• Progress in Medical Physics
• /
• v.21 no.3
• /
• pp.281-290
• /
• 2010

Cone-beam digital tomosynthesis (CBDT) has greatly been paid attention in the image-guided radiation therapy because of its attractive advantages such as low patient dose and less motion artifact. Image quality of tomograms is, however, dependent on the imaging conditions such as the scan angle (${\beta}_{scan}$) and the number of projection views. In this paper, we describe the principle of CBDT based on filtered-backprojection technique and investigate the optimization of imaging conditions. As a system performance, we have defined the figure-of-merit with a combination of signal difference-to-noise ratio, artifact spread function and floating-point operations which determine the computational load of image reconstruction procedures. From the measurements of disc phantom, which mimics an impulse signal and thus their analyses, it is concluded that the image quality of tomograms obtained from CBDT is improved as the scan angle is wider than 60 degrees with a larger step scan angle (${\Delta}{\beta}$). As a rule of thumb, the system performance is dependent on $\sqrt{{\Delta}{\beta}}{\times}{\beta}^{2.5}_{scan}$. If the exact weighting factors could be assigned to each image-quality metric, we would find the better quantitative imaging conditions.

• Journal of Chest Surgery
• /
• v.30 no.5
• /
• pp.501-505
• /
• 1997

It was reported that use of aprotinin in elderly patients undergoing hypothermic circulatory arrest was associated with an increased risk of renal dysfunction, and myocardial infarction as a result of intravascular coagulation. We reviewed 20 patients who received high-dose aprotinin under deep hypothermic circulatory arrest with(NP group, n= 11) or without selective cerebral perfusion(SP group, n=9). The activated clotting time was exceeded 750 seconds in all but 1 patient. After opening aortic arch, retrograde low flow perfusion was maintained through femoral artery to prevent air embolization to the visceral arteries. Four patients among 20 died during hospitalization'due to bleeding, coronary artery dissection pulmonary hemorrhage and multiple cerebral infarction. Postoperatively, cerebrovascular accidents occurred in two patients; one with preoperative carotid artery dissection and the other with unknown multiple cerebral infarction. In conclusion, use of aprotinin in young patients undergoing hypothermic circulatory arrest did not increase the risk of renal dysfunction or intravascular coagulation if ACT during circulatory arrest is maintained to exceed 750 seconds with low-flow perfusion.

• Korean Journal of Clinical Pharmacy
• /
• v.21 no.2
• /
• pp.122-130
• /
• 2011

Objective: Although recombinant human erythropoietin (rhEPO) has revolutionized the treatment of anemia in chronic kidney disease (CKD) receiving hemodialysis (HD) with no need of blood transfusion, some patients have a blunted or appear to be resistant to rhEPO. There is a controversy in the causes of rhEPO resistance in maintenance HD patients with anemia. This study is to examine current anemia treatment outcomes and the factors influencing the rhEPO responsiveness in HD patient with CKD. Methods: The clinical parameters or factors relating to erythrompoietin treatment outcomes and erythropoietin responsiveness were collected from the HD patients in two large dialysis centers for three months. The collected paramenters included serum iron, total iron biding capacity (TIBC), transferrin saturation rate, ferritin, albumin, intact PTH, C-reactive protein (CRP), nPCR and medications such as an angiotensin converting enzyme inhbitor, an angiotension II receptor blocker and an HMG-CoA reductase inhibitor (HMG-CoA RI). The data were analyzed to examine the degree of acheiveing the anemia treatment goal and factors relating to ERI. Results: Among total 111 patients, 42 (42.3%) and 47 (37.8%) patients achieved the target Hct and Hb based on the Health Insurance Review and Assessment Services (HIRA) reimbursement criteria. In the higher ERI group (upper quartile), the patients had higher CRP levels (0.5 mg/dl) (p=0.0096), and lower TIBC score (<$240{\mu}g/dl$) (p=0.0027), and less patients were taking HMG-CoA RI (p=0.0019). Male patients (p=0.0204), patients with high TIBC score ($R^2$=0.084, p=0.0021) and patients taking HMG-CoA RI (p=0.0052) required to administer less dose of rhEPO meaning higher erythropoietin responsiveness. Conclusion: Less than 50% of CKD patients were achieving the goals of anemia by erythropoietin administration in large hospitals in Korea even though the goals were lower than those of NKF-K/DOQI practice guideline. The factors influencing ERI were sex, TIBC and HMG-CoA RI administration status, and neither an ACEI nor an ARB did not influence ERI.

