• Journal of The Korean Association For Science Education
• /
• v.26 no.4
• /
• pp.568-580
• /
• 2006

The purpose of this study was to investigate the brain activities by 4-types of Generating Process of Scientific Emotion (GPSE) in the hypothesis-generating biological phenomena by using fMRI. Four-types of GPSE were involved in the Basic Generating Process (BGP), Retrospective Generating Process (RGP), Cognitive Generating Process (CGP) and Attributive Generating Process (AGP). For this study, we made an experimental design capable of validating the 4-types of generating process (e.g. BGP, RGP, CGP and AGP), and then measured BOLD signals of 10 pre-service teachers' brain activities by 3.0T fMRI system. Subjects were 10 healthy females majoring in biology education. As a result, there were clear differences among 4-types of GPSE. Brain areas activated by BGP were at right occipital lobe (BA 17), at left thalamus and left parahippocampal gyrus, while in the case of RGP, at left superior parietal lobe (BA 8, 9), at left pulvinar and left globus pallidus were activated. Brain areas activated by CGP were the right posterior cingulate and left medial frontal gyrus (BA 6). In the case of AGP, the most distinctively activated brain areas were the right medial frontal gyrus (BA 8) and left inferior parietal lobule (BA 40). These results would mean that each of the 4-types of GPSE has a specific neural networks in the brain, respectively. Furthermore, it would provide the basis of brain-based learning in science education.

• The Korean Journal of Nuclear Medicine
• /
• v.37 no.1
• /
• pp.63-72
• /
• 2003

Functional MRI (fMRI) provides an indirect mapping of cerebral activity, based on the detection of the local blood flow and oxygenation changes following neuronal activity (Blood Oxygenation Level Dependent). fMRI allows us to study noninvasively the normal and pathological aspects of functional cortical organization. Each fMRI study compares two different states of activity. Echo-Planar Imaging is the technique that makes it possible to study the whole brain at a rapid pace. Activation maps are calculated from a statistical analysis of the local signal changes. fMRI is now becoming an essential tool in the neurofunctional evaluation of normal volunteers and many neurological patients as well as the reference method to image normal or pathologic functional brain organization.

• Korean Journal of Radiology
• /
• v.23 no.6
• /
• pp.625-637
• /
• 2022

With regard to the indolent clinical characteristics of prostate cancer (PCa), the more selective detection of clinically significant PCa (CSC) has been emphasized in its diagnosis and management. Magnetic resonance imaging (MRI) has advanced technically, and recent international cooperation has provided a standardized imaging and reporting system for prostate MRI. Accordingly, prostate MRI has recently been investigated and utilized as a triage tool before biopsy to guide tissue sampling to increase the detection rate of CSC beyond the staging tool for patients in whom PCa was already confirmed on conventional systematic biopsy. Radiologists must understand the current paradigm shift for better PCa diagnosis and management. This article reviewed the recent literature, demonstrating the diagnostic value of pre-biopsy prostate MRI with targeted biopsy and discussed unsolved issues regarding the paradigm shift in the diagnosis of PCa.

• Journal of the Korean Society of Radiology
• /
• v.82 no.3
• /
• pp.613-623
• /
• 2021

Purpose To evaluate the MRI findings and clinical factors that are characteristic of patients who ultimately undergo surgery for medial epicondylitis. Materials and Methods Fifty-two consecutive patients who were diagnosed with medial epicondylitis and underwent an elbow MRI between March 2010 and December 2018 were included in this retrospective study. The patients' demographic information, clinical data, and MRI findings were evaluated. All variables were compared between the conservative treatment and surgical treatment groups. Logistic regression analyses were conducted to identify which factors were associated with surgical treatment. Results Common flexor tear (CFT) tear size showed a statistically significant difference in both the transverse and longitudinal planes (p < 0.001, p = 0.013). The CFT abnormality grade significantly differed in both the transverse and longitudinal planes (p = 0.022, p = 0.003). A significant difference was also found in the medial collateral ligament abnormality (p = 0.025). Logistic regression analyses showed that only the transverse diameter of the CFT tear size (odds ratio: 1.864; 95% confidence interval: 1.264-2.750) was correlated with surgical treatment. Conclusion Of patients diagnosed with medial epicondylitis, patients with a larger transverse CFT tear size tend to undergo surgical treatment ultimately.

