• Nuclear Engineering and Technology
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• 제46권6호
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• pp.773-782
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• 2014

The general path model (GPM) is one approach for performing degradation-based, or Type III, prognostics. The GPM fits a parametric function to the collected observations of a prognostic parameter and extrapolates the fit to a failure threshold. This approach has been successfully applied to a variety of systems when a sufficient number of prognostic parameter observations are available. However, the parametric fit can suffer significantly when few data are available or the data are very noisy. In these instances, it is beneficial to include additional information to influence the fit to conform to a prior belief about the evolution of system degradation. Bayesian statistical approaches have been proposed to include prior information in the form of distributions of expected model parameters. This requires a number of run-to-failure cases with tracked prognostic parameters; these data may not be readily available for many systems. Reliability information and stressor-based (Type I and Type II, respectively) prognostic estimates can provide the necessary prior belief for the GPM. This article presents the Bayesian updating framework to include prior information in the GPM and compares the efficacy of including different information sources on two data sets.

• 대한핵의학회지
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• 제37권4호
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• pp.207-218
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• 2003

Myocardial perfusion imaging has been increasingly used to provide prognostic data and guidance on the choice of appropriate management of patients with known or suspected coronary artery disease. The electrocardiogram gated myocardial SPECT program is corning into wide use with an advent of $^{99m}Tc-labeled$ tracers and an improvement of SPECT machines. The gated technique permits measurement of important cardiac prognostic indicators without any further discomforts or radiation burden in patients underwent standard myocardial perfusion SPECT. In addition, gated study significantly improves diagnostic yield by reducing the number of borderline interpretations and could find myocardial stunning and viable myocardium. Gated single photon emission computed tomography (SPECT) imaging allows the automated calculation of end-diastolic volume, end-systolic volume, ejection fraction, myocardial mass and the assessment of regional wall motion and thickening, and it have dramatically improved assessment of coronary artery disease in routine nuclear practice. This allows the simultaneous assessment of both perfusion and function within the same acquisition, and serves as a cost-effective technique for providing more diagnostic data with fewer diagnostic tests. Because the diagnostic and prognostic power derived from knowledge of left ventricular function can be added to that provided by assessing myocardial perfusion, gated SPECT imaging has rapidly gained widespread acceptance and is now used on a routine clinical basis in a growing number of laboratories, including South Korea. The gated SPECT technique for measurement of left ventricular parameters has been validated against a variety of well established techniques. In this work, overview of gated myocardial perfusion SPECT focus on functional parameters is presented.

• 대기
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• 제29권2호
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• pp.227-239
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• 2019

This paper reviews various bulk-type cloud microphysics parameterizations (BCMPs). BCMP, predicting the moments of size distribution of hydrometeors, parameterizes the grid-resolved cloud and precipitation processes in atmospheric models. The generalized gamma distribution is mainly applied to represent the hydrometeors size distribution in BCMPs. BCMP can be divided in three different methods such as single-moment, double-moment, and triple-moment approaches depending on the number of prognostic variables. Single-moment approach only predicts the hydrometeors mixing ratio. Double-moment approach predicts not only the hydrometeors mixing ratio but also the hydrometeors number concentration. Triple-moment approach predicts the dispersion parameter of hydrometeors size distribution through the prognostic reflectivity, together with the number concentrations and mixing ratios of hydrometeors. Triple-moment approach is the most time expensive method because it has the most number of prognostic variables. However, this approach can allow more flexibility in representing hydrometeors size distribution relative to single-moment and double-moment approaches. At the early stage of the development of BMCPs, warm rain processes were only included. Ice-phase categories such as cloud ice, snow, graupel, and hail were included in BCMPs with prescribed properties for densities and sedimentation velocities of ice-phase hydrometeors since 1980s. Recently, to avoid fixed properties for ice-phase hydrometeors and ad-hoc category conversion, the new approach was proposed in which rimed ice and deposition ice mixing ratios are predicted with total ice number concentration and volume.

• Asian Pacific Journal of Cancer Prevention
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• 제16권17호
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• pp.7809-7812
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• 2015

Background: In non-small cell lung cancer (NSCLC) patients with preoperative high serum carcinoembryonic antigen (CEA) level, patients with a persistently high serum CEA level after surgery have been reported to have a poor prognosis. In addition, in other cancers, the post/preoperative serum CEA ratio has been reported as a useful parameter. Materials and Methods: We enrolled 123 NSCLC patients with preoperative high CEA levels (${\geq}5ng/mL$) who underwent curative surgery between 2004 and 2011. Prognostic significance of postoperative serum CEA level and the CEA ratio was examined. Results: The 5-year survival of patients with persistently high serum CEA level after surgery was poor. On the other hand, patients with normal postoperative serum CEA levels had significant favorable prognosis. The patients with CEA ratio>1 had poor prognosis, however the number was only 7 (5.7%). The 5-year survival rates of patients with other subgroup based on the CEA ratio ($0.5{\geq}CEA$ ratio and $0.5{\leq}CEA$ $ratio{\leq}1$) was similar. Multivariate analysis revealed prognostic significance for the postoperative serum CEA level but not the CEA ratio. Conclusions: For NSCLC patients with preoperative high serum CEA level, their postoperative serum CEA levels is a more significant prognostic factor than the post/preoperative serum CEA ratio.

