• Journal of the Korean Society of Radiology
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• v.82 no.1
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• pp.255-260
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• 2021

Primary central nervous system T-cell lymphoma (PCNSTL) is an extremely rare type of brain tumor. There are only few reports on the imaging findings of patients with PCNSTL. Herein, we report the imaging findings of a patient with peripheral T-cell lymphoma-not otherwise specified that presented with numerous small nodular and patchy strongly enhancing lesions on MRI.

• Korean Journal of Biological Psychiatry
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• v.4 no.1
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• pp.60-66
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• 1997

Objective : Accumulating evidence suggests a greater number of subcortical hyperintensities in the brain of patients with bipolar disorder. We studied the Clinical correlates of subcortical hyperintensities on magnetic resonance imaging in patients with Bipolar Disorder : Methods : Magnetic resonance images of the brain were obtained for 32 patients with bipolar disorder. The presence and location of hyperintensities were assessed. We compared clinical variables between patients with subcortical hyperintensities and patients without them. Results : Seven patients(21.8%) had subcortical hyperintensities, but among 8 patients who were 40 years or older, 5 patients(62%) had them. Age and age at onset of patients with subcortical hyperintensities were significantly older than patients without them. Psychotic symptoms were more frequent in patients with hyperintensities. Patients without hyperintensities had more familial loadings. Conclusion : Given the limitations of the study, our results should be seen as preliminary. This study, however, provides preliminary evidence supporting the notion that the onset, clinical feature and course of some bipolar disorders of late onset may be determined by underlying subcortical abnormalities, with such abnormalities being the consequence of factors related to aging or neurodegeneration(such as impaired cerebral circulation) rather than genetic factors which predispose to early-onset bipolar disorders.

• Journal of Biomedical Engineering Research
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• v.24 no.4
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• pp.241-246
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• 2003

To evaluate the usefulness if functional MR imaging(MRI) for the determination of language dominance system and to assess differences in the visual and auditory instrument language generation task according to activation task or activated area. Functional maps of the language area were obtained during visual and auditory instructions in word generation tasks in 6 healthy volunteer with right-handness were examined on a 1.5T scanner and the EPI BOLD technique, and three pulse sequence technique get of the true axial planes. Both task consisted of 96 phases including 6 activations and rests contents. Postprocessing were done on MRDx program by using cross correlation method. Two task compare the blain activation area surveyed of 1anguage lateralization index. To evaluated of the detection rates of Broca. Wernicke, pre-frontal lobe, Supplementary Motor Area (SMA) and pre-motor cortex areas and the differences of language lateraliaztion among two word generation task To lateralization index survey in 1anguage area on right and left in brain get to activation area pixel in brain. Compared to visual and auditory instrument task in the language areas get to the lateralization index. Two language generation task high detection rates of Broca and Wernicke areas. The visual instruction no detected in the auditory area, and auditory instruction no detected in the visual area. There was statistics significant different of them among language generation task. 1'his indicated that language area obtained image of the brain functional MR imaging usefulness in the visual and auditory task instrument.

• Journal of Veterinary Clinics
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• v.24 no.3
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• pp.406-409
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• 2007

A 12-year-old female mixed Chihuahua dog was referred because of acute blindness and progressive tetraparesis. Mutifocal lesions in the cerebrum were noted on brain magnetic resonance images and cerebrospinal fluid analysis showed monocytic pleocytosis. Based on these results, granulomatous meningoencephalitis (GME) was strongly suspected. Cerebral lesions were definitely diagnosed as GME based on histopathological findings and positive results of immunohistological stains of brain with T-cell marker (CD3). This report describes the clinical findings, diagnostic imaging characteristics, and immunohistopathologic features of GME in an old dog. In addition, this case demonstrates that clinical signs of GME were mediated by perivascular infiltration of T lymphocytes and identification of causes in T cell-mediated inflammation should be further studied.

