• Proceedings of the Korean Society of Medical Physics Conference
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• 2003.09a
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• pp.46-46
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• 2003

Several MRI studies have reported reductions in temporal lobe volumes in Alzheimer´s disease (AD). Measures have been usually obtained with regions of interest (ROI) drawn manually on selected medial and lateral portions of the temporal lobes, with variable choices of anatomical borders across different studies. We used the automated voxel based morphometry (VBM) approach to investigate gray matter abnormalities over the entire extension of the temporal lobe in 11 AD patients (MMSE 14 - 25) and 11 healthy controls. Foci of significantly reduced gray matter volume in AD patients were detected in both medial and lateral temporal regions, most significantly in the right and left posterior parahippocampal gyri. At a more flexible statistical threshold (P<0.001, uncorrected for multiple comparisons), circumscribed foci of significant gray matter reduction were also detected in the right amygdala/enthorinal cortex, the anterior and posterior borders of the superior temporal gyrus bilaterally, and the anterior portion of the left middle temporal gyrus. These VBM results confirm previous findings of temporal lobe atrophic changes in AD, and suggest that these abnormalities may be confined to specific sites within that lobe, rather than showing a widespread distribution.

• The Journal of the Korea Contents Association
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• v.5 no.3
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• pp.45-51
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• 2005

This paper emphasizes on the accomplishment of compensated proton density image and T2 weighted image taken from the shrinkage surface of the Brain. From the images, the Brain's surface shrinkage in the normal image and the surface shrinkage in the abnormal image can be observed. After the separation of white matter, gray matter, and CSF, this algorithm calculates the volume of each of them automatically. Results are subdivided into particular ages and saved in the database to be analyzed and to be processed statistically. Therefore, by using this algorithm the normal and abnormal stages can be detected in the early stages to diagnose. This result easily discernment Alzheimer patient and is useful for Alzheimer diagnostic and early detection.

• Korean Journal of Biological Psychiatry
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• v.18 no.4
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• pp.232-238
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• 2011

Objectives Optimized voxel based morphometry (VBM) has been increasingly applied to investigate differences in the brain morphology between a group of patients with mild cognitive impairment (MCI) and control subjects. Optimized VBM permits comparison of gray matter (GM) volume at voxel-level from the entire brain. The purpose of this study was to assess the regional GM volume change measured by optimized VBM in MCI subjects compared to controls. Methods Twenty patients with MCI and 20 control subjects with normal cognition were recruited for this study. We applied the optimized VBM protocol to the image data including study-specific template and the modulation of the data with the Jacobian determinants. GM volume differences between the MCI subjects and the control subjects and their correlations with the neuropsychological performances were investigated. Results Optimized VBM analysis revealed GM volume reduction in hippocampus, precentral gyrus, insula and parietal operculum in the MCI group compared to the control group (family wise error corrected p < 0.05). Korean version of the Consortium to Establish a Registry for Alzheimer's disease (CERAD-K) word list recall scores were significantly correlated with the GM volumes of hippocampus, precuneus and posterior cingulate in the MCI group (FWE corrected p < 0.05). Conclusions The results confirm previous findings of atrophic changes in medial temporal lobe and parietal lobe in the MCI group and suggest that these abnormalities may be related with cognitive decline and prognosis in patients with MCI.

• Investigative Magnetic Resonance Imaging
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• v.19 no.1
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• pp.1-9
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• 2015

Purpose: Several morphometric studies have been performed to investigate brain abnormalities in congenitally deaf people. But no report exists concerning structural brain abnormalities in congenitally deaf adolescents. We evaluated the regional volume changes in gray matter (GM) using voxel-based morphometry (VBM) in congenitally deaf adolescents. Materials and Methods: A VBM8 methodology was applied to the T1-weighted magnetic resonance imaging (MRI) scans of eight congenitally deaf adolescents (mean age, 15.6 years) and nine adolescents with normal hearing. All MRI scans were normalized to a template and then segmented, modulated, and smoothed. Smoothed GM data were tested statistically using analysis of covariance (controlled for age, gender, and intracranial cavity volume). Results: The mean values of age, gender, total volumes of GM, and total intracranial volume did not differ between the two groups. In the auditory centers, the left anterior Heschl's gyrus and both inferior colliculi showed decreased regional GM volume in the congenitally deaf adolescents. The GM volumes of the lingual gyri, nuclei accumbens, and left posterior thalamic reticular nucleus in the midbrain were also decreased. Conclusions: The results of the present study suggest that early deprivation of auditory stimulation in congenitally deaf adolescents might have caused significant underdevelopment of the auditory cortex (left Heschl's gyrus), subcortical auditory structures (inferior colliculi), auditory gain controllers (nucleus accumbens and thalamic reticular nucleus), and multisensory integration areas (inferior colliculi and lingual gyri). These defects might be related to the absence of general auditory perception, the auditory gating system of thalamocortical transmission, and failure in the maturation of the auditory-to-limbic connection and the auditorysomatosensory-visual interconnection.

