Se-Jong Yoo

Development of a Femur Neck Bone Mineral Density Measuring Device for Accurate Examination

In bone density examinations, a change in the measured BMD occurs owing to the differences between the measured areas. To address this problem, we aimed to develop a new auxiliary device that could be rotated by 15o by fixing the ankle to the distal femur neck. Dual energy X-ray absorptiometry (DXA) of BMD examinations were performed once a year, but 10 patients were examined over three sessions to analyze the area for measuring the femur neck BMD. The goal of this test was to determine the device’s reliability, and the results were expressed in terms of the standard deviation of measurements. After performing bone density measurements using the new auxiliary device on 10 normal patients, with three measurements for each patient, the obtained standard deviation was 0.03. The standard deviation of the measured BMD was 0.19 when using the currently existing auxiliary device, while the standard deviation of the measured BMD was 0.03 when using the new auxiliary device. By using the new auxiliary device, the standard deviation could be reduced by ~80%. Accurate rotation of the femur neck was possible in all examinations, and the standard deviation of BMD measurements could be reduced by up to 80% compared with the measurements performed using the currently existing auxiliary device. We hope that this advantageous new design can be used as a standard auxiliary device for measuring the femur neck BMD.

Evaluation of the reduced scalp dose at Volumetric Modulated Arc Therapy(VMAT)

The use of WBRT(whole brain radiation therapy) has increased due to the increase in the incidence of metastatic brain tumors. The development of radiation therapy techniques is expected to improve the quality of life. The VMAT (Volumetric Modulated Arc Therapy) is an excellent treatment technique that can distinguish the dose in each volume. Therefore, this study compared conventional WBRT and VMAT for hair loss according to the scalp dose using a head phantom. The CI (Conformity Index), HI (Homogeneity Index) and QOC (Quality of Coverage) were measured brain tissue. A 20 percent and 50 percent dose was measured at the scalp, eyeball, lens, and c-spine. Conventional WBRT is excellent at 10 percent of brain tissue. VMAT is far superior at 1000 percent at the other organs. VMAT at the prescribed dose can be used as radiation therapy of metastatic brain tumors with less hair loss.

The Clinical usefulness of the tangential projection view of Radius groove after Distal Radius Fracture operation using the T-type Plat

Introduction : The projection method to check existence and nonexistence of radius groove penetration of screw after distal radius fracture operation clinical using the T-type plate and the radiation of radial groove tangential is to propose a new test. Material and Methods : On the tangential projection view of radius groove, elevation angle of distal radius is 2.5, 5, 7.5, 10 degree. and forearm and radiation detector of angle is 60, 70, 80, degree each changed. that analyzed check existence and nonexistence of radius groove penetration of screw. Results : For the image of Radial groove tangential. the case of not radius groove penetration of screw(63.95%, n=55), medial penetration of radius groove(10.47%, n=9) or lateral penetration of radius groove(25.58%, n=22) was analysis. The radius groove penetrating of screw length was a range of 0.43 ∼ 2.72mm, the average was 1.06mm. the check existence and nonexistence of radius groove penetration of medial or lateral was analysis that it accurate for the image of Radial groove tangential. the radiography of radial groove is well described elevation angle of distal radius 2.5 to 7.5 degree(90% over), forearm and radiation detector of angle 70degree(80%over) Conclusion : It is elevation angle of distal radius is 5degree, forearm and radiation detector of angle 70degree recommended.