• Clinical and Experimental Pediatrics
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• v.49 no.6
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• pp.653-658
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• 2006

Purpose : Because voiding cystourethrography(VCUG) is an invasive method, we studied whether VCUG could be postponed through evaluation of alternative non-invasive tests including renal ultrasonography and $^{99m}Tc$-DMSA renal scan. Methods : We reviewed the medical records of 175 patients initially diagnosed with febrile urinary tract infection during the one year period of 1999, and compared 3-tests : renal ultrasongraphy, $^{99m}Tc$-DMSA renal scan, and VCUG. Results : Renal ultrasonography didn't contribute to the prognostication of pyelonephritis(photopenic areas) or vesicoureteral reflux(VUR). Presentation of photopenic areas in $^{99m}Tc$-DMSA renal scan was related to VUR. If both findings of renal ultrasonography and $^{99m}Tc$-DMSA renal scans were normal, this condition was closely related to normal results in VCUG. And if both examinations were abnormal, the condition was closely related to VUR. But this state could not always guarantee the normal result from VCUG because of low sensitivity in finding VUR. Conclusion : In cases in which acute phyelonephritis is demonstrated by $^{99m}Tc$-DMSA renal scan, VCUG is required. In addition to this, if the conditions of hydronephrosis, vesicoureteral dilatation, increases of renal volume, and changes of echogenesity are shown by renal ultrasonography, VCUG should be performed. If a patient has difficulty undergoing VCUG, temporary postponement of VCUG can be taken into consideration, but only in cases where both examinations of renal ultrasonography and $^{99m}Tc$-DMSA renal scan are normal. Nevertheless, close observation is be advised even in this case.

• The Korean Journal of Nuclear Medicine
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• v.32 no.3
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• pp.266-275
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• 1998

Purpose: We measured pulmonary epithelial permeability by $^{99m}Tc-DTPA$ radioaerosol clearance in patients with diabetes and correlated with the presence of microangiopathy to understand the pathophysiology of pulmonary microangiopathy and evaluate $^{99m}Tc-DTPA$ radioaerosol clearance as a diagnostic test to assess pulmonary microangiopathy. Materials and Methods: We performed $^{99m}Tc-DTPA$ radioaerosol scan in 10 normal subjects, 10 asymptomatic smokers, 20 diabetic patients without history of smoking (10 with microangiopathy, 10 without microangiopathy). $^{99m}Tc-DTPA$ clearance half-time ($T_{1/2}$) was calculated, then compared with the result of chest radiography and pulmonary function test. Results: Chest radiography and pulmonary function test were normal in all subjects. There were no significant difference of clinical or laboratory characteristics between these groups except age. The diabetic patients with microangiopathy were significantly older (p<0.05). The $T_{1/2}$ of normal subjects and asymptomatic smokers were significantly different ($65.2{\pm}23.7min$ vs $39.6{\pm}9.8min$, p<0.05). For diabetic patients with microangiopathy, the $T_{1/2}$ was $90.5{\pm}46.5min$ and significantly delayed when compared with those of normals and asymptomatic smokers (p<0.05). However, the $T_{1/2}$ of diabetic patients without microangiopathy, $70.0{\pm}12.7min$, was not significantly different from those of normals or asymptomatic smokers (p>0.05). No significant correlation was found between the $T_{1/2}$ and spirometric parameters including DLco, FVC, $FEV_1,\;FEV_1/FVC$ (%) and $FEF_{25-75%}$ in all subjects, and between the $T_{1/2}$ and duration of diabetes ;in diabetic patients. Conclusion: Eventhough the influence of age can't be excluded, delayed $^{99m}Tc-DTPA$ clearance half-time ($T_{1/2}$) in diabetic patients with microangiopathy indicates decreased pulmonary capillary permeability as one of the pathophysiologic results of pulmonary microangiopaththy. Further studies are needed in larger number of age matched control and diabetic patients to evaluate the diagnostic efficacy.

