• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.1
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• pp.32-36
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• 2016

Purpose In nuclear medicine examination, $^{131}I$ is widely used in nuclear medicine examination such as diagnosis, treatment, and others of thyroid cancer and other diseases. $^{131}I$ conducts examination and treatment through emission of ${\gamma}$ ray and ${\beta}^-$ ray. Since $^{131}I$ (364 keV) contains more energy compared to $^{99m}Tc$ (140 keV) although it displays high integrated rate and enables quick discharge through kidney, the objective of this study lies in comparing the difference in exposure dose of $^{131}I$ before and after wearing apron when handling $^{131}I$ with focus on 3 elements of external exposure protection that are distance, time, and shield in order to reduce the exposure to technicians in comparison with $^{99m}Tc$ during the handling and administration process. When wearing apron (in general, Pb 0.5 mm), $^{99m}Tc$ presents shield of over 90% but shielding effect of $^{131}I$ is relatively low as it is of high energy and there may be even more exposure due to influence of scattered ray (secondary) and bremsstrahlung in case of high dose. However, there is no special report or guideline for low dose (74 MBq) high energy thus quantitative analysis on exposure dose of technicians will be conducted based on apron wearing during the handling of $^{131}I$. Materials and Methods With patients who visited Department of Nuclear Medicine of our hospital for low dose $^{131}I$ administration for thyroid cancer and diagnosis for 7 months from Jun 2014 to Dec 2014 as its subject, total 6 pieces of TLD was attached to interior and exterior of apron placed on thyroid, chest, and testicle from preparation to administration. Then, radiation exposure dose from $^{131}I$ examination to administration was measured. Total procedure time was set as within 5 min per person including 3 min of explanation, 1 min of distribution, and 1 min of administration. In regards to TLD location selection, chest at which exposure dose is generally measured and thyroid and testicle with high sensitivity were selected. For preparation, 74 MBq of $^{131}I$ shall be distributed with the use of $2m{\ell}$ syringe and then it shall be distributed after making it into dose of $2m{\ell}$ though dilution with normal saline. When distributing $^{131}I$ and administering it to the patient, $100m{\ell}$ of water shall be put into a cup, distributed $^{131}I$ shall be diluted, and then oral administration to patients shall be conducted with the distance of 1m from the patient. The process of withdrawing $2m{\ell}$ syringe and cup used for oral administration was conducted while wearing apron and TLD. Apron and TLD were stored at storage room without influence of radiation exposure and the exposure dose was measured with request to Seoul Radiology Services. Results With the result of monthly accumulated exposure dose of TLD worn inside and outside of apron placed on thyroid, chest, and testicle during low dose $^{131}I$ examination during the research period divided by number of people, statistics processing was conducted with Wilcoxon Signed Rank Test using SPSS Version. 12.0K. As a result, it was revealed that there was no significant difference since all of thyroid (p = 0.345), chest (p = 0.686), and testicle (p = 0.715) were presented to be p > 0.05. Also, when converting the change in total exposure dose during research period into percentage, it was revealed to be -23.5%, -8.3%, and 19.0% for thyroid, chest, and testicle respectively. Conclusion As a result of conducting Wilcoxon Signed Rank Test, it was revealed that there is no statistically significant difference (p > 0.05). Also, in case of calculating shielding rate with accumulate exposure dose during 7 months, it was revealed that there is irregular change in exposure dose for inside and outside of apron. Although the degree of change seems to be high when it is expressed in percentage, it cannot be considered a big change since the unit of accumulated exposure dose is in decimal points. Therefore, regardless of wearing apron during high energy low dose $^{131}I$ administration, placing certain distance and terminating the administration as soon as possible would be of great assistance in reducing the exposure dose. Although this study restricted $^{131}I$ administration time to be within 5 min per person and distance for oral administration to be 1m, there was a shortcoming to acquire accurate result as there was insufficient number of N for statistics and it could be processed only through non-parametric method. Also, exposure dose per person during lose dose $^{131}I$ administration was measured with accumulated exposure dose using TLD rather than through direct-reading exposure dose thus more accurate result could be acquired when measurement is conducted using electronic dosimeter and pocket dosimeter.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.162-166
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• 2012

