• Journal of Korean Neurosurgical Society
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• 제46권1호
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• pp.38-44
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• 2009

Objective : The authors studied the risk factors of silent cerebral microbleeds (MBs) and old hematomas (OHs) and their association with concurrent magnetic resonance (MR) imaging findings in the patients of intracerebral hemorrhages (ICHs). Methods : From April 2002 to June 2007, we retrospectively studied 234 patients of primary hemorrhagic stroke. All patients were evaluated with computed tomography (CT) and 3.0-tesla MR imaging studies within the first week of admission. MBs and OHs were assessed by using $T2^{\ast}$-weighted gradient-echo (GRE) MR imaging. The patients were divided into 2 groups, depending on whether or not they had two GRE lesions of chronic hemorrhages. A correlation between MBs and OHs lesions were also statistically tested. Lacunes and white matter and periventricular hyperintensities (WMHs, PVHs) were checked by T1- and T2-weighted spin-echo and fluid attenuated inversion recovery sequences. Variables on the clinical and laboratory data and MR imaging abnormalities were compared between both groups with or without MBs and OHs. Results : MBs were observed in 186 (79.5%) patients and a total of 46 OHs were detected in 45 (19.2%) patients. MBs (39.6%), OHs (80.4%), and ICHs (69.7%) were most commonly located in the ganglionic/thalamic region. Both MBs and OHs groups were more frequently related to chronic hypertension and advanced WMHs and PVHs. The prevalence and number of MBs were more closely associated with OHs groups than non-OH patients. Conclusion : This study clearly demonstrated the presence of MBs and OHs and their correlation with hypertension and cerebral white matter microangiopathy in the ICHs patients. Topographic correlation between the three lesions (MBs, OHs, and ICHs) was also noted in the deep thalamo-basal location.

• Journal of Korean Neurosurgical Society
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• 제39권3호
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• pp.210-214
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• 2006

Objective : We investigate risk factors of cerebral microbleeds[MBs] and their relation to concomitant magnetic resonance[MR] findings in intracerebral hemorrhages[ICHs] patients. Methods : We studied 100 consecutive patients with primary ICH over a 1-year period. These patients underwent brain MR images using 3.0-T scanners within the first week of the hemorrhage. MBs and old hematomas were located and counted by using $T2^*-weighted$ gradient-echo MR imaging. We also counted lacunes and graded white matter and periventricular hyperintensity on T1- and T2-weighted spin-echo sequences. The association between MBs and vascular risk factors and MR abnormalities were analyzed. Results : MBs were seen in 77 of ICH patients, and their number ranged from 1 to 65 lesions [mean 11, median 6]. The locations of MBs were subcortex-cortex [40.6%], basal ganglia [26.7%], thalamus [14.1 %], brain stem [12.5%], and cerebellum [9.1 %]. Analysis of clinical data revealed that age, hypertension, history of stroke, and duration of hypertension were frequently associated with MBs. The incidence of lacunes, old hematomas, and advanced leukoaraiosis was significantly higher in the MBs group, compared with the patients without MBs. Conclusion : MBs are frequently observed in ICH patients with advancing age, chronic hypertension, and previous hemorrhagic stroke, and are also closely related with morphological signs of occlusive type microangiopathy, such as lacunar infarct and severe leukoaraiosis.

• Journal of Yeungnam Medical Science
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• 제40권3호
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• pp.225-232
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• 2023

Cognitive dysfunction is relatively less considered a complication of hypertension. However, there is sufficient evidence to show that high blood pressure in middle age increases the risk of cognitive decline and dementia in old age. The greatest impact on cognitive function in those with hypertension is on executive or frontal lobe function, similar to the area most damaged in vascular dementia. Possible cognitive disorders associated with hypertension are vascular dementia, Alzheimer disease, and Lewy body dementia, listed in decreasing strength of association. The pathophysiology of cognitive dysfunction in individuals with hypertension includes brain atrophy, microinfarcts, microbleeds, neuronal loss, white matter lesions, network disruption, neurovascular unit damage, reduced cerebral blood flow, blood-brain barrier damage, enlarged perivascular damage, and proteinopathy. Antihypertensive drugs may reduce the risk of cognitive decline and dementia. Given the high prevalence of dementia and its impact on quality of life, treatment of hypertension to reduce cognitive decline may be a clinically relevant intervention.