• Journal of Cardiovascular Imaging
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• 제31권4호
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• pp.200-206
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• 2023

BACKGROUND: Right ventricular (RV) dysfunction is a significant risk of major adverse cardiac events in patients with acute heart failure (AHF). In this study, we evaluated RV-pulmonary artery (PA) coupling, assessed by tricuspid annular plane systolic excursion (TAPSE)/pulmonary artery systolic pressure (PASP) and assessed its prognostic significance, in AHF patients. METHODS: We measured the TAPSE/PASP ratio and analyzed its correlations with other echocardiographic parameters. Additionally, we assessed its prognostic role in AHF patients. RESULTS: A total of 1147 patients were included in the analysis (575 men, aged 70.81 ± 13.56 years). TAPSE/PASP ratio exhibited significant correlations with left ventricular (LV) ejection fraction(r = 0.243, p < 0.001), left atrial (LA) diameter(r = -0.320, p < 0.001), left atrial global longitudinal strain (LAGLS, r = 0.496, p < 0.001), mitral E/E' ratio(r = -0.337, p < 0.001), and right ventricular fractional area change (RVFAC, r = 0.496, p < 0.001). During the median follow-up duration of 29.0 months, a total of 387 patients (33.7%) died. In the univariate analysis, PASP, TAPSE, and TAPSE/PASP ratio were significant predictors of mortality. After the multivariate analysis, TAPSE/PASP ratio remained a statistically significant parameter for all-cause mortality (hazard ratio [HR], 0.453; p = 0.037) after adjusting for other parameters. In the receiver operating curve analysis, the optimal cut-off level of TAPSE/PASP ratio for predicting mortality was 0.33 (area under the curve = 0.576, p < 0.001), with a sensitivity of 65% and a specificity of 47%. TAPSE/PASP ratio < 0.33 was associated with an increased risk of mortality after adjusting for other variables (HR, 1.306; p = 0.025). CONCLUSIONS: In AHF patients, TAPSE/PASP ratio demonstrated significant associations with RVFAC, LA diameter and LAGLS. Moreover, a decreased TAPSE/PASP ratio < 0.33 was identified as a poor prognostic factor for mortality.

• Radiation Oncology Journal
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• 제33권2호
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• pp.117-125
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• 2015

Purpose: To investigate the relationship between early treatment response to definitive chemoradiotherapy (CRT) and survival outcome in patients with limited stage small cell lung cancer (LS-SCLC). Materials and Methods: We retrospectively reviewed 47 patients with LS-SCLC who received definitive CRT between January 2009 and December 2012. Patients were treated with systemic chemotherapy regimen of etoposide/carboplatin (n = 15) or etoposide/cisplatin (n = 32) and concurrent thoracic radiotherapy at a median dose of 54 Gy (range, 46 to 64 Gy). Early treatment volume reduction rate (ETVRR) was defined as the percentage change in gross tumor volume between diagnostic computed tomography (CT) and simulation CT for adaptive RT planning and was used as a parameter for early treatment response. The median dose at adaptive RT planning was 36 Gy (range, 30 to 43 Gy), and adaptive CT was performed in 30 patients (63.8%). Results: With a median follow-up of 27.7 months (range, 5.9 to 75.8 months), the 2-year locoregional progression-free survival (LRPFS) and overall survival (OS) rates were 74.2% and 56.5%, respectively. The mean diagnostic and adaptive gross tumor volumes were 117.9 mL (range, 5.9 to 447 mL) and 36.8 mL (range, 0.3 to 230.6 mL), respectively. The median ETVRR was 71.4% (range, 30 to 97.6%) and the ETVRR >45% group showed significantly better OS (p < 0.0001) and LRPFS (p = 0.009) than the other group. Conclusion: ETVRR as a parameter for early treatment response may be a useful prognostic factor to predict treatment outcome in LS-SCLC patients treated with CRT.

