• Childhood Kidney Diseases
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• v.22 no.2
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• pp.47-51
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• 2018

Purpose: Urinary tract infection (UTI) is one of the common infectious diseases in children. Several imaging modalities can be used to confirm the presence of acute pyelonephritis (APN). Among them the 99mTcdimercaptosuccinic acid renal scan (DMSA scan) is used as a gold standard for diagnosis. Ultrasonography technology is evolving. Therefore, in this study, we investigated the sensitivity and specificity of Power Doppler ultrasonography (PDU) compared to the results from the previous study. Methods: There were 260 patients included in this study, aged between 1 and 12 months old. The patients were admitted to the Yeungnam University Medical Center between January 2008 and December 2015. All patients underwent both DMSA scan and PDU within 5days of admission. Voiding cystourethrography (VCUG) was performed in 195 patients with abnormal DMSA scan or PDU. Results: The diagnostic sensitivity of APN using PDU was 45.5% and specificity was 85.5% in 260 patients following detection of a defect on DMSA scan that was defined as APN. The diagnostic sensitivity and specificity of PDU for VUR were 65.5 % and 60.1%, respectively. The diagnostic sensitivity and specificity of DMSA scan for VUR were 95.7% and 14.1%, respectively. Conclusion: PDU has a high specificity but low sensitivity, so there are limitations in using it to replace a DMSA scan for the diagnosis of APN in children. DMSA scan and PDU have different sensitivity and specificity in diagnosis of VUR, respectively. Therefore, we suggest that the sensitivity and specificity of each test can be helpful in diagnosing APN and VUR when used in conjunction.

• The Korean Journal of Nuclear Medicine
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• v.35 no.4
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• pp.268-273
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• 2001

Thymoma is the most common primary tumor of anterior mediastinum, accounting for 20% to 30% of all mediastinal tumors. The recurrence rate after total resection of the thymoma ranges 8% to 18%. We reported one patient of recurrent malignant thymoma imaged with Tc-99m MIBI, Tc-99m Tetrofosmin and Tc-99m (V) DMSA. Early and delayed Tc-99m MIBI and Tc-99m Tetrofosmin scintigraphies showed an increased uptake in the mediastinal area. Also, Tc-99m (V) DMSA scintigraphy revealed an increased uptake tn the corresponding area. Coronal SPECT images of Tc-99m MIBI, Tc-99m Tetrofosmin and Tc-99m (V) DMSA revealed increased uptake of each radiopharmaceutical in the tumor lesion corresponding to the mediastinal lesion on the chest CT. However, the normal blood pool activities of the heart and great vessels of Tc-99m (V) DMSA obscured the recurrent malignant thymoma. Although Tc-99m (V) DMSA is a useful tumor seeking agent, we recommend Tc-99m MIBI and Tc-99m Tetrofosmin SPECT rather than Tc-99m (V) DMSA to detect primary and recurrent malignant thymoma.

• Childhood Kidney Diseases
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• v.26 no.1
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• pp.52-57
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• 2022

Purpose: To determine predictive factors for detecting renal parenchymal damages (RPDs) in infants with recurrent febrile urinary tract infection (fUTI). Methods: From January 2015 to December 2021, 102 infants with recurrent fUTI and who underwent ^99mTc-dimercaptosuccinic acid (DMSA) renal scan in our hospital were included in this study. Controls included infants with normal DMSA results performed 3 months apart from the 2nd episode of fUTI. DMSA-positive group included infants with positive DMSA results performed 3 months apart from the 2nd episode of fUTI or at the 3rd episode of fUTI. The recurrence rate, causative bacteria, renal size discrepancy of both kidneys, and laboratory findings including C-reactive protein (CRP) and spot urine sodium-to-potassium ratio (uNa/K) were compared between both groups. Results: Only 3.8% of 79 infants with a 2nd episode of fUTI showed positive DMSA results. fUTI recurred more frequently within 12 months of follow-up in the DMSA-positive group than in the control group (69% vs. 13%, P<0.001). CRP values were significantly higher in the DMSA-positive group than in the control group (7.3 mg/dL vs. 3.7 mg/dL, P<0.001). Spot uNa/K were significantly lower in the DMSA-positive group than in the control group (0.6 vs. 1.1, P<0.001). Conclusions: Congenital renal scar and RPDs on the DMSA scan were more frequently found in infants with recurrent fUTI than those in the control group. High CRP values and low spot uNa/K in acute infections were helpful in predicting the presence of RPD in infants with recurrent fUTI.

