• The Journal of Korean Society for Radiation Therapy
• /
• v.18 no.2
• /
• pp.89-96
• /
• 2006

Purpose: To study effectiveness of heterogeneity correction of internal-body inhomogeneities and patient positioning immobilizers in dose calculation, using images obtained from CT-Simulator. Materials and Methods: A water phantom($250{\times}250{\times}250mm^3$) was fabricated and, to simulate various inhomogeneity, 1) bone 2) metal 3) contrast media 4) immobilization devices(Head holder/pillow/Vac-lok) were inserted in it. And then, CT scans were peformed. The CT-images were input to Radiation Treatment Planning System(RTPS) and the MUs, to give 100 cGy at 10 cm depth with isocentric standard setup(Field Size=$10{\times}10cm^2$, SAD=100 cm), were calculated for various energies(4, 6, 10 MV X-ray). The calculated MUs based on various CT-images of inhomogeneities were compared and analyzed. Results: Heterogeneity correction factors were compared for different materials. The correction factors were $2.7{\sim}5.3%$ for bone, $2.7{\sim}3.8%$ for metal materials, $0.9{\sim}2.3%$ for contrast media, $0.9{\sim}2.3%$ for Head-holder, $3.5{\sim}6.9%$ for Head holder+pillow, and $0.9{\sim}1.5%$ for Vac-lok. Conclusion: It is revealed that the heterogeneity correction factor calculated from internal-body inhomogeneities have various values and have no consistency. and with increasing number of beam ports, the differences can be reduced to under 1%, so, it can be disregarded. On the other hand, heterogeneity correction from immobilizers must be regarded enough to minimize inaccuracy of dose calculation.

• Journal of Korean Academy of Fundamentals of Nursing
• /
• v.2 no.2
• /
• pp.199-211
• /
• 1995

This study analyzed the practical education in fundamentals of nursing, for the 36 nursing schools including 12 4-year nursing schools and 24 junior college nursing schools. This survey was done from september 5th to october 5th in 1995. The results of this study were as follows : 1. Required credit in fundamentals of nursing. 1) The highest incidence of the total required credit was 7 in 4-year nursing school and 9 in junior college. 2) For the lecture course credit, the large number of 4-year nursing school gave 5 credit lessons and 6 credits provided in junior nursing colleges. 3) For the credit of practical education the major portion of 4-year nursing school gave 2 credits instruction, however junior nursing school provided 3 credits. 2. Laboratory practice in fundamentals of nursing. In laboratory practice, the ratio of instructor and student was 1 : 20 in 83.4% of the 4-year nursing school and in 66.7% of the junior nursing school. 3. Contents and hours of fundamental nursing practice. 1) In the area of health assessment and nursing process, the large number of schools allocated following hours : 6 hours for vital signs, 4 hours for nursing process, 2 hours for recording but practice for physical examination and communication was done in few schools. 2) In the area of functional health pattern, the large number of schools allocated practice hours like followings : 2 hours for I/O, 2 hours for gavage feeding, 2 hours for elimination, 6 hours for catheterization, 6 hours for bed making, 2 hours for positioning, 6 hours for personal hygiene, 2 hours for R.O.M, 4 hours for moving turning lifting, 2 hours for inhalation and suction. But C.P.R and terminally ill patient care were taught in smaller number of schools. 3) In the area of special nursing measures, the major portion of nursing schools allocated hours like followings. It consisted of 6 hours for asepsis, 16-18 hours for medication, 2 hours for heat and cold application, 2 hours for wound care. 4) 22.2% of the nursing schools had total review practice time and 36.1% of the nursing schools had the students clinical practice. Based on above mentioned results, 4-year nursing school had faithful practical education of fundamental nursing than junior nursing school. But for the contents and allocated hours for practice education, junior nursing schools were much more contents and hours than 4 year school.

