There are several reasons to take X-ray in case of inpatients. Some of them who cannot ambulate or have any risk if move are taken portable X-ray at their wards. Usually, in this case, many other people-patients unneeded X-ray test, family, hospital workers etc-are indirectly exposed to X-ray by scatter ray. For that reason I try to be aware of free space scatter dose accurately and make the point at issue of portable X-ray better in this study. kVp dose meter is used for efficiency management of portable X-ray equipment. Mobile X-ray equipment, ionization chamber, electrometer, solid water phantom are used for measuring of free space scatter dose. First of all the same surroundings condition is made as taken real portable X-ray, inquired amount of X-ray both chest AP and abdomen AP most frequently examined and measured scatter ray distribution of two tests individually changing distance. In the result of measuring horizontal distribution with condition of chest AP it is found that the mAs is decreased as law of distance reverse square but no showed mAs change according to direction. Vertical distribution showed the mAs slightly higher than horizontal distribution but it isnt found out statistical characteristic. In abdomen AP, compare with chest AP, free space scatter dose is as higher as five-hundred times and horizontal, vertical distribution are quite similar to chest AP in result. In portable X-ray test, in order to reduce the secondary exposure by free space scatter dose first, cut down unnecessary portable order the second, set up the specific area at individual ward for the test the third, when moving to a ward for the X-ray test prepare a portable shielding screen. The last, expose about 2m apart from patients if unable to do above three ways.

Far reducing medical radiation exposure and managing patient doses, Entrance surface doses(ESDs) were measured at Diagnostic Radiology Department in ASAN medical center, also we determined and compared with the Diagnostic Reference Level(DRL) of some other countries. ESDs were measured far the most common types of X-ray procedures, such as chest PA, lumbar spine AP, lumbar spine lateral, Pelvis AP, Skull PA. ESDs were measured by Glass dosimeter and Unfors Xi meter. Those were applied collimation center of phantom's entrance skin surface. The results of ESDs were compared Glass dosimeter with Unfors Xi meter. Those were measured within 5% statistical difference. It seemed well agreement at two devices. In most cases ESDs measured far the different types of X ray procedures were found to be lower than the DRL of IAEA, but ESDs on chest PA, lumbar spine AP, lumbar spine lateral, Pelvis AP, Skull PA were proximity ar excesses at DRL of advanced country. Through this study, we need an investigation and improvement at present diagnostic radiology exam system. Also, radiologists make an effort to reduce patient dose and having a technical skill.

In operation room, the use of the C-arm unit is increasing. So, the radiation dose of the person who work in operation room was even more increased than before. Thus, this study is shown the measurement of expose dose and the way for decrease of the radiation dose by using the C-arm unit. The experiment was performed with the C-arm unit and used a phantom which is similar to tissue of the human body and fluoro-glass dosimeter for dose measurement. The expose dose were measured by the tube position(over tube, under tube) of the C-arm unit, distance(50, 100$\sim$200cm), direction(I, II, III, IV), runtime(1min, 3min), wearing of the apron. The radiation dose was decreased twice and three times at under tube rather than over tube. The I direction was measured 20$\sim$30% more than the others. The biggest expose dose is 50cm from center on distance. The expose dose is decreased to far from center. In case of Wearing of the apron, the radiation dose was decreased 60$\sim$90% by the distance. But there weren't change of the radiation dose by C-arm tube position. In present, by increasing the usage of the C-arm unit, the radiation dose is inevitable. So, this study recommends us to use the under tube of the C-arm unit. Also, Wearing of the apron is required for minimum of the radiation exposure.

In this study, we compared the alteration of test positions according to various test equipments when testing shoulder joint superoinferior axial to estimate the clinical usefulness of tiltable standing detector. Our objectives were patients who visited our hospital. Among them we chose patients who were prescribed to get a shoulder axial test, again we selected 30 patients whose abduction is more than 90 degree.(2008. Nov.$\sim$2009 Jan.) With the patients cooperation, we used CR(Agfa, Belgium), fixed-detector(Canon, japan), Tiltable-detector(Philips, Netherlands). Tested with only one equipment(tiltable detector), and posed with the other two. We surveyed 5 inspectors and 30 patients, asking them to rate the convenience of test position. Also, we checked how long it takes to have the image appear on screen after testing with the equipment We provided a standard for an assessment of the image to an expert in bone radiology, an orthopedist and a radiologist with 5 years experience. When the patients were asked about the convenience of the equipments, 15 people(50%) answered CR is convenient and 14 people(46.7%) answered the Tilting detector is convenient, showing not much difference. However, when the inspectors were asked the same question, 4people(80%) out of 5 answered that the Tilting detector is more convenient The time test showed that CR takes 2 minutes and 50 seconds, the Fixed detector 1minute and 48 seconds andor had no distortion showing the shoulder joint space. However, even though the Fixed detector showed ac the Tilting detector takes 1 minute and 43 seconds to bring the image to the screen after the position. The results of the value of image taken by each equipment, CR and the Tilting detectromion, coracoid process, due to the unstable pose, they were quite distorted and scored poor in observing glenoid fossa. By this study, we can see that testing the shoulder joint superoinferior axial projection with a detector that has a tilting device would be more convenient than testing it with a CR.

This study was conducted to improve performance flow of PACS registration and output of external medical images by developing or adding File Transfer Protocol(FTP) Module on Order Communication System(OCS) and to upgrade efficiency of performance. The numbers of requests for examination of external medical images from January 2004 to December 2007 were investigated and the numbers of cases of examinations and losses were done respectively from January to June, 2007 as a period before the improvement and from July to December, 2007 as a period after it. Satisfaction of persons inputting external medical images of CD was asked directly before and after the improvement. When the numbers of requests for examination of external medical images from 2004 to 2007 2004 were investigated, they were 12,783, 16,774, 21,613 and 27,487 cases in 2004, 2005, 2005 and 2007 respectively. For the numbers of the requests from January to December, 2007 it was the lowest in February by recording 1846 and it was 2800 in October. While the number of loss of external medical images was averagely 3.6 before using FTP Module on OCS, it reduced to 0 and satisfaction increased to 98% after it. By utilizing FTP Module on OSC for PACS registration of external medical images, the images were delivered simultaneously with occurrence of order, PACS registration of many patients was conducted together and CDs were returned to patients immediately after sending images from outpatient clinics or wards to remove possibility of losing them. In addition, because the module was established on OCS and data were sent associated with order, problems related with order were decreased. By eliminating movement distance it was turned out to be very effective in terms of time and space.

Geometry calculation Using Abdominal internal organ image from traditional laparoscopy or robotic surgery system we can make depth informations through measured 3D structure informations is very helpful to doctors, depth information is mare useful then others that use traditional laparoscopy or robotic surgery system to many doctors. however, traditional method are incomplete. less experienced doctors make much mare prohability of mistake. Hence, 3D information of organ is very helpful to the less experienced doctors. it will be greate role of reducing medical accidents and surgical time. We can get 3D informations using geometrical calculation method in robotic surgical system. also suggested method is needed in traditional surgical method without the need to create a new system, finally, We can get 3D information from traditional system without any new system, it take advantage in cost and create high efficiency. mare information will provided to many doctors.