• The Korean Journal of Nuclear Medicine Technology
• /
• v.15 no.2
• /
• pp.83-87
• /
• 2011

Purpose: Recently in diagnostics area PET/CT is using a variety of areas including oncology, as well as in cardiology, neurology, etc. While increasing in the importance of PET/CT, there are various researches in the image quality related to reconstruction method. We compared and tested Iterative 2D Reconstruction Method with True X Reconstruction method by Siemens through phantom experiment, so we can see increasing of clinical usefulness of PET/CT. Materials and Methods: We measured contrast ratio and FWHM due to evaluating images on dose and experiment using Biograph 40 True Point PET/CT (Siemens, Germany). Getting a result of contrast ratio and FWHM, we used NEMA IEC PET body phantom (Data Spectrum Corp.) and capillary tube. We used the current TrueX and the previous Iterative 2D algorithm for all images which have 10 minutes long. Also, a clinical suitability of parameter for Iterative 2D and a recommended parameter by Siemens for True X are applied to the experiment. Results: We tested FWHM using capillary tube. As a result, TrueX was less than Iterative 2D. Also, the differences of FWHM get bigger in low dose. On the other hand, we tested contrasts ratio using NEMA IEC PET body phantom. As a result, TrueX was better aspect than Iterative 2D. However, there was no difference in dose. Conclusion: In this experiment, TrueX get higher results of contrast ratio and spatial resolution than Itertive 2D through experiment. Also, in the reconstruction result through TrueX, TrueX had better aspect of resolution than Iterative 2D in low dose. However, contrast ratio had no specific difference. In other words, TrueX reconstruction method in PET/CT had higher clinical value in use because TrueX can reduce exposure of patient and had a better quality of screen.

• Tuberculosis and Respiratory Diseases
• /
• v.57 no.4
• /
• pp.320-328
• /
• 2004

Background : Pulmonary vascular changes which occur early in the course of chronic obstructive pulmonary disease (COPD) are prevalent manifestation and later cause pulmonary hypertension, which is a bad prognostic factor in COPD. Beraprost sodium (BPS), an orally active prostacyclin analogue, has been shown to improve survival in patients with primary pulmonary hypertension. This study investigated the effect of BPS in the patients with COPD. Methods : This is a double-blind randomized placebo-controlled, two center clinical trial. Twenty one consecutive patients with COPD were enrolled from June 2003 to June 2004 (patients treated with BPS for 3 months, BPS group, n=11; those with placebo, placebo group, n=10). The baseline demographic, pulmonary function and hemodynamic data were not significantly different between two groups. Results : On echocardiographic examination, trans tricuspid valve pressure gradient has decreased significantly after 3 months with beraprost in the BPS group [17.7(${\pm}11.4$) to 8.2(${\pm}8.9$) mm Hg, p-value<0.05], while there was no significant change in the control group. Six-minute walking distance has decreased in the control group and increased in the BPS group, but there was no statistical significance. Conclusion : In patients with COPD oral administration of BPS reduced the pulmonary arterial pressure. The clinical significance of this finding, that is improving symptoms and natural course of the disease, needs further study.

• Tuberculosis and Respiratory Diseases
• /
• v.62 no.5
• /
• pp.389-397
• /
• 2007

Background B-type natriuretic peptide (BNP) has been shown to be strong mortality predictors in a wide variety of cardiovascular syndromes. Little is known about BNP in patients with acute respiratory distress syndrome (ARDS). We studied whether BNP can predict mortality in patients with ARDS. Method Echocardiographic study was done to all patients with ARDS, and we excluded patient with low ejection fraction (less than 50%) or showing any features of diastolic dysfunction. 47 patients were enrolled between December, 2003 and February, 2006. Parameters including BNP were obtained within 24h hours at the time of enrollment. Result Mean BNP concentrations and APACHE II scores differed between the survivors and nonsurvivors (BNP, $219.5{\pm}57.7pg/mL$ vs $492.3{\pm}88.8pg/mL$; p=0.013, APACHE II score, $17.4{\pm}1.6$ vs $23.1{\pm}1.3$, p=0.009, respectively). With the use of the threshold value for BNP of 585 pg/mL, the specificity for the prediction of mortality was 94%. The threshold value for APACHE II of 15.5 showed sensitivity of 87%. 'APACHE II + $11{\times}logBNP$' showed sensitivity 63%, and specificity 82%, using threshold value for 46.14. Conclusion BNP concentrations and APCHE II scores were more elevated in nonsurvivors than survivors in patients with ARDS who have normal ejection fraction. BNP can predict mortality. Further study should be done.

