• 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
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• v.33 no.2
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• pp.131-142
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• 1999

Purpose: Either gated myocardial perfusion SPECT or attenuation corrected SPECT can be used to improve specificity in the diagnosis of coronary artery disease. We investigated in this study whether gating or attenuation correction improved diagnostic performance of rest/stress perfusion SPECT in patients having intermediate pre-test likelihood of coronary artery disease. Materials and Methods: Sixty-eight patients underwent rest attenuation-corrected T1-20l/dipyridamole stress gated attenuation-corrected Tc-99m -MIBI SPECT using an ADAC vertex camera (M:F=29:39, aged $59{\pm}12$ years, coronary artery stenosis ${\geq}70%$, one vessel: 13, two vessel: 18, three vessel: 8, normal: 29). Using a five-point scale, three physicians graded the post-test likelihood of coronary artery disease for each arterial territory (1:normal, 2: possibly normal, 3:equivocal, 4. possibly abnormal, 5: abnormal). Sensitivity, specificity and area under receiver-operating-characteristic curves were compared for each operator between three methods : (A) non-attenuation-corrected SPECT; (B) gated SPECT added to (A): and (C) attenuation-corrected SPECT added to (B). Results: When grade 3 was used as the criteria for coronary artery disease, no differences in sensitivity and specificity were found between the three methods for each operator. Areas under receiver-operating-characteristic curves for diagnosis of coronary artery disease revealed no differences between each modality (p>0.05). Conclusion: In patients at intermediate risk of coronary artery disease, gated SPECT and attenuation- corrected SPECT did not improve diagnostic performance.

• The Korean Journal of Nuclear Medicine
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• v.38 no.6
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• pp.498-505
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• 2004

Purpose: We compared captopril renal scintigraphic criteria for the diagnosis of renovascular hypertension by unilateral renal artery stenosis. Materials and Methods: The study group consisted of 24 patients (m/f : 16/8, age: $39{\pm}18$ years) with unilateral renal artery stenosis who underwent renal artery revascularization and captopril renal scintigraphy with $^{99m}Tc$-diethylenetriaminepentaacetic acid between May 1995 and April 2004. The blood pressure response was classified as cure/improvement or failure. We evaluated captopril-induced changes in relative function (BCfun) and renogram grade (0 to 5: 0=normal, and 5=renal failure pattern without measurable uptake) (CBren) and the difference of renograms between the normal and stenotic kidney on captopril scan (CNren). Results: light of 24 patients were cured and 11 improved and 5 patients were classified as failed revascularization. Significant predictors of a cure or improvement of blood pressure were younger age, stenosis by fibromuscular dysplasia or arteritis, BCfun, CBren and CNren. Areas under the receiver operating characteristic curve of age, BCfun, CBren and CNren were not significantly different. Positive and negative predictive values of predictors were 100% and 42% (age ${\leq}38$): 92% and 50% (BCfun ${\geq}1%$): 92% and 75% (CBren ${\geq}1$), and 90% and 60% (CNren ${\geq}1$), respectively. Conclusion: Captopril induced changes in renal function and renogram can reliably predict hypertension response to revascularization. Renogram pattern on captopril scan can diagnose renovascular hypertension without baseline data in patients with unilateral renal artery stenosis.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.78-78
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• 2011

수열합성법을 이용하여 Si(111) 기판에 ZnO 박막을 성장하였다. ZnO 박막의 성장을 위한 씨앗층은 plasma-assisted molecular beam epitaxy (PA-MBE)를 이용하였다. 씨앗층의 표면 거칠기(root-mean-square roughness)는 2.5 nm이고, 씨앗층 위에 성장된 ZnO 박막은 다양한 크기의 입자들로 이루어져 있었으며 두께는 약 $1.8{\mu}m$로 매우 일정하였다. 배향성을 알아보기 위하여 texture coefficient (TC)를 계산해 보았다. TC(100)과 TC(200)은 a-축 배향성을, TC(002)는 c-축 배향성을 나타내는데, c-축으로 더 우세한 배향성(99.5%)을 보였다. TC 비율(TCa-axis/TCc-axis)은 열처리 온도를 $700^{\circ}C$까지 올렸을 때, 점차적으로 증가하였고, 그 이상의 열처리 온도(< $900^{\circ}C$)에서는 급격히 감소하였다. 잔류응력과 Zn와 O의 bond length도 유사한 경향을 보였다. $700^{\circ}C$까지 열처리 온도가 증가함에 따라, 잔류응력은 증가하였고 bond length는 감소하였다. Near-band-edge emission (NBE)의 피크 강도는 열처리 온도가 $700^{\circ}C$까지 증가함에 따라 점차적으로 증가하였다. 열처리 온도가 $800^{\circ}C$ 이상 증가함에 따라 deep-level emission (DLE)가 적색편이(red-shift)하였다. $700^{\circ}C$로 열처리를 한 ZnO 박막이 가장 우세한 (002)방향의 배향성을 보였을 뿐만 아니라 가장 큰 발광효율 증가를 보였다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.3
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• pp.238-245
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• 2012

