• Journal of the Korean Arthroscopy Society
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• v.6 no.2
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• pp.109-114
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• 2002

Propose : The purpose of this retrospective study was to test the posterior cruciate ligament (PCL index) for diagnosis of a tear of the anterior cruciate ligament (ACL) by means of MR imaging. Materials and Methods : From Mar. 1997 to Feb. 2001, concomitant magnetic resonance imaging (MRI) and knee joint arthroscopy were performed in 56 patients of either pain or instability of the knee. The shortest distance between the femoral and tibial attachment of PCL (X) and the distance from that line to the tip of the arc marked by the PCL (Y) on the sagittal plane images were measured. The quotient of these two parameters (Y/X) defined the PCL index. Results : Using MRI diagnosis, there were 35 patients diagnosed with ACL rupture and 21 patients were ruled out of ACL injury. Using arthroscopy, 32 of the 35 patients diagnosed by MRI showed ACL rupture, and 20 of the 21 patients were ruled out of ACL injury. The mean PCL index was 0.40 in the 33 patients diagnosed with ACL rupture through arthroscopy. The mean PCL index was 0.23 in 23 patients with an uninjured ACL through arthroscopy. In 33 patients with ruptured ACL, this value exceeds 0.31. The index value was 0.31 in 3 patients with uninjured ACL. The value of the index was not above 0.31 with an uninjured ACL. PCL index on MRI had a sensitivity of $91\%$ and a specificity of $94\%$ for determining the status of the anterior cruciate ligament. Conclusion : Injury to the ACL changes the PCL index markedly. In diagnostically unreliable MR images, amelioration of the PCL index could help in the diagnosis of ACL injury.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.5937-5942
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• 2012

This study used silicon that is similar to the density of the tissue of the human body to compensate for the uneven areas that are in contact with air in order to reduce susceptible artifacts. The subjects of the study were 16 normal people and the areas of the human body in which there are a lot of uneven areas with complicated structure and a lot of susceptible artifacts were formed since the surface area that comes into contact with the air is large were the areas that were chosen to be examined. A 3.0T superconducting magnetic resonance device was used as the test equipment and SPIR images that are sensitive to magnetic differences were obtained as sagittal planes on a line that extended the metatarsal and the phalanges, including the middle of the longitudinal arc and the 5 distal phalanxes. The method of analysis was to reduce the susceptibility between the tissue and the air to discover the reduction of susceptible artifacts by comparing the SNR and CNR before and after applying silicon. A statistical analysis was utilized for the sample matching T examination. The results of the study revealed that the susceptible artifacts were reduced in the images of the uneven areas that were compensated and applied with silicon. The SNR increased in significant amount in correlation from $3.91{\pm}1.33$ before application to $21.69{\pm}4.52$ after application and the CNR decreased in significant amount in correlation from $28.97{\pm}8.20$ before application to $4.88{\pm}2.14$. In conclusion, this study did not affect the voxel but it was an innovative method of improvement that compensated for the fundamental issue of the difference in susceptibility between the air and the body. The application is simple and the study has great significance in that it proposed a method to reduce susceptible artifacts in a low cost and highly efficient manner.

• Journal of the Korean Society of Radiology
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• v.11 no.6
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• pp.493-500
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• 2017

