• Journal of radiological science and technology
• /
• v.36 no.4
• /
• pp.263-271
• /
• 2013

The decrease of bone mineral density gives rise to the outbreak of osteopenia and makes the possibility of a bone fracture. It makes health problems in society. It's very important to prevent osteopenia in advance. Also it's critical to prevent and take care of it in adolescent because it's the most developing period comparing to middle ages because that bone mineral density decreases. There are genetic, physical and enviromental factors that affect bone mineral density. Recently, a lifestyle and eating habits are also changing as the society atmosphere is gradually doing. This study have shown that 134 women and 75 men was chosen and responded to the survey of measuring bone mineral density and investigating a lifestyle. The measure of bone mineral density is to use Dual energy X-ray absorptiometry(DEXA) and check femoral neck and lumbar spine. Also questionaries was required to pre-made survey about their lifestyles. Analysis of data was done with SPSS program. Multiple regression analysis was used for the relation of bone mineral density, the heigths and BMI. The sample of Groups are checked for drinking, smoking or excercising about differences by t-test. The results of the experiments were; first, there is statistically significant differences in the comparisons between BMD and BMD. But there isn't any special correlation between drinking, smoking and BMD. Secondly, bone mineral density becomes low related to an intake of caffeine. Particularly, this is statically significant on women. Also there is statically significant correlation between femoral neck and quantity of motion for both men and women. Third, there is significant relation between eating habits and bone mineral density on women's lumbar spine. However, there is no significant relation between men's lumbar spine and women's one. Therefore, to prevent osteopenia, it's good to abstain from intaking caffeine within an hour after a meal. In addition, it's helpful to walk or run regularly and have a balanced meal.

• Investigative Magnetic Resonance Imaging
• /
• v.10 no.2
• /
• pp.98-107
• /
• 2006

Magnetization Transfer (MT) imaging generates contrast dependent on the phenomenon of magnetization exchange between free water proton and restricted proton in macromolecules. In biological materials in knee, MT or cross-relaxation is commonly modeled using two spin pools identified by their different T2 relaxation times. Two models for cross-relaxation emphasize the role of proton chemical exchange between protons of water and exchangeable protons on macromolecules, as well as through dipole-dipole interaction between the water and macromolecule protons. The most essential tool in medical image manipulation is the ability to adjust the contrast and intensity. Thus, it is desirable to adjust the contrast and intensity of an image interactively in the real time. The proton density (PD) and T2-weighted SE MR images allow the depiction of knee structures and can demonstrate defects and gross morphologic changes. The PD- and T2-weighted images also show the cartilage internal pathology due to the more intermediate signal of the knee joint in these sequences. Suppression of fat extends the dynamic range of tissue contrast, removes chemical shift artifacts, and decreases motion-related ghost artifacts. Like fat saturation, phase sensitive methods are also based on the difference in precession frequencies of water and fat. In this study, phase sensitive methods look at the phase difference that is accumulated in time as a result of Larmor frequency differences rather than using this difference directly. Although how MT work was given with clinical evidence that leads to quantitative model for MT in tissues, the mathematical formalism used to describe the MT effect applies to explaining to evaluate knee disorder, such as anterior cruciate ligament (ACL) tear and meniscal tear. Calculation of the effect of the effect of the MT saturation is given in the magnetization transfer ratio (MTR) which is a quantitative measure of the relative decrease in signal intensity due to the MT pulse.

• Journal of Chest Surgery
• /
• v.39 no.12 s.269
• /
• pp.900-905
• /
• 2006

Background: Homografts and bioprostheses are most commonly used for Rastelli operation in congenital heart disease, but the limited durability is responsible for multiple reoperations associated with increased morbidity This study evaluated long-term results after Rastelli operation with a mechanical valved conduit. Material and Method: A total of 20 patients underwent Rastelli operation with mechanical valved conduit from January 1990 to July 1992. Operative mortality was 1 of 20 patients, and a retrospective review of 19 patients(10 males, 9 females) was done. Initial diagnosis was congenitally corrected transposition of great arteries(cc-TGA, n=4), complete TGA (n=2), ventricular septal defect with pulmonary atresia(VSD with PA, n=9), truncus arteriosus(n=2), double outlet right ventricle with pulmonary stenosis(DORV with PS, n=2). The mean age at Rastelli operation was $4.6{\pm}3.4$ years, and mean follow-up period was $12.8{\pm}2.7$ years. Patients underwent Rastelli opearation using 16 CarboMedics mechanical valve, and 3 Bjork-Shiley mechanical valve($17{\pm}2$ mm). Result: There were 15 reoperations for failed mechanical valved conduit. The freedom from reoperation at 5 and 10 years was 53% and 37%. Most patients were received oral anticoagulation with warfarin, and maintained the international normalized ratio(INR) of 1.5 to 2.0. There was no anticoagulation or thromboembolism related complication. There was a significant difference in the causes of a conduit failure between early(within 3 years) and late(after 3 years) failure groups. The six patients reported early prosthetic valve failure, mainly due to valvular dysfunction by thrombosis or pannus formation. The other nine patients reported late prosthetic valve failure, mainly due to dacron conduit stenosis at anastomosis sites, whereas their valvar motion was normal except 1 patient. Conclusion: To avoid early prosthetic valve failure, strict anticoagulation therapy would be helpful. About the late development of obstructive intimal fibrocalcific peels within the Dacron conduit, an improvement of conduit material is necessary to reduce late prosthetic valve failure. In selected patients, the long term results were satisfactory.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.26 no.1
• /
• pp.49-64
• /
• 2014

