• Journal of Chest Surgery
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• 제50권6호
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• pp.448-452
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• 2017

Background: Proper monitoring of cerebral perfusion during carotid artery surgery is crucial for determining if a shunt is needed. We compared the safety and reliability of near-infrared spectroscopy (NIRS) w ith transcranial Doppler (TCD) for cerebral monitoring. Methods: This single-center, retrospective review was conducted on patients who underwent carotid endarterectomy (CEA) using selective shunt-based TCD or NIRS at Daegu Catholic University Medical Center from November 2009 to June 2016. Postoperative complications were the primary outcome, and the distribution of risk factors between the 2 groups was compared. Results: The medical records of 74 patients (45 TCD, 29 NIRS) were reviewed. The demographic characteristics were similar between the 2 groups. One TCD patient died within the 30-day postoperative period. Postoperative stroke (n=4, p=0.15) and neurologic complications (n=10, p=0.005) were only reported in the TCD group. Shunt usage was 44.4% and 10.3% in the TCD and NIRS groups, respectively (p=0.002). Conclusion: NIRS-based selective shunting during CEA seems to be safe and reliable for monitoring cerebral perfusion in terms of postoperative stroke and neurologic symptoms. It also reduces unnecessary shunt usage.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 춘계학술대회
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• pp.279-282
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• 1996

Sequential brain SPECT imaging has been used to assess the cerebral perfusion reserve(CPR) in cerebrovascular diseases(CVD). We have realized a parametric images of CPR using normalized difference ratio and deadtime correction. For the anatomical localization of CPR, the parametric images were registered to the contours of the cerebral regions using optimal threshold method. The parametric imags reflected the CPR more reliably and distinctively. We conclude that the qunatitative estimation of CPR using normalized difference ratio image could be useful for the diagnosis and assessment of postoperative prognosis in CVD.

• Korean Journal of Radiology
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• 제22권3호
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• pp.395-404
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• 2021

Objective: To compare the utility of computed tomography perfusion (CTP) and three different 4-point scoring systems in computed tomography angiography (CTA) in confirming brain death (BD) in patients with and without skull defects. Materials and Methods: Ninety-two patients clinically diagnosed as BD using CTA and/or CTP for confirmation were retrospectively reviewed. For the final analysis, 86 patients were included in this study. Images were re-evaluated by three radiologists according to the 4-point scoring systems that consider the vessel opacification on 1) the venous phase for both M4 segments of the middle cerebral arteries (MCAs-M4) and internal cerebral veins (ICVs) (A60-V60), 2) the arterial phase for the MCA-M4 and venous phase for the ICVs (A20-V60), 3) the venous phase for the ICVs and superior petrosal veins (ICV-SPV). The CTP images were independently reviewed. The presence of an open skull defect and stasis filling was noted. Results: Sensitivities of the ICV-SPV, A20-V60, A60-V60 scoring systems, and CTP in the diagnosis of BD were 89.5%, 82.6%, 67.4%, and 93.3%, respectively. The sensitivity of A20-V60 scoring was higher than that of A60-V60 in BD patients (p < 0.001). CTP was found to be the most sensitive method (86.5%) in patients with open skull defect (p = 0.019). Interobserver agreement was excellent in the diagnosis of BD, in assessing A20-V60, A60-V60, ICV-SPV, CTP, and good in stasis filling (κ: 0.84, 0.83, 0.83, 0.83, and 0.67, respectively). Conclusion: The sensitivity of CTA confirming brain death differs between various proposed 4-point scoring systems. Although the ICV-SPV is the most sensitive, evaluation of the SPV is challenging. Adding CTP to the routine BD CTA protocol, especially in cases with open skull defect, could increase sensitivity as a useful adjunct.