Purpose : Vitamin $B_{12}$ and Folate are for anemia work-up which is well known for its sensitivity of light; the screening manual also specifies to be careful with light conditions. According to this, our laboratory minimized the exposure of light when inspecting the Vitamin $B_{12}$ and Folate, but the exposure cannot be wholly blocked due to other various factors such as when conducting specimen segregation. Thus, this inspection is to identify to what extent light can influence and whether the exclusion of light is mandatory during the Vitamin $B_{12}$/Folate test. Materials and Methods : We have conducted two experiments of identifying the extent of light's influence when conducting the Vitamin $B_{12}$/Folate test and also when specimens are under preservation. These experiments were progressed with various concentrations of patients' specimens which were requested to our hospital in March 2012. The first experiment is to verify the results on Vitamin $B_{12}$/Folate dependent on light exposure during the experiment. In the process, we have compared the results of light exposure/exclusion during the incubation process after the reagent division. The second experiment is about the impact of light exposure on the results on Vitamin $B_{12}$/Folate during the preservation. For 1, 2, 7 days the light on the specimen were wholly blocked and were preserved under $-15^{\circ}C$ temperature refrigeration. Then, we compared the results of light-excluded specimen and the exposed one. Results : When conducting first experiment, there were no noticeable changes in the Standard and specimen's cpm, but for Vitamin $B_{12}$, the average result of specimen exposed to light increased 7.8% compare to that of excluded one's. Furthermore, in the significant level 0.05, the significance probability or the p-value was 0.251 which means it has no impact. For Folate, the result being exposed to light decreased 5.4%, the significance probability was 0.033 which means it has little impact. For the second preservation, the result was dependent on the light exposure. The first day of preservation of Vitamin $B_{12}$, the clinical material exposed to light was 11.6%, second day clinical material exposed to light was 10.8%, seventh day clinical material exposed to light increased 3.8%, the significance probability of the $1^{st}$, $2^{nd}$, $7^{th}$ day is 0.372, 0.033, 0.144 respectively, and which indicates that the $1^{st}$ and $7^{th}$ day seems to have no impact. For Folate's case, the clinical material exposed to light has increased 1.4% but hardly had impact, $2^{nd}$ day clinical material being exposed to light was 6.1%, $7^{Th}$ day clinical material being exposed to light decreased 5.2%. The significance probability of Folate on the $1^{st}$, $2^{nd}$, $7^{th}$ day is 0.378, 0.037, 0.217 respectively, and the $1^{st}$ day and the $7^{th}$ day seems to have no impact. Conclusion : After scrutinizing the impact of light exposure/exclusion, Vitamin $B_{12}$ has no impact, while Folate seems to have no noticeable influence but light exclusion is recommended due to its significance probability of 0.033 when conducting experiment. During the preservation, the $2^{nd}$ day result depend on the light exclusion seems to have impact or influence. However, to consider the complication of the experimental process, the experiment including technical errors is predictable. Hence, it is likely to have no impact of light. Nevertheless, it is recommendable to exclude the light during the long preservation as per the significance probability (p-value) of $1^{st}$ and $7^{th}$ day has been diminished.

• Tuberculosis and Respiratory Diseases
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• v.51 no.6
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• pp.559-569
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• 2001