Seabed beneath and near the coastal structures may undergo large excess pore water pressure composed of oscillatory and residual components in the case of long durations of high wave loading. This excess pore water pressure may reduce effective stress and, consequently, the seabed may liquefy. If the liquefaction occurs in the seabed, the structure may sink, overturn, and eventually fail. Especially, the seabed liquefaction behavior beneath a gravity-based structure under wave loading should be evaluated and considered for design purpose. In this study, to evaluate the liquefaction potential on the seabed, numerical analysis was conducted using 2-dimensional numerical wave tank. The 2-dimensional numerical wave tank was expanded to account for irregular wave fields, and to calculate the dynamic wave pressure and water particle velocity acting on the seabed and the surface boundary of the structure. The simulation results of the wave pressure and the shear stress induced by water particle velocity were used as inputs to a FLIP(Finite element analysis LIquefaction Program). Then, the FLIP evaluated the time and spatial variations in excess pore water pressure, effective stress and liquefaction potential in the seabed. Additionally, the deformation of the seabed and the displacement of the structure as a function of time were quantitatively evaluated. From the analysis, when the shear stress was considered, the liquefaction at the seabed in front of the structure was identified. Since the liquefied seabed particles have no resistance force, scour can possibly occur on the seabed. Therefore, the strength decrease of the seabed at the front of the structure due to high wave loading for the longer period of time such as a storm can increase the structural motion and consequently influence the stability of the structure.

• Archives of design research
• /
• v.19 no.5 s.67
• /
• pp.119-128
• /
• 2006

The scale of visual expression has expanded from freeze frame to motion picture as media have developed. Moving pictures such as animation, movies, TV CM and GUI become formative elements whose movement is necessary compared to freeze frame as apparent movement phenomenon and unit structure such as short and scene appear. Therefore, of formative elements such as a shape, color, space, size and movement, movement is importantly distinguished in the moving image. The expression and form of image as a relationship between the signified and signifier explained by Saussure are accepted as a sign by mutual complement even though they limit the content. This makes it possible to infer that the formal feature of movement participates in the message content. To verify this, the result of moving picture visual perception experiment based on the gestalt grouping principle result shows that 70-80 percent of subjects think that 'movement' is the important grouping clue in perception. Movement affects the maintenance of the context of message content in the communication process when the meaning structure of moving picture is analyzed based on the structural feature. The identity can be maintained with if there is a movement with similar directive point even if the color and shape of people, things and background are changed. Second, the clarity of the content is elevated by a distinguished object as a figure by movement. Third, it acts as a knowledge representation which can predict similar movement process of next information processing. Forth, movement gives the content consistency even though more than two scenes have fast switch and complicated editing structure like cross-cutting. Movement becomes a clue which can make grouping information input by visual perception reaction. Also, it gives the order to the visual expression which can be used improperly by formation of structural frame of image message and has the effectiveness which elevates the clarity of signification. Moving picture has discourse with several mixed unit structures because it fundamentally contains time and the common and distinguished expression is needed by media-mix circumstances. Therefore, by the application of gestalt grouping principle to moving picture field, movement becomes the more distinguished than other formative elements and affects the formation of meaning structure. This study propose a viewpoint that develops structural formative beauty and new image expression in the media image field.

