• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.6
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• pp.61-66
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• 2004

To make a guide line of property control of angiography equipments, we made standard evaluation sheet forms of facility and management of angiography suite, physical properties of angiography equipments, and image quality of film and then surveyed them at 29 hospital nationwide. Survey and development of standard evaluation sheet form of physical properties of angiography equipments. By using resolution & radiation dose, physical properties of angiography equipments of 49 in number nationwide were evaluated. Most of them (91%) had good performance.

• Nuclear Engineering and Technology
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• v.53 no.4
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• pp.1318-1322
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• 2021

To unveil and delineate the elements applicable to the radiation protection of a femoral entry shield, calculate its mass attenuation coefficient, and demonstrate its dose reduction efficacy for interventional radiologist performing transarterial embolization (TAE) of ruptured hepatocellular carcinoma (rHCC). The lead equivalency of the shield was firstly validated. Electron microscopy was used to confirm the femoral entry shield being lead-free and to analyze the elemental content, with which the mass attenuation coefficient of the shield was calculated. An adult phantom, irradiated at the upper abdomen to simulate the TAE of rHCC, was used together with a dosimeter attached to the palm of a hand phantom. The dose rates at the hand phantom were measured, with the rHCC clinical protocol, without and with the femoral entry shield placed over the right femoral access site of the adult phantom. Without using the shield, the average hand dose rate was measured to be 0.325 µSv/sec. While using the shield, it was determined to be 0.110 µSv/sec. There was significant 66% dose reduction to the hand dose of IRs performing angiographic intervention with the femoral entry shield.

• Journal of Korean Neurosurgical Society
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• v.62 no.2
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• pp.136-143
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• 2019

Moyamoya disease (MMD) is a progressive cerebrovascular disease with unknown etiology, characterized by bilateral steno-occlusive changes at the terminal portion of the internal carotid artery and an abnormal vascular network formation at the base of the brain. MMD has an intrinsic nature to convert the vascular supply for the brain from internal carotid (IC) system to the external carotid (EC) system, as indicated by Suzuki's angiographic staging. Insufficiency of this 'IC-EC conversion system' could result not only in cerebral ischemia, but also in intracranial hemorrhage from inadequate collateral anastomosis, both of which represent the clinical manifestation of MMD. Surgical revascularization prevents cerebral ischemic attack by improving cerebral blood flow, and recent evidence further suggests that extracranial-intracranial bypass could powerfully reduce the risk of re-bleeding in MMD patients with posterior hemorrhage, who were known to have extremely high re-bleeding risk. Although the exact mechanism underlying the hemorrhagic presentation in MMD is undetermined, most recent angiographic analysis revealed the characteristic angio-architecture related to high re-bleeding risk, such as the extension and dilatation of choroidal collaterals and posterior cerebral artery involvement. We sought to update the current management strategy for hemorrhagic MMD, including the outcome of surgical revascularization for hemorrhagic MMD in our institute. Further investigations will clarify the optimal surgical strategy to prevent hemorrhagic manifestation in patients with MMD.

• Korean Journal of Radiology
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• v.22 no.4
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• pp.568-576
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• 2021

Arteriovenous malformations (AVMs) are direct communications between primitive reticular networks of dysplastic vessels that have failed to mature into capillary vessels. Based on angiographic findings, peripheral AVMs can be classified into six types: type I, type IIa, type IIb, type IIc, type IIIa, and type IIIb. Treatment strategies vary with the types. Type I is treated by embolizing the fistula between the artery and the vein with coils. Type II (IIa, IIb, and IIc) AVM is treated as follows: first, reduce the blood flow velocity in the venous segment of the AVM with coils; second, perform ethanol embolotherapy of the residual shunts. Type IIIa is treated by transarterial catheterization of the feeding arteries and injection of diluted ethanol. Type IIIb is treated by transarterial or direct puncture approaches. A high concentration of ethanol is injected through the transarterial catheter or direct puncture needle. When the fistula is large, coil insertion is required to reduce the amount of ethanol. Type I and type II AVMs showed the best clinical results; type IIIb showed a satisfactory response rate. However, type IIIa showed the poorest response rate, either alone or in combination with other types. Clinical success can be achieved by using different treatment strategies for different angiographic AVM types.

• Journal of Korean Neurosurgical Society
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• v.58 no.3
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• pp.184-191
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• 2015

Objective : Anterior communicating artery (AcomA) aneurysms represent the most common intracranial aneurysms and challenging to treat due to complex vascularity. The purpose of this study was to report our experience of endovascular treatment of AcomA aneurysms. Methods : Between January 2003 and December 2013, we retrospectively reviewed the medical records of 134 AcomA aneurysm patients available more than 6 months conventional angiographic and clinical follow-up results. We focused on aneurismal or AcomA vascular characters, angiographic and clinical follow-up results, and retreatment. Results : The rate of ruptured cases was 75.4%, and the small (<10 mm) aneurysms were 96.3%. Based on the subtypes defined by dominance of A1, 79 patients (59%) had contralateral A1 hypoplasia or agenesis. The immediate post-procedural angiography confirmed complete occlusion in 75.4%, partial occlusion in 24.6%. Procedure related complications were observed in 25 (18.6%) patients. Most of the adverse events were asymptomatic. Follow-up conventional angiography at ${\geq}6$ months was performed in all patients (mean 16.3 months) and major recanalization was noted in 6.7% and regrowth in one case. The aneurysm size (p=0.016), and initial treatment results (p=0.00) were statistically significant risk factors related to aneurysm recurrence. An overall improvement in mRS was observed during the clinical follow-up period and no rebleeding episode occurred. Conclusion : This study demonstrated that endovascular treatment is an effective treatment modality for AcomA aneurysms with low morbidity. Patients should take long term clinical and angiographic follow-up in order to assess the recurrence and warrant retreatment, especially ruptured, large, and initially incomplete occluded aneurysms.

