• Investigative Magnetic Resonance Imaging
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• v.12 no.2
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• pp.148-152
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• 2008

Purpose : To find the MR findings and evaluate the usefulness of MR in flexor hallucis longus(FHL) dysfunction. Materials and Methods : From 1992 to 2003, fourty patients were found to have surgically confirmed FHL dysfunction. 24 cases of 22 patients who had performed MR were included in this study. We analyzed the signal intensity of FHL tendon and muscle, tendon sheath, sheath effusion, and bone lesions, retrospectively. Results : Non-specific, increased sheath effusion of FHL tendon was seen in 12 cases (50%). Large amount of sheath effusion(grade 3) was observed in 5 cases (21%). The signal intensity of FHL tendon was normal in all cases. High signal intensity at the FHL muscle, proximal to musculotendinous junction was seen in 1 case (4%). One case (4%) of marrow edema of the talus and another one case (4%) of osteochondritis dissecans of the talus was seen. Conclusion : Non-specific, increased sheath effusion of FHL tendon was observed on MR in FHL dysfunction patients. Therefore, MR has a limited role in diagnosis of FHL dysfunction and is useful to exclude other bone and tendon diseases causing medial ankle pain.

• Journal of the Korean Arthroscopy Society
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• v.12 no.3
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• pp.191-197
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• 2008

Purpose: To evaluate the postoperative magnetic resonance image (MRI) findings of anterior cruciate ligament (ACL) reconstructed with a tension load technique using auto-Achilles tendon, and to compare the results with knees with a native ACL. Materials and Methods: We evaluated 21 postoperative MRI scan of 21 patients (group A) who had undergone ACL reconstruction between January 1995 and November 1996. The control group (group B) consisted of 50 patients whose meniscus tear had been operated by arthroscopy and whose ACL was intact. We measured the orientation of the graft in the sagittal and coronal planes and compared it with that of the native ACL. Results: The mean sagittal angle of the ACL angle in group A ($55.7{\pm}5.6^{\circ}$, range $47.2{\sim}68.8^{\circ}$) was statistically lesser than group B ($58.7{\pm}3.8^{\circ}$, range $50.4{\sim}67.5^{\circ}$) (p=0.036). But there was no statistically significant difference between the two groups with regard to the mean ACL-Blumensaat line angle (group A: $8.1^{\circ}{\pm}4.9^{\circ}$, range $1.7^{\circ}{\sim}22.0^{\circ}$, group B: $8.6^{\circ}{\pm}3.6^{\circ}$, range $2.6^{\circ}-18.1^{\circ}$) and the mean coronal angle of the ACL (group A: $64.9^{\circ}{\pm}9.1^{\circ}$, range $46.9^{\circ}{\sim}76.4^{\circ}$, group B: $65.9^{\circ}{\pm}4.4^{\circ}$, range $57.7^{\circ}{\sim}75.2^{\circ}$)(p=0.88, p= 0.62). In the sagittal plane, the mean center of tibial insertion of the ACL graft in group A ($31.9{\pm}7.1%$, range 22.4-47.9%) was positioned more anteriorly than group B ($37.0{\pm}4.9%$, range $18.5{\sim}44.7%$)(p=0.005). But in the coronal plane, there was no statistically significant difference between the two groups(group A: $46.3{\pm}2.8%$, range $42.1{\sim}52.5%$, group B: $45.7{\pm}2.8%$, range $41.0{\sim}49.1%$)(p=0.392). Conclusion: We performed an ACL reconstruction with the tension load technique using auto-Achilles tendon and we found that the graft orientation in MRI was as good as that of the native ACL.