In this study, the molecular structures of tet(M) and tet(G) carried by tetracycline (Tc) resistant bacteria in intestinal microflora from the imported ornamental fish were characterized and compared with each other depend on the imported countries. Of the total isolates, approximately 8.9% of the Ent-lac+(lactose fermentative bacteria on coliform media) Tc resistant isolates in fish from three different countries, Singapore, Taiwan and Brazil, were appeared to contain tet(M). Three representative isolates of different countries, Aeromonas spp. JSM-1 (Singapore), JTM-1 (Taiwan) and JBM-1 (Brazil), were isolated and analyzed the molecular structures of tet(M) gene. Interestingly, partial sequence of tet(M) genes (1099 bp) in JBM-1 (Brazil) showed 99.5% homology with the tet(M) found in the Vibrio spp. RV16 isolate, obtained from marine fish in Korea and known to carry Tn1545 parent type of tet(M). In contrast, tet(M) gene in JSM-1 and JTM-1 showed mosaic structure of Tn1545 and Tn916, and 100% homology with each other. It may suggest the presence of various characteristics in terms of tet(M) gene structure. The determined sequence of the tet(G) from Aeromonas spp. JSG-1 and JBG-1 isolated from Singapore and Indonesia ornamental fish respectively showed similar nucleotide sequence homology but revealed a few nucleotide changes in comparison with the sequence of the prototype tet(G) gene (S52437 in GenBank).

• Nuclear Medicine and Molecular Imaging
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• v.42 no.1
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• pp.77-78
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• 2008

A 71-year-old woman was assigned to our department for Tc-99m myocardial perfusion SPECT(MPS) and coronary CT angiography. She admitted for substernal pain, via the ER, 2 days ago. The heart was scanned after intravenous injection of 925 MBq of $^{99m}Tc$-sestamibi adenosine-induced stress SPECT using dual head gamma camera (Hawkeye, GE healthcare. USA). The MPS shows decreased tracer uptake in the apical & mid area of anterior & lateral wall and mid & basal inferior wall. Coronary CT angiograph was obtained using Discovery VCT (GE healthcare). 3D angiography portrayed significant stenosis of ramus intermedius(RI) and posterolateral branch of right coronary artery(PLB) with fibrocalcified plaque. Two images were fused using Cardiac IQ fusion softwear package (Advantage workstation 4.4, GE healthcare) The fusion images explain the perfusion defect of anterior, lateral and inferior wall is due to stenosis of the RI and PLB. And 3 days later, coronary angiography was done and revealed the marked stenosis of RI and PLB. Then balloon angioplasty and stent was instituted in RI. Cardiac SPECT/CT fusion imaging provides additional information about hemodynamic relevance and facilitates lesion interpretation by allowing exact allocation of perfusion defects to its subtending coronary artery.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.3 no.2
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• pp.103-112
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• 2017

The combination of nanoparticle with radioisotope could give the in vivo information with high sensitivity and specificity. However, radioisotope labeling of nanoparticle is very difficult and radioisotopes have different physicochemical properties, so the radioisotope selection of nanoparticle should be carefully considered. $^{18}F$ was first option to be considered for labeling of nanoparticle. For the labeling of $^{18}F$ with nanoparticle, Prosthetic group is widely used. Iodine, another radioactive halogen, is often used. Since radioiodine isotopes are various, they can be used for different imaging technique or therapy in the same labeling procedures. $^{99m}Tc$ can easily be obtained as pertechnatate ($^{99m}{TcO_4}^-$) by commercial generator. Ionic $^{68}Ga$ (III) in dilute HCl solution is also obtained by generator system, but $^{68}Ga$ can be substituted for $^{67}Ga$ because of the short half-life (67.8 min). $^{64}Cu$ emits not only positron but also ${\beta}-particle$. Therefore $^{64}Cu$ can be used for imaging and therapy at the same time. These radioactive metals can be labeled with nanoparticle using the bifunctional chelator. $^{89}Zr$ has longer half-life (78.4 h) and is used for the longer imaging time. Unlike different metals, $^{89}Zr$ should use the other chelate such as DFO, 3,4,3-(LI-1,2-HOPO) or DFOB.