• Nuclear Medicine and Molecular Imaging
• /
• v.42 no.2
• /
• pp.153-163
• /
• 2008

Medical imaging modalities to image either anatomical structure or functional processes have developed along somewhat independent paths. Functional images with single photon emission computed tomography (SPECT) and positron emission tomography (PET) are playing an increasingly important role in the diagnosis and staging of malignant disease, image-guided therapy planning, and treatment monitoring. SPECT and PET complement the more conventional anatomic imaging modalities of computed tomography (CT) and magnetic resonance (MR) imaging. When the functional imaging modality was combined with the anatomic imaging modality, the multimodality can help both identify and localize functional abnormalities. Combining PET with a high-resolution anatomical imaging modality such as CT can resolve the localization issue as long as the images from the two modalities are accurately coregistered. Software-based registration techniques have difficulty accounting for differences in patient positioning and involuntary movement of internal organs, often necessitating labor-intensive nonlinear mapping that may not converge to a satisfactory result. These challenges have recently been addressed by the introduction of the combined PET/CT scanner and SPECT/CT scanner, a hardware-oriented approach to image fusion. Combined PET/CT and SPECT/CT devices are playing an increasingly important role in the diagnosis and staging of human disease. The paper will review the development of multi modality instrumentations for clinical use from conception to present-day technology and the application software.

• Proceedings of the KSMRM Conference
• /
• 2003.10a
• /
• pp.103-105
• /
• 2003

After fifteen years of development, Magnetic Resonance (MR) technology for human imaging and spectroscopy is reaching a refined state with FDA approved 3T clinical products from Siemens, GE, and Philips. Broker has cleared CE approval with a 4T system. Varian supports a 4T system platform as well. Shielded magnets are standard at 3T from GE, Oxford, Magnex, and IGC. A shielded 4T whole body magnet is available from Oxford. Stronger switched gradients and dynamic shim coils, desired at any field, areespecially useful at higher static magnetic fields B0. In addition to the higher currents required for higher resolution slice or volume selection afforded by higher SNR, whole body gradient coils will be driven at increasing slew rates to meet the needs of new cardiac applications and other requirements. For example 3T and 4T systems are now being equipped with 2kV, 500A gradient coils and amplifiers capable of generating 4G/cm in 200msec, over a 67+/-cm bore diameter. High field EPI applications require oscillation rates at 1 kHz and higher. To achieve a benchmark 0.2 ppm shim over a 30cm sphere in a high field magnet, at least four stages of shimming need to be considered. 1) A good high field magnet will be built to a homogeneity spec. falling in the range of 100 to 150 ppm over this 30cm spherical "sweet spot" 2) Most modern high field magnets will also have superconducting shim coils capable of finding 1.5 ppm by their adjustment during system installation. 3) Passive ferro-magnetic shimming combined with 4) active, high order room temperature shim coils (as many as five orders are now being recommended) will accomplish 0.2 ppm over the 30cm sphere, and 0.1 ppm over a human brain in even the highest field magnets for human studies. Safety concerns for strong, fast gradients at any B0 field include acoustic noise and peripheral nerve stimulation. One or more of the mechanical decoupling methods may lead to quieter gradients. Patient positioning relative to asymmetric or short gradient coils may limit peripheral nerve stimulation at higher slew rates. Gradient designs combining a short coil for local speed and strength with a longer coil for coverage are being developed for 3T systems. Local gradients give another approach to maximizing performance over a limited region while keeping within the physiologically imposed dB0/dt performance limits.

• Progress in Medical Physics
• /
• v.12 no.2
• /
• pp.147-153
• /
• 2001

We have discussed that the total body irradiation(TBI) dose distribution of 6 and 10 MV photon beams, also differences between calculation dose use of compensator sheet and measurements in humanoid phantom. Total body irradiation and hemi-body irradiation(HBI) can be effectively performed when uniformity of dose distribution is estabilished. The method of TBI and HBI dosimatry requires special considerations related to technique, long distance and very large field, machine parameter, patient positioning. TBI and HBI with megavoltage photon beams requires basic dosimatric data which have to be measured directly or derived from the standard beam data. The semiconductor detector and ion chamber were positioned at a dmax depth, mid depth, and its specific ratio was determined using a scanning data by RFA-7 3-dimensional water phantom and solid phantom. The effective source axis distance 380 cm, the field size from 120 cm to 152 cm, isodose distributions were analyzed as a function of the thickness in phantom. Also, have discussed that the measurement of basic data for clinical photon beams for dosage calculations, data calculation sheet and the use of tissue compensation to improve dose uniformity. We have improved a dose uniformity in the TBI and HBI method.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.29 no.6
• /
• pp.509-512
• /
• 2007