Background : Pleural effusion is one of the most common clinical manifestations associated with a variety of pulmonary diseases such as malignancy, tuberculosis, and pneumonia. However, there are no useful laboratory tests to determine the specific cause of pleural effusion. Therefore, an attempt was made to analyze the various types of pleural effusion and search for useful laboratory tests for pleural effusion in order to differentiate between the diseases, especially between a malignant pleural effusion and a non-malignant pleural effusion. Methods : 93 patients with a pleural effusion, who visited the Severance hospital from January 1998 to August 1999, were enrolled in this study. Ultrasound-guided thoracentesis was done and a confirmational diagnosis was made by a gram stain, bacterial culture, Ziehl-Neelsen stain, a mycobacterial culture, a pleural biopsy and cytology. Results : The male to female ratio was 56 : 37 and the average age was $47.1{\pm}21.8$ years. There were 16 cases with a malignant effusion, 12 cases with a para-malignant effusion, 36 cases with tuberculosis, 22 cases with a para-pneumonic effusion, and 7 cases with transudate. The LDH2 fraction was significantly higher in the para-malignant effusion group compared to the para-pneumonic effusion group [$30.6{\pm}6.4%$ and $20.2{\pm}7.5%$, respectively (p<0.05)] and both the LDH1 and LDH2 fraction was significantly in the para-malignant effusion group compared to those with tuberculosis [$16.4{\pm}7.2%$ vs. $7.6{\pm}4.7%$, and $30.6{\pm}6.4%$ vs.$17.6{\pm}6.3%$, respectively (p<0.05)]. The pleural effusion/serum LDH4 fraction ratio was significantly lower in the malignant effusion group compared to those with tuberculosis [$1.5{\pm}0.8$ vs. $2.1{\pm}0.6$, respectively (p<0.05)]. The LDH4 fraction and the pleural effusion/serum LDH4 fraction ratio was significantly lower in the para-malignant effusion group compared to those with tuberculosis [$17.0{\pm}5.8%$ vs. $23.5{\pm}4.6%$ and $1.3{\pm}0.4$ vs. $2.1{\pm}0.6$, respectively (p<0.05)]. Conclusion : These results suggest that the LDH isoenzyme was the only useful biochemical test for a differential diagnosis of the various diseases. In particular, the most useful test was the pleural effusion/serum LDH4 fraction ratio to distinguish between a para-malignant effusion and a tuberculous effusion.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.11 no.2
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• pp.282-289
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• 2000

This study was designed to examine the validity of HPR subscale in Korean Personality Inventory for Children(KPI-C) and Attention Problems subscale in Korean Child Behavior Checklist(K-CBCL) as diagnostic tool for Attention-Deficit/Hyperactivity Disorder(ADHD). Nineteen ADHD-1 type, twenty-three ADHD-H type, sixteen Neurosis, and fifteen normal children with the age from 6 to12 were selected based on DSM-IV, and their responses of the KPI-C and CBCL were analyzed. Omnibus F-test results showed that there were significant differences in the F scores of HPR and Attention Problems T scores(p<.05). But in Posthoc analysis, the HPR and AP scores in three clinical groups were significantly higher than in normal group, but there was no group difference among three clinical groups(p<.05). These results shows that HPR subscale and Attention Problems subscale may be useful tools for screening clinical groups(vs normal group) but there was a limit to the clinical validity of two subscales as diagnostic tools for the subtypes of ADHD.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.4 s.316
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• pp.60-69
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• 2007

The human eye usually experiences a loss of color sensitivity when it is subjected to high levels of luminance, and perceives a discrepancy in color between high and normal-luminance displays, generally known as a hue shift. Accordingly, this paper models the hue-shift phenomenon and proposes a hue-correction method to provide perceptual matching between high and normal-luminance displays. The value of hue-shift is determined by perceived hue matching experiments. At first the phenomenon is observed at three lightness levels, that is, the ratio of luminance is the same between high and normal-luminance display when the perceived hue matching experiments we performed. To quantify the hue-shift phenomenon for the whole hue angle, color patches with the same lightness are first created and equally spaced inside the hue angle. These patches are then displayed one-by-one on both displays with the ratio of luminance between two displays. Next, the hue value for each patch appearing on the high-luminance display is adjusted by observers until the perceived hue for the patches on both displays appears the same visually. After obtaining the hue-shift values, these values are fit piecewise to allow shifted-hue amounts to be approximately determined for arbitrary hue values of pixels in a high-luminance display and then used for correction. Essentially, input RGB values of an image is converted to CIELAB values, and then, LCh (lightness, chroma, and hue) values are calculated to obtain the hue values for all the pixels. These hue values are shifted according to the amount calculated by the functions of the hue-shift model. Finally, the corrected CIELAB values are calculated from corrected hue values, after that, output RGB values for all pixels are estimated. For evaluation, an observer's preference test was performed with hue-shift results and Almost observers conclude that the images from hue-shift model were visually matched with images on normal luminance display.