• Investigative Magnetic Resonance Imaging
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• 제19권2호
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• pp.107-113
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• 2015

Purpose: Susceptibility weighted imaging (SWI) is a new magnetic resonance technique that can exploit the magnetic susceptibility differences of various tissues. Intracranial hemorrhage (ICH) looks a dark blooming on the magnitude images of SWI. However, the pattern of ICH on phase images is not well known. The purpose of this study is to characterize hemorrhagic lesions on the phase images of SWI. Materials and Methods: We retrospectively enrolled patients with ICH, who underwent both SWI and precontrast CT, between 2012 and 2013 (n = 95). An SWI was taken, using the 3-tesla system. A phase map was generated after postprocessing. Cases with an intracranial hemorrhage were reviewed by an experienced neuroradiologist and a trainee radiologist, with 10 years and 3 years of experience, respectively. The types and stages of the hemorrhages were determined in correlation with the precontrast CT, the T1- and T2-weighted images, and the FLAIR images. The size of the hemorrhage was measured by a one- directional axis on a magnitude image of SWI. The phase values of the ICH were qualitatively evaluated: hypo-, iso-, and hyper-intensity. We summarized the imaging features of the intracranial hemorrhage on the phase map of the SWI. Results: Four types of hemorrhage are observed: subdural and epidural; subarachnoid; parenchymal hemorrhage; and microbleed. The stages of the ICH were classified into 4 groups: acute (n = 34); early subacute (n = 11); late subacute (n = 15); chronic (n = 8); stage-unknown microbleeds (n = 27). The acute and early subacute hemorrhage showed heterogeneous mixed hyper-, iso-, and hypo-signal intensity; the late subacute hemorrhage showed homogeneous hyper-intensity, and the chronic hemorrhage showed a shrunken iso-signal intensity with the hyper-signal rim. All acute subarachnoid hemorrhages showed a homogeneous hyper-signal intensity. All parenchymal hemorrhages (> 3 mm) showed a dipole artifact on the phase images; however, microbleeds of less than 3 mm showed no dipole artifact. Larger hematomas showed a heterogeneous mixture of hyper-, iso-, and hypo-signal intensities. Conclusion: The pattern of the phase value of the SWI showed difference, according to the type, stage, and size.

• 보험의학회지
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• 제28권1_2호
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• pp.11-14
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• 2009

It is common to find cerebral infarct and hemorrhage without definite neurologic signs but with lesions on neuroimaging. These lesions are called silent lacunar infarct and cerebral microbleed. Silent lacunar infarct are frequently seen in the elderly and are associated with clinically apparent stroke and vascular dementia. Known stroke risk factors, such as hypertension, diabetes mellitus, smoking, hypercholesterolemia and heart problems may increase the risk of silent lacunar infarct. Metabolic syndrome, homocysteinemia, renal failure and intima media thickness(IMT) are also other risk factors of the silent lacunar infarct. Cerebral microbleed, lacunar infarct and intracerebral hemorrhage(ICH) have similar pathology and pathogenesis. So, cerebral microbleed are coexisted with lacunar infarct, leukoaraiosis, hypertensive ICH and vascular dementia. Cerebral microbleed are associated with volume and recurrence of ICH. Also cerebral microbleed may reflect baseline status of blood brain barrior disruption. Silent lacunar infarct and cerebral microbleed are very important to clinical management, but in the aspect of insurance medicine and independent medical examiners, these lesions are not subject of evaluation for handicap.

• Investigative Magnetic Resonance Imaging
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• 제22권2호
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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 Medicine and Life Science
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• 제17권3호
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• pp.65-73
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• 2020

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a single-gene disease of the cerebral small blood vessels caused by mutations in the NOTCH3 gene on chromosome 19. Although CADASIL was known as a rare disease, recent research has suggested that the NOTCH variants could be found frequently even in the general population. The main clinical features included recurrent stroke, migraine, psychiatric symptoms, and progressive cognitive decline. On brain magnetic resonance imaging, patients with CADASIL showed multifocal white matter hyperintensity lesions, lacunar infarcts, microbleeds, and brain atrophy. Among them, lacunar infarcts and brain atrophy are important in predicting the clinical outcomes of patients with CADASIL. In the Jeju National University Hospital, we have diagnosed 213 CADASIL patients from 2004 to 2020. Most NOTCH3 mutations were located in exon 11 (94.4%), and p.Arg544Cys was the most common mutation. The mean age at diagnosis was 61.0±12.8 years. The most common presenting symptoms were ischemic stroke (24.4%), followed by cognitive impairment(15.0%), headache (8.9%), and dizziness(8.0%). Although the exact prevalence of CADASIL in Jeju is still unknown, the disease prevalence could be as high as 1% of the population considering the prevalence reported in Taiwan. Therefore, it is necessary to discover efficient biomarkers and genetic tests that can accurately screen and diagnose patients suspected of having CADASIL in this region. Ultimately, it is urgent to explore the exact pathogenesis of the disease to identify leading substances of treatment potential, and for this, multi-disciplinary research through active support from the Jeju provincial government as well as the national government is essential.

