• Journal of the Korean Society of Radiology
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• v.10 no.4
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• pp.241-246
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• 2016

The purpose of this study was to investigate the problems of low signal-to-noise ratio(SNR) of single-shot turbo spin echo(SS-TSE) by quantifying numerically decreased signal to noise ratio. Thirty five patients without brain disease underwent diffusion MRI in 3T scanner from July to October in 2015. Single shot echo planar imaging(SS-EPI) which is conventionally used in MRI was taken to compared SS-TSE in SNR of medulla oblongata. As a result, SNR of SS-TSE diffusion(b0=$314.41{\pm}42.96$, b1000=$117.33{\pm}14.04$) is than SS-EPI diffusion(b0=$514.84{\pm}48.97$, b=$208.65{\pm}25.70$) lower in b=0 image(38.9%) and b=1,000 image(43.8%). Thus, diffusion MR using SS-EPI of MS-EPI should be taken for diagnosis of disease in brain stem due to decreased SNR of diffusion using SS-TSE.

• Proceedings of the KSMRM Conference
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• 2003.10a
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• pp.94-94
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• 2003

목적： 기능적 자기공명영상과 확산텐서영상기법을 이용하여 전음성 난청과 감각신경성 난청에서의 뇌활성화 양상 그리고 청신경경로상의 차이점을 비교 연구하고자 하였다. 대상 및 방법： 전음성 난청군 (n=4)과 감각신경성 난청군(n=5) 그리고 정상군(n=5)에서의 기능적 자기 공명영상과 확산텐서영상을 획득하였다. 기능적 자기공명영상의 경우 1.5T Siemens MR scanner에서 BOLD 기법을 이용하여 500 Hz 순음 청각자극에 대한 뇌활성화 영역을 검출하였고 영상촬영시 발생하는 기계적 소음을 차폐하기 위한 청각자극기를 특별히 제작하여 사용하였다. 뇌백질신경로를 영상화하는 확산텐서영상은 3.0T GE whole body MR scanner를 사용하였으며 미세한 확산운동을 검출하기 위해 초고속 영상기법인 EPI 기법을 사용하였다. 영상의 화질을 높이기 위해 공간적으로 25개의 다른 방향으로 확산경사자장을 가하였다. 청신경로의 비등방성 영상, 신경로 방향 영상등을 구현하기 위해 획득한 확산영상들에 대한 영상 후처리과정을 시행하였다.

• The Korean Journal of Nuclear Medicine
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• v.25 no.1
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• pp.17-26
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• 1991

뇌 혈류의 기능적 영상화는 간질병소의 국소화에 이용되고 있으며 측두엽성간질의 편측화에 여러가지 진단 방법이 이용되고 있으나 만족할만한 결과를 보이지 못하고 있다. 최근 PET또는 SPECT를 이용하여 측두엽성간질에서 발작 간에 측두엽 병소의 대사율 및 혈류의 감소가 나타나며, 이러한 소견은 발작 유발 병소의 편측화에 매우 유용할것이라는 보고들이 있다. 저자들은 측두엽성간질에서 간질 병소를 편측화 하는데에 $^{99m}Tc-HMPAO$ SPECT의 유용성을 평가 하고자 측두엽성간질 31예에서 발작 간의 $^{99m}Tc-HMPAO$ SPECT 소견, 뇌파, 자기 공명 영상 및 전산화 단층 소견을 비교하였다. SPECT 소견에 따른 나이, 병력 기간과 병발시 나이 등의 임상 지수 간에는 유의한 차이가 없었다. 31예의 환자중 23예에서(74.2%) 국소 뇌 혈류 감소를 보였으며 17예(54.8%)에서 측두엽에 관류 감소가 관찰 되었다. 비인두 뇌파 표준 뇌파는 24예(77.4%)에서 측두엽에 편측화를 보였으며 SPECT와 뇌파 양자가 모두 편측화된 경우 일치도는 8/12예 (66.7%) 였다. 16예에서 시행된 전산화 단층 영상은 모두 편측화를 보이지 못했으며 27예에서 시행된 자기 공명 영상에서는 단지 1예에서 편측화를 보였다. 이상의 결과로서 발작 간의 $^{99m}Tc-HMPAO$ SPECT는 측두엽성간질 병소의 편측화에 유용한 보조 검사로 생각된다.

