• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.3-4
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• 2023

자연어처리는 수많은 정보가 수집된 전자의무기록의 비정형 데이터에서 유의미한 정보나 패턴 등을 추출해 의료진의 의사결정을 지원하고, 환자에게 더 나은 진단이나 치료 등을 지원할 수 있어 큰 잠재력을 가지고 있다. 그러나 전자의무기록은 개인정보와 같은 민감한 정보가 다수 포함되어 있어 접근하기 어렵고, 이로 인해 충분한 양의 데이터를 확보하기 어렵다. 따라서 본 논문에서는 신뢰할 수 있는 의료 합성 텍스트를 생성하기 위해 ChatGPT 기반 의료 텍스트 증강 도구를 개발하였다. 이는 사용자가 입력한 실제 의료 텍스트로 의료 합성 데이터를 생성한다. 이를 위해, 적합한 프롬프트와 의료 텍스트에 대한 전처리 방법을 탐색하였다. ChatGPT 기반 의료 텍스트 증강 도구는 입력 텍스트의 핵심 키워드를 잘 유지하였고, 사실에 기반한 의료 합성 텍스트를 생성할 수 있다는 것을 확인할 수 있었다.

• Journal of the Korean Society of Radiology
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• v.81 no.3
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• pp.488-500
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• 2020

Accumulating evidence suggests that Alzheimer's disease (AD) is not only caused by accumulation of abnormal proteins, including amyloid and tau, but is also closely associated with abnormalities in the microvascular environment including the blood-brain barrier (BBB), both of which lead to neuroinflammation and neurodegeneration. Application of in vivo magnetic resonance imaging (MRI) has recently increased to assess BBB permeability in AD and related diseases. Here, we provide a narrative review of BBB permeability-related pathology in Alzheimer dementia and recent MRI research on BBB permeability changes in AD and related diseases. Furthermore, we briefly introduce the measurement of BBB permeability using MRI and its methodological issues.

• Journal of the Korean Society of Radiology
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• v.81 no.5
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• pp.1239-1245
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• 2020

Reversible cerebral vasoconstriction syndrome (RCVS) is a clinical and radiological syndrome with primary features that include hyperacute onset of severe headache and segmental vasoconstriction of the cerebral arteries, which resolve within 3 months. Vessel wall enhancement has been reported in some cases of RCVS; however, its pathophysiological and diagnostic implications remain unclear. We review a case of RCVS in a patient with transient vessel wall enhancement on contrast-enhanced fluid-attenuated inversion recovery images, focusing on the pathophysiological and diagnostic implications.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.26 no.1
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• pp.30-36
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• 2024

Objective: This study aims to investigate the efficacy of microsurgery with intraoperative indocyanine green (ICG) angiography as a treatment approach for ethmoidal dural arteriovenous fistula (DAVF). Methods: Between January 2010 and July 2021, our institution encountered a total of eight cases of ethmoidal DAVF. In each of these cases, microsurgical treatment was undertaken utilizing a bilateral sub-frontal interhemispheric approach, with the aid of intraoperative ICG angiography. Results: ICG angiography identified bilateral venous drainage with single dominance in four cases (50%) of ethmoidal DAVF, a finding that eluded detection during preoperative transfemoral cerebral angiography (TFCA). The application of microsurgical treatment, in conjunction with intraoperative ICG angiography, resulted in consistently positive clinical outcomes for all patients, as evaluated using the Glasgow Outcome Scale (GOS) at the 6-month postoperative follow-up assessment; six patients showed GOS score of 5, while the remaining two patients attained a GOS score of 4. Conclusions: The use of intraoperative ICG angiography enabled accurate identification of both dominant and non-dominant venous drainage patterns, ensuring complete disconnection of the fistula and reducing the risk of recurrence.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.25 no.4
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• pp.429-433
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• 2023

84 years old gentle man with past medical history of hypertension and diabetes presented with sudden onset right sided weakness and aphasia for two hours. Initial neurological assessment revealed National Institute of Health Stroke Scale (NIHSS) 17. Computed tomography (CT) scan demonstrated minimal early ischemic changes along left insular cortex with occlusion of left middle cerebral artery (MCA). Based on clinical and imaging findings, decision was made to perform mechanical thrombectomy procedure. Initially, right common femoral artery approach was utilized. However, due to unfavorable type-III bovine arch, left internal carotid artery could not be engaged via this approach. Subsequently, access was switched to right radial artery. Angiogram revealed small caliber radial artery, with larger caliber ulnar artery. Attempt was made to advance the guide catheter through the radial artery, however significant vasospasm was encountered. Subsequently, ulnar artery was accessed and successful thrombolysis in cerebral infarction (TICI) III left MCA reperfusion was achieved with a single pass of mechanical thrombectomy via this approach. Post procedure neurological examination demonstrated significant clinical improvement. Doppler ultrasound 48 hours after the procedure demonstrated patent flow in radial and ulnar arteries with no evidence of dissection.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.25 no.4
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• pp.434-439
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• 2023

