• Investigative Magnetic Resonance Imaging
• /
• v.12 no.2
• /
• pp.188-196
• /
• 2008

Purpose : To describe the clinical, MR imaging, and pathologic findings of pediatric meningiomas. Materials and Methods : The authors retrospectively reviewed the medical records and MR images of 16 pediatric patients with pathologically proven meningioma. Mean patient age at diagnosis was 14 years (range, 3-18). MR images were reviewed for details of lesion sizes, locations, signal intensity (SI), marginal characteristics, internal architectures, enhancements, and dural and parenchymal changes. The findings of other imaging modalities and of pathological examinations were also analyzed. Results : Mean tumor size was 5.24 cm (range, 1.3-18.1 cm) and locations were supratentorial in 12 and infratentorial in 4. SI of masses were variable, that is, high in 9, iso in 4, and low in 3 on T2 weighted images (T2WI), and low (n=11), iso (n=4), or high (n=1) on T1WI images. All lesions were visualized as well-demarcated enhancing masses. Five of the tumors were heterogeneous with cystic or necrotic components. Dural attachment was observed in 11 patients and adjacent brain edema in 10. Tumors exhibited hyperdense (n=6) or isodense (n=4) on non-enhanced CT scans, and 3 of the 7 angiograms demonstrated blood supply from the internal carotid artery. Pathologic examinations revealed the following subtypes; transitional cell (n=4), meningotheliomatous (n=4), chordoid (n=2), fibrous (n=2), clear cell (n=1), hyalinized (n=1), rhabdoid papillary (n=1), and atypical (n=1). Conclusion : Pediatric meningiomas occur usually in teenagers, have diverse pathological types, and may produce atypical imaging findings, such as, a heterogeneous internal content or findings suggestive of intraaxial tumors.

• Investigative Magnetic Resonance Imaging
• /
• v.18 no.4
• /
• pp.352-356
• /
• 2014

A 51-year-old man developed anterograde amnesia following the ingestion of glufosinate ammonium. Brain MRI revealed hyperintense lesions involving the bilateral hippocampus and parahippocampal gyrus, and the right occipital lobe. The mechanism underlying acute glufosinate ammonium intoxication and the differential diagnosis of hippocampal lesions are discussed.

• Korean Journal of Biological Psychiatry
• /
• v.28 no.2
• /
• pp.36-49
• /
• 2021

Suicide is a leading cause of death worldwide, especially among adolescents and young adults. Considering this fact, it is imperative that we understand the neural mechanisms underlying suicidal thoughts and behaviors in youth from a neurodevelopmental perspective. In this review, we focused on the magnetic resonance imaging studies that examined the neural correlates of suicidal ideations (SI) or attempts (SA) in youth. We reviewed twenty-three cross-sectional studies reporting the structural and functional alterations in association with SI or SA among adolescents and young adults with various mental disorders. The previous literature suggests that the dorsolateral prefrontal cortex, anterior cingulate cortex, and ventral frontolimbic circuit, may play an important role in the pathophysiology of suicidal behavior in youth through altered top-down control over emotion and impulsivity. Future studies with a longitudinal design and using multimodal imaging techniques may be of help to identify novel therapeutic targets specific for youth with suicidal thoughts and behaviors.

• Investigative Magnetic Resonance Imaging
• /
• v.9 no.1
• /
• pp.9-15
• /
• 2005

Purpose : This study attempted to investigate the effects of supply of highly concentrated $(30\%)$ oxygen on human ability of visuospatial cognition using time course data analysis of functional Magnetic Resonance Imaging (fMRI). Materials and Methods : To select an item set in the visuospatial performance test, two questionnaires with similar difficulty were developed through group testing. A group test was administered to 263 college students. Two types of questionnaire containing 20 questions were developed to measure the ability of visuospatial cognition. Eight college students (right-handed male, average age of 23.5 yrs) were examined for fMRI study. The experiment consisted of two runs of the visuospatial cognition testing, one with $21\%$ level of oxygen and the other with $30\%$ oxygen level. Each run consisted of 4 blocks, each containing control and visuospatial items. Functional brain images were taken from 37 MRI using the single-shot EPI method. Using the subtraction procedure, activated areas in the brain during visuospatial tasks were color-coded by t-score. To investigate the time course data in each activated area from brain images, 4 typical regions (cerebellum, occipital lobe, parietal lobe, and frontal lobe) were selected. Results : The average accuracy was $50.63{\pm}8.63$ and $62.50{\pm}9.64$ for $21\%\;and\;30\%$ oxygen respectively, and a statistically significant difference was found in the accuracy between the two types of oxygen (p<0.05). There were more activation areas observed at the cerebellum, occipital lobe, parietal lobe and frontal lobe with $30\%$ oxygen administration. The rate of increase in the cerebellum, occipital lobe and parietal lobe was $17\%$ and that of the frontal lobe, $50\%$. Especially, there were increase of intensity of BOLD signal at the parietal lobe with $30\%$ oxygen administration. The increase rate of the left parietal lobe was $1.4\%$ and that of the right parietal lobe, $1.7\%$. Conclusion : It is concluded that while performing visuospatial tasks, high concentrations of oxygen administration make oxygen administration sufficient, thus making neural network activate more, and the ability to perform visuospatial tasks increase.