• Journal of the Korean Society of Radiology
• /
• v.81 no.5
• /
• pp.1184-1193
• /
• 2020

Purpose This study was performed to evaluate the relationship between callosal microbleeds and anoxic brain injury. Materials and Methods Twenty-seven patients with anoxic brain injuries were analyzed and retrospectively compared to the control group of patients without a history of anoxic brain injury using Fisher's exact test regarding comorbidities and cerebral microbleeds. The patient group was subdivided according to the presence of callosal microbleeds. Fisher's exact test was used to compare the presence of typical MRI findings of anoxic brain injury, use of cardiopulmonary resuscitation, and prognosis. The Mann-Whitney U test was used to compare the interval between the occurrence of anoxic brain injury to MRI acquisition. Results The prevalence of cerebral microbleeds in the patient group was 29.6%, which was significantly higher than that in the control group at 3.7% (p = 0.012). All cerebral microbleeds in the patient group were in the corpus callosum. Compared with the callosal microbleed-absent group, the callosal microbleed-present group showed a tendency of good prognosis (6/8 vs. 11/19), fewer typical MRI findings of anoxic brain injury (2/8 vs. 10/19), and more cardiopulmonary resuscitation (6/8 vs. 12/19), although these differences did not reach statistical significance (p = 0.35, p = 0.19, and p = 0.45, respectively). Conclusion Callosal microbleeds may be an adjunctive MRI marker for anoxic brain injury.

• Investigative Magnetic Resonance Imaging
• /
• v.11 no.1
• /
• pp.10-19
• /
• 2007

Conventional MRI methods using T1-, T2-, diffusion-, perfusion-weighting, and functional imaging rely on characterizing the physical and functional properties of the tissue. In this review, we introduce an imaging modality based on measured the mechanical properties of soft tissue, namely magnetic resonance elastography (MRE). The use of palpation to identify the stiffness of tissue remains a fundamental diagnostic tool. MRE can quantify the stiffness of the tissue thereby providing a objective means to measure the mechanical properties. To accomplish a successful clinical setting using MRE, hardware and software techniques in the area of transducer, pulse sequence, and imaging processing algorithm need to be developed. Transducer, a mechanical vibrator, is the core of MRE application to make wave propagate invivo. For this reason, considerations of the frame of human body, pressure and friction of the interface, and high magnetic field of a MRI system needs to be taken into account when designing a transducer. Given that the wave propagates through human body effectively, developing an appropriate pulse sequence is another important issue in obtaining an optimal image. In this review paper, we introduce the technical aspects needed for MRE experiments and introduce several applications of this new field.

• Investigative Magnetic Resonance Imaging
• /
• v.14 no.2
• /
• pp.115-120
• /
• 2010

Purpose : To separate and evaluate the low frequency spontaneous fluctuation BOLD signals from the functional magnetic resonance imaging data using sensorimotor active task. Materials and Methods : Twenty female archery players and twenty three control subjects were included in this study. Finger-tapping task consisted of three cycles of right finger tapping, with a subsequent 30 second rest. Blood oxygenation level-dependent (BOLD) data were collected using $T2^*$-weighted echo planar imaging at a 3.0 T scanner. A 3-D FSPGR T1-weighted images were used for structural reference. Image processing and statistical analyses were performed using SPM5 for active finger-tapping task and GIFT program was used for statistical analyses of low frequency spontaneous fluctuation BOLD signal. Results : Both groups showed the activation in the left primary motor cortex and supplemental motor area and in the right cerebellum for right finger-tapping task. ICA analysis using GIFT revealed independent components corresponding to contralateral and ipsilateral sensorimotor network and cognitive-related neural network. Conclusion : The current study demonstrated that the low frequency spontaneous fluctuation BOLD signals can be separated from the fMRI data using finger tapping paradigm. Also, it was found that these independent components correspond to spontaneous and coherent neural activity in the primary sensorimotor network and in the motor-cognitive network.