• Journal of Oral Medicine and Pain
• /
• v.30 no.3
• /
• pp.337-344
• /
• 2005

A tactile sensor employs a piezoelectric element to detect contact frequency shifts and thereby measure the stiffness or softness of material such as tissue, which allows the sensor to be used in many fields of research for urology, cardiology, gynecology, sports medicine and caner detection and especially for cosmetics and skin care. In this study, reliability of the tactile sensor system was investigated with its manual application to the muscles susceptible to temporomandibular disorders. Stiffness and elasticity of anterior temporalis, masseter and trapezius muscles were calibrated bilaterally from 5 healthy men with an average of 24.5$\pm$0.94 years. The tactile sensor used in this study had a computer-controlled and motor-driven sensor unit which automatically pressed down on the skin surface over the muscles being measured and retracted, thereby providing the hysteresis curve. The slope of the tangent of the hysteresis curve (${\Delta}f/{\Delta}x$) is defined as stiffness of the muscle being measured and the distance between the two parts of the curve as its elasticity. To determine inter-examiner reliability, all the measurements were performed by the two examiners A and B, respectively and the same examination were repeated with an interval of 2 days for intra-examiner reliability. The results from this study demonstrated high reliability in measuring stiffness and elasticity of anterior temporalis, masseter and upper trapezius muscles using a tactile sensor system. It is suggested that the tactile sensor system can be a highly reproducible and effective instrument for quantitative evaluation of the muscle in head and neck region.

• The Korean Journal of Nuclear Medicine
• /
• v.39 no.6
• /
• pp.473-480
• /
• 2005

Purpose: Adenosine myocardial perfusion SPECT has proven to be useful in the detection of coronary artery disease, in the follow up the success of various therapeutic regimens and in assessing the prognosis of coronary artery disease. The purpose of this study is to define the reproducibility of myocardial perfusion SPECT using adenosine stress testing between two consecutive Tc-99m sestaMIBI (MIBI) SPECT studies in the same subjects. Methods: Thirty patients suspected of coronary artery disease in stable condition underwent sequential Tc-99m MIBI SPECT studies using intravenous adenosine. Gamma camera, acquisition and processing protocols used for the two tests were identical and no invasive procedures were performed between two tests. Mean interval between two tests were 4.1 days (range: 2-11 days). The left ventricular wall was divided into na segments and the degree of myocardial tracer uptake was graded with four-point scoring system by visual analysis. Images were interpretated by two independent nuclear medicine physicians and consensus was taken for final decision, if segmental score was not agreeable. Results: Hemodynamic responses to adenosine were not different between two consecutive studies. There were no serious side effects to stop infusion of adenosine and side effects profile was not different. When myocardial uptake was divided into normal and abnormal uptake, 481 of 540 segments were concordant (agreement rate 89%, Kappa index 0.74). With four-grade storing system, exact agreement was 81.3% (439 of 540 segments, tau b=0.73). One and two-grade differences were observed in 97 segments (18%) and 4 segments (0.7%) respectively, but three-grade difference was not observed in any segment. Extent and severity scores were not different between two studios. The extent and severity scores of the perfusion defect revealed excellent positive correlation between two test (r value for percentage extent and severity score is 0.982 and 0.965, p<0.001) Conclusion: Hemodynamic responses and side effects profile were not different between two consecutive adenosine stress tests in the same subjects. Adenosine Tc-99m sestaMIBI SPECT is highly reproducible, and could be used to assess temporal changes in myocardial perfusion in individual patients.