Purpose: The Le Fort I osteotomy is a commonly performed maxillary procedure for dentofacial deformity. One of the risks of this procedure is major hemorrhage resulting from injury to the descending palatine artery. So it is very important to know the exact position of the descending platine artery. An increased understanding of the position of this artery can minimize the intra-operative bleeding while allowing extension of the bone cuts to achieve exact positioning maxilla. The aim of this investigation was to study the position of the descending palatine artery as it relates to the Le Fort I osteotomy. Methods and patients: Total 40 patients who underwent Le Fort I osteotomy in SNUDH OMFS were studied in this study. We measured the distance from the pyriform aperture to the descending palatine artery (DPA distance) using a ruler. We investigated the relationship between DPA distance, the distance from A point to the McNamara line on lateral cephalography and the patient's body height. Results: The average distances from the pyriform rim to the descending palatine artery were 35.3 mm on the right (range: $30{\sim}40mm$) and 33.7mm (range: $30{\sim}41mm$) on the left in males. Those in females were 33.4 mm on the right (range: $28{\sim}40mm)$ and 32.8mm (range: $27{\sim}38mm$) on the left. The significances between the distance the DPA distance, the body height and the distance from A point to McNamara line were not found. Conclusion: Injury to the descending palatine artery during Le Fort I osteotomy can be minimized by not extending the osteotomy more than 30 mm posterior to the pyriform aperture in mal, and 27 mm in female.

• The Journal of Korean Academy of Prosthodontics
• /
• v.18 no.1
• /
• pp.73-86
• /
• 1980

Recently, the controversy continues as to whether maximum intercuspation of teeth should occur at the terminal hinge position(the condylar theory) or at the myo-co(the neuromuscular theory). There is also much controversy regarding the antero-posterior position of myo-co. The object of this study was to measure and compare with the positional relations of centric relation, centric occlusion and myo-co, and free-way space using Mandibular Kinesiograph and Myo-monitor in the 40 subjects without stomatognathic problems. Mandibular Kinesiograph(M.K.G.) was originally conceived as a research instrument to track mandibular movement and position. As its use in research progressed, its great diagnostic value became apparent in case by case. And Myo-monitor was developed as a means of applying the neuromuscular approach to occlusion. Thus the Myo-monitor technique is an intra-systemic approach to occlusal positioning using patient's own musculature, and Myo-monitor is used to relax the musculature by a light myopulse induced electronically. From this experiment, the following results were obtained. 1. The adaptive free-way space before muscle relaxation was an average of $1.6{\pm}60mm$, and the true free-way space after muscle relaxation using Myo-monitor was an average of $2.4{\pm}0.74mm$. 2. It took an average of $25{\pm}3.11$ minutes to relax the mandibular musculature by Myo-monitor and administration of 5mg. Diazepam and an average of $38{\pm}4.73$ minutes by Myo-monitor without administration of Diazepam. 3. Myo-co existed anterior to centric occlusion, with an average of $0.53{\pm}0.31$ mm, and centric relation existed posterior to centric occlusion, with an average of $0.57{\pm}0.58mm$ before muscle relaxation and with an average of $0.57{\pm}0.43mm$ after muscle relaxation. 4. Centric relation coincided with centric occlusion in 5 of 40 subjects(12.5%), and posterior to centric occlusion in the rest of cases (87.5%). 5. Myo-co existed anterior to centric occlusion in 38 of 40 subjects(95%), except 1 subject that coincided with centric occlusion and 1 subject that existed posterior to centric occlusion. 6. Myo-co and centric relation existed inferior to centric occlusion and the lateral displacement was various with individual difference. 7. The total displacement from centric occlusion to centric relation was an average of $0.74{\pm}0.64mm$ before muscle relaxation, and an average of $0.68{\pm}0.53mm$ after muscle relaxation, and the total displacement from centric occlusion to myo-co was an average of $1.07{\pm}0.58mm$.