• Korean Journal of Radiology
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• 제2권1호
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• pp.1-7
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• 2001

Objective: To determine the usefulness of perfusion MR imaging in assessing the histologic grade of cerebral gliomas. Materials and Methods: In order to determine relative cerebral blood volume (rCBV), 22 patients with pathologically proven gliomas (9 glioblastomas, 9 anaplastic gliomas and 4 low-grade gliomas) underwent dynamic contrast-enhanced T2^*-weighted and conventional T1- and T2-weighted imaging. rCBV maps were obtained by fitting a gamma-variate function to the contrast material concentration versus time curve. rCBV ratios between tumor and normal white matter (maximum rCBV of tumor / rCBV of contralateral white matter) were calculated and compared between glioblastomas, anaplastic gliomas and low-grade gliomas. Results: Mean rCBV ratios were 4.90°±1.01 for glioblastomas, 3.97°±0.56 for anaplastic gliomas and 1.75°±1.51 for low-grade gliomas, and were thus significantly different; p < .05 between glioblastomas and anaplastic gliomas, p < .05 between anaplastic gliomas and low-grade gliomas, p < .01 between glioblastomas and low-grade gliomas. The rCBV ratio cutoff value which permitted discrimination between high-grade (glioblastomas and anaplastic gliomas) and low-grade gliomas was 2.60, and the sensitivity and specificity of this value were 100% and 75%, respectively. Conclusion: Perfusion MR imaging is a useful and reliable technique for estimating the histologic grade of gliomas.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2002년도 학술대회지
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• pp.721-722
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• 2002

The aim of this work is to analyze changes in cerebral hemodynamics and intracranial pressure mediated by cerebral blood flow challenges in patients with acute heart arrest. Lumped parameter model with feedback mechanism is utilized to simulate the hemodynamics of brain blood flow in case 40 min T-PLS operation is applied to patients of cardiac arrest. Numerical solutions show that cerebral blood flow and perfusion pressure in patients of cardiac arrest are sharply recovered in the initial state of T-PLS operation.

• Journal of Yeungnam Medical Science
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• 제11권1호
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• pp.49-54
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• 1994

숭모판 치환술이 예정된 10명의 환자를 대상으로 심폐우회술 동안 발생할 수 있는 뇌산소 요구량과 소모량 사이의 불균형을 조사하기 위해 내경정맥 내의 산소포화도를 체외순환 5분전과 시작후 1분 이내, 저체온 상태가 안정되었을 때와 재가온하여 체온이 $34^{\circ}C$가 되었을 때, 그리고 체외순환 종료 후 15분 이내 등 5단계로 나누어 혈액을 채취하여 평균 동맥압, 체온, 동맥내 이산화탄소 분압, 혈색 소치, PH 등을 비교 분석하여 다음과 같은 결과를 얻었다. 1. 심폐우회술 중 이산화탄소 분압과 혈색소치 및 PH의 특이한 변화는 없었다. 2. 체외순환 직후 체온 및 평균 동맥압과 혈색 소치의 급격한 변화가 있었으나 임상적인 의미는 없었으며, $SjO_2$의 변화도 없었다. 3. 저체온 상태가 안정되었을때 $SjO_2$ 평균치가 72.4%이었으나 체온을 $34^{\circ}C$로 재가온하였을 때 56.1%로 감소하였다. 4. 재가온 시기에 $SjO_2$감소를 예방하기 위해 재가온 속도를 천천히 하고 이산화탄소를 증가시킴으로써 뇌혈류를 증가시키고 마취약제 등을 이용하여 산소에 대한 뇌대사율을 관류지수를 증가시켜야 하겠다.

• 대한핵의학회지
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• 제26권1호
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• pp.26-32
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• 1992

Minimal deterioration of cerebral perfusion or microanatomical changes were undetectable on conventional Brain CT or MRI. So evaluation of focal functional changes of the brain parenchyme is essential in chronic head injury patients, who did not show focal anatomical changes on these radiological studies. However, the patients who had longstanding neurologic sequelae following head injury, there had been no available imaging modalities for evaluating these patients precisely. Therefore we tried to detect the focal functional changes on the brain parenchyme using $^{99m}Tc-HMPAO$ Brain SPECT on the patients of chronic head injuries. Twenty three patients who had suffered from headache, memory dysfunction, personality change and insomnia lasting more than six months fellowing head injury were included in our cases, which showed no anatomical abnormalities on Brain CT or MRI. At first they underwent psychological test whether the symptoms were organic or not. Also we were able to evaluate the cerebral perfusion changes with $^{99m}Tc-HMPAO$ Brain SPECT in 22 patients among the 23, which five patients were focal and 17 patients were nonfocally diffuse perfusion changes. Thus we can predict the perfusion changes such as local vascular deterioration or functional defects using $^{99m}Tc-HMPAO$ Brain SPECT in the patients who had suffered from post-traumatic sequelae, which changes were undetectable on Brain CT or MRI.