• Journal of Trauma and Injury
• /
• v.25 no.2
• /
• pp.49-56
• /
• 2012

Purpose: For determining the prognosis of critically injured patients, transporting patients to medical facilities capable of providing proper assessment and management, running rapid assessment and making rapid decisions, and providing aggressive resuscitation is vital. Considering the high mortality and morbidity rates in critically injured patients, various studies have been conducted in efforts to reduce those rates. However, studies related to diagnostic factors for predicting severity in critically injured patients are still lacking. Furthermore, patients showing stable vital signs and alert mental status, who are injured via a severe trauma mechanism, may be at a risk of not receiving rapid assessment and management. Thus, this study investigates diagnostic factors, including physical examination and laboratory results, that may help predict severity in trauma patients injured via a severe trauma mechanism, but showing stable vital signs. Methods: From March 2010 to December 2011, all trauma patients who fit into a diagnostic category that activated a major trauma team in CHA Bundang Medical Center were analyzed retrospectively. The retrospective analysis was based on prospective medical records completed at the time of arrival in the emergency department and on sequential laboratory test results. PASW statistics 18(SPSS Inc., Chicago, IL, USA) was used for the statistical analysis. Patients with relatively stable vital signs and alert mental status were selected based on a revised trauma score of more than 7 points. The final diagnosis of major trauma was made based on an injury severity score of greater than 16 points. Diagnostic variables include systolic blood pressure and respiratory rate, glasgow coma scale, initial result from focused abdominal sonography for trauma, and laboratory results from blood tests and urine analyses. To confirm the true significance of the measured values, we applied the Kolmogorov-Smirnov one sample test and the Shapiro-Wilk test. When significance was confirmed, the Student's t-test was used for comparison; when significance was not confirmed, the Mann-Whitney u-test was used. The results of focused abdominal sonography for trauma (FAST) and factors of urine analysis were analyzed using the Chi-square test or Fisher's exact test. Variables with statistical significance were selected as prognostics factors, and they were analyzed using a multivariate logistics regression model. Results: A total of 269 patients activated the major trauma team. Excluding 91 patients who scored a revised trauma score of less than 7 points, 178 patients were subdivided by injury severity score to determine the final major trauma patients. Twenty-one(21) patients from 106 major trauma patients and 9 patients from 72 minor trauma patients were also excluded due to missing medical records or untested blood and urine analysis. The investigated variables with p-values less than 0.05 include the glasgow coma scale, respiratory rate, white blood cell count (WBC), serum AST and ALT, serum creatinine, blood in spot urine, and protein in spot urine. These variables could, thus, be prognostic factors in major trauma patients. A multivariate logistics regression analysis on those 8 variables showed the respiratory rate (p=0.034), WBC (p=0.005) and blood in spot urine (p=0.041) to be independent prognostic factors for predicting the clinical course of major trauma patients. Conclusion: In trauma patients injured via a severe trauma mechanism, but showing stable vital signs and alert mental status, the respiratory rate, WBC count and blood in the urine can be used as predictable factors for severity. Using those laboratory results, rapid assessment of major trauma patients may shorten the time to diagnosis and the time for management.

• Journal of Chest Surgery
• /
• v.35 no.1
• /
• pp.20-26
• /
• 2002

Background: Due to the concern of flow competition or retrograde steal, it has been generally suggested that the right gastroepiploic artery(RGEA) pedicled graft should be used in critical coronary stenosis lesion. The study was designed to evaluate the potential of retrograde flow competition in the RGEA pedicled graft by measuring the native pressure differences(PD) between the normal coronary artery and celiac arterial pressure, which would be compared with trans-stenosis pressure gradients(TSPG) in coronary artery occlusive disease. Material and Method: Between July, 1998 and February, 1999, pressures of the right coronary artery and the right gastroepiploic artery(or the celiac artery) were measured in patients with the patent right coronary artery(n=12). The PD between the arteries was compared with the TSPG in the occlusive coronary arteries(n=32). Result: The pressures of the normal right coronary artery and celiac artery were 143$\pm$23 vs. 134$\pm$17mmHg in systole(p<0.005), 74$\pm$13 vs. 73$\pm$14mmHg in diastole(p=NS), and 100$\pm$16 vs. 97$\pm$15mmHg in mean (p<0.05). The PD between the arteries were -8~25mmHg in systole, -4~7mmHg in diastole, and -1~10mmHg in mean. The TSPG measured in the occlusive coronary arteries were -4~19(7$\pm$5.8)mmHg in the lesion less than 75% stenosis vs. 7~74(27$\pm$18.3)mmHg in the 75% or over stenosis lesion(p<0.005). The normally existing pressure difference between the coronary arteries and RGEA(15~20mmHg) was significantlyless than the TSPG in .the occlusive coronary artery with 75% or over stenosis(p<0.001). Conclusion: If the pressure gradient between the RGEA and the coronary artery distal to the stenosis is the main determinant of development of retrograde flow competiton in the RGEA pedicled graft, the above data suggests that there will be little chance of competition when It is used in the coronary lesion with 75% or over stenosis.