In this study, data analysis has been conducted by INFINITT program to analyze the effect of signal to noise ratio(SNR) and contrast to noise ratio(CNR) of flow related enhancement(FRE) and computed tomography Angiography(CTA) on cerebrovascular diseases for qualitative evaluations. Based on the cerebrovascular image results achieved from 63 patients (January to April, 2017, at C University Hospital), we have selected 19 patients that performed both FRE-MRA and CTA. From the 19 patients, 2 were excluded due to artifacts from movements in the cerebrovascular image results. For the analysis conditions, we have set the 5 part (anterior cerebral artery, right and left Middle cerebral artery, right and left Posterior cerebral artery) as the interest area to evaluate the SNR and CNR, and the results were validated through Independence t Test. As a result, by averaging the SNR, and CNR values, the corresponding FRE-MRA achieved were: anterior cerebral artery ($1500.73{\pm}12.23/970.43{\pm}14.55$), right middle cerebral artery ($1470.16{\pm}11.46/919.44{\pm}13.29$), left middle cerebral artery ($1457.48{\pm}17.11/903.96{\pm}14.53$), right posterior cerebral artery ($1385.83{\pm}16.52/852.11{\pm}14.58$), left posterior cerebral artery ($1318.52{\pm}13.49/756.21{\pm}10.88$). by averaging the SNR, and CNR values, the corresponding CTA achieved were: anterior cerebral artery ($159.95{\pm}12.23/123.36{\pm}11.78$), right middle cerebral artery ($236.66{\pm}17.52/202.37{\pm}15.20$), left middle cerebral artery ($224.85{\pm}13.45/193.14{\pm}11.88$), right posterior cerebral artery ($183.65{\pm}13.47/151.44{\pm}11.48$), left posterior cerebral artery ($177.7{\pm}16.72/144.71{\pm}11.43$) (p < 0.05). In conclusion, MRA had high SNR and CNR value regardless of the cerebral infarction or cerebral hemorrhage observed in the 5 part of the brain. Although FRE-MRA consumed longer time, it proved to have less side effect of contrast media when compared to the CTA.

• Journal of the Korean Arthroscopy Society
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• v.15 no.2
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• pp.92-98
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• 2011

Purpose: We describe a all-arthroscopic technique for decompression of spinoglenoid ganglion cyst and present our clinical results for this procedure. Materials and Methods: From March 2006 to June 2009, eight patients (7 males, 1 female; mean age 40.6 years; range: 21~61) were included who underwent arthroscopic decompression of spinoglenoid ganglion cyst. The most common symptoms were vague shoulder pain and external rotation weakness, which lasted 6.4 months (range: 3~8) on average. Five of eight patients were noted abnormalities on electromyographic (EMG) examination to have suprascapular nerve neuropathy and magnetic resonance imaging (MRI) showed spinoglenoid ganglion cysts in all eight patients and the cyst size was 2.6 cm (range: 1.8~3.6). Labral pathology was identified intraoperatively in all patients and the cysts were decompressed by the posterosuperior capsulotomy under arthroscopic control and labral repair with suture anchors was performed in six patients. Results: The average clinical outcome scores including Constant and Murley, Simple shoulder test (SST) all improved significantly at the time of the final follow-up and there were no complications resulting from the procedures. All patients including the patients with abnormal EMG study recovered strength on isokinetic strength testing. Follow-up MRI scans were performed on all patients at a mean of 5.2 months postoperatively (range: 3~12) revealed complete resolution of the cysts and no evidence of recurrences were seen at an average of 18 months (range: 12~26) of follow-up. Conclusion: Arthroscopic decompression of spinoglenoid ganglion cyst effectively restores patient function and all patients in this study showed improvement in their postoperative MRI findings. Arthroscopic decompression is also useful in the appropriate treatment for labral pathology and may contribute to decreased risk of cyst recurrence.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.8
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• pp.759-769
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• 2013

Electronic equipment has been applied to virtually every area associated with commercial, industrial, and military applications. Specifically, electronics have been incorporated into avionics components installed in aircraft. This equipment is exposed to dynamic loads such as vibration, shock, and acceleration. Especially, avionics components installed in a helicopter are subjected to simultaneous sine and random base excitations. These are denoted as sine on random vibrations according to MIL-STD-810F, Method 514.5. In the past, isolators have been applied to avionics components to reduce vibration and shock. However, an isolator applied to an avionics component installed in a helicopter can amplify the vibration magnitude, and damage the chassis, circuit card assembly, and the isolator itself via resonance at low-frequency sinusoidal vibrations. The objective of this study is to investigate the dynamic characteristics of an avionics component installed in a helicopter and the structural dynamic modification of its tray plate without an isolator using both a finite element analysis and experiments. The structure is optimized by dynamic loads that are selected by comparing the vibration, shock, and acceleration loads using vibration and shock response spectra. A finite element model(FEM) was constructed using a simplified geometry and valid element types that reflect the dynamic characteristics. The FEM was verified by an experimental modal analysis. Design parameters were extracted and selected to modify the structural dynamics using topology optimization, and design of experiments(DOE). A prototype of a modified model was constructed and its feasibility was evaluated using an FEM and a performance test.