• Journal of Biomedical Engineering Research
• /
• v.25 no.4
• /
• pp.243-251
• /
• 2004

This study was to quantitative analysis compare to dynamic characteristic change of the regional cerebral blood volume (rCBV) after development of cerebral fat embolism in cats using perfusion MR Imaging. Forty-four adult rats were used. Triolein (n = 15), oleic acid (n = 9) and linoleic acid (n = 11) were injected into the internal carotid artery using microcatheter through the transfemoral approach. Polyvinyl alcohol (Ivalon) (n = 9) was injected as a control group. Perfusion MR images were obtained at 30 minutes and 2 hours after embolization, based on T2 and diffusion-weighted images. The data was time-to-signal intensity curve and ΔR$_2$＊ curve were obtained continuously with the aid of home-maid image proc in.leased significantly at 2 hours compared with those of 30 minutes (P＜0.005). In conclusion, cerebral blood flow decreased in cerebral fat embolism immediately after embolization and recovered remarkably in time course. It is thought that clinically informations to dynamic characteristic change of the cerebral hemodynamics to the early finding in cerebral infarction by DWI and PWI

• Investigative Magnetic Resonance Imaging
• /
• v.4 no.1
• /
• pp.34-41
• /
• 2000

Purpose: To evaluate the clinical usefulness of diffusion weighted MR imaging(DWI) in the differential diagnosis of brain tumors. Materials and methods: DWI and conventional MR images of nineteen patients with brain tumors(10 metastatic tumors, 4 high grade gliomas, 4 low grade astrocytomas, one oligodendroglioma)were obtained on 1.5T unit. DWI was obtained using single shot spin echo planar imaging with b-value near 1000. We analyzed the signal intensities of lesions including solid portion, necrotic or cystic portion and peritumoral edema of brain tumors (classified five grades comparison with the signal intensities of brain parenchyma and CSF)and calculate the SIR(signal intensity ratio)of lesions to the contralateral normal brain parenchyma. We analyzed statistically the signal intensities and SIR of tumors using independence T test. Results: In solid portions of tumors, all the metastatic tumors and high grade gliomas showed high signal intensities, but low grade astrocytomas and oligodendroglioma showed iso or slight high signal intensities to the normal brain parenchyma. The SIR of solid portion has positive correlation with malignant pot ential(metastatic tumors 1.52, high grade gliomas 1.38, low grade astrocytomas 1.16, oligodendroglioma 1.31)(p < 0.05). In peritumoral edema where seen in 14 tumors, seven of 10 metastatic tumors and two of 4 high grade gliomas showed iso signal intensities, whereas edemas in other 5 brain tumors showed hyperintense to the normal brain parenchyma. The SIRs of peritumoral edemas in metastatic tumors (1.14) was lower than high grade gliomas(1.31),but statistically insignificant. The SIR of cystic or necrotic portion of brain tumors was 0.63. In non enhancing solid portions, three of six cases showed hyperintense to the adjacent peritumoral edema. Conclusion: On DWI, the signal intensities of solid portion has positive correlation with malignant potential, and perilesional edema of brain tumors appear various signal intensities owing to "T2 shine through effect" and the extensiveness of vasogenic edema. Another merit using DWI on the evaluation of brain tumors is to improved better delineation of tumor margins from the adjacent edemas, especially at the non enhancing solid portion of the tumors.

