:24, age $6.7{\pm}3.2$ years) pediatric patients with moyamoya disease, who underwent basal/acetazolamide stress brain perfusion SPECT within 6 before and after revascularization surgery (encephalo-duro-arterio-synangiosis (EDAS) with frontal encephalo-galeo-synangiosis (EGS) and EDAS only followed on contralateral hemisphere), and followed-up more than 6 months after post-operative SPECT, were included. A mean follow-up period after post-operative SPECT was $33{\pm}21$ months. Each patient's SPECT image was spatially normalized to Korean template with the SPM2. For the regional count normalization, the count of pons was used as a reference region. The basal/acetazolamide-stressed cerebral blood flow (CBF), the cerebral vascular reserve index (CVRI), and the extent of area with significantly decreased basal/acetazolamide- stressed rCBF than age-matched normal control were evaluated on both medial frontal, frontal, parietal, occipital lobes, and whole brain in each patient's images. The post-operative clinical outcome was assigned as good, poor according to the presence of transient ischemic attacks and/or fixed neurological deficits by pediatric neurosurgeon. Results: In a paired t-test, basal/acetazolamide-stressed rCBF and the CVRI were significantly improved after revascularization (p<0.05). The significant difference in the pre-operative basal/acetazolamide-stressed rCBF and the CVRI between the hemispheres where EDAS with frontal EGS was performed and their contralateral counterparts where EDAS only was done disappeared after operation (p<0.05). In an independent student t-test, the pre-operative basal rCBF in the medial frontal gyrus, the post-operative CVRI in the frontal lobe and the parietal lobe of the hemispheres with EDAS and frontal EGS, the post-operative CVRI, and ${\Delta}CVRI$ showed a significant difference between patients with a good and poor clinical outcome (p<0.05). In a multivariate logistic regression analysis, the ${\Delta}CVRI$ and the post-operative CVRI of medial frontal gyrus on the hemispheres where EDAS with frontal EGS was performed were the significant predictive factors for the clinical outcome (p =0.002, p =0.015), Conclusion: With probabilistic map, we could objectively evaluate pre/post-operative hemodynamic changes of pediatric patients with moyamoya disease. Specifically the post-operative CVRI and the post-operative CVRI of medial frontal gyrus where EDAS with frontal EGS was done were the significant predictive factors for further clinical outcomes.

• Journal of Yeungnam Medical Science
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• v.11 no.2
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• pp.202-212
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• 1994

뇌헐혈증은 다양한 요인으로 유발될 수 있겠으나 궁극적으로는 국소적 뇌혈류량이 적정수준 이하로 감소됨으로 해서 초래된다. 이렇게 뇌혈류가 감소된 부위의 중심에는 이미 괴사가 일어난 부위도 있겠지만, 그 주위에 현재 뇌기능은 없으나 장차 혈류가 충분해 지면 소생 가능한 penumbra 영역이 있다. 이런 penumbra영역으로 다시 혈류가 충분히 보충되면 뇌기능이 소생되어 호전의 양상을 보이게 되나, 혈류가 계속 저하되어 있으면 비가역적 뇌손상을 받게 되어 증상이 악환된다. 병변 부위는 자율조절기능(autoregulation)이 파괴되어 혈관이 이완된 상태이기 때문에 측부혈행을 통하여 뇌혈류를 공급시키기기 위해서 혈압을 올리면서 혈액유동을 원활하게 해주는 보존적인 방법을 시행하면서 적응증이 되는 경우에는 수술적으로 외내경동맥문합술과 같은 여러 방법의 bypass혈관 수술이나 경동맥내막절제술로 뇌허혈 부위에 뇌혈류를 적극적으로 증강시켜 호전시킬 수 있다.

• The Korean Journal of Nuclear Medicine
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• v.33 no.4
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• pp.352-361
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• 1999

Purpose: Carotid endarterectomy nay benefit patients with bilateral carotid stenosis by improving cerebro-vascular hemodynamics of ipsilateral as well as contralateral cerebral hemispheres. We investigated cerebro-vascular hemodynamics after carotid endarterectomy in patients with contralateral carotid occlusion by acetazolamide stress brain SPECT. Materials and Methods: Subjects were 14 symptomatic patients (all men, mean age 66 yrs) with carotid stenosis (>50%) with contralateral carotid occlusion. Acetazolamide stress Tc-99m ECD brain SPECTs were performed within 2 weeks before and after carotid endarterectomy using one day protocol. Cerebral blood flow (CBF) and cerebrovascular reserve (CVR) were assessed visually. In 12 patients, correlation between the patency of proximal anterior cerebral or anterior communicating arteries (A1/A-comm) and the improvement of CBF or CVR after endarterectomy was assessed. Results: Preoperative SPECT showed reduced CBF in 2 ipsilateral and 10 contralateral hemispheres. CVR was reduced in 4 ipsilateral and 9 contralateral hemispheres. Of 12 hemispheres with reduced CBF, 2 hemispheres (16.7%) showed improvement of CBF after endarterectomy. However, reduced CVR was improved in all 4 ipsilateral and 7 of 9 (78%) of contralateral hemispheres after endarterectomy. Three of4 with stenotic Al/A-comm and 4 of 8 with patent A1/A-comm had reduced contralateral CVR. Reduced contralateral CVR improved in all 3 patients with stenotic A1/A-comm and 3 of 4 with patent A1/A-comm. Conclusion: Acetazolamide stress brain SPECT demonstrated improvement of compromised cerebrovascular reserve in not only ipsilateral but also contralateral hemispheres of patients with contralateral carotid occlusion after carotid endarterectomy, and may, therefore, be useful for evaluating cerebral blood flow and cerebrovascular reserve after carotid endarterectomy.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.1
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• pp.8-16
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• 2008

