• Korean Journal of Radiology
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• v.21 no.12
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• pp.1305-1316
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• 2020

In approximately 10% of patients with acute myocardial infarction (MI), angiography does not reveal an obstructive coronary stenosis. This is known as myocardial infarction with non-obstructive coronary arteries (MINOCA), which has complex and multifactorial causes. However, this term can be confusing and open to dual interpretation, because MINOCA is also used to describe patients with acute myocardial injury caused by ischemia-related myocardial necrosis. Therefore, with regards to this specific context of MINOCA, the generic term for MINOCA should be replaced with troponin-positive with non-obstructive coronary arteries (TpNOCA). The causes of TpNOCA can be subcategorized into epicardial coronary (causes of MINOCA), myocardial, and extracardiac disorders. Cardiac magnetic resonance imaging can confirm MI and differentiate various myocardial causes, while cardiac computed tomography is useful to diagnose the extracardiac causes.

• 대한핵의학회:학술대회논문집
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• 1999.11a
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• pp.39.1-39.1
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• 1999

• Proceedings of the Korea Contents Association Conference
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• 2017.05a
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• pp.385-386
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• 2017

진단을 위해 조영제를 연속해서 사용하는 검사는, 첫 번째 주입으로 인해 조영제가 영상에 미치는 효과를 고려해야 한다. 본 연구에서는 mask 영상의 획득 시점을 통해 이를 개선하고자, 관류영상 획득 후 조영영상을 감산하는 새로운 방법을 제시하여, 혈관 겹침의 원인이 정맥의 신호강도를 유의하게 감소시켰다. 따라서, 본 연구의 방법을 이용하면, 복잡한 재구성이나 추가적인 기법 없이도, 효율적으로 정맥신호를 제거 할 수 있어 유용하리라 사료된다.

• Proceedings of the KOSOMBE Conference
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• v.1993 no.11
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• pp.20-22
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• 1993

• Korean Journal of Radiology
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• v.2 no.3
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• pp.179-182
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• 2001

The authors present a case of giant serpentine aneurysm (a partially thrombosed aneurysm containing tortuous vascular channels with a separate entrance and outflow pathway). Giant serpentine aneurysms form a subgroup of giant intracranial aneurysms, distinct from saccular and fusiform varieties, and in this case, too, the clinical presentation and radiographic features of CT, MR imaging and angiography were distinct.

• Journal of the Korean Society of Radiology
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• v.82 no.6
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• pp.1619-1627
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• 2021

Central venous stenosis is a relatively common complication in hemodialysis patients; however, jugular venous reflux (JVR) and increased intracranial pressure are rare, and associated progressive visual disturbance was reported in only a few cases. Here, we report a case of JVR with visual disturbance and increased intracranial pressure. Notably, the MRI was accompanied by a dilatation of the superior ophthalmic vein, which was mistaken for a cavernous sinus dural arteriovenous fistula (CSdAVF). The patient had JVR on time-of-flight MR angiography (TOF-MRA) and severe stenosis of the left brachiocephalic vein on conventional angiography. After balloon angioplasty for central venous stenosis, he was discharged after improvement of his visual disturbance. Although JVR due to central venous stenosis and CSdAVF might show similar symptoms, treatment plans are different. Therefore, it is important to distinguish radiologically based on a thorough review of MRI and TOF-MRA and confirm the central venous stenosis on cerebral angiography for the accurate diagnosis.

• Investigative Magnetic Resonance Imaging
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• v.22 no.2
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• pp.131-134
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• 2018

Susceptibility-weighted imaging (SWI) is well known for detecting the presence of hemorrhagic transformation, microbleeds and the susceptibility of vessel signs in acute ischemic stroke. But in some cases, it can provide the tissue perfusion state as well. We describe a case of a patient with hyperacute ischemic infarction that had a slightly hypodense, patchy lesion at the left thalamus on the initial SWI, with a left proximal posterior cerebral artery occlusion on a magnetic resonance (MR) angiography and delayed time-to-peak on an MR perfusion performed two hours after symptom onset. No obvious abnormal signals at any intensity were found on the initial diffusion-weighted imaging (DWI). On a follow-up MR image (MRI), an acute ischemic infarction was seen on DWI, which is the same location as the lesion on SWI. The hypointensity on the initial SWI reflects the susceptibility artifact caused by an increased deoxyhemoglobin in the affected tissue and vessels, which reflects the hypoperfusion state due to decreasing arterial flow. It precedes the signal change on DWI that reflects a cytotoxic edema. This case highlights that, in some hyperacute stages of ischemic stroke, hypointensity on an SWI may be a finding before the hyperintensity is seen on a DWI.