Pseudoaneurysms are rare but devastating complications of penetrating head traumas. They require rapid surgical or endovascular intervention due to their high risk of rupture; however, complex presentations may limit treatment options. Our objective is to report a case of severe vasospasm, flow diversion, and in-stent stenosis complicating the treatment of a middle cerebral artery pseudoaneurysm following a gunshot wound. A 33-year-old woman presented with multiple calvarial and bullet fragments within the right frontotemporal lobes and a large right frontotemporal intraparenchymal hemorrhage with significant cerebral edema. She underwent an emergent right hemicraniectomy for decompression, removal of bullet fragments, and evacuation of hemorrhage. Once stable enough for diagnostic cerebral angiography, she was found to have an M1 pseudoaneurysm with severe vasospasm that precluded endovascular treatment until the vasospasm resolved. The pseudoaneurysm was treated with flow diversion and in-stent stenosis was found at 4-month follow-up angiography that resolved by 8 months post-embolization. We report the successful flow diversion of an middle cerebral artery (MCA) pseudoaneurysm complicated by severe vasospasm and later in-stent stenosis. The presence of asymptomatic stenosis is believed to be reversible intimal hyperplasia and a normal aspect of endothelial healing. We suggest careful observation and dual-antiplatelet therapy as a justified approach.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.25 no.4
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• pp.440-446
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• 2023

Craniotomy is known as a cause of iatrogenic dural cerebral arteriovenous fistula (AVF). However, mixed pial and dural AVFs after craniotomy are extremely rare and require accurate diagnosis and prompt treatment due to their aggressiveness. We present a case of an iatrogenic mixed pial and dural AVF diagnosed 2 years after pterional craniotomy for surgical clipping of a ruptured anterior choroidal aneurysm. The lesion was successfully treated using single endovascular procedure of transvenous coil embolization through the engorged vein of Labbe and the superficial middle cerebral vein. The possibility of the AVF formation after the pterional approach should always be kept in mind because it usually occurs at the middle cranial fossa, which frequently has an aggressive nature owing to direct cortical venous or leptomeningeal drainage patterns. This complication is believed to be caused by angiogenetic conditions due to coagulation, retraction, and microinjuries of the perisylvian vessels, and can be prevented by performing careful sylvian dissection according to patient-specific perisylvian venous anatomy.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.26 no.1
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• pp.79-84
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• 2024

Intracranial non-galenic pial arteriovenous fistula (PAVF) is an extremely rare vascular malformation, where one or more pial arteries feeds directly into a cortical vein without any intervening nidus. Though occasionally they can be asymptomatic, neurological symptoms such as headache, seizure, or focal neurological deficit are more common presenting features. Life threatening or fatal hemorrhage is not uncommon, hence needed to be treated more often than not. Spontaneous occlusion of PAVF is reported only four times before. We report a 49-year-old gentleman, who was diagnosed to have a PAVF, possibly secondary to trauma. He presented 5 months and 22 days from initial digital subtraction angiography (DSA) for treatment, and follow-up angiogram showed complete obliteration. He denied any significant event, medication or alternate treatment during this period. His clinical symptoms were stable as well. We postulate iodinated contrast medium induced vasculopathy as a possible cause, which has been described for other vascular pathologies, but never for PAVF.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.25 no.2
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• pp.196-202
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• 2023

One of the common complications that can occur during coil embolization of cerebral aneurysms, is migration of coil lump alone. The removal of these migrated coils has been reported on a few occasions. On the other hand, rare complications would include the migration of the coil with subsequent stent dislocation. Currently, there is no standardized method to correct the complications of stent dislocation, and very few instances of this complication have been reported previously. In this report, we introduce a case of coil migration combined with stent dislocation. This occurred during coil embolization of an unruptured aneurysm of the distal, left internal carotid artery for a 52-year old woman. We retrieved both the damaged stent and migrated coil using another retrievable stent successfully with no more further complications. In the present report, we describe in detail how we corrected the complication successfully stent, and we discuss why this rescue maneuver is reasonable option for the complication mentioned above.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.26 no.1
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• pp.71-78
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• 2024

Dural arteriovenous fistula (DAVF) is a rare condition affecting approximately 1.5% of 1,000,000 individuals annually. It frequently occurs in the transsigmoid and cavernous sinuses. An isolated sigmoid sinus is extremely rare and is treated by performing transfemoral transvenous embolization along the opposite transverse sinus. A 69-year-old woman presented with asymptomatic Borden type III/Cognard type III DAVF involving an isolated sigmoid sinus. She underwent a staged operation in which a navigation system was used to expose the sigmoid sinus in the operating room before transferring the patient to the angio suite for transvenous embolization. Various modalities have been used to treat DAVF, including surgical disconnection, transarterial embolization, transvenous embolization, and stereotactic radiosurgery. However, treating DAVF cases where the affected sinus is isolated can be challenging because an easily accessible surgical route may not be available. In this case, direct sinus cannulation and transvenous embolization were the most effective treatments.