• Journal of Korean Neurosurgical Society
• /
• v.30 no.8
• /
• pp.976-980
• /
• 2001

Objectives : For Parkinsonian patients who had not reacted favorably on drug therapy are good candidate for ventroposterolateral pallidotomy, although not curative. We studied these patients after unilateral pallidotomy, to confirm the effectiveness and safety of this procedure. Methods : We evaluated the 17 patients with idiopathic Parkinson's diesease who had undergone unilateral posteroventral pallidotomy. All patients responded to levodopa initially. Mean age was 55 years(38-75years), and mean duration of disease was 9.8 years(3-20years). Pre-and postoperative evaluation at 3 month intervals included Unified Parkinson's Disease Rating scale(UPDRS) scoring, Hoehn and Yahr(H & Y) staging, and neuropsychological examinations. Results : Pallidotomy significantly improved parkinsonian symptom(tremor, rigidity, bradykinesia, dyskinesia, sensory symptom). Nine of 10 patients who showed dyskinesia preoperatively significant improvement. The mean dose of levodopa in 9 patients was lowered. The mean H & Y score and UPDRS score were improved in on and/or off time in 15 patients. Among patients who were not improved, one patient worsened, and the others showed no change. The mean overall UPDRS off score changed from 76 preoperatively to 44(33%) at 6 months and from 70 to 52(25%) at 1 year. Transient surgical morbidity was showen in four patients and included dysarthria, hypotonia and confusion. Conclusion : We conclude that pallidotomy is safe and effective in patients who have levodopa-reponsive parkinsonism with severe symptom fluctuation. Unilateral pallidotomy also considered helpful to ipsilateral symptom. Unilateral pallidotomy can improve all of parkinsonian's symptom and allow to reduce the levodopa medication. Most of patients show satisfactory results.

• Journal of Korean Neurosurgical Society
• /
• v.44 no.4
• /
• pp.199-204
• /
• 2008

Objective : This study was designed to compare the efficacy of micro-vascular decompression (MVD) and Gamma knife radiosurgery (GKRS) for elderly idiopathic trigeminal neuralgia patients by analyzing the clinical outcome. Methods : In the past 10 years, 27 elderly patients were treated with MVD while 18 patients were treated with GKRS (>65-years-old). We reviewed their clinical characteristics and clinical courses after treatment as well as the treatment outcomes. For patients who were treated with MVD, additional treatment methods such as rhizotomy were combined in some areas. In GKRS, we radiated the root entry zone (REZ) with the mean maximum dose of 77.8 (70-84.3) Gy and one 4 mm collimator. Results : The mean age was 68.1 years for MVD, and 71.1 years for GKS group. The average time interval between first presenting symptom and surgery was 84.1 (1-361) months, and 51.4 (1-120) months, respectively. The mean follow-up period after the surgery was 35.9 months for MVD, and 33.1 months for GKRS. According to Pain Intensity Scale, MVD group showed better prognosis with 17 (63%) cases in grade I-II versus 10 (55.6%) cases in GKRS group after the treatment. The pain recurrence rate during follow up did not show much difference with 3 (11.1%) in MVD, and 2 (11.1%) in GKRS. After the treatment, 2 cases of facial numbness, and 1 case each of herpes zoster, cerebrospinal fluid (CSF) leakage, hearing disturbance, and subdural hematoma occurred in MVD Group. In GKRS, there was 1 (5.6%) case of dysesthesia but was not permanent. Three cases were retreated by GKRS but the prognosis was not as good as when the surgery was used as primary treatment, with 1 case of grade I-II, and 1 case of recurrence. The maximal relieve of pain was seen just after surgery in MVD group, and 1 year after treatment in GKRS group. Conclusion : For trigeminal neuralgia patients with advanced age, MVD showed advantages in immediately relieving the pain. However, in overall, GKRS was preferable, despite the delayed pain relief, due to the lower rate of surgical complications that arise owing to the old age.

• Clinical and Experimental Pediatrics
• /
• v.51 no.6
• /
• pp.655-659
• /
• 2008

Intestinal pseudo-obstruction (IPO) is a rare and poorly understood manifestation of systemic lupus erythematosus (SLE), especially in children. The characteristic clinical feature of IPO is obstruction without an identifiable obstructive lesion. The authors a 13-year-old girl whose first symptom of SLE was IPO. The patient presented with a 3-day history of nausea, bilious vomiting, abdominal distention, and no bowel movement. Simple abdominal radiographs revealed mild dilatation with partial air-fluid levels in the small intestine. Abdominal CT and methylcellulose small bowel studies showed massive ascites, engorgement of the small mesenteric vessels, pleural effusion, and diffuse bowel wall thickening of the gastric antrum, duodenum. and jejunum. The delayed passage of contrast for 15 days after the methylcellulose small bowel studies was suggestive of decreased bowel motility. Laboratory findings were positive for ANA, anti-double-stranded DNA, anti-Smith and lymphopenia. After 10-day treatment with high-dose corticosteroids, the symptoms improved. IPO associated with SLE should be considered in the differential diagnosis for patients presenting with symptoms of intestinal obstruction. Early recognition of IPO in SLE and appropriate therapy are important for prevention of complications and unnecessary surgery. This case raises awareness among pediatricians that although rare, IPO can be the presenting symptom of SLE in children.