• Journal of the Korean Society of Radiology
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• v.9 no.2
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• pp.101-107
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• 2015

In anteroposterior radiation test for cervical vertebra, it is general that the incidence angle of X-ray is $15^{\circ}$ to $20^{\circ}$ degrees to head regardless of position. So this study suggests appropriate incidence angle of cervical vertebra depended on the position. From 1 January 2013 to 31 December 2013, cervical spine radiographys and magnetic resonance imaging was performed in 107 people who visited P Hospital located in Pusan. Among them, 39 people(men 24, women 15) were below 80 above 20 years old(average age 54 years) with normal cervical lordosis(normal $40^{\circ}{\pm}5^{\circ}$). In erect position, the incidence angle of cervical vertebra is measured from lateral radiographic images. And in supine position, it measured from MRI sagittal images. Results based on gender, the incidence angle of cervical vertebra in erect position was $25.9^{\circ}$ for men, women was $23.1^{\circ}$, showed statistically significant (p<0.05). And the angle in supine was $11.6^{\circ}$ for men, women was $12.6^{\circ}$, showed not statistically significant (p>0.05) An analysis of age group shows, the incidence angle of cervical vertebra in erect position was $24.6^{\circ}$ under 50, and $25.0^{\circ}$ over 50. The angle in supine was $12.0^{\circ}$ under 50, and $11.9^{\circ}$ over 50. And all of them showed not statistically significant (p>0.05). At all ages, the average of incidence angles in erect position were $24.8^{\circ}$, and the angle in supine was $12.0^{\circ}$, showed statistically significant (p<0.05). The cervical vertebra incidence angle for X-ray was $15^{\circ}$ to $20^{\circ}$ degrees to head in general. But, through the results, it is recommended that the angle is $24.8^{\circ}$ in erect and $12.0^{\circ}$ in supine position. It could be shown true anteroposterior(AP) view of cervical vertebra and accurate intervertebral fusion fixing devices.

• Journal of the Korean Society of Radiology
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• v.8 no.5
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• pp.231-240
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• 2014

The purpose of this study were to analyze that the Seoul neuropsychological screening battery (SNSB) for the evaluating cognitive assessment of the Parkinson's disease patients with mild cognitive impairment (PD-MCI) and the changes of the cerebral ventricle volume in the brain magnetic resonance imaging (MRI), and we has been bring forward the guideline to determine the diagnostic criteria for the PD-MCI. To achieve this, we was diagnosed with Parkinson's disease patients (PD-MCI group: 34 patients; Parkinson's disease with normal cognition, PD-NC group: 34 patients) to perform the SNSB test for the attention, language, memory, visuospatial, and frontal/executive functions and the brain MRI. Additionally, to compared the change of the cerebral ventricle volume, we performed the brain MRI for the 32 normal control (NC) group. The volumetric analysis for a specific cerebral ventricle performed by using Freesurfer Ver. 5.1 (Massachusetts general Hospital, Boston MA, USA). As a results, compared to the PD-NC group, the PD-MCI group were statistically significant reduction in the ability to perform the memory and the visuospatial function (p<0.05). The volumetric changes for a specific cerebral ventricle were statistically significant variation in the left and right lateral ventricle, left and right inferior lateral ventricle, and 3rd ventricle. Although, in order to compared the objectification, the normalized percentage applied to the volumetric changes showed to extend the PD-MCI group than the PD-NC group. Specially, the left and right ventricle extension for the PD-MCI patients conspicuously had showed a quantitative linear relationship between the memory and the visuospatial function for the SNSB (r>0.5, p<0.05). Therefore, we were able to judge the diagnostic criteria of the PD-MCI through that can observe the volumetric variation of the specific cerebral ventricle by using Freesurfer in brain MRI, and to analyze the correlation between the SNSB.