• Clinical and Experimental Pediatrics
• /
• v.49 no.5
• /
• pp.523-528
• /
• 2006

Purpose : The purpose of this study was to investigate the relationship between depression and resilience in adolescents with congenital heart disease(CHD) and to identify the variables associated with depression. Methods : The Resilience Scale(cronbach's ${\alpha}=0.92$), Children's Depression Inventory(cronbach's ${\alpha}=0.72$) and Maternal Behavior Research Instrument(cronbach's ${\alpha}=0.88$) were applied and analyzed to assess depression and resilience among 231 adolescents after surgery for CHD from three major cardiac centers in Korea. This group consist of 114 males and 117 females. The mean age was 15.8 years(range : 13-18 years). The clinical severity of illness was rated by CHD functional index and NYHA functional class. Results : The mean score for depression and resilience was 16.74(range : 0-49) and 115.84(range : 70-132) respectively. Depression was significantly related to age(r=0.25, P<0.001) and NYHA functional class(r=0.35, P<0.001), as well as being negatively correlated with oxygen saturation(r=-0.39, P<0.001), academic achievement(r=-0.41, P<0.001), parental attitude(r=-0.49, P<0.001) and resilience (r=-0.59, P<0.001). The results of multiple regression analysis showed that parental attitude(${\beta}=-0.48$, P<0.01) and resilience(${\beta}=-0.62$, P<0.01) were related to depression. Conclusion : This study demonstrated that adolescents with CHD had a higher resilience and were less depressed with an affectionate parent. With respect to medical and nursing intervention programs, it is essential to identify strengths of adolescents with CHD in order to increase their resilience. Additionally, it is also important that parenting and counseling programs be implemented for the parents of adolescents with CHD.

• Journal of Chest Surgery
• /
• v.41 no.5
• /
• pp.568-572
• /
• 2008

Background: Minimally invasive surgery is currently popular, but this has been applied very sparingly to cardiac surgery because of some limitations. Our study evaluated the safety and efficacy of atrial septal defect (ASD) closure through a video-assisted mini-thoracotomy. Material and Method: Fifteen patients were analyzed. Their mean age was $31{\pm}6$ years. The mean ASD size was $24{\pm}5mm$ and there were 3 cases of significant tricuspid regurgitation. The working window was made through the right 4th intercostal space via a $4{\sim}5cm$ inframammary skin incision, CPB was conducted with performing peripheral cannulation. After cardioplegic arrest, the ASDs were closed with a patch (n=11) or direct sutures (n=4), and the procedures were assisted by using a thoracoscope. There were 3 cases of tricuspid repair and 1 case of mitral valve repair. The mean CPB time and aortic occlusion time were $160{\pm}47\;and\;70{\pm}26 $minutes, respectively. Result: There was no mortality, but there were 3 minor complications (one pneumothorax, one wound dehiscence and one arrhythmia). The mean hospital stay was $5.9{\pm}1.8$ days. The mean follow-up duration was $10.7{\pm}6.4$ months. The follow-up echocardiogram noted no residual ASD or significant tricuspid regurgitation. Three patients suffered from pain or numbness. Conclusion: This study showed satisfactory clinical and cosmetic results. Although the operative time is still too long, more experience and specialized equipment would make this technique a good option for treating ASD.

• The Journal of Korean Society for Radiation Therapy
• /
• v.24 no.2
• /
• pp.197-203
• /
• 2012

Purpose: In this study, we considerate our radiation therapy process for the breast cancer patient implanted a pacemaker applying the machine movement surgery, shielding, beam selection. Materials and Methods: We perform radiation therapy to a 54 years old, breast cancer patient implanted a pacemaker. The patient underwent a surgery to move the position of a pacemaker to right side breast after consultation with cardiology department. Prescribed dose was 5,040 cGy and daily dose 180 cGy for 28 fractions. The 10 MV photon energy, field size 0/$9.5{\times}20$ cm, half beam and opposing portal irradiation are used. To find out appropriate thickness of shielding board, we carried out an experiment using a solid water phantom ($30{\times}30{\times}7$ cm), a Farmer-type chamber (TN30013, PTW, Germany) and a shielding board (Pb $28{\times}27{\times}0.1$ cm). We calculated expected absorbed dose to te pacemaker with absorb ratio and shielding ratio. In the PTP system (Eclipse, Varian, USA), we figured out how much radiation would be absorbed to the machine with and without shielding. First day of the radiation therapy, we measured head scatter to the pacemaker with MOSFET Dose Verification System (TN-RD-70-W, Medical Canada Ltd., Canada). Results: In the phantom measurement, we found out appropriate thickness was 2 mm of shielding board. In the RTP, when using 2 mm shielding the pacemaker will be absorbed 11.5~38.2 cGy and DVH is 77.3 cGy. In the first day of the therapy, 4.3 cGy was measured so 120.4 cGy was calculated during total therapy. The patient was free from any side effects, and the machine also normally functioned. Conclusion: As the report of association which have public confidence became superannuated, there is lack of data about new machine. We believe that radiation therapy to thiese kind of patients could be done successfully with co-operation, patient-suitable planning, accurate QA, frequent in-vivo dosimetry and monitoring.