1.Context-Dependent Classification of Multi-Echo MRI Using Bayes Compound Decision Model.
Journal of the Korean Society of Magnetic Resonance in Medicine 1999;3(2):179-187
PURPOSE: This paper introduces a computationally inexpensive context-dependent classification of multi-echo MRI with Bayes compound decision model. In order to produce accurate region segmentation especially in homogeneous area and along boundaries of the regions, we propose a classification method that uses contextual information of local neighborhood system in the image. MATERIAL AND METHOD: The performance of the context free classifier over a statistically heterogeneous image can be improved if the local stationary regions in the image are disassociated from each other through the mechanism of the interaction parameters defined at the local neighborhood level. In order to improve the classification accuracy, we use the contextual information which resolves ambiguities in the class assignment of a pattern based on the labels of the neighboring patterns in classifying the image. Since the data immediately surrounding a given pixel is intimately associated with this given pixel, then if the true nature of the surrounding pixel is known this can be used to extract the true nature of the given pixel. The proposed context-dependent compound decision model uses the compound Bayes decision rule with the contextual information. As for the contextual information in the model, the directional transition probabilities estimated from the local neighborhood system are used for the interaction parameters. RESULTS: The context-dependent classification paradigm with compound Bayesian model for multi-echo MR images is developed. Compared to context free classification which does not consider contextual information, context-dependent classifier show improved classification results especially in homogeneous and along boundaries of regions since contextual information is used during the classification. CONCLUSION: We introduce a new paradigm to classify multi-echo MRI using clustering analysis and Bayesian compound decision model to improve the classification results.
Bays*
;
Classification*
;
Magnetic Resonance Imaging*
;
Residence Characteristics
2.A Case of Isolated Granulocytic Sarcoma of the Ovary in Nonleukemic Patients.
Yong Il KWON ; Dong Jin KWON ; Tae Chul PARK ; Jin Woo LEE ; Soo Pyung KIM
Korean Journal of Obstetrics and Gynecology 1999;42(10):2362-2367
An isolated granulocytic sarcoma (chloroma) of the left ovary occured in the absence of leukemia in a 12-year-old woman. This lesion is defined as a localized tumor mass composed of immature cells of the granulocytic series. Granulocytic sarcomas can occur at extramedullary sites including ovary but, isolated myelosarcoma in the absence of usual manifestations of AML may be rare and has some difficulties in diagnosis. Contrary to findings in other series, granulocytic sarcoma arising in this nonleukemic patient did not progress to acute leukemia during two years she has been followed.
Child
;
Diagnosis
;
Female
;
Humans
;
Leukemia
;
Ovary*
;
Sarcoma, Myeloid*
3.Clinical Analysis of Subtrochanteric Fracture of the Femur
Chang Uk CHOI ; Soo Kyoon RAH ; Yon Il KIM ; Byung Il LEE ; Hee KWON
The Journal of the Korean Orthopaedic Association 1988;23(5):1278-1286
The management of subtrochanteric fracture of the femur is one of the most difficult problems. Subtrochanteric area is predominantly composed of cortical bone and highly concentrating portion of stress. So, there is high incidence of Complication after treatment of subtrochanteric fractures. The results were as follows :l. Of 56 cases, 45 occurred in male, 11 in female. 2. The fractures occured mainly between 20 to 40 years of age(55.4%) and mean age was 41.4 years. 3. The most common cause of fracture was traffic accident.(67.9%) 4. According to the Seinsheimer classification, 16 cases were type IIb(most common), 13 type IIIa and 9 type IIIb. 5. 49 cases with treated wutg open reduction and internal fixation and 7 cases conservatively. 6. The average weight bearing time was 14.0 weeks; 13 weeks in operatively treated group and 18.3 week in conservative group. 7. Radiological union was obtained in average 25.1 weeks ; shortest group was type IIc(16 weeks) and longest group was type IV(30 weeks). 8. Complication were as follows; 8 cases of delayed union, 3 nonunion, 4 metallic failures, 7 varus deformities and 1 nail migration. 9. In the cases treated by Judet plate or compression hip screw, there was no complications and relatively short duration of bony union than other implants. So, they are one of the good implant for the treatment of subtrochanteric fracture of the femur.
Classification
;
Congenital Abnormalities
;
Female
;
Femur
;
Hip
;
Hip Fractures
;
Humans
;
Incidence
;
Male
;
Weight-Bearing
4.Effect of Lidocaine and Ketamine Pretreatment on Vascular Pain Associated with Intravenous Propofol Injection.
