• Journal of KIISE
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• v.42 no.7
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• pp.910-918
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• 2015

This paper presents a parameter visualization technique to overcome the limitation of the naked eye in contrast-enhanced ultrasonography. A method is also proposed to compensate for the distortion and noise in ultrasound image sequences. Meaningful parameters for diagnosing liver disease can be extracted from the dynamic patterns of the contrast enhancement in ultrasound images. The visualization technique can provide more accurate information by generating a parametric image from the dynamic data. Respiratory motions and noise from micro-bubble in ultrasound data may cause a degradation of the reliability of the diagnostic parameters. A multi-stage algorithm for respiratory motion tracking and an image enhancement technique based on the Markov Random Field are proposed. The usefulness of the proposed methods is empirically discussed through experiments by using a set of clinical data.

• Journal of Korean Neurosurgical Society
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• v.47 no.3
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• pp.199-202
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• 2010

Objective : Balloon kyphoplasty is a minimally invasive procedure that is mainly performed for refractory pain due to osteoporotic compression fractures. The purpose of this study was to evaluate the results of balloon kyphoplasty performed at different times after an injury. Methods : In this retrospective study, the records of 99 patients who underwent one level of balloon kyphoplasty between January 2005 and December 2007 were reviewed. The patients were divided into three groups : 21 patients treated within 3 weeks of an injury (the acute group), 49 treated within 3 weeks to 2 months of an injury (the subacute group), and 29 patients treated at more than 2 months after an injury (the chronic group). Clinical outcomes were assessed using a visual analogue scale (VAS). In addition, modified MacNab's grading criteria was used to assess the subjective patient outcome. The radiology findings, including vertebral height restoration and procedure related complications, were analyzed based on the different time intervals after the injury. Results : Patients in all three groups achieved marked pain relief in terms of the VAS within 7 days of the procedure. Good or excellent results were achieved by most patients in all three groups. However, the height restoration, the main advantage to performing a balloon kyphoplasty, was not achieved in the chronic group. Moreover, evidence of complications including cement leakage was observed significantly less frequently in the subacute group compared to the other two groups. Conclusion : Although balloon kyphoplasty is an effective treatment for osteoporotic compression fractures, with regard to pain relief, the subacute stage appears to be optimal for treating patients with a balloon kyphoplasty in terms of achieving the best outcomes with minimal complications.

• Kidney Research and Clinical Practice
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• v.37 no.4
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• pp.384-392
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• 2018

Background: A very low protein diet (VLPD) with ketoacid analogs of essential amino acids (KA/EAA) administration can remarkably influence protein synthesis and metabolic disturbances of patients with advanced chronic kidney disease (CKD), and may also slow the decline in renal function. Methods: A retrospective cohort study was carried out to monitor renal progression and metabolic and nutritional status among 140 patients with CKD stage III or IV. One group (n = 70) was on a low protein diet (LPD) with 0.6 g of protein intake, and another group (n = 70) was on a VLPD with 0.3 g of protein and KA/EAA supplementation of 100 mg/kg/day for 12 months. Results: At 12-month follow-up, estimated glomerular filtration rate (GFR) significantly decreased from $41.6{\pm}10.2$ to $36.4{\pm}8.8mL/min/1.73m^2$ (P < 0.001) and urine protein increased from $0.6{\pm}0.5$ to $0.9{\pm}1.1g/day$ (P = 0.017) in the LPD group, but no significant changes in estimated GFR and urine protein were found in the VLPD plus KA/EAA group. A significant mean difference in rate of change in estimated GFR ($-5.2{\pm}3.6mL/min/1.73m^2$ per year; P < 0.001) was observed between the two groups. After Cox regression analysis, treatment with VLPD plus KA/EAA significantly protected against the incidence of declining GFR > 10% annually (adjusted hazard ratio, 0.42; 95% confidence interval, 0.23-0.79; P = 0.006) and significant correlations were found between using VLPD plus KA/EEA and increased GFR. Conclusion: VLPD supplementation with KA/EAA is associated with delayed renal progression while preserving the nutritional status in the patients with CKD. Co-administration of VLPD and KA/EAA may prove an effective alternative to conservative management of CKD.

• Clinical and Experimental Reproductive Medicine
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• v.32 no.3
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• pp.223-230
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• 2005