• The Journal of Korean Society for Radiation Therapy
• /
• v.28 no.2
• /
• pp.149-159
• /
• 2016

Purpose : To evaluate the usefulness of the breathing exercise,we analyzed the change in the RPM signal and the diaphragm imagebefore 4D respiratory gated radiation therapy planning of lung cancer patients. Materials and Methods : The breathing training was enforced on 11 patients getting the 4D respiratory gated radiation therapy from April, 2016 until August. At the same time, RPM signal and diaphragm image was obtained respiration training total three steps in step 1 signal acquisition of free-breathing state, 2 steps respiratory signal acquisition through the guide of the respiratory signal, 3 steps, won the regular respiration signal to the description and repeat training. And then, acquired the minimum value, maximum value, average value, and a standard deviation of the inspiration and expiration in RPM signal and diaphragm image in each steps. Were normalized by the value of the step 1, to convert the 2,3 steps to the other distribution ratio (%), by evaluating the change in the interior of the respiratory motion of the patient, it was evaluated breathing exercise usefulness of each patient. Results : The mean value and the standard deviation of each step were obtained with the procedure 1 of the RPM signal and the diaphragm amplitude as a 100% reference. In the RPM signal, the amplitudes and standard deviations of four patients (36.4%, eleven) decreased by 18.1%, 27.6% on average in 3 steps, and 2 patients (18.2%, 11 people) had standard deviation, It decreased by an average of 36.5%. Meanwhile, the other four patients (36.4%, eleven) decreased by an average of only amplitude 13.1%. In Step 3, the amplitude of the diaphragm image decreased by 30% on average of 9 patients (81.8%, 11 people), and the average of 2 patients (18.2%, 11 people) increased by 7.3%. However, the amplitudes of RPM signals and diaphragm image in 3steps were reduced by 52.6% and 42.1% on average from all patients, respectively, compared to the 2 steps. Relationship between RPM signal and diaphragm image amplitude difference was consistent with patterns of movement 1, 2 and 3steps, respectively, except for No. 2 No. 10 patients. Conclusion : It is possible to induce an optimized respiratory cycle when respiratory training is done. By conducting respiratory training before treatment, it was possible to expect the effect of predicting the movement of the lung which could control the patient's respiration. Ultimately, it can be said that breathing exercises are useful because it is possible to minimize the systematic error of radiotherapy, expect more accurate treatment. In this study, it is limited to research analyzed based on data on respiratory training before treatment, and it will be necessary to verify with the actual CT plan and the data acquired during treatment in the future.

• Clinics in Shoulder and Elbow
• /
• v.15 no.2
• /
• pp.91-98
• /
• 2012

Purpose: The objective of this study is to evaluate the functional outcome and identify prognosis of retear patients in patients aged 65 years or over undergoing surgical repair for a large to massive full-thickness rotator cuff tear. Materials and Methods: From 1995 September to 2010 March, 147 patients aged 65years or over (40 male, 107 female, with an average age of 69.6) undergoing surgical repair for large to massive full thickness rotator cuff tear (large 67 cases, massive 80 cases). For functional evaluation, preoperative and postoperative 1 year range of motion and muscle power checked. For subjective evaluation, American shoulder and elbow surgeons score and Constant score were checked. For anatomical evaluation, 87 patients were checked shoulder MRI at the time of the postoperative 1 year. Results: ASES score improved from to 50.4 to 88.9, Constant score improved from 47.1 to 75.2. Supraspinatus power improved from 51.1% to 80.8%, external rotator muscle power improved from 64.5% to 83.1%. Forward elevation improved from 117.4 degrees to 153 degrees, external rotation improved from 23.6 degrees to 41.8 degrees. Follow up MRI showed re-tear in 23%, all re-tear patients were from massive tear except one patient. All re-tear patients showed improved clinical outcomes, but supraspinatus and external rotator muscle power were not improved. Conclusions: Patients aged 65 years or over undergoing surgical repair for a large to massive full-thickness rotator cuff tear showed successful outcomes over 90 percent. Re-tear patients also showed successful clinical outcomes. In elderly patients with large to massive full thickness rotator cuff tear, aggressive surgical repair leads good clinical outcomes.

• Journal of Korean Orthopaedic Sports Medicine
• /
• v.8 no.2
• /
• pp.109-114
• /
• 2009