• Journal of radiological science and technology
• /
• v.40 no.4
• /
• pp.543-548
• /
• 2017

The aim of this study was to evaluate anteroposterior oblique(RPO, LPO) and posteroanterior oblique(LAO, RAO) projections of the cervical spine, at various kVp and mA s increments, in order to compare thyroid surface dose. Using Rando phantom, dosimeter was attached to the Cervical spine 4~5 to measure the surface dose in the same thyroid position. As a result, the surface dose was $595.08{\pm}215.01{\mu}Gy$ for anteroposterior oblique(RPO, LPO) projections and $64.21{\pm}33.49{\mu}Gy$ for posteroanterior oblique(LAO, RAO) projections by changing kVp increment. The surface dose was $445.20{\pm}230.90{\mu}Gy$ for anteroposterior oblique(RPO, LPO) projections and $44.51{\pm}22.77{\mu}Gy$ for posteroanterior oblique(LAO, RAO) projections by changing mAs increment. The posteroanterior oblique method could reduce about 90% the surface dose than the anteroposterior oblique method. There were statistically significant differences among the examinations(p<0.001). Change the direction of position to reduce the surface dose at oblique projection of cervical spine. Therefore, we consider posteroanterior oblique projections than anteroposterior oblique projections of cervical spine examination in other to reduce patient surface dose.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.36 no.4
• /
• pp.1-18
• /
• 2023

Objectives : This study retrospectively analyzed the medical records of patients admitted to Korean medicine ophthalmology, otolaryngology and dermatology department of Daejeon Korean medicine hospital from March 2018 to February 2023 to analyze the characteristics of patients receiving inpatient treatment. Methods : We retrospectively analyzed inpatients who admitted to ophthalmology & otolaryngology & dermatology clinic of Daejeon Korean medicine hospital from March 1st, 2018 to February 28th, 2023, according to gender, age, year, season, detailed subdivision. The statistical analysis performed using IBM SPSS 29.0 for Windows. Results : 1. Examining the gender distribution of the patient group, there were 367 female patients, accounting for 71.7% of the total patients, and 145 male patients, accounting for 28.3% of the total patients. 2. When analyzing inpatients by subdivision, otology accounted for more than half of the total number of inpatients, and the combined number of otology and dermatology accounted for more than 80% of the total. 3. As a result of analyzing inpatients by frequent disease, Sudden hearing loss was a significantly higher number of patients, accounting for 22.7% of all inpatients. Conclusions : It was found that the proportion of patients with otologic diseases was very prominent. It is thought that further research is needed to see if the trend of increasing demand for otologic diseases continues.

• Journal of the Korean Society of Radiology
• /
• v.81 no.1
• /
• pp.21-40
• /
• 2020

Magnetic resonance imaging (MRI) is an essential modality for the diagnosis of musculoskeletal system defects because of its higher soft-tissue contrast and spatial resolution. With the recent development of MRI-related technology, faster imaging and various image plane reconstructions are possible, enabling better assessment of three-dimensional musculoskeletal anatomy and lesions. Furthermore, the image quality, diagnostic accuracy, and acquisition time depend on the MRI protocol used. Moreover, the protocol affects the efficiency of the MRI scanner. Therefore, it is important for a radiologist to optimize the MRI protocol. In this review, we will provide guidance on patient positioning; selection of the radiofrequency coil, pulse sequences, and imaging planes; and control of MRI parameters to help optimize the MRI protocol for the six major joints of the musculoskeletal system.