• The Korean Journal of Nuclear Medicine
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• v.26 no.1
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• pp.72-81
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• 1992

Pharmacologic coronary vasodilation in conjunction with myocardial scintigraphy has become an accepted alternative to dynamic exercise testing for the diagnosis of coronary artery disease. Although dipyridamole has traditionally been used for this purpose, it causes frequent side effect, which at times can be life-threatening. Moreover, dipyridamole dose not elicit maximal coronary vasodilation in a substantial number of patients receiving the usual i.v. dose. Adenosine is an endogenously produced compound that has significant effects as a coronary vasodilator and rapid onset action and extremely short half-life (< 10 seconds). The diagnostic accuracy and safety profile of adenosine $^{99m}Tc-MIBI$ myocardial scintigraphy were evaluated and comparison with exercise $^{99m}Tc-MIBI$ was performed. Twenty-eight subjects underwent $^{99m}Tc-MIBI$ imaging after adenosine infusion and exercise $^{99m}Tc-MIBI$ imaging. Adenosine was infused intravenously at a dose of 0.14mg/kg/body weight per minute for 6 min and MIBI was injected at 3 minute. Adenosine caused an incerease in heart rate ($64{\pm}12$ at baseline versus $74{\pm}16$ beats/min at peak effect, p<0.001), a mild decrease in systolic and diastolic blood pressure and a slightly increase in PR interval(p; NS). Side effects were reported in 92% of patients and were mostly mild in nature and promptly resolved within 1 or 2 minutes of termination of adenosine infusion. Facial flushing (53%), chest pain (36%), mild dyspnea (39%), headache (21%), throat discomfort (21%) were frequent symptoms. ST segment depression (> 1 mm) and second degree AV block in electrocardiography occured in 11% of the patients, respectively. The overall sensitivity and specificity for individual coronary stenoses in 16 patients underwent coronary angiography were 88% and 95%, respectively. The agreement ratio of segmental perfusion between adenosine and exercise images was 92% (Kappa index=0.82). In conclusion, $^{99m}Tc-MIBI$ myocardial perfusion scintigraphy with intravenous adenosine is a feasible, safe and highly accurate noninvasive technique for the detection of coronary artery disease and results are at least comparable with those of exercise $^{99m}Tc-MIBI$ scintigraphy.

• Archives of Pharmacal Research
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• v.27 no.9
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• pp.961-967
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• 2004

The development of an antibody labeling method with $^{99m}$Tc is important for cancer imaging. Most bifunctional chelate methods for $^{99m}$Tc labeling of antibody incorporate a $^{99m}$Tc chelator through a linkage to lysine residue. In the present study, a novel site-specific $^{99m}$Tc labeling method at carbohydrate side chain in the Fc region of 2 antibodies (T101 and rabbit anti-human serum albumin antibody (RPAb)) using dihydrazinophthalazine (DHZ) which has 2 hydrazino groups was developed. The antibodies were oxidized with sodium periodate to pro-duce aldehyde on the Fc region. Then, one hydrazine group of DHZ was conjugated with an aldehyde group of antibody through the formation of a hydrazone. The other hydrazine group was used for labeling with $^{99m}$Tc. The number of conjugated DHZ was 1.7 per antibody. $^{99m}$Tc labeling efficiency was 46-85％ for T101 and 67∼87％ for RPAb. Indirect labeling with DHZ conjugated antibodies showed higher stability than direct labeling with reduced antibodies. High immunoreactivities were conserved for both indirectly and directly labeled antibodies. A biodistribution study found high blood activity related to directly labeled T1 01 at early time point as well as low liver activity due to indirectly labeled T101 at later time point. However, these findings do not affect practical use. No significantly different biodistribution was observed in the other organs. The research concluded that DHZ can be used as a site-specific bifunctional chelating agent for labeling antibody with $^{99m}$Tc. Moreover, $^{99m}$Tc labeled antibody via DHZ was found to have excellent chemical and biological properties for nuclear medicine imaging.edicine imaging.

• Journal of Yeungnam Medical Science
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• v.15 no.2
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• pp.254-262
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• 1998

We evaluated the effectiveness of Tc-99m labeled antigranulocyte antibody immunoscintigraphy in differentiating the causes of vertebral compression fracture. This study involved 16 patients with vertebral compression fracture; 8 were due to trauma or osteoporosis, 3 were due to metastasis and 5 were due to tuberculous spondylitis. We retrospectively analyzed the location and the extent of decreased tracer uptake in tomographic images of Tc-99m labeled antigranulocyte antibody immunoscintigraphy. Eight patients had a 16 vertebral compression fractures due to trauma or osteoporosis, three patients had 3 vertebral compression fractures due to metastasis and 5 patients had 6 vertebral compression fractures due to tuberculous spondylitis. Sixteen vertebral compression fractures by trauma or osteoporosis showed a normal tracer uptake in pedicle, laminar and spinous process, but there was noted with 6 decreased uptake, 8 absence of tracer uptake and 2 normal tracer uptake in the vertebral body. Two vertebral compression fractures by metastasis showed the absence of uptake in vertebral body, pedicle, laminar and spinous process, and one showed an absence of vertebral body and spinous process. Six vertebral compression fractures by tuberculous spondylitis showed the absence of uptake in six compression fractures, the absence of pedicle in five compression fractures. We concluded Tc-99m labeled antigranulocyte antibody immunoscintigraphy may be helpful to differentiate the causes of vertebral compression fractures.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.57-61
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• 2012