• Investigative Magnetic Resonance Imaging
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• v.11 no.1
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• pp.33-38
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• 2007

Purpose : To investigate the applicability of the new three-dimensional overlapped reconstruction MR angiography (3-D ORMRA) technique in patients with hemifacial spasm and to compare the new 3-D reconstruction images with conventional MRA source images. Materials and Methods : The study group comprised 27 patients with surgically proven hemifacial spasm. In all patients, conventional MRA source images and 3-D fast imaging employing steady-state acquisition (FIESTA) images were obtained prospectively. After 3-D MR angiographic images were obtained, the 3-D MRA and FIESTA images were overlapped at the workstation by using GE A/W 4.2 add/sub software. We analyzed the relationship between the offending vessels and root exit zone of the facial nerve using both 3-D ORMRA images and conventional MRA source images. Results : In 25 of 27 patients, the offending vessel at the REZ of the facial nerve could be correctly identified on conventional MRA source images. In all patients, the presumed offending vessels depicted by the overlapped 3-D reconstruction MRA image corresponded well with the intraoperative findings. The 3-D reconstruction image showed more clear visualization of the spatial relationship between the offending vessels and the root exit zone of the facial nerve. Conclusion : The overlapped 3-D reconstruction MR angiography technique is very useful and informative in patients with hemifacial spasm, as compared with conventional MRA angiography technique.

• Journal of Korean Neurosurgical Society
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• v.65 no.6
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• pp.801-815
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• 2022

Objective : To evaluate the stent apposition of a low-profile visualized intraluminal support (LVIS) device in distal internal carotid artery (ICA) aneurysms, examine its correlation with clinical and angiographic outcomes, and determine the predictive factors of ischemic adverse events (IAEs) related to stent-assisted coiling. Methods : We retrospectively analyzed a prospectively maintained database of 183 patients between January 2017 and February 2020. The carotid siphon from the cavernous ICA to the ICA terminus was divided into posterior, anterior, and superior bends. The anterior bends were categorized into angled (V) and non-angled (C, U, and S) types depending on the morphology and measured angles. Complete stent apposition (CSA) and incomplete stent apposition (ISA) were evaluated using unsubtracted angiography and flat-panel detector computed tomography. Dual antiplatelet therapy with aspirin 200 mg and clopidogrel 75 mg was administered. Clopidogrel resistance was defined as fewer responders (≥10%, <40%) and non-responders (<10%) based on the percent inhibition (%INH) of the VerifyNow system. These were counteracted by a dose escalation to 150 mg for fewer responders or substitution with cilostazol 200 mg for non-responders. IAEs included intraoperative in-stent thrombosis, transient ischemic attack, cerebral infarction, and delayed in-stent stenosis. A multivariate logistic regression analysis was used to determine the predictive factors for ISA and IAEs. Results : There were 33 ISAs (18.0%) and 27 IAEs (14.8%). The anterior bend angle was narrower in ISA (-4.16°±25.18°) than in CSA (23.52°±23.13°) (p<0.001). The V- and S-types were independently correlated with the ISA (p<0.001). However, treatment outcomes, including IAEs (15.3% vs. 12.1%), aneurysmal complete occlusion (91.3% vs. 88.6%), and recanalization (none of them), did not differ between CSA and ISA (p>0.05). The %INH of 27 IAEs (13.78%±14.78%) was significantly lower than that of 156 non-IAEs (26.82%±20.23%) (p<0.001). Non-responders to clopidogrel were the only significant predictive factor for IAEs (p=0.001). Conclusion : The angled and tortuous anatomical peculiarity of the carotid siphon caused ISA of the LVIS device; however, it did not affect clinical and angiographic outcomes, while the non-responders to clopidogrel affected the IAEs related to stent-assisted coiling.

• Journal of Biomedical Engineering Research
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• v.2 no.2
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• pp.109-116
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• 1981

The objective of this research is to develop the hardware and software systenls of the digital intravenous angiographic system. The system will be used in clinical diagnosis of cardiovascular and cerebrovascular diseases. By utilizing computer image processing technique and digital subtraction method, the system can decrease the patient's harzard and expenses in performing intravenous angiography, as compared with conventional angiograms of the arterial injection.

• Journal of Chest Surgery
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• v.25 no.4
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• pp.418-423
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• 1992

Tracheo-innominate artery fistula[TIF] is the uncommon delayed fatal complication of tracheostomy. The mortality rate of the lesion, if not treated surgically, approaches 100%. A 64-year-old man presenting with a TIF after tracheostomy was treated by lateral repair and muscle interposition between the innominate artery and trachea. Preoperatively, bleeding was controlled by gauze packing around the tude under manual compression and hyperinflation of the balloon cuff of the tracheostomy tube. No abnormality was found by angiographic evaluation. The patient failed to regain consciousness and died 4 days later from sepsis.

• Journal of Korean Neurosurgical Society
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• v.56 no.6
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• pp.492-495
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• 2014

A ruptured distal lenticulostriate artery (LSA) aneurysm is detected occasionally in moyamoya disease (MMD) patients presented with intracerebral hemorrhage. If the aneurysm is detected in hemorrhage site on angiographic evaluation, its obliteration could be considered, because it rebleeds frequently, and is associated with poorer outcome and mortality in MMD related hemorrhage. In this case report, the authors present two MMD cases with ruptured distal LSA aneurysm treated by endovascular embolization.