Purpose: To assess the effect of extracranial-intracranial (EC-IC) bypass surgery on hemodynamic improvement, we evaluated serial regional cerebral hemodynamic change of the middle cerebral artery (MCA) in symptomatic patients with atherosclerotic occlusion of the internal carotid artery (ICA) or MCA using $^{99m}Tc$-ECD acetazolamide stress brain perfusion SPECT (Acetazolamide SPECT). Materials and Methods: The patients who had suffered a recent stroke with atherosclerotic ICA or MCA occlusion underwent EC-IC bypass surgery and Acetazolamide SPECT at 1 week before and three to six months after surgery. For image analysis, attenuation corrected images were spatially normalized to SPECT templates with SPM2. Anatomical automated labeling was applied to calculate mean counts of each Volume-Of-Interest (VOI). Seven VOIs of bilateral frontal, parietal, temporal regions of the MCA territory and the ipsilateral cerebellum were defined. Using mean counts of 7 VOIs, cerebral perfusion index and perfusion reserve index were calculated. Results: Seventeen patients (M:F =12:5, mean age $53{\pm}2yr$) were finally included in the analysis. The cerebral blood flow of the parietal region increased at 1 week (p = 0.003) and decreased to the preoperative level at 3-6 months (p = 0.003). The cerebrovascular reserve of the frontal and parietal regions increased significantly at 1 week after surgery (p<0.01) and improved further at 3-6 months. Conclusion: Cerebrovascular reserve of the MCA territory was significantly improved at early postoperative period after EC-IC bypass and kept improved state during long-term follow-up, although cerebral blood flow did not significantly improved. Therefore, cerebrovascular reserve may be a good indicator of postoperative hemodynamic improvement resulted from bypass effect.

• Journal of Chest Surgery
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• v.34 no.6
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• pp.465-471
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• 2001

Background: Hypothermia protects the brain by suppressing the cerebral metabolism and it is performed well enough before the total circulatory arrest(TCA) in the operation of aortic disease. Generally, TCA has been performed depending on the rectal or nasopharyngeal temperatures; however, there is no definite range of optimal temperature for TCA or an objective indicator determining the temperature for safe TCA. In this study, we tried to determine the optimal range of temperature for safe hypothermic circulatory arrest by using the intraoperative electroencephalogram(EEG), and studied the role of EEG as an indicator of optimal hypothermia. Material and Method: Between March, 1999 and August 31, 2000, 27 patients underwent graft replacement of the part of thoracic aorta using hypothermia and TCA with intraoperative EEG. The rectal and nasopharyngeal temperatures were monitored continuously from the time of anesthetic induction and the EEG was recorded with a ten-channel portable electroencephalography from the time of anesthetic induction to electrocerebral silence(ECS). Result: On ECS, the rectal and nasopharyngeal temperatures were not consistent but variable(rectal 11$^{\circ}C$ -$25^{\circ}C$, nasopharynx 7.7$^{\circ}C$ -23$^{\circ}C$). The correlation between two temperatures was not significant(p=0.171). The cooling time from the start of cardiopulmonary bypass to ECS was also variable(25-127min), but correlated with the body surface area(p=0.027). Conclusion: We have found that ECS appeared at various body temperatures, and thus, the use of rectal or nasopharyngeal temperature were not useful in identifying ECS. Conclusively, we can not fully assure cerebral protection during hypothermic circulatory arrest in regards to the body temperatures, and therefore, the intraoperative EEG is one of the necessary methods for determining the range of optimal hypothermia for safe circulatory arrest. :

• Journal of Chest Surgery
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• v.39 no.6 s.263
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• pp.440-448
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• 2006

Background: Surgery of descending thoracic or thoracoabdominal aorta has the potential risk of causing neurological injury including spinal cord damage. This study was designed to find out the risk factors leading to spinal cord and brain damage after surgery of descending thoracic and thoracoabdominal aorta. Material and Method: Between October 1995 and July 2005, thirty three patients with descending thoracic or thoracoabdominal aortic disease underwent resection and graft replacement of the involved aortic segments. We reviewed these patients retrospectively. There were 23 descending thoracic aortic diseases and 10 thoracoabdominal aortic diseases. As an etiology, there were 23 aortic dissections and 10 aortic aneurysms. Preoperative and perioperative variables were analyzed univariately and multivariately to identify risk factors of neurological injury. Result: Paraplegia occurred in 2 (6.1%) patients and permanent in one. There were 7 brain damages (21%), among them, 4 were permanent damages. As risk factors of spinal cord damage, Crawford type II III(p=0.011) and intercostal artery anastomosis (p=0.040) were statistically significant. Cardiopulmonary bypass time more than 200 minutes (p=0.023), left atrial vent catheter insertion (p=0.005) were statistically significant as risk factors of brain damage. Left heart partial bypass (LHPB) was statistically significant as a protecting factor of brain (p=0.032). Conclusion: The incidence of brain damage was higher than that of spinal cord damage after surgery of descending thoracic and thoracoabdominal aorta. There was no brain damage in LHPB group. LHPB was advantageous in protecting brain from postoperative brain injury. Adjunctive procedures to protect spinal cord is needed and vigilant attention should be paid in patients with Crawford type II III and patients who have patent intercostal arteries.