• The Korean Journal of Nuclear Medicine
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• v.32 no.1
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• pp.81-88
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• 1998

The purpose of this study was to examine the radiolabeling and biodistribution of $^{188}Re(V)$-DMSA as a therapeutic cancer radiopharmaceutical. We made a DMSA kit($NaHCO_3$ 1.5 mg, meso-2,3-dimercaptosuccinic acid 1.0 mg, L(+)-ascorbic acid 0.7 mg, $SnCl_2{\cdot}2H_2O$ 0.34 mg, pH 2.9) for labeling with $^{188}Re$. In this kit, $^{188}ReO_4{^-}$ 5 mCi/2 ml added and boiled at $100^{\circ}C$ for 3 hr in water bath. The final pH adjusted to 7.5 with 7% $NaHCO_3$ solution. We checked the labelling efficacy with TLC-SG(n-butanol : acetic acid : $H_2O$ = 3 : 2 : 3) and examined the stability both in room temperature and in serum at $37^{\circ}C$. Biodistribution(1, 3, 13, 24, 48 hr) of $^{188}Re(V)$-DMSA compound was evaluated in Sarcoma 180 tumor-bearing mice. Each labeling efficiency and stability at room temperature for 48 hours was over 98% and 95%, respectively. The stability in serum were 82%(6 hr) and 85%(48 hr). Tumor uptake of $^{188}Re(V)$-DMSA in Sarcoma 180-bearing mice were $0.66{\pm}0.15%$(1 hr), $0.51{\pm}0.10%$(3 hr), $0.19{\pm}0.05%$(24 hr) and $0.13{\pm}0.02%$(48 hr). These result are consistent with those of $^{99m}Tc(V)$-DMSA which were reported previously. In conclusion, $^{188}Re(V)$-DMSA may be a useful therapeutic radiopharmaceutical for treating some cancers and metastatic bone lesion.

• Clinical and Experimental Pediatrics
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• v.49 no.6
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• pp.648-652
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• 2006

Objective : $^{99m}Tc$-dimercaptosuccinic acid(DMSA) scan is considered to be the most sensitive examination for detection of renal scars. However, because of its high radiation exposure to the kidney and its limited usefulness for patients with low grade vesicoureteral reflux(VUR), some authors have suggested that DMSA scans should be reserved primarily for children with VUR grade 3 and above. The aim of this study was to reevaluate the necessity of DMSA scans as a screening test in infants without reflux or with low grade reflux. Methods : In this retrospective study, 189 infants(mean age : 6.2 months) diagnosed as UTI were enrolled. Voiding cystourethrogram(VCUG), DMSA scan and renal ultrasonography were performed within 1 month of UTI. VUR grade was classified into three subgroups; low grade(grade 1-2), moderate grade(grade 3), and high grade(grade 4-5), respectively. Results : Renal defects were present in 67 of 189 infants, and 82 of the 378 renal units. The incidence of renal defects was significantly correlated with VUR grade(P<0.01); 28 percent without reflux, 38 percent with low grade, 53 percent with moderate grade, 100 percent with high grade, respectively. However, there was no significant differences in incidence of renal defects between the low grade and moderate grade group. Conclusion : In this study, renal defects were found in quite high percentages; 28 percent patients without reflux and 38 percent patients with low grade VUR, respectively. Moreover, there was no significant difference in the incidence of renal defects between the low grade and moderate grade groups. Therefore, DMSA scan should be performed for infants with UTI as a screening test regardless of the presence of VUR.

• Childhood Kidney Diseases
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• v.11 no.2
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• pp.212-219
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• 2007

Purpose : It is difficult to diagnose acute pyelonephritis(APN) in young children, because of their nonspecific symptoms. The younger the age, the higher the risk of renal scars after APN, which can be prevented by early diagnosis and treatment. We compare the significance of renal imaging studies by age for diagnosis of APN in febrile urinary tract infection(UTI) in children. Methods : Fifty-three hospitalized children(34 patients under age 2 and 19 patients over age 2) with febrile UTI and who had undergone dimercaptosuccinic acid(DMSA) scan, renal ultra sonography(RUS) and voiding cystourethrography(VCUG) during the acute stage were re-viewed. We compared the renal imaging studies between the different age groups. Results : The DMSA scan showed cortical defects in 23.5% of patients under age 2, which was significantly lower than 63.2% of patents over age 2(P<0.05). The renal cortical defects on DMSA scan were associated only with a high peripheral leukocyte count, but not with fever duration, erythrocyte sedimentation rate(ESR), and C-reactive protein(CRP). And there was no correlation between the DMSA scan, VCUG or RUS findings. Conclusions : The DMSA scan is not sensitive for diagnosis of APN in children less than 2 years of age and the findings cannot predict the presence of vesicoureteral reflux(VUR). VCUG may be necessary for proper management in this age group.

