電算化 斷層 撮影에서 X-線源과 濾過 線速, 制限 및 檢出에 관한 考察

유장수,김경근 대구산업정보대학 1995 논문집 Vol.9 No.2

The X-ray source requirements in CT depend on the radiation attenuation and the intensity rate desired. Clinical CT scanners use conventional X-ray source, since they provide the greatest radiation intensity. Two types of sources are used. These are fixed anode oil cooled tubes and rotating anode air cooled tubes, which can be pulsed in operation. The purpose of a filter in CT is twofold. First, it uncreases beam quality by absorbing low energy waves, and, secondly, it can be shaped to provide uniform X-ray transmission. The techique of collimation is important in CT, since it relates to patient dose and image quality. Detectors used in CT are of two types. These are scintillation detectors and gas ionization detectors. A scintillation detector uses a scintillation crystal coupled to a photomultipiler tube. The system coverts radiation into electric current signals, which are fed into the computer for processing. The gas ionization detector uses a pressurized gas chamber, which converts the radiation to electric current signals that are fed into the computer for processing. The research findings of a split detector system and the use of HgI₂ as CT detectors are presented. The elctrical signals received from the detectors are converted into digital information for computer reconstruction. A comparison of the criteria for data acquisition and response time is given.

흉부 방사선 촬영 조건과 촬영기기 현황에 관한 연구

유장수 대구산업정보대학 2002 논문집 Vol.16 No.-

In this study, the quality of X-ray equipment and radiographical condition on chest radiography were investigated. it could provide the groundwork of diagnostic information for reducing the exposure dose. The data was surveyed from the radiography equipment at 105 medical facilities by using questionnaire from September in 2001 to January in 2002. The following resulted from the study: 1. It showed that they used 21% of the equipment with the maximum tube voltage of 150kV, 68% with that of 125kV and 57% that had 500mA for the rating capacity. half of the units could use high voltage radiography. 2. In real chest radiographical condition, only 7% of them were used at 80kV and over for high tube voltage while 86% of them were at 60-80kV that might result from that there were more small facilities in number. 3. More half of radiography equipment had 0.06-0.10 second in average exposure time. most(96%) of them had 200-300mA of X-ray tube current, 83% had 180cm of distance between focus and film, 92% had the focus size from 1.0mm to 2.0mm, 82% had the tube current dose 11-25rnAs. 4. Most facilities used aluminum filters, 53% of whom were 1.0-1.9mm. wether they use complex filter didn't be found. 5. They didn't like to use ortho chromatic system that adapted in 36%. 66% used 8:1 or less of the grid ratio at chest radiography and 28% didn't use the grid. In conclusion Patients under chest radiography at medical facilities in Daegu are expected to expose to high dose of radiation. For my perspective it is recommended to use proper filters and grid ratio, the combination of high quality screen system and film so that they can reduce exposure dose to the patients.

두부손상 환자의 뇌신경손상에 대한 임상적 분석

유장수,한용표,김헌주,홍순기,허철 대한신경외과학회 1991 Journal of Korean neurosurgical society Vol.20 No.1-3

The clinical analysis of cranial nerve injuries was performed on 435 cases with cranoicrerbral trauma. This prospective study included the correlation between cranial nerve injuries and risk factors such as intracranial hematoma, initial Glasgow Coma Scale(GCS) score, pneumocephalus, and other combined injuries. The results were revealed as follows : 1) 133 cranial nerve injuries(on 97 patients) were noted among 435 craniocerebral trauma victims(91/435= 22.2%). 2) The order of frequent cranial nerve injuries was facial nerve(7.3%), olfactory nerve(6.9%), oculomotor nerve(4.4%), abducens nerve(3.9%), optic nerve(3.2%), etc. 3) Bilateral involvment of cranial nerve injuries was noted in 16.5% (22/133). 4) The incidence of immediate onset of cranial nerve injuries was 66.9% (89/133) 5) The incidence of cranial nerve injuries was significantly high in patients with pneumocephalus and low initial GCS score. 6) The functional recovery of injured cranial nerve within 3 months was noted in 30.1% (40/133).