Purpose : The whole body bone scan on nuclear medicine is a widely accepted examination and procedure. However, unusual nonosseous uptake can be observed, which reflects a rare interaction between the radiopharmacceutical and the patient. This study aimed to evaluate the influence of MRI(Magnetic Resonance Imaging) contrast and $^{99m}Tc$-DPD(Dicarboxpropane diphosphonate) on whole body bone scan. Materials and Methods : We analyzed the 982 patients who were examined by $^{99m}Tc$-DPD on whole body bone scan in nuclear medicine department of pusan national university hospital from january to december 2010. All these 982 patients had MRI contrast administration prior to whole body bone scan. We analyzed laboratory test. Results : 46 patients(men 39, women 7) showed diffuse hepatic uptake on whole body bone scan. These uptakes were disappeared on the follow-up whole body bone scan. There were no significant difference of CBC test, liver function tests and renal function tests. Conclusion : The study might be an indirect evidence that diffuse hepatic and splenic uptake of 99mTc-DPD on whole body bone scan after intravenous administration of Gadolinium(Gd) MRI contrast. To perform a precise examination, Gd-contrast agent should be removed from the body before performing a whole body bone scan.

• The Korean Journal of Nuclear Medicine
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• v.33 no.2
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• pp.172-177
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• 1999

Purpose: The purpose of this study was to ascertain whether radiation adaptive response could be induced by Tc-99m-methylene diphosphonate (Tc-99m-MDP) in peripheral lymphocytes of patients undergoing bone scintigraphy. Materials and Methods: Lymphocytes from 22 patients (6 males, 16 females, mean age $50{\pm}14$ years) were collected before and after bone scintigraphy using 740 MBq Tc-99m-MDP Lymphocytes from 10 controls (6 males, 4 females, mean age $43{\pm}7$ years) were also collected. They were exposed to challenge dose of 2 Gy gamma rays using a cell irradiator. Number of ring-form and dicentric chromosomes per 600 cells (chromosomal aberrations) was counted under the light microscope. Results: Chromosomal aberrations in patients before bone scintigraphy ($385.1{\pm}30.5$) was not different from that of controls ($367.8{\pm}36.6$). However, chromosomal aberrations in patients after bone scintigraphy was significantly decreased to $192.6{\pm}22.1$ (p=0.0001). Conclusion: Low dose gamma-irradiation by Tc-99m-MDP used for bone scintigraphy induces a cytogenetic adaptive response in peripheral lymphocytes.

• The Korean Journal of Nuclear Medicine
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• v.26 no.2
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• pp.274-279
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• 1992

Clinical role of $^{99m}Tc-MIBI$ myocardial scintigraphy in the diagnosis of coronary artery disease (CAD) is now well accepted, however, the role of it in the identification of viable myocardium in patients with chronic CAD has not yet been clarified. To determine the usefulness of rest-injected $^{99m}Tc-MIBI$ scan as a marker of myocardial viability, the regional uptake of this agent at rest was compared with that of $^{201}Tl$ on reinjection and 24 hours after reinjection images. Subject patients were 13 chronic CAD patients who showed irreversible perfusion defect(s) on standard pharmacologic (dipyridamole) stress-redistribution images. Immediately after the redistribution images were obtained, 37 MBq thallium was injected at rest, and images were reacquired at 10 minutes and 24 hours after reinjection. After then 740 MBq $^{99m}Tc-MIBI$ was injected, and 1 hour later rest MIBI myocardial imaging was performed. Five sets of imagestress, redistribution, reinjection, delayed images of thallium, and rest image of MIBI) were then analyzed qualitatively and quantitatively. Left ventricle was arbitrarily divided into 9 segments (apex, basal and apical portions of anterior, septal, inferior, and lateral walls). Seven patients and 30 regions showed a fixed perfusion defect on the stress-redistribution images. Among 30 regions, 15 showed positive uptakes and 6 showed negative uptakes on both $^{201}Tl$ reinjection/delayed images and $^{99m}Tc-MIBI$ rest images. Five regions showed only thallium uptake and were regarded as viable clinically. Of four regions which showed only $^{99m}Tc-MIBI$ uptake, two were regarded as viable, while the other two were regarded as a nonviable scar tissue clinically. In conclusion, $^{201}Tl$ reinjection technique was more reliable in the identification of viable myocardium. However, the role of $^{99m}Tc-MIBI$ in identification of viable myocardium was still remained to be clarified because 2 of 9 regions showed only $^{99m}Tc-MIBI$ uptake and were regarded as viable tissues.