Wha Ja KANG ; Dong Gun LEE ; Dong Ok KIM ; Moo Il KWON ; Dong Soo KIM ; Kwang Il SHIN
Korean Journal of Anesthesiology 1997;33(4):716-720
BACKGROUND: Propofol has a high incidence of pain with intravenous injection, and different methods have been used to minimize the incidence and severity of this pain. In this study, we have compared the effect of lidocaine pretreatment with that of ketamine pretreatment on propofol injection pain. METHODS: Ninety healthy female patients scheduled for general anesthesia were randomly divided into three groups; saline group (n=30), lidocaine group (n=30) and ketamine group (n=30). Each patient received 2 ml of pretreatment solution (normal saline, 1% lidocaine, 0.5% ketamine) via 18G angiocatheter inserted in the antecubital fossa after applying an arm tourniquet inflated to 50 mmHg. The tourniquet was released 1 minute later, followed by intravenous injection of 2.5 mg/kg of propofol. The assessment of pain was made at the induction of anesthesia and in the recovery room, and the severity of pain was classified as none, mild, moderate, severe by one observer. RESULTS: The severity and incidence of pain diminished significantly in the lidocaine group and the ketamine group compared with the saline group at the induction of anesthesia (p<0.05) and there was no significant difference between the lidocaine group and the ketamine group. We had similar results in the recovery room and one patient from the saline group and the ketamine group had no recall regarding injection pain. CONCLUSION: Intravenous ketamine pretreatment is as effective as intravenous lidocaine pretreatment in alleviating the propofol injection pain.
Anesthesia
;
Anesthesia, General
;
Arm
;
Female
;
Humans
;
Incidence
;
Injections, Intravenous
;
Ketamine*
;
Lidocaine*
;
Propofol*
;
Recovery Room
;
Tourniquets
5.A Case of Giant-cell Tumor of the Thoracic Spine.
Jun Ho CHO ; Soo Il YOO ; Young Dae KWON ; Yong Sung LEE
Journal of Korean Neurosurgical Society 2000;29(7):940-944
No abstract available.
Spine*
6.Sonographically Detected Testicular Microlithiasis.
Jae Il KWON ; Se Joong KIM ; Young Soo KIM
Korean Journal of Urology 1997;38(3):312-314
Testicular microlithiasis (TM) is an uncommon abnormality in which concentric laminated bodies are scattered throughout the testis within seminiferous tubules. The sonographic appearance of TM is characteristic. In a retrospective analysis of 281 testicular sonograms, TM were found in 7 cases (2.5%). The presence of TM was associated with the presence of acute epididymitis (n=3), varicocele (n =l), hydrocele (n =l), testicular tumor (n =l), and cryptorchidism (n =l). The pathogenesis of TM is still poorly understood and its clinical relevance is unclear. However, because TM may be associated with testicular tumor, we advocate careful evaluation and follow up of the testes when this abnormality is detected.
Cryptorchidism
;
Epididymitis
;
Follow-Up Studies
;
Male
;
Retrospective Studies
;
Seminiferous Tubules
;
Testis
;
Ultrasonography
;
Varicocele
7.Permanent Preserving the Bony Fragments Digged Up from Haemi Nameless Martyrdom Holy Place Burial Sites.
Won Sik KIM ; O Yu KWON ; Chang Yong LEE ; Woong Ghi SHIN ; Soo Il KIM
Korean Journal of Physical Anthropology 1996;9(2):135-139
Bone materials diggd up from the Haemi nameless martyrdom holy place burial sites were severely broken into fragments of various size, clay matrix filled the bone marrow cavities, grass roots were spreaded into the periosteum and the fragments were very soft enough to be flaken. To make permanent specimens, bony fragments impregnated within unsaturated polyester resin with catalyzer MEKP, promotor 8% cobalt octoate, and UV absorber. Permanent specimens were so very transparent that all the macroscopic structures can be observed, and they were hard enough not to be broken or cracked. This method of preserving bony fragments is considered to be used in archaeologic preservation and in making teaching materials of various human organs or tissues.
Bone Marrow
;
Burial*
;
Cobalt
;
Humans
;
Methods
;
Periosteum
;
Poaceae
;
Polyesters
;
Teaching Materials
8.3-Dimensional Dosimetry of Small Field Photon Beam.
Korean Journal of Medical Physics 2012;23(1):54-61
A polymer gel dosimeter was fabricated. A 3-dimensional dosimetry experiment was performed in the small field of the photon of the cyberknife. The dosimeter was installed in a head and neck phantom. It was manufactured from the acrylic and it was used in dosimetry. By using the head and neck CT protocol of the CyberKnife system, CT images of the head and neck phantom were obtained and delivered to the treatment planning system. The irradiation to the dosimeter in the treatment planning was performed, and then, the image was obtained by using 3.0T magnetic resonance imaging (MRI) after 24 hours. The dose distribution of the phantom was analyzed by using MATLAB. The results of this measurement were compared to the results of calculation in the treatment planning. In the isodose curve on the axial direction, the dose distribution coincided with the high dose area, 0.76mm difference on 80%, rather than the low dose area, 1.29 mm difference on 40%. In this research, the fact that the polymer gel dosimeter and MRI can be applied for analyzing a small field in a 3 dimensional dosimetry was confirmed. Moreover, the feasibility of using these for the therapeutic radiation quality control was also confirmed.