• Progress in Medical Physics
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• v.14 no.3
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• pp.203-210
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• 2003

PET (positron emission tomography) permits the investigation of physiological and biochemical processes in vivo. The accuracy of quantifying PET data is affected by its finite spatial resolution, which causes partial volume effects. In this study, we developed a method for partial volume correction using Hoffman phantom PET and MR data, and applied various FWHM (full width at half maximum) levels. We also applied this method to PET images of normal controls and tested for the possibility of clinical application. $^{18}$ F-PET Hoffman phantom images were co-registered to MR slices. The gray matter and white matter regions were then segmented into binary images. Each binary image was convolved by 4, 8, 12, 16 mm FWHM levels. These convolved images of gray and white matter were merged corresponding to the same level of FWHM. The original PET images were then divided by the convolved binary images voxel-by-voxel. These corrected PET images were multiplied by binary images. The corrected PET images were evaluated by analyzing regions of interests, which were drawn on the gray and white matter regions of the original MR image slices. We calculated the ratio of white to gray matter. We also applied this method to the PET images of normal controls. On analyzing the corrected PET images of Hoffman phantom, the ratios of the corrected images increased more than that of the uncorrected images. With the normal controls, the ratio of the corrected images increased more than that of the uncorrected images. The ratio increase of the corrected PET images was lower than that of the corrected phantom PET images. In conclusion, the method developed for partial volume correction in PET data may be clinically applied, although further study may be required for optimal correction.

• Journal of Biomedical Engineering Research
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• v.26 no.2
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• pp.73-86
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• 2005

We need to flatten the brain cortex to smooth surface, sphere, or 2D plane in order to view the buried sulci. The rendered 3D surface of the segmented white matter and gray matter does not have the topology of a sphere due to the partial volume effect and segmentation error. A surface without correct topology may lead to incorrect interpretation of local structural relationships and prevent cortical unfolding. Although some algorithms try to correct topology, they require heavy computation and fail to follow the deep and narrow sulci. This paper proposes a method that corrects topology of the rendered surface fast, accurately, and automatically. The proposed method removes fractions beside the main surface, fills cavities in the inside of the main surface, and removes handles in the surface. The proposed method to remove handles has three-step approach. Step 1 performs smoothing operation on the rendered surface. In Step 2, vertices of sphere are gradually deformed to the smoothed surfaces and finally to the boundary of the segmented white matter and gray matter. The Step 2 uses multi-resolutional approach to prevent the deep sulci from geometrical intersection. In Step 3, 3D binary image is constructed from the deformed sphere of Step 2 and 3D surface is regenerated from the 3D binary image to remove intersection that may happen. The experimental results show that the topology is corrected while principle sulci and gyri are preserved and the computation amount is acceptable.

• Investigative Magnetic Resonance Imaging
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• v.14 no.2
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• pp.103-114
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• 2010

Purpose : To generate a Korean specific brain template, especially in patients with Alzheimer's disease (AD) by optimizing the voxel-based analysis. Materials and Methods : Three-dimensional T1-weighted images were obtained from 123 subjects who were 43 cognitively normal subjects and patients with 44 mild cognitive impairment (MCI) and 36 AD. The template and the corresponding aprior maps were created by using the matched pairs approach with considering differences of age, gender and differential diagnosis (DDX). We measured several characteristics in both our and the MNI templates, including in the ventricle size. Also, the fractions of gray matter and white matter voxels normalized by the total intracranial were evaluated. Results : The high resolution template and the corresponding aprior maps of gray matter, white matter (WM) and CSF were created with the voxel-size of $1{\times}1{\times}1\;mm$. Mean distance measures and the ventricle sizes differed between two templates. Our brain template had less gray matter and white matter areas than the MNI template. There were volume differences more in gray matter than in white matter. Conclusion : Gray matter and/or white matter integrity studies in populations of Korean elderly and patients with AD are needed to investigate with this template.