• Investigative Magnetic Resonance Imaging
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• v.16 no.1
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• pp.67-75
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• 2012

Purpose : We studied enhanced method to view the vessels in the brain using Magnetic Resonance Angiography (MRA). Noticing that Maximum Intensity Projection (MIP) image is often used to evaluate the arteries of the neck and brain, we propose a new method for view brain vessels to stereo image in 3D space with more superior and more correct compared with conventional method. Materials and Methods: We use 3T Siemens Tim Trio MRI scanner with 4 channel head coil and get a 3D MRA brain data by fixing volunteers head and radiating Phase Contrast pulse sequence. MRA brain data is 3D rotated according to the view angle of each eyes. Optimal view angle (projection angle) is determined by the distance between eye and center of the data. Newly acquired MRA data are projected along with the projection line and display only the highest values. Each left and right view MIP image is integrated through anaglyph imaging method and optimal stereoscopic MIP image is acquired. Results: Result image shows that proposed method let enable to view MIP image at any direction of MRA data that is impossible to the conventional method. Moreover, considering disparity and distance from viewer to center of MRA data at spherical coordinates, we can get more realistic stereo image. In conclusion, we can get optimal stereoscopic images according to the position that viewers want to see and distance between viewer and MRA data. Conclusion: Proposed method overcome problems of conventional method that shows only specific projected image (z-axis projection) and give optimal depth information by converting mono MIP image to stereoscopic image considering viewers position. And can display any view of MRA data at spherical coordinates. If the optimization algorithm and parallel processing is applied, it may give useful medical information for diagnosis and treatment planning in real-time.

• Investigative Magnetic Resonance Imaging
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• v.3 no.2
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• pp.154-158
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• 1999

Purpose : The purpose of this study was to find the optimum TE value for enhancing $T_2^{*}$ weighting effect and minimizing the SNR degradation and to compare the BOLD effects according to the changes of TE in 1.5T and 3.0T MRI systems. Materials and Methods : Healthy normal volunteers (eight males and two females with 24-38 years old) participated in this study. Each volunteer was asked to perform a simple finger-tapping task (sequential opposition of thumb to each of the other four fingers) with right hand with a mean frequency of about 2Hz. The stimulus was initially off for 3 images and was then alternatively switched on and off for 2 cycles of 6 images. Images were acquired on the 1.5T and 3.0T MRI with the FLASH (fast low angle shot) pulse sequence (TR : 100ms, FA : $20^{\circ}$, FOV : 230mm) that was used with 26, 36, 46, 56, 66, 76ms of TE times in 1.5T and 16, 26, 36, 46, 56, 66ms of TE in 3.0T MRI system. After the completion of scan, MR images were transferred into a PC and processed with a home-made analysis program based on the correlation coefficient method with the threshold value of 0.45. To search for the optimum TE value in fMRI, the difference between the activation and the rest by the susceptibility change for each TE was used in 1.5T and 3.0T respectively. In addition, the functional $T_2^{*}$ map was calculated to quantify susceptibility change. Results : The calculated optimum TE for fMRI was $61.89{\pm}2.68$ at 1.5T and $47.64{\pm}13.34$ at 3.0T. The maximum percentage of signal intensity change due to the susceptibility effect inactivation region was 3.36% at TE 66ms in 1.5T 10.05% at TE 46ms in 3.0T, respectively. The signal intensity change of 3.0T was about 3 times bigger than of 1.5T. The calculated optimum TE value was consistent with TE values which were obtained from the maximum signal change for each TE. Conclusion : In this study, the 3.0T MRI was clearly more sensitive, about three times bigger than the 1.5T in detecting the susceptibility due to the deoxyhemoglobin level change in the functional MR imaging. So the 3.0T fMRI I ore useful than 1.5T.

• Investigative Magnetic Resonance Imaging
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• v.9 no.1
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• pp.2-8
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• 2005

Purpose : The purpose of this study was to implement a software to visualize tumor and its surrounding fiber tracts simultaneously using diffusion tensor imaging and examine the feasibility of our software for investigating the influence of tumor on its surrounding fiber connectivity. Material and Methods : MR examination including T1-weigted and diffusion tensor images of a patient with brain tumor was performed on a 3.0 T MRI unit. We used the skull-striped brain and segmented tumor images for volume/surface rendering and anatomical information from contrast-enhanced T1-weighted images. Diffusion tensor images for the white matter fiber-tractography were acquired using a SE-EPI with a diffusion scheme of 25 directions. Fiber-tractography was performed using the streamline and tensorline methods. To correct a spatial mismatch between T1-weighted and diffusion tensor images, they were coregistered using a SPM. Our software was implemented under window-based PC system. Results : We successfully implemented the integrated visualization of the fiber tracts with tube-like surfaces, cortical surface and the tumor with volume/surface renderings in a patient with brain tumor. Conclusion : Our result showed the feasibility of the integrated visualization of brain tumor and its surrounding fiber tracts. In addition, our implementation for integrated visualization can be utilized to navigate the brain for the quantitative analysis of fractional anisotropy to assess changes in the white matter tract integrity of edematic and peri-edematic regions in a number of tumor patients.