• 대한족부족관절학회지
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• 제12권1호
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• pp.86-92
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• 2008

Purpose: To evaluate the safety and prognostic factors of intramedullary nailing of distal tibia fractures in terms of function and symptoms of the ankle joint. Materials and Methods: We retrospectively analyzed 22 distal tibial fractures with intramedullary nailing. The mean duration of follow-up was 43 months. We reviewed medical records to describe each case. We measured radiographic parameters such as fracture configuration, arthritic change of the ankle joint and status of reduction. We also assessed clinical results by AOFAS ankle hind foot scoring system, degree of pain by VAS and range of motion to find out prognostic factors for functional result of the ankle joint. Results: Bone healing was obtained in all cases without any wound complications. Mean AOFAS ankle score was 94. There were 4 cases with mild (VAS<3/10) ankle pain and 2 cases with mild limitation of ankle motion. The comminution of fracture had a significant relationship with delayed angular deformity of ankle joint (p=0.032). There was no other significant parameter affecting ankle joint function except the location of nail-end. Conclusion: Intramedullary nailing in distal tibia fracture is a safe and effective procedure. But further study may need to evaluate the relationship between the position of nail-end and the function of ankle joint.

• Journal of Korean Neurosurgical Society
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• 제38권5호
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• pp.350-354
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• 2005

Objective : The aim of this study is to assess the immediate and long-term efficacy of percutaneous vertebroplasty for treating painful vertebral osteoporotic fractures. Methods : A retrospective review of 149patients who had undergone 167 vertebroplasty procedures for osteoporotic fractures was performed. Clinical, radiologic, and procedural datas were analyzed as parameters of prognostic significance, including age, sex, bone marrow density score, symptom duration, bone cement filling grade, number of fractured vertebrae, compression grade of vertebrae, leakage of bone cement, volume of bone cement injected and complications. Results : In 158 of the 167 procedures assessed, immediate pain relief was obtained [94.6%]. The extent of collapse of the vertebral body was assessed as a parameter for prognostic significance [p=0.015]. Three months postoperatively, no improvement of the pain was observed in four of the 167 procedures that had undergone the vertebroplasty [2%]. At long-term follow-up, the improvement of pain was not correlated with the compression grade of vertebrae [p=0.420]. Conclusion : The immediate outcome of vertebroplasty are less effective in vertebrae more collapsed.

• 대한임상독성학회지
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• 제4권2호
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• pp.113-121
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• 2006

Purpose: Previous studies have reported that plasma cholinesterase (AchE) concentration can serve as a useful prognostic parameter in cases of acute organophosphate (OP) poisoning. However, there has been considerable disagreement regarding the degree of its prognostic value. Earlier cross-sectional and one- time point studies were plagued with methodologic flaws, making it difficult to interpret their results. The purpose of this study was to clarify the prognostic value of time-variable cholinesterase levels and their relationship with clinical outcomes in OP poisoning. Methods: We reviewed medical and intensive care records of patients with acute OP poisoning admitted to our emergency department between March 1998 and Sep 2006. We collected patient information regarding poisoning, clinical, and demographic features. Patients were assessed for clinical outcomes and AchE concentrations on days 1, 2, 3, 5, and 7 and on the final day. Results: During the study period, 58 patients were enrolled in this study. There was a statistically significant difference in the AchE differentials on 1-3 days for patients requiring mechanical ventilation and for patients with mild poisoning (p<0.05). Also, the decrease in the log AchE concentration correlated with longer durations of mechanical ventilation (r=-0.411, p=0.002). Conclusion: In severe OP poising, measurements of time-variable AchE concentrations can be helpful in the prediction of mortality, the development of intermediate syndrome, and duration of mechanical ventilation.

• 대한소아치과학회지
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• 제23권2호
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• pp.503-524
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• 1996

A series of 31 patients with primary oral squamous cell carcinoma (SCC) who were treated at Chonbuk National University Hospital during the years 1991-1995, were evaluated by dual parameter analysis in flow cytometric DNA measurement, Bryne's malignancy grading system, and the TNM classification. The aims of the present study were to discover that previously undetected aneuploid clones could be detected by dual parameter analysis and to determine the prognostic value of the above parameters. 1. Using dual parameter analysis of cytokeratin and DNA on disintegrated paraffin-embedded samples, aneuploid clones which were undetected by regular single parameter DNA analysis could be found among the cytokeratin-selected cells. DNA aneuploidy from paraffin-embedded samples were 15 cases compared with 10 cases using conventional DNA analysis. 2. The portion of aneuploid tumors showed slightly higher clinical stage and tumor size than the portion of diploid tumors, but the difference was not significant. The portion of DNA aneuploid tumors showed significantly higher mean mitosis and total malignancy scores than the portion of DNA diploid tumors. 3. The majority of the patients presented with clinical stage III and IV lesions showed significantly higher mean total malignancy score as compared to those with clinical stage I and II. 4. Histopathologic mean total malignancy score of the 31 cases was 12.7. Among the histologic parameters, mean mitosis score was correlated to the status of DNA ploidy and total malignancy score were correlated to the DNA ploidy and clinical staging.