• Korean Journal of Veterinary Research
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• v.41 no.4
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• pp.571-578
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• 2001

To evaluate if the apoptotic fragment assay could be used to estimate the dose prediction after radiation exposure, we examined apoptotic mouse crypt cells per 1,000 cells after whole body $^{60}Co$ $\gamma$-rays and 50MeV ($p{\rightarrow}Be^+$) cyclotron fast neutron irradiation in the range of 0.25 to 1 Gy, respectively. The incidence of apoptotic cell death rose steeply at very low doses up to 1 Gy, and radiation at all doses tigger rapid changes in crypt cells in stem cell region. These data suggest that apoptosis may play an important role in homeostasis of damaged radiosensitive target organ by removing damaged cells. The curve of dose-effect relationship for the data of apoptotic fragments was obtained by the linear-quadratic model $y=0.18+(9.728{\pm}0.887)D+(-4.727{\pm}1.033)D^2$ ($r^2=0.984$) after $\gamma$-rays irradiation, while $y=0.18+(5.125{\pm}0.601)D+(-2.652{\pm}0.7000)D^2$ ($r^2=0.970$) after neutrons in mice. The dose-response curves were linear-quadratic, and a significant dose-response relationship was found between the frequency of apoptotic cell and dose. These data show a trend towards increase of the numbers of apoptotic crypt cells with increasing dose. Both the time course and the radiation dose-response curve for high and low linear energy transfer (LET) radiation modalities were similar. The relative biological effectiveness (RBE) value for crypt cells was 2.072. In addition, there were significant peaks on apoptosis induction at 4 and 6h after irradiation, and the morpholoigcal findings of the irradiated groups were typical apoptotic fragments in crypt cells that were hardly observed in the control group. Thus, apoptosis in crypt cells could be a useful in vivo model for studying radio-protective drug sensitivity or screening test, microdosimetric indicator and radiation-induced target organ injury. Since the apoptotic fragment assay is simple, rapid and reproducible in the range of 0.25 to 1 Gy, it will also be a good tool for evaluating the dose response of radiation-induced organ damage in vivo and provide a potentially valuable biodosimetry for the early dose prediction after accidental exposure.

• Tuberculosis and Respiratory Diseases
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• v.45 no.3
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• pp.519-528
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• 1998

Background: Diagnosis of pulmonary tuberculosis is not easy when the sputum smear for Mycobacterium tuberculosis(M. Tb) is negative. We evaluated the clinical utility of polymerase chain reaction(PCR) for detecting M. Tb in bronchoalveolar lavage(BAL) samples. Methods: We recruited 84 patients whose sputum smear for M. Tb were negative or not available due to no production of sputum. We performed bronchoalveolar lavage for acid-fast stain, culture of mycobacteria, and PCR assay of BAL fluid. We analyzed the results of microbiologic examination. Results: The sensitivity of BAL fluid smear, culture, and PCR were 20%, 38%, and 40%, respectively. The specificity of BAL fluid PCR was 95%. The positive predictive value of PCR was 89%. The smear of BAL fluid was positive in 17%. The PCR of BAL fluid was the only diagnostic test in 17%. Therefore, the BAL fluid analysis including smear and PCR was diagnostic in 34 % within 24 hours. The BAL fluid analysis including smear, PCR, and culture was diagnostic in 55% within 2 month. Conclusion: The BAL fluid PCR was valuable method in the diagnosis of pulmonary tuberculosis in patients whose sputa were not available or reveal negative smear.

• Tuberculosis and Respiratory Diseases
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• v.47 no.1
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• pp.50-56
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• 1999

Background : Pleural effusion is a common clinical problem and many clinical and laboratory evaluations, such as tumor marks, have been studied to discriminate malignant pleural fluid from benign pleural fluid. However their usefulness in the diagnosis of pleural effusion is still not established fully. We studied the diagnostic value of cyfra 21-1 in diagnosis of malignant pleural effusion. Methods: Pleural fluid was obtained from 45 patients with malignant diseases(32 lung cancer patients, 13 metastatic malignant diseases) and 47 patients with benign diseases. The level of cyfra 21-1 in the pleural fluid and serum were determined using a CYFRA 21-1 enzyme immunoassay kit(Cis-Bio International Co.). The t-test was used for comparison between two diseases groups and receiver operating characteristic(ROC) curves were constructed by calculating the sensitivities and specificities of the cyfra 21-1 at several points to determine the diagnostic accuracy of the cyfra 21-1. Results: In patients with primary lung cancer, the level of cyfra 21-1 in the pleural fluid was significantly higher than those of patients with benign diseases and had positive correlations between the level of cyfra 21-1 in the pleural fluid and serum levels. In the ROC curve analysis of the pleural fluid, the curve for primary lung cancer group was located closer to the left upper comer and the cut off value, sensitivity and specificity of the cyfra 21-1 of the primary lung cancer group was determined as 22.25ng/ml, 81.8% and 78.7% respectively. Conclusions: Our data indicates that the measurement of cyfra 21-1 level in pleural effusion has useful diagnostic value to discriminate malignant pleural effusion in primary lung cancer from benign pleural effusion.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.3
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• pp.152-155
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• 2009