Objective: This study was performed to evaluate the accuracy of hysterosalpingography (HSG) for evaluating female infertility patients by comparison with hysteroscopic and laparoscopic examination. Methods and Material: Total 219 infertile patients were retrospectively analyzed between January 1, 2002 and December 31, 2003. Ninety seven patients (44.3%) were primary infertility, 122 patients (55.7%) were secondary infertility. We performed hysteroscopic and laparoscopic examination on next cycle when HSG revealed any abnormal finding, and 3~6 cycles later if HSG was normal. Results: The accuracy of HSG was 65.2% compared with hysteroscopic examination (sensitivity 88.4%, specificity 46.4%, false positive rate 53.6%, false negative rate 11.6%). The most common abnormal finding of hysteroscopy was uterine synechia (67.4%) followed by endometrial polyp, uterine anomaly (e.g. uterine septum), endometrial hyperplasia. Compared with laparoscopic examination, the accuracy of HSG was 76.9% (sensitivity 98.9%, specificity 70.6%, +LR 3.36, -LR 0.02). The positive predictive value of normal patent tube was excellent (99.6%) but that of proximal tubal blockage was only 46.7%. The unilateral tubal obstruction of HSG was poor accuracy (+LR 3.85 -LR 0.68) and 70% of those was patent by laparoscopic examination. Laparoscopic examination also revealed that 53% of patients had peritubal adhesion and 37% of patients has additional pelvic findings, especially endometriosis. Among the patients had normal HSG, 53.5% patients with normal ultrasonography was diagnosed endometriosis (25.6% of them had endometriosis stage I-II). Conclusion: Normal HSG shows a high negative predictive value. Nevertheless, the incidence of associated pelvic disease in the normal HSG group is high enough to warrant diagnostic laparoscopy if nonsurgical treatment is unsuccessful. Because HSG has poor accuracy in predicting distal tubal blockage and peritubal adhesion, and poor positive predictive value of proximal tubal blockage, laparoscopic examination could be considered in abnormal HSG group.

• Journal of Korean Neurosurgical Society
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• v.64 no.6
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• pp.975-982
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• 2021

Objective : The occurrence of posterior fossa teratomas in adulthood is extremely rare. In this study, we aimed to report our experience with two cases of posterior fossa mature teratoma in adults who underwent surgical resection. We also performed a systematic review of published papers available to date. Methods : We retrospectively reviewed the electronic medical records of patients who had onset of posterior fossa teratomas in adulthood at our institute between 1995 and 2020. We evaluated the clinical, radiographic, and pathological features of mature teratomas at the posterior fossa in adulthood. Furthermore, we searched the PubMed, EMBASE, and Web of Science database and reviewed published articles. Results : We found 507 articles on database review; of them, 102 were duplicates and 389 were excluded based on the inclusion criteria. Finally, 16 cases of posterior fossa from the web search and related articles. Subsequently, we added two cases that underwent surgery at our institute. We analyzed a total of 18 cases of mature teratomas. Headache was the most common (55.6%) symptom. The teratomas showed heterogeneous signals on magnetic resonance imaging. Thirteen patients (72.2%) had lesion at midline, five patients (27.8%) had calcification. Surgical resection was performed in all patients. No studies reported recurrence after resection. Conclusion : The occurrence of posterior fossa teratomas in adulthood is difficult to diagnose at the initial stage. Radiographic diagnosis alone can lead to misdiagnosis. Pathological confirmation is essential. Surgical resection is a curative option for posterior fossa teratomas in adulthood.

• Imaging Science in Dentistry
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• v.51 no.3
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• pp.237-242
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• 2021

Purpose: The aim of this study was to analyse and review deep learning convolutional neural networks for detecting and diagnosing early-stage dental caries on periapical radiographs. Materials and Methods: In order to conduct this review, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA) guidelines were followed. Studies published from 2015 to 2021 under the keywords(deep convolutional neural network) AND (caries), (deep learning caries) AND (convolutional neural network) AND (caries) were systematically reviewed. Results: When dental caries is improperly diagnosed, the lesion may eventually invade the enamel, dentin, and pulp tissue, leading to loss of tooth function. Rapid and precise detection and diagnosis are vital for implementing appropriate prevention and treatment of dental caries. Radiography and intraoral images are considered to play a vital role in detecting dental caries; nevertheless, studies have shown that 20% of suspicious areas are mistakenly diagnosed as dental caries using this technique; hence, diagnosis via radiography alone without an objective assessment is inaccurate. Identifying caries with a deep convolutional neural network-based detector enables the operator to distinguish changes in the location and morphological features of dental caries lesions. Deep learning algorithms have broader and more profound layers and are continually being developed, remarkably enhancing their precision in detecting and segmenting objects. Conclusion: Clinical applications of deep learning convolutional neural networks in the dental field have shown significant accuracy in detecting and diagnosing dental caries, and these models hold promise in supporting dental practitioners to improve patient outcomes.

• Clinical and Experimental Reproductive Medicine
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• v.47 no.4
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• pp.237-244
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• 2020

Endometrial cancer (EC) in young women tends to be early-stage and low-grade; therefore, such cases have good prognoses. Fertility-sparing treatment with progestin is a potential alternative to definitive treatment (i.e., total hysterectomy, bilateral salpingo-oophorectomy, pelvic washing, and/or lymphadenectomy) for selected patients. However, no evidence-based consensus or guidelines yet exist, and this topic is subject to much debate. Generally, the ideal candidates for fertility-sparing treatment have been suggested to be young women with grade 1 endometrioid adenocarcinoma confined to the endometrium. Magnetic resonance imaging should be performed to rule out myometrial invasion and extrauterine disease before initiating fertility-sparing treatment. Although various fertility-sparing treatment methods exist, including the levonorgestrel-intrauterine system, metformin, gonadotropin-releasing hormone agonists, photodynamic therapy, and hysteroscopic resection, the most common method is high-dose oral progestin (medroxyprogesterone acetate at 500-600 mg daily or megestrol acetate at 160 mg daily). During treatment, re-evaluation of the endometrium with dilation and curettage at 3 months is recommended. Although no consensus exists regarding the ideal duration of maintenance treatment after achieving regression, it is reasonable to consider maintaining the progestin therapy until pregnancy with individualization. According to the literature, the ovarian stimulation drugs used for fertility treatments appear safe. Hysterectomy should be performed after childbearing, and hysterectomy without oophorectomy can also be considered for young women. The available evidence suggests that fertility-sparing treatment is effective and does not appear to worsen the prognosis. If an eligible patient strongly desires fertility despite the risk of recurrence, the clinician should consider fertility-sparing treatment with close follow-up.

