In-Chul Im

Measurement of the Skin Dose of Patient Using the Optically Stimulated Luminescent Dosimeter at Diagnostic Radiography

The purpose of this study is an measurement of the skin dose of a patient by using the OSLD(optically stimulated luminescent dosimeter) under several irradiation conditions of the X-ray beam for diagnostic radiography. The measurements of skin dose were performed for head, chest, and pelvis. And test of reproducibility was carried out at the chest. As a result, we obtained the skin dose at forehead of head to be 1.30 mSv. The skin doses at xiphoid process, breast and apex of the lung of the chest were acquired 0.92, 0.52 and 0.70 mSv, respectively. And we obtained the skin doses at the left pelvis and the right pelvis to be 2.78 and 3.08 mSv, respectively. As for reproducibility, a coefficient of variation was 0.033. The skin doses were exhibited the values corresponding from 1/100 to 1/17 of the dose limit of the public(50 mSv) at the deterministic effect. In order to make accurate measurements of the skin doses for each tube voltage, the measured values have to multiply by the displayed values of reader by a correction factor. The energy response of the OSLD with the tube voltage will be studied in the near future.

Analyzed the Computed Tomography Dose Index (CTDI) to the Pediatric Brain CT by Reason of the Observation for the Exposure Dose: Base on a Hospital

The purpose of this study was to derive the proposals and to suggest the exposure dose reduction scheme on pediatric head CT scan by analyzing and comparing CT dose index (CTDI) and the national diagnostic reference levels. From January 2014 to December, 231 children under 10years who were requested a pediatric head CT scan with head injury were examined. Research methods were to research and analyze the general characteristics kVp, mA test coverage and DLP referring to dose reports and electronic medical record (EMR). As a result, 7.4%(17 patients) of the total subjects in showed a national diagnostic reference levels exceeding. For DLP 41.6%(96 patients) in excess was relatively higher than . DLP was exceeded more than about 60% that is higher than the CT dose index presented by Korea Food & Drug Administration. it is cause of high DLP that scan range increased more than about 30% wider than the standard test coverage presented in Health Insurance Review & Assessment Service. In conclusion, it is able to significantly lower the dose if it is complied with checking the baseline scan range of pediatric head CT scan and appropriately adjusting the protocol.

Evaluating Surface dose of Treatment Immobilization Devices according to their Electron Energy

This study evaluated surface dose of treatment immobilization devices such as Themo-plastic, Vac-lock, Cotton and Plaster according to their electron energy. Using a linear accelerater, a plane parallel chamber was set up on 6Mev, 9Mev, 12Mev and 15Mev. A distance between a source and a surface was 100cm and a field size was 10cm*10cm. An incident angle was 0 degree and a radiation dose was 100MU. To decrease an error, the measurement repeated 3 times. The analysis reveals that the surface dose of Vac-lock was the highest and Themo-plastic, Plaster and Cotton were high in order.

Ottonello Projection Techniques using the Metronome

The ottonello method is used to see a front view image of cervical 1-7 number. The study found a systematic examination method to find a better image through an experiment using metronome. The results are as follows: In an evaluation of MTF, when used 0.5 standard of MTF, oral explanation resulted 1.2 LP/mm, Moderato-100 1.4 LP/mm, Allegro-138 1.6 LP/mm, Presto-184 2.4 LP/mm. Among them presto-184 showed the highest sharpness with 2.4 LP/mm. In an image reading by a medicine doctor of radiology, when oral explanation was 17%, Moderato-100 15%, Allegro-138 18%, Presto-184 50%. Among themprest-184 was evaluated as the best image. The result of was a method to reduce an image repeat, patients radiation exposure, patients waiting time for examination, material and so on.