Purpose: The purpose of this study is to compare the clinical results of ACL reconstruction between two groups using hamstring tendon autograft and tibialis anterior tendon allograft. Materials and Methods: Between January 2006 and June 2007, we analyzed 68 cases of ACL reconstruction, 32 cases using hamstring tendon autograft and 36 cases using tibialis anterior tendon allograft, with a minimum follow-up of 24 months. For the clinical evaluation, we evaluated the Lysholm score, anterior laxity by Telos device and KT-2000 arthrometer. Results: The mean diameter of graft were 8.0 mm (7.0~9.0 mm) in autograft group and 9.1 mm (8.0~10.0 mm) in allograft group. In all cases, the range of motion was above 135 degrees. The average side to side difference in Telos stress test decreased from $7.3{\pm}1.0$ mm to $2.4{\pm}1.1$ mm in autograft group and from $7.4{\pm}1.2$ mm to $2.3{\pm}1.3$ mm in allograft group. The average Lysholm knee score improved from $72.6{\pm}3.4$ to $92.3{\pm}3.5$ in autograft group and from $72.3{\pm}3.5$ to $91.6{\pm}3.3$ in allograft group. There was no significant difference between two groups in clinical results. Conclusion: Both hamstring tendon autograft and tibialis anterior tendon allograft groups showed satisfactory clinical results, with no significant difference in outcomes between the groups. We suggest that both hamstring tendon autograft and tibialis anterior tendon allograft will be considered as acceptable graft for anterior cruciate ligament reconstruction.

• Journal of the Korean Arthroscopy Society
• /
• v.14 no.1
• /
• pp.7-12
• /
• 2010

Purpose: To evaluate the effects of total or subtotal meniscectomy on anterior cruciate ligament reconstruction. Materials and Methods: We reviewed the 455 cases of arthroscopic ACLR (anterior cruciate ligament reconstruction) from February, 2003 to February, 2007 and followed-up more than 1 year. The 93 cases were enrolled. The 45 cases who underwent only ACLR were included and the 48 cases who underwent ACLR with total or subtotal meniscectomy were included in this study except grade 3 or 4 chondral lesion, partial meniscetomy or meniscal repair. We divided the patient into 4 groups which were isolated ACLR group (group I, 45cases), ACLR with lateral meniscectomy group (group II, 10cases), ACLR with medial meniscectomy group (group III, 28cases) and ACLR with both medial and lateral meniscectomy group (group IV, 10cases). The clinical evaluation was done by range of motion (ROM), IKDC subjective score, Lysholm score, anterior drawer test, Lachman test, Pivot shift test and KT-1000 arthrometer. Results: At final follow up, group IV was inferior than group I in IKDC subjective score and Lysholm score, and inferior than group II in IKDC subjective score. In KT-1000 arhtometric test, group I had better results than group III and group IV. Also in anterior drawer test and Lachman test, group 1 had better result than group III and group IV. In pivot shift test, there was no significant difference among four groups. Conclusion: Medial or both medial and lateral meniscectomy had greater laxity in anterior drawer test, Lachman test and KT-1000 arthrometric test and both medial and lateral meniscectomy had a lower subjective score than both meniscus intact group.

• The Journal of Korean Society for Radiation Therapy
• /
• v.23 no.1
• /
• pp.1-6
• /
• 2011

Purpose: Immobilizations used in order to maintain the reproducibility of a patient set-up and the stable posture for a long period are important more than anything else for the accurate treatment when the stereotactic body radiotherapy is underway. So the purpose of this study is to adapt the optimum immobilizations for the stereotactic body radiotherapy by comparing two commercial immobilizations with the self-manufactured immobilizations. Materials and Methods: Five people were selected for the experiment and three different immobilizations (A: Wing-board, B: BodyFix system, C: Arm up holder with vac-lock) were used to each target. After deciding on the target's most stable respiratory cycles, the targets were asked to wear a goggle monitor and maintain their respiration regularly for thirty minutes to obtain the respiratory signals. To analyze the respiratory signal, the standard deviation and the variation value of the peak value and the valley value of the respiratory signal were separated by time zone with the self-developed program at the hospital and each tie-downs were compared for the estimation by calculating a comparative index using the above. Results: The stability of each immobilizations were measured in consideration of deviation changes studied in each respiratory time lapse. Comparative indexes of each immobilizations of each experimenter are shown to be A: 11.20, B: 4.87, C: 1.63 / A: 3.94, B: 0.67, C: 0.13 / A: 2.41, B: 0.29, C: 0.04 / A: 0.16, B: 0.19, C: 0.007 / A: 35.70, B: 2.37, C: 1.86. And when all five experimenters wore the immobilizations C, the test proved the most stable value while four people wearing A and one man wearing D expressed relatively the most unstable respiratory outcomes. Conclusion: The self-developed immobilizations, so called the arm up holder vac-lock for the stereotactic body radiotherapy is expected to improve the effect of the treatment by decreasing the intra-fraction organ motions because it keeps the respiration more stable than other two immobilizations. Particularly in case of the stereotactic body therapy which requires the maintenance of set-up state for a long time, the self-developed immobilizations is thought to more useful for stereotactic body radiotherapy rather than the rest two immobilizations with instable respiratory cycle as time passes.