Hoi-Woun Jeong

Preparation of encapsulated alliinase in alginate microparticles

Alliinase (alkylsulphenate lyase, EC 4.4.1.4), which catalyses the production of allicin, was immobilized in alginate microparticles. Addition of pyridoxal 5′-phosphate to the microparticles enhanced alliinase activity. Encapsulated alliinase were significantly higher (30 and 22%, respectively) than those of non-encapsulated alliinase at 60°C and at pH 2. Therefore, microencapsulation of alliinase with alginate can offer an effective way of sustaining enzyme activity during oral administration and passage through the stomach.

Neutron dosimetry depending on the number of portals for prostate cancer IMRT(Intensity-Modulated Radiation Therapy)

Abstract The aim of this study was provide basic information and establish the criteria in radiation therapy planningby measuring the absorbed neutron dose of normal tissues and lesions according to the number of portals. From September 2013 to January 2014, 20 patients who were diagnosed with prostate cancer and were previously treated with radiation therapy were replanned retrospectively to measure the absorbed neutron dose distribution according to the number of portals. The absorbed neutron dose was measured in each of the 5, 7 and 9 portals using a 15 MV energy, which meant a therapeutic dose of 220 cGy. The optical stimulation luminescence dosimeter was separated by 20cm and 60cm away from the center of the field of view. As a result, the average radiation dose in the abdomenappeared to have a positive relationship with the number of portals, which was statistically significant (p<.05). The average radiation dose was 4.34±1.08. The average radiation dose in the thyroid was 2.71±.37. Although it showeda positive relationship with the number of portals, it did not have statistical significance. The number of portals andthe neutron dose depending on the position showed a significant positive relationship, particularly in the abdomen. As a result of linear regression analysis, as the number of the portal increased in steps, the average volume of the neutrons increased significantly (0.416 times). In conclusion, efficient selection of the number of portals is needed considering the difference in the absorbed neutron dose in the normal tissues depending on the number of the portals.

Evaluation of quantitative on T-spine exhalation technique and T-spine breathing technique of natural breathing

Abstract Measurements of CNR(Contrast to Noise Ratio) and SNR(Signal to Noise Ratio) of T-spine breathing technique (TBT) using spontaneous breathing and T-spine exhalation technique (TET) with full exhalation were carried out, and with which the more appropriate method was suggested. Both TBT and TET were examined in a sample of fifty-three patients who visit to our hospital for spinal disease from June 2012 to November 2012. All images were evaluated with CNR measured from the differences between the mean pixels and contrast density as setting ROI of spinous process, pedicle, vertebral body, intervertebral foramen, and intervertebral disk using Image J. SNR was measured with the mean pixels and the standard deviation as setting ROI of vertebral body using Image J. In CNR comparison and SNR comparison of TET and TBT, TBT was indicated as excellent in ROI of pedicle, vertebral body, intervertebral foramen and intervertebral disk, and statistical analysis were significant(p<.01). As TBT indicated excellent images compared to the existing T-spine lateral radiography, T-spine lateral radiography would be reestablished and significant as applying to various medical institutions.

Measurement of Image Quality According to the Time of Computed Radiography System

진단의 높은 정확성을 유지하기 위하여 영상 품질의 정기적인 quality assurance (QA) 검사는 필수적이다. 이 연구의 목적은 2006년부터 2015년까지 시간에 따른 (2006, 2009, 2012, 2015) computed radiography (CR) system의 modulation transfer function (MTF: 변조전달함수), the noise power spectrum (NPS: 잡음전력...

Evaluation of Image Quality for Various Electronic Portal Imaging Devices in Radiation Therapy

MV방사선 치료는 둘러싸여 있는 정상조직의 피폭선량을 최소화 하면서, target volume 내에 정확하게 선량을 전달하는데 있어 중요한 요인이다. 본 연구에서는 방사선 치료의 높은 정확성을 유지하기 위하여 megavoltage X-ray imaging (MVI)에서 edge block 을 사용한 digital radiography (DR) system 검출기의 modulatio...