Purpose: The most widely accepted tool for follow up management of thyroid cancer patients is serum thyroglobulin (Tg) measurement, but its value is limited by the interference of anti-thyroglobulin antibodies (anti-Tg Ab). Recently thyroglobulin measurement in the wash out of fine-needle aspiration biopsy specimens (Tg-FNAB) is frequently used for differential diagnosis of recurrences/metastases. The aim of this study was the investigation of the diagnostic utility of Tg-FNAB compared with serum Tg. Materials and Methods: We enrolled 41 consecutive patients with thyroid cancer who were evaluated for Tg-FNAB between January 2007 and February 2008 retrospectively. We ruled out 6 patients who anti-Tg Ab positive (${\geq}$100 U/mL) in the RIA (BRAHMS anti-Tgn RIA 100Det; BRAHMS Aktiengesell schaft, Berlin, Germany). Serum Tg and Tg-FNAB were measured by immunoradiometric assay (BRAHMS Tg pluS RIA 100 Det; BRAHMS Aktienge sellschaft, Berlin, Germany). We evaluated for Tg-FNAB compared with serum Tg and corresponding cytological smear. To compare the values of the two the t-test was used. Results: Tg-FNAB values were significantly higher (median 1,060 ng/mL, range 0.2~434,000 ng/mL) than serum Tg (median 2.5 ng/mL, range 0.9~131 ng/mL) (p=0.0394). The rate of correspondence with Tg-FNAB between cytological result was 87.9% and 65.9% in the case of serum Tg. Tg-FNAB was positive in 28 (24 with positive and 4 with suspicious cytology). Of the remaining 13 patients with negative Tg-FNAB, 1 had suspicious and 12 had unsuspicious cytology. serum Tg was positive in 26 (17 with positive and 3 with suspicious and 6 with unsuspicious cytology), Of the remaining 15 patients with negative serum Tg, 8 was positive in cytological result and 1 had suspicious and 6 had unsuspicious cytology. Conclusions: Tg-FNAB measurement is more accurate with high sensitivity (87.9%) than serum Tg (65.9%). The Tg-FNAB was a useful predictor for detecting recurrences/metastases with serum Tg.

• Journal of the Korean Arthroscopy Society
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• v.6 no.2
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• pp.109-114
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• 2002

Propose : The purpose of this retrospective study was to test the posterior cruciate ligament (PCL index) for diagnosis of a tear of the anterior cruciate ligament (ACL) by means of MR imaging. Materials and Methods : From Mar. 1997 to Feb. 2001, concomitant magnetic resonance imaging (MRI) and knee joint arthroscopy were performed in 56 patients of either pain or instability of the knee. The shortest distance between the femoral and tibial attachment of PCL (X) and the distance from that line to the tip of the arc marked by the PCL (Y) on the sagittal plane images were measured. The quotient of these two parameters (Y/X) defined the PCL index. Results : Using MRI diagnosis, there were 35 patients diagnosed with ACL rupture and 21 patients were ruled out of ACL injury. Using arthroscopy, 32 of the 35 patients diagnosed by MRI showed ACL rupture, and 20 of the 21 patients were ruled out of ACL injury. The mean PCL index was 0.40 in the 33 patients diagnosed with ACL rupture through arthroscopy. The mean PCL index was 0.23 in 23 patients with an uninjured ACL through arthroscopy. In 33 patients with ruptured ACL, this value exceeds 0.31. The index value was 0.31 in 3 patients with uninjured ACL. The value of the index was not above 0.31 with an uninjured ACL. PCL index on MRI had a sensitivity of $91\%$ and a specificity of $94\%$ for determining the status of the anterior cruciate ligament. Conclusion : Injury to the ACL changes the PCL index markedly. In diagnostically unreliable MR images, amelioration of the PCL index could help in the diagnosis of ACL injury.