• Korean Journal of Biological Psychiatry
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• v.16 no.3
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• pp.190-197
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• 2009

Objectives : The purpose of this study was to examine structural abnormalities of brain in patients with pathological gambling(PG) using voxel-based morphometry. Methods : We compared gray matter(GM) volumes between 10 patients with PG and 14 age- and IQ-matched healthy controls and examined the relationship of GM volumes with clinical variables in patients with PG. Results : We found significant increase of GM volume in the superior, middle, and inferior frontal gyri, the midbrain, the middle temporal gyrus, the precuneus, and the fusiform gyrus of patients with PG. A significant decrease of GM volume was observed in the parahippocampal gyrus and the lingual gyrus of the patient group. In addition, GM volumes in some of these regions were positively associated with South Oaks Gambling Screen score and negatively with age of onset in patients with PG. Conclusion : Current findings indicate that structural abnormalities in the fronto-temporal cortex, the midbrain, and the precuneus might be involved in the pathophysiology of PG, and contribute to some of the behavioral changes observed in patients with PG.

• Investigative Magnetic Resonance Imaging
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• v.24 no.2
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• pp.76-84
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• 2020

Background: Determination of inter-method differences between clinically available volumetry methods are essential for the clinical application of brain volumetry in a wider context. Purpose: The purpose of this study was to examine the inter-method reliability and differences between the Siemens morphometry (SM) software and the NeuroQuant (NQ) software. Materials and Methods: MR images of 86 subjects with subjective or objective cognitive impairment were included in this retrospective study. For this study, 3D T1 volume images were obtained in all subjects using a 3T MR scanner (Skyra 3T, Siemens). Volumetric analysis of the 3D T1 volume images was performed using SM and NQ. To analyze the inter-method difference, correlation, and reliability, we used the paired t-test, Bland-Altman plot, Pearson's correlation coefficient, intraclass correlation coefficient (ICC), and effect size (ES) using the MedCalc and SPSS software. Results: SM and NQ showed excellent reliability for cortical gray matter, cerebral white matter, and cerebrospinal fluid; and good reliability for intracranial volume, whole brain volume, both thalami, and both hippocampi. In contrast, poor reliability was observed for both basal ganglia including the caudate nucleus, putamen, and pallidum. Paired comparison revealed that while the mean volume of the right hippocampus was not different between the two software, the mean difference in the left hippocampus volume between the two methods was 0.17 ml (P < 0.001). The other brain regions showed significant differences in terms of measured volumes between the two software. Conclusion: SM and NQ provided good-to-excellent reliability in evaluating most brain structures, except for the basal ganglia in patients with cognitive impairment. Researchers and clinicians should be aware of the potential differences in the measured volumes when using these two different software interchangeably.

• Journal of radiological science and technology
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• v.43 no.6
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• pp.453-460
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• 2020

The price of the Brain phantom (Hoffman 3D brain phantom) used in nuclear medicine is quite expensive, it is difficult to be purchased by a medical institution or an educational institution. Therefore, the purpose of present research is to produce a low-price 3D brain phantom and evaluate its usefulness by using a 3D printer capable of producing 3D structures. The New 3D brain phantom consisted of 36 slices 0.7 mm thick and 58 slices 1.5 mm thick. A 0.7 mm thick slice was placed between 1. 5 mm thick slices to produce a composite slice. ROI was set at the gray matter and white matter scanned with CT to measure and compare the HU, in order to verify the similarity between PLA which was used as the material for the New 3D brain phantom and acrylic which was used as the material for Hoffman 3D brain phantom. As a result of measuring the volume of each Phantom, the error rate was 3.2% and there was no difference in the signal intensity in five areas. However, there was a significant difference in the average values of HU which was measured at the gray and white matter to verify the similarity between PLA and acrylic. By reproducing the previous Hoffman 3D brain phantom with a 100 times less cost, I hope this research could contribute to be used as the fundamental data in the areas of 3D printer, nuclear medicine and molecular imaging and to increasing the distribution rate of 3D brain phantom.