• Korean Journal of Biological Psychiatry
• /
• v.22 no.3
• /
• pp.109-112
• /
• 2015

Since the early 2000s, there has been a continued interest in lie detection using functional magnetic resonance imaging (fMRI) in neuroscience and forensic sciences, as well as in newly emerging fields including neuroethics and neurolaw. Related fMRI studies have revealed converging evidence that brain regions including the prefrontal cortex, anterior cingulate cortex, parietal cortex, and anterior insula are associated with deceptive behavior. However, fMRI-based lie detection has thus far not been generally accepted as evidence in court, as methodological shortcomings, generalizability issues, and ethical and legal concerns are yet to be resolved. In the present review, we aim to illustrate these achievements and limitations of fMRI-based lie detection.

• Proceedings of the Optical Society of Korea Conference
• /
• 2009.10a
• /
• pp.151-152
• /
• 2009

최근 신경과학 분야에서 대뇌피질 영역 간 연관성 분석은 신경학적 질병 (자폐증, 간질, 정신 분열증)의 분석 및 진단에 적용되고 있다. 기존 대뇌피질 영역 간 연관성 분석은 뇌전도 (EEG), 기능적 자기공명영상 (fMRI), 뇌자도 (MEG)등이 이용되었지만, 뇌전도의 낮은 공간분해능, 기능적 자기공명영상의 낮은 시분해능 등은 영역 간 연관성 분석에 단점으로 작용되고 있다. 반면, 근적외선 분광법(NIRS)은 대뇌피질에서의 혈류변화(oxy-, deoxy-hemoglobin)를 비침습적이며 빠른 시분해능으로 측정할 수 있는 방법으로 최근 신경과학 분야에 응용되고 있다 [1-2]. 본 논문에서는 근적외선 분광법을 이용한 대뇌피질영역 간 연관성 분석의 효용성을 입증하기 위해, 쥐의 수염자극 시 대응되는 지역 (일차-, 이차 체감각피질, 일차 운동피질 영역)에서의 혈류변화 신호의 영역 간 연관성 분석을 하였다. 본 연구결과에 의하면 수염자극 시 일차-, 이차 체감각피질 영역에서의 방향성은 확인할 수 없었고, 일차-, 이차 체감각피질 영역에서 일차 운동피질영역으로의 방향성은 확인할 수 있었다. 본 결과는 기존 수염자극 시 활성화되는 전기신호의 패턴과 일치하며, 향후 신경과학적 질병의 분석 및 진단에 근적외선을 이용한 대뇌피질 영역 간 연관성 분석이 유용할 수 있음을 보여준다.

• Clinical and Experimental Pediatrics
• /
• v.49 no.2
• /
• pp.212-216
• /
• 2006

Neurocutaneous melanosis is a rare congenital syndrome characterized by the presence of large or multiple congenital melanocytic nevi and benign pigment cell tumors of the leptomeninges. Neurocutaneous melanosis is thought to represent an error in the morphogenesis of embryonal neuroectoderm. We experienced a neonate who presented with giant, dark colored pigmented nevi covering chest, abdomen, neck and arms, with satellite lesions. Magnetic resonance image showed a nodular hyperintense lesion in the amygdala of the right temporal lobe, and T1-weighted images showed hyperintensities in the adjacent leptomeninges. We report a rare case of neurocutaneous melanosis with a brief review of related literature.

• Investigative Magnetic Resonance Imaging
• /
• v.14 no.2
• /
• pp.126-133
• /
• 2010

Purpose : The study was to evaluate the localization of the abnormal gyral and sulcal patterns obtained by means of brain surface rendering imaging. Materials and Methods : Nineteen patients with cortical dysplasia who underwent brain surface rendering MR imaging were included in this study. We acquired MP-RAGE sequence and created the 3-D surface rendering MR images by using $VoxelPlus^{(R)}$. Anatomical locations and configurations of abnormal gyri and sulci were reviewed. Results : Abnormal gyral and sulcal patterns were seen 18 in 19 patients. The configuration and orientation of affected gyri and sulci were clearly evaluated in the brain surface rendering images. In a lissencephaly, the a cortex was not delineated and showed markedly thick and smooth gyral pattern. In a schizencephaly, there were wheel shaped broad gyral pattern around the cleft. In a hemimegalencephaly, an affected hemisphere were enlarged and displayed thick and wide gyral pattern. In CBPS, the insular cortex was exposed and the gyri of the lesion were thickened. In focal cortical dysplasia, there were irregular serrated or thick and enlarged gyri. Conclusion : Brain surface rendering MR imaging is useful for the evaluation of a detailed gyral pattern and accurate involvement site of abnormal gyri.