• The Korean Journal of Nuclear Medicine
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• v.25 no.2
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• pp.237-244
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• 1991

$^{99m}Tc-DMSA$ renal scan has been evaluated not only the renal functional cell mass but also some anatomical structures at a loss of the renal parenchymal function. The author classified a renal morphology of the posterior image of $^{99m}Tc-DMSA$ renal scan as the groups of symmetric and asymmetric morphology, the groups of the large, normal and small sized kidneys, the groups of the central photon defects (PD) which could be noted in a dilated pelvocalyceal system due to obstructive uropathy and the cortical photon defects (CD) due to focal parenchymal lesions or scars after a loss of function and the last groups of the single and multiple CD for a suggestion of the clinical usefulness. Regarding to measurement of normal renal size, the longest size of the kidneys were evaluated with 5 cm of a lead scale on the posterior renal image, and those were decided to the limits beteen 104.1 and 119.4 mm as comparison with the renal size of intravenous pyelogram (IVP) in 59 cases who were underwent $^{99m}Tc-DMSA$ and IVP concommitantly. Among 85 cases of PD in $^{99m}Tc-DMSA$ renal scan, the 61 (71.8%) were cases of a dilated pelvocalyceal system related with obstructive uropathy, meanwhile the 28 (27.0%) of 162 cases with CD were cases of obstructive and infectious uropathy. The probability of a presence of some uropathy in cases of CD were 99.3%, meanwhile that of the presence of CD in cases of some uropathy were 37.9%. Besides, there were some specific anatomical findings such as polycystic kidneys with symmetric enlarged kidneys with multiple CD and the kidneys of chronic renal failure and/or hypertension with symmetric small size in $^{99m}Tc-DMSA$ renal stan.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.5 no.1
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• pp.18-25
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• 2019

2-Nitroimidazole derivatives have been reported to accumulate in hypoxic tissue. We prepared a novel $^{99m}Tc-MAG_3$-2-nitroimidazole and evaluated the feasibility for hypoxia imaging agent. $Bz-MAG_3$-2-nitroimidazole was synthesized by direct coupling of $Bz-MAG_3$ and 2-nitroimidazole using dicyclohexylcarbodiimide. $Bz-MAG_3$-2-nitroimidazole was labeled with $^{99m}Tc$ in the presence of tartaric acid and $SnCl_2-2H_2O$ at $100^{\circ}C$ for 30 min. And the reaction mixture was purified by $C_{18}$ Sep-pak cartridge. The labeling efficiency and the radiochemical purity were checked by ITLC-SG/acetonitrile. The tumor was grown in balb/c mice for 8~13 days after the subcutaneous injection of tumor cells, CT-26 (murine colon adenocarcinoma cell). Biodistribution study and tumor autoradiography were performed in the xenografted mice after i.v injection of 74 kBq/0.1 mL and 19 MBq/0.1 mL of $^{99m}Tc-MAG_3$-2-nitroimidazole, respectively. In vivo images of $^{99m}Tc-MAG_3$-2-nitroimidazole in tumor bearing mice were obtained 1.5 hr post injection. The labeling efficiency was $45{\pm}20%$ and the radiochemical purity after purification was over 95%. Paper electrophoresis confirmed negative charge of $^{99m}Tc-MAG_3$-2-nitroimidazole. $^{99m}Tc-MAG_3$-2-nitroimidazole was very stable at room temperature and its protein binding was 53%. The $^{99m}Tc-MAG_3$-2-nitroimidazole exhibited high uptake in the liver, stomach and intestine. In biodistribution study using tumor bearing mice, the uptakes (% ID/g) of the tumor were $0.5{\pm}0.1$, $0.4{\pm}0.0$, $0.2{\pm}0.1$ and $0.1{\pm}0.1$ at 5, 15, 30 min and 4 hrs. Tumor/muscle ratio were $1.4{\pm}0.1$, $2.2{\pm}0.83$, $3.0{\pm}0.9$, and 3.7 (n=2) for 5, 15, 30 min and 4 hrs. The uptake in hypoxic area was found higher than in non-hypoxic area of tumor tissue by autoradiography. In vivo images showed the relatively faint uptake to the hypoxic tumor region. $^{99m}Tc-MAG_3$-2-nitroimidazole was successfully synthesized and found feasible for imaging hypoxia.