• Journal of the Korean Data and Information Science Society
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• v.20 no.3
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• pp.541-550
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• 2009

This research attempted to find out any implications for strategies to design and develop the connections between the activities of the brain function and the fields of English learning (dictation, word level, speaking, word memory, listening). Thus, in developing the brain based learning model for the English education, attempts need to be made to help learners to keep the whole brain toward learning. On this point, this study indicated the significant results for the exclusive brain location and the brainwaves on the each English learning field by the quantitative EEG analysis. The results of this study presented the guidelines for the balanced development of the left brain and the right brain to train the specific site of the brain connected to the English learning fields. In addition, whole brain training model is developed by the quantitative EEG data not by the theoretical learning methods focused on the right brain training.

• Neonatal Medicine
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• v.18 no.2
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• pp.310-319
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• 2011

Purpose: The aim of this study was to investigate the effect of perinatal risk factors on brain maturation and the relationship of brain maturation and neurodevelopmental outcomes with brain maturation scoring system in brain MRI. Methods: ELBWI infants born at the Seoul National University Children's Hospital from January 2006 to December 2010 were included. A retrospective analysis was performed with their medical record and brain MR images acquired at near full term. We read brain MRI and measured maturity with total maturation score (TMS). TMS is a previously developed anatomic scoring system to assess brain maturity. The total maturation score was used to evaluate the four parameters of maturity: (1) myelination, (2) cortical infolding, (3) involution of glial cell migration bands, and (4) presence of germinal matrix tissue. Results: Images from 124 infants were evaluated. Their mean gestational age at birth was 27.1${\pm}$2.1 weeks, and mean birth weight was 781.5${\pm}$143.9 g. The mean TMS was 10.8${\pm}$2.0. TMS was significantly related to the postmenstrual age (PMA) of the infant, increasing with advancing postmenstrual age (P<0.001). TMS showed no significance with neurodevelopmental delay, and with brain injury, respectively. Conclusion: TMS was developed for evaluating brain maturation in conventional brain MRI. The results of this study suggest that TMS was not useful for predicting neurodevelopmental delay, but further studies are needed to make standard score for each PMA and to re-evaluate the relationship between brain maturation and neurodevelopmental delay.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.5
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• pp.39-54
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• 2012

Picture Archiving and Communication System (PACS) has been planted as one of the key infrastructures with an overall improvement in standards of medical informationization and the stream of digital hospitalization in recent days. The kind and data of digital medical imagery are also increasing rapidly in volume. This trend emphasizes the medical image compression for storing large-scale medical image data. Digital Imaging and Communications in Medicine (DICOM), de facto standard in digital medical imagery, specifies Run Length Encode (RLE), which is the typical lossless data compressing technique, for the medical image compression. However, the RLE is not appropriate approach for medical image data with bilateral symmetry of the human organism. we suggest two preprocessing algorithms that detect interested area, the minimum bounding rectangle, in a medical image to enhance data compression efficiency and that re-code image pixel values to reduce data size according to the symmetry characteristics in the interested area, and also presents an improved image compression technique for brain CT imagery with high bilateral symmetry. As the result of experiment, the suggested approach shows higher data compression ratio than the RLE compression in the DICOM standard without detecting interested area in images.

• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.1
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• pp.12-16
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• 2015

Purpose Principal component analysis (PCA) is a method often used in the neuroimagre analysis as a multivariate analysis technique for describing the structure of high dimensional correlation as the structure of lower dimensional space. PCA is a statistical procedure that uses an orthogonal transformation to convert a set of observations of correlated variables into a set of values of linearly independent variables called principal components. In this study, in order to investigate the usefulness of PCA in the brain PET image analysis, we tried to analyze C[11]-PIB PET image as a representative case. Materials and Methods Nineteen subjects were included in this study (normal = 9, AD/MCI = 10). For C[11]-PIB, PET scan were acquired for 20 min starting 40 min after intravenous injection of 9.6 MBq/kg C[11]-PIB. All emission recordings were acquired with the Biograph 6 Hi-Rez (Siemens-CTI, Knoxville, TN) in three-dimensional acquisition mode. Transmission map for attenuation-correction was acquired using the CT emission scans (130 kVp, 240 mA). Standardized uptake values (SUVs) of C[11]-PIB calculated from PET/CT. In normal subjects, 3T MRI T1-weighted images were obtained to create a C[11]-PIB template. Spatial normalization and smoothing were conducted as a pre-processing for PCA using SPM8 and PCA was conducted using Matlab2012b. Results Through the PCA, we obtained linearly uncorrelated independent principal component images. Principal component images obtained through the PCA can simplify the variation of whole C[11]-PIB images into several principal components including the variation of neocortex and white matter and the variation of deep brain structure such as pons. Conclusion PCA is useful to analyze and extract the main pattern of C[11]-PIB image. PCA, as a method of multivariate analysis, might be useful for pattern recognition of neuroimages such as FDG-PET or fMRI as well as C[11]-PIB image.

• Proceedings of the KSMRM Conference
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• 2006.11a
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• pp.75-75
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• 2006

• Journal of Yeungnam Medical Science
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• v.16 no.2
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• pp.237-243
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• 1999

We conducted this study to find the optimal correction factor(${\alpha}$) of Lassen's linearization algorithm which has been applied for correction of flow-limited uptake at a high flow range in $^{99m}Tc$ d,l-hexamethylpropy leneamine oxime(HMPAO) and $^{99m}Tc$ ethyl cysteinate dimer(ECD). Ten patients with chronic cerebral infarction were involved in this study. We obtained the corrected $^{99m}Tc$ HMPAO and $^{99m}Tc$-ECD brain SPECT(single photon emission computed tomography) using the algorithm with ${\alpha}$ values that varied from 0.1 to 10 and compared the results with regional cerebral blood flow determined by positron emission tomography (PET-rCBF). The multi-modal volume registration by maximization of mutual information was used for matching between PET-rCBF and SPECT images. The highest correlation coefficient between $^{99m}Tc$-HMPAO and $^{99m}Tc$-ECD brain uptake and PET-rCBF was revealed at ${\alpha}$ 1.4 and 2.1, respectively. We concluded that the ${\alpha}$ values of Lassen's linearization algorithm for $^{99m}Tc$-HMPAO and $^{99m}Tc$-ECD brain SPECT images were 1.4 and 2.1, respectively to indicate cerebral blood flow with comparison of PET-rCBF.

• Investigative Magnetic Resonance Imaging
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• v.3 no.1
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• pp.53-59
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• 1999

Purpose : To evaluate the usefulness of functional MR imaging (fMRI) for language mapping and determination of language lateralization. Materials and Methods : Functional maps of the language area were obtained during word generation tasks and decision task in ten volunteers (7 right handed, 3 left-handed). MR examinations were performed at 1.5T scanner with EPI BOLD technique. Each task consisted of three resting periods and two activation periods with each period of 30 seconds. Total acquisition time was 162 sec. SPM program was used for the postprocessing of images. Statistical comparisons were performed by using t-statistics on a pixel-by- pixel basis after global normalization by ANCOVA. Activation areas were topographically analyzed (p>0.001) and activated pixels in each hemisphere were compared quantitatively by lateralization index. Results : Significant activation signals were demonstrated in 9 of 10 volunteers. Activation signals were found in the premotor and motor cortices, the inferior frontal, inferior parietal, and mid-temporal lobes during stimulation tasks. In the right handed seven volunteers, activation of language areas was lateralized to the left side. Verb generation task produced stronger activation in the language areas and higher value of lateralization index than noun generation task or decision task. Conclusion : fMRI could be a useful non-invasive method for language mapping and determination of language dominance.