• Journal of the Korean Orthopaedic Association
• /
• v.54 no.2
• /
• pp.150-156
• /
• 2019

Purpose: This study examined the diagnostic accuracy of an imaging study to find the factors that affect the presence of residual tumors after an unplanned excision of sarcomas. Materials and Methods: Ninety-eight patients, who underwent a re-excision after unplanned surgery between January 2008 and December 2014, were enrolled in this study. Magnetic resonance imaging (MRI) was performed before reoperation in all patients. Positron emission tomography (PET)-computed tomography was performed on 54 patients. A wide re-excision and histology diagnosis were performed in all cases. The clinical variables were evaluated using univariate logistic regression and multivariate logistic regression. Results: The presence of a deep-seated tumor increases the risk of remnant tumors (odds ratio: 3.21, p=0.02, 95% confidence interval: 1.25-8.30). The sensitivity for detecting residual tumors is high in MRI (sensitivity 0.79). Conclusion: Deep-seated tumors have a significantly higher risk of remnant tumors. Because the negative predictive value of MRI and PET scans is very low, reoperation should be performed regardless of a negative result.

• Progress in Medical Physics
• /
• v.24 no.2
• /
• pp.108-118
• /
• 2013

Currently, an arterial spin labeling (ASL) magnetic resonance imaging (MRI) technique does not routinely used in clinical studies to measure perfusion in brain because optimization of imaging protocol is required to obtain optimal perfusion signals. Therefore, the objective of this study was to investigate changes of perfusion-weighed signal intensities with varying several parameters on a pulsed arterial spin labeling MRI technique obtained from a 3T MRI system. We especially evaluated alternations of ASL-MRI signal intensities on special brain areas, including in brain tissues and lobes. The signal targeting with alternating radiofrequency (STAR) pulsed ASL method was scanned on five normal subjects (mean age: 36 years, range: 29~41 years) on a 3T MRI system. Four parameters were evaluated with varying: 1) the labeling gap, 2) the labeling delay time, 3) the labeling thickness, and 4) the slice scan order. Signal intensities were obtained from the perfusion-weighted imaging on the gray and white matters and brain lobes of the frontal, parietal, temporal, and occipital areas. The results of this study were summarized: 1) Perfusion-weighted signal intensities were decreased with increasing the labeling gap in the bilateral gray matter areas and were least affected on the parietal lobe, but most affected on the occipital lobe. 2) Perfusion-weighted signal intensities were decreased with increasing the labeling delay time until 400 ms, but increased up to 1,000 ms in the bilateral gray matter areas. 3) Perfusion-weighted signal intensities were increased with increasing the labeling thickness until 120 mm in both the gray and white matter. 4) Perfusion-weighted signal intensities were higher descending scans than asending scans in both the gray and white matter. We investigated changes of perfusion-weighted signal intensities with varying several parameters in the STAR ASL method. It should require having protocol optimization processing before applying in patients. It has limitations to apply the ASL method in the white matter on a 3T MRI system.

• The Journal of the Korea Contents Association
• /
• v.15 no.9
• /
• pp.403-410
• /
• 2015

Since 1970, MRI has greatly been developing in terms of strength of magnetic field, the number of receipt channels, and short time of examination. With the development of digital systems and wireless network, hospitals have also acquired, saved, and managed digital images taken by various kinds of medical imaging equipment. However, domestic universities fail to provide practice training course independently thanks to expensive practice equipment and high maintenance cost, and rely on clinical training. Therefore, this study developed a MR patient diagnosis program based on Windows PC to help out students before their working in clinical filed. The designed Relational Database of MRI Simulator is made up of seven tables according to functions and data characteristics. Regarding the designed patient information, each stepwise function was classified by the patient registration method in clinical field. In addition, on the assumption of the basic information for diagnosis, each setting and content were classified. The menu by execution step was arrayed on the left side for easy view. For patient registration, a patient's name, gender, unique ID, birth date, weight, and other types of basic information were entered, and the patient's posture and diagnosis direction were set up. In addition, the body regions for diagnosis and Pulse Sequence were listed for selection. Also, Protocol name and other additional factors were allowed to be entered. The final window was designed to check diagnosis images, patient information, and diagnosis conditions. By learning how to enter patient information and change diagnosis conditions in this program, users will be able to understand more theories and terms learned in practice and thereby to shorten their learning time in actual clinical work.