• Journal of Chest Surgery
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• v.38 no.7 s.252
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• pp.489-495
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• 2005

In the surgical treatment of aortic dissection, aortic arch replacement under total circulatory arrest is often performed after careful inspection to determine the severity of disease progression. Under circulatory arrest, antegrade or retrograde cerebral perfusion is required for brain protection. Recently, antegrade cerebral perfusion has been used more, because of the limitation of retrograde cerebral perfusion. This study is to compare these two methods especially in the respect to neurological complications. Material and Method: Forty patients with aortic dissection involving aortic arch from May 2000 to May 2004 were enrolled in this study, and the methods of operation, clinical recovery, and neurological complications were retrospectively reviewed. Result: In the ACP (antegrade cerebral perfusion) group, axillary artery cannulation was performed in 10 out of 15 cases. In the RCP (retrograde cerebral perfusion) group, femoral artery Cannulation was performed in 24 out of 25 cases. The average esophageal and rectal temperature under total circulatory arrest was $17.2^{\circ}C\;and\;22.8^{\circ}C$ in the group A, and $16.0^{\circ}C\;and\;19.7^{\circ}C$ in the group B, respectively. Higher temperature in the ACP group may have brought the shorter operation and cardiopulmonary bypass time. However, the length of period for postoperative clinical recovery and admission duration did not show any statistically significant differences. Eleven out of the total 15 cases in the ACP group and thirteen out of the total 25 cases in the RCP group showed neurological complication but did not show statistically significant difference. In each group, there were 5 cases with permanent neurological complications. All 5 cases in the ACP group showed some improvements that enabled routine exercise. However all 5 cases in RCP group did not show significant improvements. Conclusion: The Antegrade, cerebral perfusion, which maintains orthordromic circulation, brings moderate degree of hypothermia and, therefore, shortens the operation time and cardiopulmonary bypass time. We concluded that Antegrade cerebral perfusion is safe and can be used widely under total circulatory arrest.

• Journal of Chest Surgery
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• v.32 no.12
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• pp.1087-1092
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• 1999

배경 :경동맥 내막 절제술의 목적은 뇌졸중 예방에 있다. 경동맥 내막 절제술시 경동맥 혈류를 차단하였을 때 뇌허혈 상태를 초래하는지 가 가장 중요한 문제이다. 경동맥 혈류 역류압은 뇌내 측부혈류 상태를 반영하므로 경동맥 혈류 차단시 역류압과 뇌파검사 소견에 딸라 shunt 삽입여부 기준을 알아보려고 하였다 대상 및 방법 : 1996년 2월부터 1999년 3월까지 경동맥 내막 절제술을 시행받은 16명을 대상으로 하였다 남자가 14명있고 여자가 2명이었으며 평균연령은 66.35$\pm$6.53이었다 수술부위 경동맥 협착은 평균 73.8$\pm$12.33%였고 반대측 경동맥 협착은 평균 60.99$\pm$23.03%였다. 수술중 모든 환자에서 뇌파감시를 하였으며 경동맥 혈류압을 측정하여 40 mmHg 이하이거나 수술반대측 경동맥 완전폐색이 있는 경우 shunt를 삽입하였다 결과 : 술후 1례에서 사망이 있었는데 이 환자는 전, 중 뇌내동맥 영역에 큰 뇌경색이 있으며 동측에 심한 경동맥 협착이 있고 의식은 기면 상태여서 바로 응급수술을 하였다 수술시경동맥 혈류 역류압은 35mmHg 여서 shunt를 사용하였다 술후 1일째 의식이 혼수상태로 나빠져 뇌 단층촬영한 결과 뇌경색 부위에 출혈이 발생하여 사망하였다. 수술 직후 모든 환자에서 뇌허혈에 따른 합병증 및 사망은 없었고 1례에서 수술후 1일째 수술부위 반대편에 적은 뇌경색이 발생하였다 평균 21.5$\pm$11.85개우러의 외래 추적 검사에서 뇌졸중 재발이 없었다. 결론 : 뇌졸중이환후 경동맥 내막 절제술은 최소 4-6주 이상 안정화 시킨 다음 수술하는 것이 좋다고 생각된다 경동맥 내막 절제술은 뇌졸중 예방에 효과적인 치료방법이며 경동맥 혈류역류압이 40mmHg 이하일 경우 shunt를 설치하여 수술하는 것이 안전하다고 사료된다.