Publications by authors named "Sung-Tae Park"

Background: This study aimed to retrospectively evaluate the influence of contralateral anterior circulation on computational fluid dynamics (CFD) of intracranial arteries, by comparing the CFD values of flow velocities in unilateral anterior circulation with the measured values from phase-contrast magnetic resonance angiography (PC-MRA).

Methods: We analyzed 21 unilateral anterior circulation models without proximal stenosis from 15 patients who performed both time-of-flight MRA (TOF-MRA) and PC-MRA. CFD was performed with the inflow boundary condition of a pulsatile flow of the internal carotid artery (ICA) obtained from PC-MRA.

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Objective: The angiographic spot sign (AS) on CT angiography (CTA) is known to be useful for predicting expansion in intracranial hemorrhage, but its use is limited due to its relatively low sensitivity. Recently, dual-energy computed tomography (DECT) has been shown to be superior in distinguishing between hemorrhage and iodine. This study aimed to evaluate the diagnostic performance of hematoma expansion (HE) using DECT AS in traumatic intracranial hemorrhage.

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Pituitary apoplexy (PA) is a clinical syndrome resulting from sudden hemorrhage and/or infarction of the pituitary gland. Recent reports documented the development of PA secondary to treatment with gonadotropin-releasing hormone (GnRH) agonists for prostate cancer. A 52-year-old woman visited our emergency room with a severe headache, occurred 1 day prior.

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Intracranial dural arteriovenous fistula (DAVF) is an abnormal arteriovenous shunt accounting for approximately 10%-15% of all intracranial vascular malformations. Most intracranial DAVFs are solitary, but multiple lesions at different sites can rarely occur. Most intracranial multiple DAVFs are synchronous types, whereas metachronous lesions are relatively uncommon.

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Stenosis of the central veins is a common complication in hemodialysis patients. However, cerebral venous hypertension and neurological symptoms caused by central vein stenosis are relatively rare. We present a rare case of cerebral venous hypertension in a 63-year-old male who showed venous reflux into the dural sinuses due to central venous stenosis on time-of-flight MR angiography.

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Dural arteriovenous fistula is an acquired vascular anomaly that can cause various symptoms. Here, we report a rare case of Borden type I sigmoid sinus dural arteriovenous fistula presenting as subarachnoid hemorrhage. Bleeding occurred from a side-wall aneurysm in the lateral pontomedullary segment of the anterior inferior cerebellar artery, which was a minor pial feeder.

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Purpose: This study aimed to compare the brain perfusion status of patients with chronic kidney disease to a normal control group to identify any significant differences.

Materials And Methods: The perfusion state of the brain was measured by MRI using the arterial spin labeling technique in 36 patients undergoing hemodialysis due to chronic kidney disease and 36 normal controls. Images were then analyzed in a voxel-wise manner to detect brain areas showing significant perfusion differences between the two groups.

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Background: Alexander disease is a rare neurological disease characterized by progressive spastic quadriparesis and bulbar palsy. Moreover, certain patients with adult-onset Alexander disease were often misdiagnosed as other neurodegenerative disorders.

Case Presentation: Herein, we report an adult a 58-year-old woman presented with typical parkinsonism with good levodopa-responsiveness.

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Cubic boron nitride (c-BN) films on tool substrates are tendency to delaminate. Therefore, many research groups have studied improvement of c-BN synthesis method and deposition processes due to many potential applications. In this paper, we show that the adhesion property of c-BN layer system can be improved by deposing multi c-BN layers.

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Background And Purpose: Diabetes mellitus is a specific risk factor for intracranial atherosclerosis (ICAS) regardless of race. However, it is largely unknown whether poor glycemic control is associated with the severity of ICAS in diabetic patients.

Methods: We selected diabetic patients with acute ischemic stroke who were prospectively registered between March 2005 and December 2015.

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Background And Purpose: Incidental thyroid lesions are frequently found on contrast-enhanced magnetic resonance (CE-MR) angiography. The purpose of this study is to determine the prevalence of thyroid incidentalomas detected by CE-MR angiography and to evaluate their clinical significance by correlation with ultrasound (US) and cytopathological results.

Materials And Methods: We retrospectively reviewed 3,299 consecutive CE-MR angiography examinations performed at our institution between January 2010 and March 2013.

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Uremic encephalopathy with bilateral basal ganglia lesions has been reported as an acute neurometabolic disease which shows reversible clinical course and brain imaging features. The exact nature and pathophysiology have not been well established. We encountered two patients who showed a relapsing and aggravating course and an atypical phenotype including parkinsonism with paroxysmal dystonic head tremor and acute onset monoparesis of the lower extremity.

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Purpose: The purpose of this study was to evaluate the feasibility, efficacy and safety of percutaneous thromboaspiration with a 7F Desilets-Hoffman sheath compared with previously established percutaneous mechanical thrombectomy techniques in occluded hemodialysis grafts.

Materials And Methods: One thousand three hundred five patients (767 women, 538 men; mean age, 61.04±13.

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We investigate the potentials and limitations of computational fluid dynamics (CFD) analysis of patient specific models from 3D angiographies. There are many technical problems in acquisition of proper vascular models, in pre-processing for making 2D surface and 3D volume meshes and also in post-processing steps for display the CFD analysis. We hope that our study could serves as a technical reference to validating other tools and CFD results.

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Purpose: Computational flow dynamic (CFD) study has not been widely applied in intracranial artery stenosis due to requirement of high resolution in identifying the small intracranial artery. We described a process in CFD study applied to symptomatic severe intracranial (M1) stenosis before and after stenting.

Materials And Methods: Reconstructed 3D angiography in STL format was transferred to Magics (Materialise NV, Leuven, Belgium) for smoothing of vessel surface and trimming of branch vessels and to HyperMesh (Altair Engineering Inc.

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The computational fluid dynamics methods for the limited flow rate and the small dimensions of an intracranial artery stenosis may help demonstrate the stroke mechanism in intracranial atherosclerosis. We have modeled the high wall shear stress (WSS) in a severe M1 stenosis. The high WSS in the systolic phase of the cardiac cycle was well-correlated with a thick fibrous cap atheroma with enhancement, as was determined using high-resolution plaque imaging techniques in a severe stenosis of the middle cerebral artery.

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Background: Accurate evaluation of local extent in bladder cancer is important to determine the optimal therapeutic strategy and to predict the outcome of treatment. The purpose of this study is to evaluate the accuracy of 3D volumetric reconstructed US in the assessment of tumor detection and serosal invasion in patients with bladder cancer.

Methods: A total of 14 patients with findings of bladder cancer determined with the use of cystoscopy was examined with the use of bladder two-dimensional (2D) US and subsequent 3D US.

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Schwannomatosis or neurilemmomatosis has been used to describe patients with multiple nonvestibular schwannomas with no other stigmata of neurofibromatosis type-2 (NF-2). In our case, schwannomatosis, multiple schwannomas were present in a 21-yr-old woman with no stigmata or family history of NF-1 or NF-2. She had no evidence of vestibular schwannoma or other intracranial tumors.

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Background And Purpose: The clinical pattern of stroke and the angiographic distribution of cerebral atherosclerosis in the Japanese and Chinese are different from those in whites. Our purpose was to evaluate the location and distribution of severe atherosclerotic stenoses in Korean patients by using cerebral angiography.

Methods: We retrospectively reviewed the cerebral angiographic findings in 268 patients (219 male, 49 female; mean age, 56 years) with one or more severe atherosclerotic stenoses (> or =70%), as shown on angiograms.

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