• Investigative Magnetic Resonance Imaging
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• v.7 no.1
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• pp.47-55
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• 2003

Purpose : Cortical dysplasia is known to be of variety of MR imaging findings. We attempted to classify MR imaging findings of cortical dysplasia into several types and to correlate those with histopathologic grades and subtypes. Materials and Methods : Preoperative MR images of 97 patients with pathologically-proven cortical dysplasia were retrospectively reviewed with knowledge of the diagnosis and operative sites. The patients were divided into MR-positive and MR-negative groups based on the presence or absence of MR imaging abnormalities. In MR-positive group, MR imaging features were arbitrarily classified into four types (atrophic, cortical-band, inward-rounding, and nonspecific types) on the basis of size of the gyrus and adjacent CSF space, cortical thickness, signal intensity of the subcortical white matter, and blurring of the gray-white matter junction. The pathologic findings were also retrospectively reviewed without knowledge of MR imaging findings and divided into three grades (mild, moderate, and severe) and two subtypes (nonballoon-cell and balloon-cell). Pathologic grades and subtypes we re compared between MR-positive and MR-negative groups. Four MR types of the MR-positive group were correlated with the pathologic grades and subtypes. Results : MR-positive and MR-negative groups consisted of 39 (40%) and 58 (60%) patients, respectively. Of the MR-positive group, atrophic type was seen in 13 patients (33 %), cortical-band type in 9 (23%), inward-rounding type in 9 (23%), and nonspecific type in 8 (21%). There was no significant difference in the pathologic grades between MR-positive and MR-negative groups, although MR-positive group tended to have higher pathologic grades than MR-negative group did. Balloon-cell subtype was found significantly higher in MR-positive group than in MR-negative group (p<0 .05): 21% (8/39) versus 5% (3/58). The inward-rounding type corresponded to the pathologically severe grade and balloon-cell subtype in 78% (7/9) and 56% (5/9) of the patients, respectively, while the atrophic type to the mild grade and nonballoon-cell subtype in 77% (10/13) and 100% (13/13), respectively. Conclusion : A variety of MR imaging abnormalities were found in 40% of the patients with cortical dysplasia and those were classified into four types (atrophic, cortical-band, inward-rounding, and nonspecific types), of which the inward-rounding type correlated well with the pathologically severe grade and balloon-cell subtype, whereas the atrophic type with the mild grade and nonballoon-cell subtype.

• Clinical and Experimental Pediatrics
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• v.50 no.9
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• pp.901-904
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• 2007

Purpose : Reversible posterior leukoencephalopathy syndrome is a complex disorder with characteristic clinical and radiologic findings that mainly involve the white/gray matter of the parieto-occipital lobes. The purpose of this study was to determine its clinical and radiological characteristics. Methods : A total of 15 pateints were involved in the study. Their medical records and radiological features of brain MRI were retrospectively reviewed and analyzed. Results : Fifteen pateints were involved. (9 males and 5 females). The patients' ages ranged from 2-20 years (mean age : 10 years). The brain MRI revealed fairly symmetric areas of increased T2 signal involving both white and gray matter of parieto-occipital regions. The condition seemed to be associated with cyclosporin A and steroid therapy or a variety of other conditions in which blood pressure rises acutely. Conclusion : Reversible posterior leukoencephalopathy syndrome is a complicated neurological condition, but a better understanding of this complex syndrome may obviate unnecessary investigations and lead to prompt and appropriate management of the associated problems.

• Journal of Korean Neurosurgical Society
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• v.30 no.3
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• pp.389-394
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• 2001

Cerebral dural sinus thrombosis(CDST) has been described as a rare disease with a variety of patho-etiological factors. The diagnosis of CDST is difficult due to various symptoms and signs, none of which is specific to CDST. But timely diagosis is critical for effective management. The introduction and widespread use of computed tomography(CT), magnetic resonance imaging(MRI) and cerebral angiography made early diagnosis of CDST possible. In particular, MR venography is the most useful tool for establishing a correct diagnosis quickly. In early literature, mortality ranked between 30% and 50% but in more recent series it is between 5.5% and 30%. With the advent of diagnostic and therapeutic tools, early diagnosis and proper management has made the prognosis better. The appropriate therapy for CDST, however, has been the subject of much cortroversy. Individual variations of the venous system and collateral vessels are key factors to decide the proper treatment. In this report, we present two cases with symptomatic CDST treated without open surgical or direct endovascular interventions with good outcome.