• Journal of the Korean Society of Radiology
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• v.83 no.1
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• pp.184-188
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• 2022

Persistent trigeminal artery (PTA) represent an unusual remnant of the fetal carotid-basilar anastomosis. Persistent trigeminal artery variant (PTAV) is a rare anastomosis between the internal carotid artery and cerebellar artery, without an interposing basilar artery segment. We report the case of 49-year-old female with an incidentally discovered, rare variation of PTA that directly terminated in the ipsilateral superior cerebellar artery. The variation was observed on CT angiography, digital subtraction angiography, and MR angiography. Additionally, we reviewed the embryogenesis of PTA and PTAV and discussed the clinical implications of this variation.

• Investigative Magnetic Resonance Imaging
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• v.22 no.2
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• pp.94-101
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• 2018

Purpose: To determine the value of the appearance of the high signal intensity halo sign for detecting carotid intraplaque hemorrhage (IPH) on maximum intensity projection (MIP) of time-of-flight (TOF) MR angiography (MRA), based on high signal intensity on magnetization-prepared rapid acquisition with gradient-echo (MPRAGE) sequencing. Materials and Methods: A total of 78 carotid arteries in 65 patients with magnetization-prepared rapid acquisition gradient-echo (MPRAGE) positive on carotid plaque MR imaging were included in this study. High-resolution MR imaging was performed on a 3.0-T scanner prior to carotid endarterectomy or carotid artery stenting. Fast spin-echo T1- and T2-weighted axial imaging, TOF, and MPRAGE sequences were obtained. Carotid plaques with high signal intensity on MPRAGE > 200% that of adjacent muscle on at least two consecutive slices were defined as showing IPH. Halo sign of high signal intensity around the carotid artery was found on MIP from TOF MRA. Continuous and categorical variables were compared among groups using the Mann-Whitney test and Fisher's exact tests. Results: Of these 78 carotid arteries, 53 appeared as a halo sign on the TOF MRA. The total IPH volume of patients with a positive halo sign was significantly higher than that of patients without a halo sign ($75.0{\pm}86.8$ vs. $16.3{\pm}18.2$, P = 0.001). The maximum IPH axial wall area in patients with a positive halo sign was significantly higher than that of patients without a halo sign ($11.3{\pm}9.9$ vs. $3.7{\pm}3.6$, P = 0.000). Conclusion: High signal intensity halo of IPH on MIP of TOF MRA is associated with total volume and maximal axial wall area of IPH.

• Proceedings of the KSMRM Conference
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• 2003.10a
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• pp.97-97
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• 2003

Contrast-enhanced MR angiography (CE-MRA) gradually occupies its position as a primary evaluation tool forsteno-occlusive disease of supra-aortic cervical arteries. It has several advantages over time-of-flight (TOF) technique such as shorter imaging time, less saturation effect, and less flow- and motion-related artifacts. Diverse methods of k-space sampling, imaging sequences, and strategies for image acquisitiontiming have been introduced since its early clinical application. Especially, methods of k-space sampling and image acquisition timing are very important to achieve maximal arterial enhancement and suppress venous signal while maintaining large scan coverage and high spatial resolution. In addition, regardless of several advantages over TOF technique, it still has a tendency to overestimate the degree of stenosis in patients with carotid or vertebralartery disease. In this exhibit, we will overview the current techniques of CE-MRA with special attention to methods of k-space sampling and image acquisition timing. We will also discuss diagnostic accuracy of CE-MRA in patients with supra-aortic cervical artery stenosis and artifacts frequently misinterpreted as steno-occlusive lesion on CE-MRA.