• The Korean Journal of Nuclear Medicine
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• v.29 no.4
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• pp.526-532
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• 1995

Introduction : $^{99m}Tc$-(V)-DMSA is a tumor seeking agent that has been used to image medullary carcinoma of thyroid, soft tissue sarcoma and lung cancer. This study was designed to assess the clinical role of $^{99m}Tc$-(V)-DMSA in the diagnosis of head and neck cancers. We has evaluated the diagnostic efficacy of planar and SPECT imaging using $^{99m}Tc$-(V)-DMSA. Patients and Method : Sixty-eight patients with head and neck mass were included in this study. All subjects were diagnosed by biopsy or surgery. Planar and SPECT images were obtained at 2 or 3 hour after intravenous injection of 740 MBq(20 mCi) $^{99m}Tc$-(V)-DMSA. Seventeen patients also underwent SPECT in aging using dual head camera. Result : The diagnostic sensitivity of $^{99m}Tc$-(V)-DMSA planar and SPECT imaging was 65% and 90%, and specificity was 80% and 66%, respectively. The sensitivity of planar imaging in squamous cell carcinoma was similar to overall sensitivity Six metastatic lesion were first diagnosed by scintigraphy. But benign lesions such as Kikuchi syndrome, tuberculous lymphadenitis also revealed increased uptake. Conclusion : $^{99m}Tc$-(V)-DMSA imaging seems to be a promising method in the evaluation of patients with head and neck mass. We recommend SPECT imaging to delineate anatomic localization of the lesion.

• Childhood Kidney Diseases
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• v.23 no.1
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• pp.36-42
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• 2019

Purpose: We investigated whether a renal size discrepancy on a renal sonogram (US) in children with febrile urinary tract infection (UTI) was correlated with the presence of cortical defects on their dimercaptosuccinic acid (DMSA) renal scan. Methods: We examined 911 children who were admitted consecutively to our hospital with their first episode of febrile UTI from March 2001 to September 2014. All enrolled children underwent a US and DMSA scan during admission. According to the US findings, including the renal size discrepancy, data were compared between children with positive and negative DMSA scan results. A positive DMSA scan result was defined as reduced or absent tracer localization and indistinct margins that did not deform the renal contour. Results: Mean renal lengths of the right and left kidneys were larger in children with positive DMSA scan results than in children with negative DMSA scan results ($63.2{\pm}11.3mm$ vs. $58.4{\pm}7.8mm$, P<0.001; $64.9{\pm}11.2mm$ vs. $59.9{\pm}7.9mm$, P<0.001; respectively). A significant difference was observed in both renal lengths between children with positive and negative DMSA scan results ($4.6{\pm}3.8mm$ vs. $3.3{\pm}2.6mm$, P<0.001). A multiple logistic regression analysis, revealed that a small kidney, cortical thinning, and a renal length discrepancy on US findings were significant factors for predicting the presence of cortical defects on an acute DMSA scan [P=0.028, 95% confidence interval (CI) 1.054-2.547; P= 0.004, 95% CI 1.354- 4.810; P<0.001, 95% CI 1.077-1.190, respectively]. Conclusion: In conclusion, a renal size discrepancy on US findings in children with their first episode of febrile UTI was a helpful tool for predicting the presence of cortical defects on an acute DMSA scan.

• The Korean Journal of Nuclear Medicine
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• v.23 no.2
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• pp.201-207
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• 1989

Patients with acute pyleonephritis may present with a spectrum of clinical symptoms and signs. There are few noninvasive diagnostic studies, however, to confirm or exclude this diagnosis. To evaluate the clinical utility of $^{99m}Tc-DMSA$ renal scan in diagnosis of acute pyelonephritis, we performed $^{99m}Tc-DMSA$ renal scan in 37 patients suspected with urinary tract infection. Simultaneously, kidney ultrasonography was done in 21 patients diagnosed with acute pyelonephritis, clinically. And we performed the followup scan after treatment in two to six weeks. The results were as follows: 1) $^{99m}Tc-DMSA$ renal scan disclosed single or multiple cortical defects and decreased radiouptake ratio of affected kidney in 23 patients among 25 patients diagnosed with acute pyleonephritis. 2) In the 21 patients with acute pyelonephritis, kidney ultrasonography showed abnormal finding in the 7 patients. And $^{99m}Tc-DMSA$ renal scan disclosed abnormal cortical defects in this 7 patients also. 3) Between the patients with acute pyelonephritis and those with lower urinary tract infection, asymptomatic bacteriuria or pyuria. right-to-left radiouptake ratios (R/L ratio) were significantly different (p < 0.001). 4) In two to six weeks after antibiotic therapy, we performed followup $^{99m}Tc-DMSA$ renal scan for 5 patients among 25 acute pyelonephritis patients. And we have found the improvement of cortical defects and the right-to-left radiouptake ratio. In conclusion, we thought that $^{99m}Tc-DMSA$ renal scan should be useful in diagnosis of acute pyelonephritis and follow-up examination.

• 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.