Antineoplastic Combined Chemotherapy Protocols
;
Cytarabine
;
Head
;
Magnetic Resonance Imaging
;
Neck
;
Polymers
;
Quality Control
;
Thioguanine
9.Expression of Neuroendocrine Cells in Benign Prostatic Hyperplasia and the Effect of Dihydrotestosterone .
Sung Joon HONG ; Soo Mee KWON ; Sun Il KIM ; Hea Young OH ; Bong Chul CHUNG
Korean Journal of Urology 2003;44(3):267-271
PURPOSE: Neuroendocrine (NE) cells of the prostate are considered to be involved in the pathogenesis of benign prostate hyperplasia (BPH). By a comparative analysis of NE cell density in BPH tissue of men who were either exposed to or not exposed to 5alpha-reductase inhibitor, we investigated the relationship between NE cells and BPH, and the effect of androgen deprivation on NE cells. MATERIALS AND METHODS: Prostate tissue specimens, obtained from 30 men by transurethral resection of the prostate or radical cystoprostatectomy, were used. Of the 30 patients, 10 had a prostate smaller than 25 ml (normal control), the other 20 had a prostate larger than 40ml, 10 of who had taken 5alpha-reductase inhibitor (finasteride) for 3 months before surgery (androgen blockade group), and 10 who had not (BPH group). The distribution of NE cells in the prostate was examined using the anti-chromogranin A (CgA) antibody, and the density of the CgA-positive cells was compared by an optical dissector method. Immunoblotting was performed using the neuron specific enolase (NSE) antibody. A Mann-Whitney U test was used in a statistical analysis. RESULTS: Most of the CgA-positive NE cells were localized between the acinar epithelial cells. The mean numbers of CgA-positive NE cells per acinus in the normal controls and the BPH groups were 1.67+/-0.78 and 4.45+/-2.54, respectively, and the difference was statistically significant (p<0.05). However, the mean number of CgA-positive NE cells in the androgen blockade group, was 4.93+/-2.17, which was similar to the BPH group. In a NSE immunoblotting study, a distinct band was observed in the BPH and androgen blockade groups, but the density of the band was higher in the androgen blockade group. CONCLUSIONS: Our results suggest that NE cells may be involved in the hyperplastic process of BPH. Inhibition of dihydrotestosterone, caused by the oral administration of the 5alpha-reductase inhibitor, failed to induce any significant change in the NE cells, probably due to the incomplete androgen blockade.
Administration, Oral
;
Cell Count
;
Dihydrotestosterone*
;
Epithelial Cells
;
Humans
;
Hyperplasia
;
Immunoblotting
;
Male
;
Neuroendocrine Cells*
;
Phosphopyruvate Hydratase
;
Prostate
;
Prostatic Hyperplasia*
10.Clinical Results of Overdistention in the Treatment of Interstitial Cystitis.
Korean Journal of Urology 1996;37(11):1278-1282
Interstitial cystitis is prevalent in the 5th decade women, characterized by frequency, urgency and pelvic pain. To diagnose interstitial cystitis, NIH diagnostic criteria was used. Patients underwent overdistention and all patients were evaluated with IPSS symptom score and urodynamic study in preoperative period, post operative(POD) 1 week and 1 month. The age distribution was 4th decade in 1 patient, 5th decade in 3, 6th decade in 2, 7th decade in 4 and then above 7th decade in 2. Symptom durations was less than 7 years in 7 patients, between 7-10 years in 2 and more than 10 years in 3. Changes in bladder irritative symptom score between preop. and POD 1 week, and preop. and POD 1 month were 6.00+/-4.40(p<0.05) and 6.36+/-2.29(p<0.05) with statistical significance, respectively. Changes in obstructive symptom scores were 4.91+/-4.27(P<0.05) and 3.91+/-4.76(P<0.05) with statistical significance. On urodyna-mic study, the volume of first voiding sensation between preop and POD 1 week was 29.45+/-52.04(p>0.05) but statistically insignificant. However, the change between pre op. and POD 1 month was 97.45+/-90.29(p<0.05) with statistical significance. Difference in maximal capacity between preop. and POD 1 week was statistically significant as 87.55+/-126.39(p<0.05). Bladder functional capacity changes between with and without anesthesia was statistically significant(p<0.05) Postop. complications were bladder rupture in 1 case, and hematuria in 12. The results of overdistention was useful in the diagnosis and treatment of interstitial cystitis. Then more evaluation and follow up will be needed.
Age Distribution
;
Anesthesia
;
Cystitis, Interstitial*
;
Diagnosis
;
Female
;
Follow-Up Studies
;
Hematuria
;
Humans
;
Pelvic Pain
;
Preoperative Period
;
Rupture
;
Sensation
;
Urinary Bladder
;
Urodynamics