X선 단순촬영에 있어서 신장결석의 출현에 관한 검토

유장수,송재관,허준 대한방사선과학회(구 대한방사선기술학회) 1989 방사선기술과학 Vol.12 No.1

X선 단순촬영에 있어서 신장결석의 출현에 관한 연구

유장수 대구산업정보대학 1989 논문집 Vol.3 No.-

This paper investigated on influence on the distinguishability of renal stone in the accordance with thickness of object, X-Ray tube voltage and base density. In the relationship between object and renal stone shadow, object and tube voltage, the obtained rresults can be summarized as the following. 1. When thickness of object was thin, the distinguishability increased in base density 2.0~2.5, but for adults was best shown in base density 1.5. 2. In the relationship between object and tube voltage, the distnguishability increased at lower tube voltages(50~60KVP), using grid. As mentioned above, it was thought that this method was very effective in describing the phenomena of renal stone in film density 1.5, tube voltages 60KVP.

대뇌겸 및 천막부위 급성 경막하 출혈에 대한 임상적 분석

유장수,허철,홍순기,김헌주,한용표 대한신경외과학회 1991 Journal of Korean neurosurgical society Vol.20 No.1-3

A prospective analysis of 50 patients with acute interhemisphric subdural hemorrhage and tentorial hemorrhage, an unusual pattern of acute subdural hematoma. who were managed in a uniform way was analyzed to related outcome to hemorrhagic site. initial Glasgow Coma Scale(GCS) and combined injuries. The incidence of acute interhemisphric subdural hemorrhage(ISH) and tentorial hemorrhage(TH) after head trauma was 3.83%. 50 cases among 1303 head injured cases. And 80% of the above hemorrhage disappeared within two weeks after trauma. There was no significant relationship between feature of hemorrhage and intial GCS (P>0. 05), but there was highly significant relationship between initial GCS and Glasgow Outcome Scale(GOS) (P<0.001). There noted significant relationship between initial combined injury and GOS(P<0.0l), and also brainstem injury and GOS(P<0.00l).

放射線 撮影 時 被曝線量 減少 因子에 關한 硏究

유장수 대구산업정보대학 2000 논문집 Vol.14 No.2

As radiography is increased these days, we cannot but consider the exposure on radiation seriously, which is the responsibility of radiotechnologists for people's health. The following are the factors decreasing the dose of exposure as far as there is no loss in the quality of image : 1. A suitable filter plate can remove the electromagnetic wave which has low energy and which isn't needed in image. 2. The improvement and the proper use of a collimator can decrease the area exposed on radiation. 3. The proper combination of high-quality-film and screen can increase the degree of sensitivity. 4. The high-light fluorescent plate and the fluorescent-image intensifier tube reduce the dose of fluoroscopy. 5. High-voltage radiography reduces the dose of exposure and fluoroscopy. 6. The improvement of developing method can increase the sensitivity and decrease exposure. 7. The operations of Auto-exposure and CR prevent the failure and the repeat of radiography. 8. The appliance preventing radiation reduces the size of exposed field. 9. The Grid should be selected properly in accordance with tube voltage. 10. The invention and the improvement of radiographic devices can reduce the dose of exposure.

DLTS 장치의 제작과 응용

兪長壽,金慶根,金仁洙 대구산업정보대학 1995 논문집 Vol.9 No.2

Deep level in horizontal Bridgman(HB) undoped GaAs were investigated by DLTS system personally manufactured. In as grown sample, T1(E_(C)-0.32eV), T2(E_(C)0.54eV) and T3(E_(C)0.82eV) were observed. These levels correspond to EL6, EL3 and EL2 respectively. As sample was annealed at 650℃, T3 level was separated into T3*(E_(C)0.74eV) and T3 level. When sample was annealed at 800℃, only T3* level was observed. For sample annealed at 900℃, T3* and T3 level were observed. From these results, we conclude that the EL2's behavior of annealing temperature can be explained by the model of As_(Ga)-V_(Ga)-A_(Sl)-V_(As).

一般X線撮影에 있어서 片面필름과 片面增感紙의應用

兪長壽 대구산업정보대학 1990 논문집 Vol.4 No.-

In clinical fields, single screen-film system will be generalized according to high speed and high image quality of intensifying screen film system in future. In single screen-film system, for image the best image, we must choice good film accordidng to speed and gredient. Double screen-film system will be replaced single screen film system in direct radiography. Author has thought that single screen film system will be developed new diagnosis area according to X-Ray film.

P.N.S.에서 Original Method와 New Method와의 비교 연구

兪長壽 대구산업정보대학 1996 논문집 Vol.10 No.2

Out study of caldwell and water's views, most common radioligical technique to delineate PNS, has verified that the ideal photographic image to diagnose PNS is, with eye socket, and with Water's view, only the one whose petrous ridge coincides with the lower edge of maxillary sinus. With the method used hitherto, it was difficult to obtain such a ideal image diagnostically. It was made possible by changing the revolving angle formed by the central ray and the head.