• Korean Journal of Transplantation
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• v.32 no.4
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• pp.104-107
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• 2018

Mucormycosis is an extremely rare but potentially life-threatening fungal infection. Gastrointestinal (GI) mucormycosis is very rare and occurs primarily in highly malnourished patients, especially in infants and children. A 55-year-old man with end-stage renal disease due to diabetic nephropathy, who had undergone deceased donor kidney transplantation 2 years prior, complained of abdominal pain and distension with a 3-day duration. Computed tomography revealed diffuse gastric wall thickening, and a huge amount of grey colored necrotic debris surrounded by erythematous erosive mucosa was observed at the antrum to upper body by GI endoscopy. The microscopic examination obtained from a GI endoscopic specimen demonstrated peptic detritus with numerous non-septate mucor hyphae in the mucosa and submucosa. Mucormycosis was diagnosed based on the clinical findings and morphological features. A total gastrectomy was performed and an antifungal agent was administered. A microscopic examination of the surgical specimen demonstrated invasive mucormycosis with numerous fungal hyphae with invasion into the mucosa to subserosa. The patient and graft were treated successfully by total gastrectomy and antifungal therapy.

• The Korean journal of internal medicine
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• v.33 no.6
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• pp.1160-1168
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• 2018

Background/Aims: The Republic of Korea is a country where the hemodialysis population is growing rapidly. It is believed that the numbers of treatments related to vascular access-related complications are also increasing. This study investigated the current status of treatment and medical expenses for vascular access in Korean patients on hemodialysis. Methods: This was a descriptive observational study. We inspected the insurance claims of patients with chronic kidney disease who underwent hemodialysis between January 2008 and December 2016. We calculated descriptive statistics of the frequencies and medical expenses of procedures for vascular access. Results: The national medical expenses for access-related treatment were 7.12 billion KRW (equivalent to 6.36 million USD) in 2008, and these expenses increased to 42.12 billion KRW (equivalent to 37.67 million USD) in 2016. The population of hemodialysis patients, the annual frequency of access-related procedures, and the total medical cost for access-related procedures increased by 1.6-, 2.6-, and 5.9-fold, respectively, over the past 9 years. The frequency and costs of access care increased as the number of patients on hemodialysis increased. The increase in vascular access-related costs has largely been driven by increased numbers of percutaneous angioplasty. Conclusions: The increasing proportion of medical costs for percutaneous angioplasty represents a challenge in the management of end-stage renal disease in Korea. It is essential to identify the clinical and physiological aspects as well as anatomical abnormalities before planning angioplasty. A timely surgical correction could be a viable option to control the rapid growth of access-related medical expenses.

• Korean Journal of Clinical Oncology
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• v.14 no.2
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• pp.128-134
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• 2018

Purpose: Previous studies have addressed the role of the hypercoagulable state in the pathogenesis of cancer progression and metastasis. In this study, we investigated the association between coagulation factors, including tissue factor (TF) expression, platelet count, and fibrinogen level, and disease recurrence in patients with non-metastatic colorectal cancer. Methods: Patients who underwent curative resection for stage II or III colorectal cancer between 2000 and 2007 were included in this study. Data from a prospectively maintained database were retrospectively reviewed. TF expression was determined by immunohistochemistry using an anti-TF monoclonal antibody. The Kaplan-Meier method was used to estimate 5-year disease-free survival. Results: TF was highly expressed in 257 of 297 patients (86.5%). TF expression was not significantly associated with the platelet counts (P=0.180) or fibrinogen level (P=0.281). The 5-year disease-free survival rate was lower in patients with high TF expression than in patients with low TF expression (72.3% vs. 83.9%, P=0.074). In Cox hazard analysis, high TF expression was an independent risk factor for tumor recurrence (hazard ratio [HR] 2.446; 95% confidence interval [CI], 1.054-5.674; P=0.037). Undifferentiated histologic type (HR, 2.911; 95% CI, 1.308-6.481; P=0.009), venous invasion (HR, 2.784; 95% CI, 1.431-5.417; P=0.003), and lymph node metastasis (HR, 2.497; 95% CI, 1.499-4.158; P<0.001), were also significantly associated with disease recurrence. Conclusion: TF expression is associated with a recurrence in patients with non-metastatic colorectal cancer. However, further studies are required to clarify the underlying mechanisms relating TF expression with oncologic outcomes and its potential role as a therapeutic target.