• The Korean Journal of Nuclear Medicine
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• v.25 no.2
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• pp.211-218
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• 1991

1983년 1월부터 1991년 2월까지 서울대학교 병원에서 진단된 위 암환자를 대상으로 시행한 359예의 골스캔을 후향적으로 재검토하여 골전이 빈도와 양상을 관찰하였으며 환자들의 의무기록을 검토하여 위암의 임상상과 비교하였다. 그 결과는 다음과 같았다. 1) 359예의 골스캔 중에서 골전이에 부합되는 이상소견은 167예(46.5%)이었다. 2) 관찰된 167예의 이상소견 빈도는 척추(66%)에 가장 많이 관찰되었고, 늑골(58%), 골반부(43%), 대퇴골(31%), 두개골(22%)순이었다. 3) 척추전이에서 흉추(65.6%)와 요추(64.5%)의 전이빈도는 거의 비슷하였고, 경추(23.6%)는 낮았다. 4) 골전이 빈도는 임상적 병기 3기 환자에서 진단후 1년 이내에 급격히 증가되었고 그 이후는 증가되지 않았다. 5) 골전이는 임상적 병기가 증가됨에 따라 증가되었으나, 조직학적 세포형태와는 무관하였다. 6) 혈청 alkaline phosphatase 치와 골스캔 상의 골전이 유무와 통제적으로 유의 한 상관관계가 관찰되었다. 이상의 결과로 위암환자의 상당 수에서 골전이가 진단되었으며 위 암환자, 특히 진행암 환자에서 골전이에 대한 주기적인 추적 검사가 필요할 것으로 생각된다.

• Childhood Kidney Diseases
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• v.8 no.2
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• pp.239-243
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• 2004

Acute poststreptococcal glomerulonephritis(APSGN) is the most common form of postinfectious glomerulonephritis, and acute pyelonephritis(APN) is the most severe form of urinary tract infection in childhood. However, the concurrence of two diseases is uncommon in the literature. We describe a case of APSGN accompanied with APN in a 5-year-old female who presented with fever, left flank pain, headache and facial edema. Urinalysis showed pyuria, microscopic hematuria, and mild proteinulra. Serial urine cultures grew Escherichia coli. ${^99m}$Tc-DMSA renal scan revealed a cortical defect in the upper pole of left kidney. She had a history of preceding pharyngitis, in addition, showed high blood pressure, high anti-streptolysin 0 titer, and low serum complement levels. The patient improved completely with supportive treatment, Including antibiotic and antihypertensive therapy. These findings suggested that APSGN and APN could be manifested simultaneously or be .superimposed on each other.

• Journal of Korean Neurosurgical Society
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• v.40 no.6
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• pp.434-440
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• 2006

Objective : The purpose of this study is to examine the influence of cranioplasty on dynamics of cerebral blood flow[CBF] and cerebrovascular reserve capacity[CVRC], and to investigate the usefulness of single photon emission computed tomography [SPECT] as a prognostic factor for neurological improvement after cranioplasty. Methods : Between March 2003 and December 2005, a prospective study was performed on 24 patients who had undergone total 25 cranioplasty operations. Cerebral blood flow velocities in the middle cerebral artery[MCA] and internal carotid artery[ICA] were obtained by transcranial Doppler ultrasonography[TCD]. The CVRC was assessed by SPECT in the natural state and after stimulation with 1g of acetazolamide. Neurological improvement after cranioplasty was compared between patients who showed hyperactivity to acetazolamide-activated SPECT [Group 1, n=7] and hypoactivity to acetazolamide-activated SPECT [Group 2, n=17]. These measurements were obtained two weeks prior to and two weeks after cranioplasty. Results : The blood flow velocities at the opposite site to the cranioplasty as well as at the cranioplasty site were significantly increased [P<0.05]. Compared with Group 2, there was significant increase in CBF and neurological improvement after cranioplasty in Group 1. Conclusion : Among patients with surgical bony defects, the patients who had normal reactivity of the CVRC showed a significant increase in CBF and neurological improvement after cranioplasty. The authors suggest that CVRC measurement prior to surgery may be an important prognostic factor for neurological improvement after cranioplasty.