• Journal of radiological science and technology
• /
• v.36 no.3
• /
• pp.193-200
• /
• 2013

There are many concerns about radiation exposure in Korea after Fukushima Nuclear Plant Accident on 2011 in Japan. As some isotope materials are detected in Korea, people get worried about the radioactive material. In addition, the mass media create an air of anxiety that jump on the people's fear instead of scientific approach. Therefore, for curbing this flow, health, medical institute from the world provide a variety of information about medical radiation safety and hold the campaign which can give people the image that medical radiation is safe. At this, the Korean Food and Drug Administration(KFDA) suggested that make the alliance of medical radiation safety and culture on August, 2011. Seven societies and institutions related medical radiation started to research and advertise the culture of medical radiation safety in Korea. In this report, mainly introduce the activities of the Korean Alliance for Radiation Safety and Culture in Medicine(KARSM) for spreading culture of medical radiation safety from 2011 to 2012.

• Korean Journal of Head & Neck Oncology
• /
• v.16 no.2
• /
• pp.228-234
• /
• 2000

Objectives: Esthesioneuroblastoma is a rare malignant neoplasm that originates from the olfactory sensory cells. This tumor grows from the upper nasal cavity and ethmoid sinus and invades surrounding structures through the cribriform plate into intracranium or orbit in advanced stage. Even though there has been some controversies in determining standard treatment due to rarity of this tumor, the combination treatment of surgery and adjuvant radiation has been recommended for the locally advanced esthesioneuroblastomas. However, the recent clinical experiences of advanced cases showed that combination chemotherapy is highly effective to reduce tumor mass and improve clinical outcomes. Materials and Methods: The authors conducted a retrospective analysis of 6 esthesioneuroblastoma patients who were treated in our hospital from 1986. Results: The age of these patients was between 19 and 86 year-old. Among the 6 cases, 2 were diagnosed at stage B and 4 at stage C, according to Kadish classification. Anti-tumor treatments were performed in 5 patients. One patient refused active treatment and was lost to follow-up. Better survival outcome were observed in 3 patients who were treated with combination chemotherapy alone or combined modality treatment including chemotherapy. Conclusion: Based on our retrospective study, the combined treatment consisting of surgery, radiotherapy, and combination chemotherapy should be used to improve treatment results. And furthermore, innovative clinical approaches such as neoadjuvant chemotherapy, high-dose chemotherapy and autologous peripheral stem cell transplantation, which have been reported to have good therapeutic results, should be considered and applied actively.

• The Korean Journal of Pain
• /
• v.11 no.2
• /
• pp.241-246
• /
• 1998

Background: Opioids and local anesthetics have been administered epidurally for the purpose of the postoperative analgesia. However opioids have a serious risk of respiratory depression and local anesthetics have the risks of hypotension, sensory block, or motor one. In recent years, reports of spinal administration of midazolam for acute postoperative pain control have appeared in the literature. This study was performed to observe the effect of epidural midazolam in patient-controlled analgesia (PCA) device. Methods: Forty-five patients scheduled for the elective total hysterectomy were randomly selected; epidurally take morphine only (group I, n=15), morphine plus 0.1% bupivacaine (group II, n=15), or morphine plus midazolam (group III, n=15). The visual analogue scale (VAS) at rest and with movement, the sedation score, the degree of the satisfaction, the total amounts of a morphine usage, and the incidence of the side effects were observed. Rusults: The VAS at rest of group II and III were decreased significantly than that of group I. The VAS with movement of group III was significantly decreased than that of group I and II. The sadation score and the cumulative dose of a morphine were statistically insignificant within groups. Conclusion: Epidural morphine plus midazolam was proven to be clinically effective in the post-operative pain control especially for the pain with movement, compared with epidural morphine only and morphine plus 0.1% bupivacaine.

• Journal of Pharmaceutical Investigation
• /
• v.39 no.6
• /
• pp.401-409
• /
• 2009

Ketrorolac tromethamine (KT), a nonsteroidal anti-inflammatory drug (NSAID) is required repeated administration due to its short blood half-life. To avoid dose-dependent side effects of KT, sustained-release pellets containing KT were prepared by coating with Eudragit$^{(R)}$ RS 100 and Eudragit$^{(R)}$ NE 30D. The in vitro and in vivo drug release behavior of KT from Eudragit$^{(R)}$ RS 100 and NE 30D coated pellet (SR-A), Eudragit$^{(R)}$ RS 100 coated pellet (SR-B) and conventional commercial immediate-release tablet (IR) was investigated. KT from SR-A and SR-B was slowly released over several hours, whereas IR showed rapid initial release in vitro. The pharmacokinetic study in vivo was performed by oral administration in beagle dogs. 5 mg IR was administered 3 times at intervals 5 hr. Five milligrams of IR was administered 3 times at intervals of 5 hr and 15 mg of SR-A and SR-B did once. After administering IR, KT concentration in blood showed high peak- trough fluctuation and stomach ulcer were discovered. On the other hand, SR-A and SR-B sustainedly released KT and reduced the occurrence of stomach ulcer. There sustained-release pellets will be effective system to minimize dosedependent of side effect and improve patient compliance.