• Progress in Medical Physics
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• v.19 no.2
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• pp.95-101
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• 2008

In this study, we observed the alteration of choline signal intensity in hippocampus region of the depressive rat model induced by forced swimming test (FST). The purpose of this study was to evaluate the antidepressant efficacy in the depressive animal model using MR spectroscopy. Fourteen experimentally naive male Sprague-Dawley rats weighting $160{\sim}180\;g$ were used as subjects. Drug injection group was exposed to the FST except for control group. The drugs were administered subcutaneously (SC) in a volume equivalent to 2ml/kg. And three injections were administered 23, 5, and 1h before beginning the given test. 1H MR spectra were obtained with use of a point resolved spectroscopy (PRESS) localization sequence performed according to the following parameters: repetition time, 2500 ms; echo time, 144 ms; 512 average; 2048 complex data points; voxel dimensions, $1.5{\times}2.5{\times}2.5\;mm^3$ ; acquisition time, 25min. There were no differences in NAA/Cr and Cho/Cr ratio between the right and the left hippocampus both normal control rats and antidepressant-injected rats. Also, no differences were observed in NAA/Cr and Cho/Cr ratio between the normal control rats and the antidepressant-injected rats both the right and the left hippocampus. In this study, we found the recovery of choline signals in the depressive animal model similar to normal control groups as injecting desipramine-HCl which was antidepressant causing anti-immobility effects. Thus, we demonstrated that MR spectroscopy was able to aid in evaluating the antidepressant effect of desipramine-HCl.

• Science of Emotion and Sensibility
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• v.22 no.1
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• pp.35-44
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• 2019

Individuals with problematic hypersexual behavior (PHB) evince the inability to control sexual impulses and arousal. Previous studies have identified that these characteristics are related to structural and functional changes in the brain region responsible for inhibitory functions. However, very little research has been conducted on the functional connectivity of these brain areas during the resting state in individuals with PHB. Therefore, this study used functional magnetic resonance imaging devices with the intention of identifying the deficit of the functional connectivity in the executive control network in individuals with PHB during the resting state. Magnetic resonance imaging data were obtained for 16 individuals with PHB and 19 normal controls with similar demographic characteristics. The areas related to the executive control network (LECN, RECN) were selected as the region of interest, and the correlation coefficient with time series signals between these areas was measured to identify the functional connectivity. Between groups analysis was also used. The results revealed a significant difference in the strength of the functional connectivity of the executive control network between the two groups. In other words, decreased functional connectivity was found between the superior/middle frontal gyrus and the caudate, and between the superior/middle frontal gyrus and the superior parietal gyrus/angular gyrus in individuals with PHB. In addition, these functional Connectivities related to the severity of hypersexual behavior. The findings of this study suggest that the inability to control sexual impulses and arousal in individuals with PHB might be related to the reduced functional connectivity of executive control circuits.

• Korean Journal of Cognitive Science
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• v.19 no.1
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• pp.75-88
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• 2008

Visual scene contains lots of redundant information. To process this redundant information without increasing brain's volume, human visual system may summarize incoming information. If similar but different information are given to visual system, visual system extracts statistical properties of the information. One example of the statistical representation is representation of mean size. The mean representation is accurate and durable. The process of mean representation is suggested to be parallel. However, previous studies on the mean representation mostly used behavioral methods. The purpose of this study was to investigate which neural regions extracted the mean size of a set of circles using fMRI method. According to previous studies, BOLD signal of certain areas that were in charge of cousin stimuli decreased when the same stimuli presented repetitively. We used this paradigm and found that BOLD signal of right occipital area was decreased when same mean site was presented repeatedly. This results suggest that right occipital area is the locus of mean representation of visual stimuli.

• The Journal of the Korea Contents Association
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• v.5 no.5
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• pp.296-304
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• 2005

Quantitative analysis compare to dynamic characteristic change of the regional cerebral blood volume(rCBV) after development of cerebral fat embolism in cats using perfusion magnetic resonance(MR) Imaging. Twenty cats were used. 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 ${\Delta}R_2^*$ curve were obtained continuously with the aid of home-maid image process algorithm and IDL(interactive data Banguage, USA) softwares. The ratios of rCBV increased 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 diffusion weighted imaging(DWI) and perfusion weighted imaging(PWI).