• 대한영상의학회지
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• 제83권3호
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• pp.486-507
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• 2022

뇌소혈관질환은 뇌 자기공명영상에서 흔히 관찰되는 혈관성 변화로 뇌백질 고신호강도, 뇌미세출혈, 열공성 경색, 혈관주위공간 등을 포함한다. 이러한 혈관성 변화가 알츠하이머병(Alzheimer's disease; 이하 AD)의 발병 및 진행과 관련되어 있고, 대표 병리인 베타 아밀로이드 및 타우 단백의 침착과도 연관되어 있다는 증거들이 축적되고 있다. 혈관성 변화는 생활습관 개선이나 약물 치료를 통해 예방과 개선이 가능하기 때문에 뇌소혈관질환과 AD 및 AD 생체지표의 관련성을 연구하는 것이 중요하다. 본 종설에서는 AD와 AD 생체지표에 대해 간략히 소개하고, AD와 혈관성 변화의 관련성에 대해 축적된 증거들을 제시한 다음, 뇌소혈관질환의 병태 생리와 MR 영상 소견을 설명하고자 한다. 또 뇌소혈관질환과 AD 진단의 위험도 및 AD 생체지표와의 관련성에 대한 기존 연구 결과들을 정리하고자 한다.

• Investigative Magnetic Resonance Imaging
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• 제18권4호
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• pp.290-302
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• 2014

목적: 자화율 강조 자기공명영상 (Susceptibility-weighted imaging)은 혈액분해산물, 석회화, 철 침착물을 발견하는데 있어 높은 민감도를 보이는 3D spoiled gradient-echo pulse sequence 이다. 본 임상화보는 자화율 강조 자기공명영상의 주된 임상적 적용에 대해 설명하고 논의하는 데에 그 목적이 있다. 대상과 방법: 자화율 강조 자기공명영상은 자기강도영상 (magnitude image)과 위상영상 (phase image)을 이용한 고해상도, 3D fully velocity-compensated gradient-echo sequence 에 기초를 두고 있다. 정맥 구조물의 가시성을 향상시키기 위해, 자기강도영상은 여과된 위상 데이터 (phase data) 로부터 발생된 위상 마스크 (phase mask)를 이용해 증폭되고, 이것은 최소강도투사 (Minimal intensive projection) 알고리즘을 이용한 3D dataset 후처리 과정을 거치게 된다. 3T 자기공명기기에서 SWI를 포함하는 자기공명영상 검사를 시행한 총 200명의 환자를 대상으로 연구하였다. 결과: 자화율 강조 자기공명영상은 다양한 뇌 질환의 발견에 매우 유용하였다. 200명의 환자 중 80명은 선천성 정맥 기형, 22명은 해면상 혈관종, 12명은 다양한 질환에서의 석회화, 21명은 혈관자화 징후 (susceptibility vessel sign) 또는 미세출혈을 동반하는 뇌혈관 질환, 52명은 뇌종양, 2명은 미만성 축삭 손상, 3명은 동정맥 기형, 5명은 뇌경막 동정맥루, 1명은 모야모야병, 그리고 2명은 파킨슨병이 관찰되었다. 결론: 자화율 강조 자기공명영상은 미세 저혈량 혈관성 병변, 석회화 그리고 미세출혈과 다양한 뇌병변의 진단에 유용하다.

• Investigative Magnetic Resonance Imaging
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• 제20권2호
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• pp.105-113
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• 2016

Purpose: Susceptibility vessel sign (SVS) on gradient echo image, which is caused by MR signal loss due to arterial thrombosis, has been reported in acute middle cerebral artery (MCA) infarction. However, the reported sensitivity and diagnostic accuracy of SVS have been variable. Susceptibility-weighted imaging (SWI) is a newly developed MR sequence. Recent studies have found that SWI may be useful in the field of cerebrovascular diseases, especially for detecting the presence of prominent veins, microbleeds and the SVS. The purpose of this study was to evaluate the diagnostic values of SWI for the detection of hyperacute MCA occlusion. Materials and Methods: Sixty-nine patients (37 males, 32 females; 46-89 years old [mean, 69.1]) with acute stroke involving the MCA territory underwent MR imaging within 6 hours after the symptom onset. MR examination included T2, FLAIR (fluid-attenuated inversion recovery), DWI, SWI, PWI (perfusion-weighted imaging), contrast-enhanced MR angiography (MRA) and contrast-enhanced T1. Of these patients, 28 patients also underwent digital subtraction angiography (DSA) within 2 hours after MR examination. Presence or absence of SVS on SWI was assessed without knowledge of clinical, DSA and other MR imaging findings. Results: On MRA or DSA, 34 patients (49.3%) showed MCA occlusion. Of these patients, SVS was detected in 30 (88.2%) on SWI. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of SWI were 88.2%, 97.1%, 96.8%, 89.5% and 92.8%, respectively. Conclusion: SWI was sensitive, specific and accurate for the detection of hyperacute MCA occlusion.