• Investigative Magnetic Resonance Imaging
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• 제5권2호
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• pp.130-137
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• 2001

목적: 대뇌 교종(glioma)에서 상대적 뇌혈액용적(relative cerebral blood volume, rCBV)과 종양의 조직학적 등급(grade)을 비교하고자 하였다. 대상 및 방법 대뇌 교종으로 진단된 총 16명의 환자에서 수술 전에 고식적 T1 및 T2 강조 자기 공명영상 및 조영제를 이용한 관류 자기공명영상을 시행하였다. 교종은 교아세포종(glioblas tora)이 7예, 역형성 성상세포종(anaplastic astrocytoma)이 2예, 역형성 핍지교세포종(anaplastic oligodendroglioma)이 1예, 저등급 성상세포종(low-grade astrocytoma)이 5예, 저등급 핍지교종(low-grade oligodendroglioma)이 1예 있었다. 관류 자기공명영상으로 얻은 교종의 최대 rCBV을 종양의 조직학적 진단 및 등급과 비교 하였다. 결과: 교아세포종의 최대 rCBV은 반대편 정상 백질과 비교하여 433%-1330% (펑균 790%)로 현저히 증가되어 있었다. 강한 조영증강을 보인 역형성 핍지교종 1예의 최대 rCBV은 502%로 증가되어 있었으나 조영증강되지 않는 역형성 성상세포종 2예의 최대 rCBV은 각각66%, 284%로 비교적 낮았다. 저등급 성상세포종의 최대 rCBV은 80%-369% (굉균 202 %)였다. 저등급 핍지교종 1예는 최대 rCBV이 1450%로 교아세포종 보다 높았다. 결론: 관류 자기공명영상을 이용한 rCBV수치는 교아세포종과 저등급 성상세포종은 분명히 구분되었으나 조영증강되지 않는 역형성 성상세포종파 저등급 성상세포종 간에는 차이가 없었다.

• 한국광학회:학술대회논문집
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• 한국광학회 2009년도 동계학술발표회 논문집
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• pp.427-428
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• 2009

Optical imaging offers excellent spatio-temporal sensitivity that is unparalleled by any other perfusion based imaging techniques. We used in vivo optical recording of intrinsic signals (ORIS) to map neurovascular hemodynamics of perfusion, oximetry and membrane potential during epileptic events in rat and mouse neocortex. Studies of hemodynamic changes with ORIS alone were also performed in human. Laboratory studies in rodent epilepsy models have demonstrated a persistent increase in deoxygenated hemoglobin (Hbr) and a decrease in tissue oxygenation during interictal spikes and ictal events. This "epileptic dip", like the "initial dip" recorded during normal sensory processing, implies that the enormous rise in cerebral blood flow (CBF) is inadequate to meet the increased metabolic demands associated with synchronized epileptic activity. These findings are critically important to the interpretation of the perfusion-based imaging studies, such as fMRI. In addition, we visualized the effect of direct cortical electrical stimulation, an alterative epilepsy treatment. The optical data following direct cortical electrical stimulation showed that hemodynamic signals are sensitive to different electrical stimulation parameters. Furthermore, our recent data demonstrated that the application of unilateral electrical stimulation is able to elicit bilateral hemodynamic responses in rat neocortex.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 2001년도 제6차 학술대회 초록집
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• pp.168-168
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• 2001

Purpose： Cerebral perfusion, as measured by interictal SPECT and PET, is known to be decreased in the affected hippocampus of the patients with hippocampal sclerosis. The purpose of th study is to evaluate the capability of perfusion MR imaging to demonstrate ipsilate hypopefusion in patients with hippocampal sclerosis.