• Journal of the Korean Society of Radiology
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• v.81 no.1
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• pp.243-247
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• 2020

We report a rare case of hyperglycemia-related osmotic demyelination syndrome (ODS) with focus on the imaging findings. A 61-year-old man with diabetes was admitted for general weakness and severe thirst. A few days later, he complained of dysarthria, dysphasia, and dysmetria. Laboratory examinations showed significant hyperglycemia, but normal electrolyte levels. Brain MRI revealed T2-signal abnormalities that were symmetrical, non-space occupying, and located in the central pons with a peripheral sparing pattern, which were suggestive of ODS. In addition, subsequent MRI revealed progression of signal hyperintensity; however, the patient's symptoms improved.

• Journal of the Korean Society of Radiology
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• v.81 no.2
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• pp.302-309
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• 2020

Fabry disease is a rare X-linked metabolic disorder that is characterized by the accumulation of glycosphingolipids in various organs, resulting from the deficiency of alpha-galactosidase A. Cardiac involvement is relatively common; myocardial inflammation, left ventricular hypertrophy, and myocardial fibrosis secondary to abnormal lipid deposition in myocytes are often observed. Hence, the diagnosis of cardiac involvement is crucial for evaluating patient prognosis. Cardiac MRI is the standard technique for measuring the function, volume, and mass of the ventricles. It is also useful for myocardial tissue characterizations. The evaluation of native myocardial T1 values can facilitate early diagnosis of cardiac involvement, while measurements of left ventricular myocardial mass can be used to monitor treatment outcomes, in patients with Fabry disease. Consequently, cardiac MRI can provide useful information for diagnosing, monitoring, and treating patients with Fabry disease.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.5931-5936
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• 2012

This study was to evaluate the clinical usefulness of the PRESS technique based on the correlation between PRESS technique and biopsy results by applying 3.0T high magnetic field MRS technique for evaluation of non-alcoholic fatty liver disease patients. This experiment were carried out using a 3.0T magnetic resonance imaging equipment. The part data of each spectrum is taken by peak area integration. The part data of resonance peak was used to calculate relative ratio. MR spectral peak in patients with non-alcoholic fatty liver disease is from 0.9 to 1.6 ppm. According to MRS method study result, Patients with NAFLD were obtained with 94% sensitivity and 80% specificity(p=0.000). When compared to normal based on MRS and Biopsy results was valid correlation(r=0.79, p=0.04). Results for NAFLD(r=0.89, p=0.002) also showed a correlation. Therefore, PRESS technique to evaluate patients with non-alcoholic fatty liver disease, the distribution difference between normal liver and fatty liver part is significantly distinguished. Biopsy and MRS fatty liver peak ratio(%) proves high lipid over grade(r = 0.7).

• Investigative Magnetic Resonance Imaging
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• v.4 no.2
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• pp.94-99
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• 2000

Purpose : With the use of localized, water-suppressed in vivo $^1H$ magnetic resonance spectroscopy (MRS), we evaluated the proton metabolic alterations in patients with chronic alcoholism and healthy normal controls. Material and Methods : Patients with chronic alcoholism (N = 10) and normal control subjects (N = 10) underwent MRS examinations using a stimulated echo acquisition mode (STEAM) pulse sequence with $2{\times}2{\times}2{\;}\textrm{cm}^3$ volume of interest (VOI) in the left cerebellum and basal ganglia. Proton metabolite ratios relative to creative (Cr) were obtained using a Marquart algorithm. Results : The specific feature in patients with chronic alcoholism was a significant decrease of N-acetylaspartate (NAA)/Cr ratio in the left cerebellum, compared with normal controls. No clear correlation of other metabolite ratios such as choline (Cho)/Cr and inositols (Ins)/Cr was established. Conclusion : Our preliminary study suggests that the reduction of NAA/Cr ratio may indicate neuronal loss in patients with chronic alcoholism. Thus, in vivo 1H MRS may be a useful modality in the clinical evaluation of patients with chronic alcoholism based on the proton metabolite ratios.