• The Journal of the Korean bone and joint tumor society
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• v.20 no.2
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• pp.60-65
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• 2014

Purpose: To diagnose soft tissue tumor, such as lipoma and Schwannoma, magnetic resonance imaging (MRI) is sufficient in most cases. However, various characteristics are found in MRI images of Schwannoma, thus other type of tumors are often misdiagnosed as Schwannoma with MRI images. In this study, we evaluate the diagnostic value of specific MRI findings of Schwannoma. Materials and Methods: From January 2002 to May 2013, 104 patients who are suspected as Schwannoma rith MRI images are included in data, and the final diagnosis is confirmed with biopsy. Patients are divided into group 1 and group 2 who are confirmed as Schwannoma and other disease with biopsy, respectively. Results: 92 patients were diagnosed as Schwannoma (group 1) and 12 patients were diagnosed as other disease (group 2). We investigate the diagnostic value of specific MRI findings of Schwannoma. 41 patients of group 1 (45%) and 0 patients of group 2 (0%) showed target sign, 47 patients of group 1 (51%) and 2 patients of group 2 (17%) showed fascicular sign, 44 patients of group 1 (48%) and 5 patients of group 2 (42%) showed fat split sign, 28 patients of group 1 (30%) and 1 patients of group 2(9%) showed nerve entering and exiting sign, and 8 patients of group 1 (9%) and 6 patients of group 2 (50%) showed none of four specific findings on their MRI images. 52 patients of group 1 (57%) and 5 patients of group 2 (42%) have tumors on the pathway of nerve. Target sign could be considered as the best diagnostic value of the sign we investigate (p<0.05). Conclusion: Although specific MRI findings have powerful diagnostic value, patients are often misdiagnosed as Schwannoma with MRI findings. Therefore, if patients who are suspected as Schwannoma based on MRI findings have no target sign on their MRI images, we should consider the possibility of other disease.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.5
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• pp.581-591
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• 2017

The purpose of this study was to examine the biological activities of gamma-irradiated Teucrium veronicoides. In photostimulated luminescence analysis, non-irradiated sample showed lower than 700 photon counts (PCs), whereas irradiated (5 and 10 kGy) samples showed higher than 700 PCs. The thermoluminescence ratio of non-irradiated samples was less than 0.1, whereas the values of irradiated samples were greater than 0.1. Electron spin resonance analysis was performed confirmed for irradiation identification. The total phenolic contents of hot-water and 50% ethanol extracts were higher than those values after irradiation at 10 kGy. Regarding 1,1-diphenyl-2-picrylhydrazyl radical inhibitory activity, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity, antioxidant protection factor, thiobarbituric acid reactive substance inhibitory activity as antioxidant test and xanthine oxidase inhibitory activity, the effect of gamma irradiation had on significant effects. On the other hand, ${\alpha}-amylase$ inhibitory activity of 10 kGy-irradiated hot-water extract was 23.6% higher than that of the non-irradiated sample. Thus, gamma irradiation could be used for the long-term storage of Teucrium veronicoides.

• Progress in Medical Physics
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• v.13 no.3
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• pp.120-128
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• 2002

To investigate differences between the metabolic ratios of normal controls and brain tumors such as astrocytomas and glioblastoma multiforme (GM) by proton MR spectroscopy (MRS) at 37 high field system. Using 3T MRI/MRS system, localized water-suppressed single-voxel technique in patients with brain tumors was employed to evaluate spectra with peaks of N-acetyl aspartate (NAA), choline-containing compounds (Cho), creatine/phosphocreatine (Cr) and lactate. On the basis of Cr, these peak areas were quantificated as a relative ratio. The variation of metabolites measurements of the designated region in 10 normal volunteers was less than 10%. Normal ranges of NAA/Cr and Cho/Cr ratios were 1.67$\pm$018 and 1.16$\pm$0.15, respectively. NAA/Cr ratio of all tumor tissues was significantly lower than that of the normal tissues (P=0.005). Cho/Cr ratio of glioblastoma multiforme was significantly higher than that of astrocytomas (P=0.001). Lactate was observed in all tumor cases. The present study demonstrated that the neuronal degradation or loss was observed in all tumor tissues. Higher grade of brain tumors was correlated with higher Cho/Cr ratio, indicating a significant dependence of Cho levels on malignancy of gliomas. This results suggest that clinical proton MR spectroscopy could be useful to predict tumor malignancy.