Girth-based administered activity for pediatric 99m Tc-DMSA SPECT

BACKGROUND

Pediatric molecular imaging requires a balance between administering an activity that will yield sufficient diagnostic image quality while maintaining patient radiation exposure at acceptable levels. In current clinical practice, this balance is arrived at by the current North American Consensus Guidelines in which patient weight is used to recommend the administered activity (AA).

PURPOSE

We have previously demonstrated that girth (waist circumference at the level of the kidneys) is better at equalizing image quality than patient weight for pediatric Tc-99m DMSA renal function imaging. However, the correlation between image quality (IQ), AA, and patient girth has not been rigorously and systematically developed. In this work, we generate a series of curves showing the tradeoff between AA and IQ as a function of patient girth, providing the data for standards bodies to develop the next generation of dosing guideline for pediatric DMSA SPECT.

METHODS

An anthropomorphic phantom series that included variations in age (5, 10, and 15 years), gender (M, F), local body morphometry (5, 10, 50, 90, and 95th girth percentiles), and kidney size (±15% standard size), was used to generate realistic SPECT projections. A fixed and clinically challenging defect-to-organ volume percentage (0.49% of renal cortex value) was used to model a focal defect with zero uptake (i.e., full local loss of renal function). Task-based IQ assessment methods were used to rigorously measure IQ in terms of renal perfusion defect detectability. This assessment was performed at multiple count levels (corresponding to various AAs) for groups of patients that had similar girths and defect sizes. Receiver-operating characteristics (ROC) analysis was applied; the area under the ROC curve (AUC) was used as a figure-of-merit for task performance. Curves showing the tradeoff between AUC and AA were generated for these groups of phantoms.

RESULTS

Overall, the girth-based dosing method suggested different amounts of AA compared to weight-based dosing for the phantoms that had a relatively large body weight but a small girth or phantoms with relatively small bodyweight but large girth. Reductions of AA to 62.9% compared to weight-based dosing guidelines can potentially be realized while maintaining a baseline (AUC = 0.80) IQ for certain 15-year-olds who have a relatively small girth and large defect size. Note that the task-based IQ results are heavily dependent on the simulated defect size for the defect detection task and the appropriate AUC value must be decided by the physicians for this diagnostic task. These results are based purely on simulation and are subject to future clinical validation.

CONCLUSIONS

The study provides simulation-based IQ-AA data for a girth-based dosing method for pediatric renal SPECT, suggesting that patient waist circumference at the level of kidneys should be considered in selecting the AA needed to achieve an acceptable IQ. This data may be useful for standards bodies to develop girth-based dosing guidelines.

Ultrafast cadmium-zinc-telluride-based renal single-photon emission computed tomography: clinical validation

BACKGROUND

One of the main limitations of 99mtechnetium-dimercaptosuccinic acid (DMSA) scan is the long acquisition time.

OBJECTIVE

To evaluate the feasibility of short DMSA scan acquisition times using a cadmium-zinc-telluride-based single-photon emission computed tomography (SPECT) system in children.

MATERIALS AND METHODS

The data of 27 children (median age: 4 years; 16 girls) who underwent DMSA SPECT were retrospectively analyzed. Both planar and SPECT DMSA were performed. SPECT images were analyzed using coronal-simulated planar two-dimensional images. A reduction in SPECT acquisition time was simulated to provide 4 series (SPECT-15 min, SPECT-10 min, SPECT-5 min and SPECT-2.5 min). A direct comparison of the planar and SPECT series was performed, including semi-quantification reproducibility, image quality (mean quality score on a scale of 0 to 2) and inter- and intra-observer reproducibility of the scintigraphic patterns.

RESULTS

The overall image quality score (± standard deviation) was 1.3 (± 0.6) for the planar data set, 1.6 (± 0.5) for the SPECT-15 min data set, 1.4 (± 0.5) for the SPECT-10 min data set, 1.0 (± 0.5) for the SPECT-5 min data set and 0.6 (± 0.6) for the SPECT-2.5 min data set. Median Kappa coefficients for inter-observer agreement between planar and SPECT images were greater than 0.83 for all series and all readers except one reader for the SPECT-2.5 min series (median Kappa coefficient = 0.77).

CONCLUSION

Shortening SPECT acquisitions to 5 min is feasible with minimal impact on images in terms of quality and reproducibility.

Differentiation between normal and abnormal kidneys using 99mTc-DMSA SPECT with deep learning in paediatric patients

AIM

To investigate the feasibility of using deep learning (DL) to differentiate normal from abnormal (or scarred) kidneys using technetium-99m dimercaptosuccinic acid (99mTc-DMSA) single-photon-emission computed tomography (SPECT) in paediatric patients.

MATERIAL AND METHODS

Three hundred and one 99mTc-DMSA renal SPECT examinations were reviewed retrospectively. The 301 patients were split randomly into 261, 20, and 20 for training, validation, and testing data, respectively. The DL model was trained using three-dimensional (3D) SPECT images, two-dimensional (2D) maximum intensity projections (MIPs), and 2.5-dimensional (2.5D) MIPs (i.e., transverse, sagittal, and coronal views). Each DL model was trained to determine renal SPECT images into either normal or abnormal. Consensus reading results by two nuclear medicine physicians served as the reference standard.

RESULTS

The DL model trained by 2.5D MIPs outperformed that trained by either 3D SPECT images or 2D MIPs. The accuracy, sensitivity, and specificity of the 2.5D model for the differentiation between normal and abnormal kidneys were 92.5%, 90% and 95%, respectively.

CONCLUSION

The experimental results suggest that DL has the potential to differentiate normal from abnormal kidneys in children using 99mTc-DMSA SPECT imaging.

Altered Biodistribution on 99m Tc-Dimercaptosuccinic Acid Renal Scan

ABSTRACT

99m Tc-dimercaptosuccinic acid ( 99m Tc-DMSA) scans are used to evaluate renal cortical defects typically related to parenchymal scarring or pyelonephritis, and ectopic renal parenchyma. 99m Tc-DMSA binds to metalloproteins in proximal tubular cells and typically localizes to the renal cortex, with minimal excretion. Planar and SPECT images are obtained 2 to 4 hours after IV administration of 99m Tc-DMSA. Altered 99m Tc-DMSA biodistribution has been reported in various conditions, including renal injury, technical issues, infiltrative processes, and hematologic disorders. Here, we present a case of altered biodistribution, with hepatic and splenic radiotracer uptake in the setting of hepatosplenomegaly and hematologic abnormalities concerning for a systemic hematologic disorder/lymphohistiocytosis.

Optimizing input parameter of the randomized singular value decomposition algorithm for compressing technetium-99m L,L, ethylenedicysteine renal dynamic study in minimum time preserving clinical information

OBJECTIVE

The SVDsketch [MATLAB function which implements a randomized singular value decomposition (rSVD) algorithm] uses tolerance (tol) to adaptively determine the rank of the matrix sketch approximation. As the tol gets larger, fewer features of input image matrix are used in the matrix sketch. The objective of this study was to optimize the value of tol for compressing technetium-99m (Tc-99m) L,L, ethylenedicysteine (LLEC) renal dynamic (RD) study in minimum time preserving clinical information.

MATERIALS AND METHODS

At different values of tol [0.00012(default), 0.1, 0.01, and 0.05] 50 Tc-99m LLEC RD studies were compressed. Two nuclear medicine (NM) physicians compared compressed images at tol = 0.1 with its input images. The SVD computation time and compression factor were calculated for each study. The image quality metrics: Error, structural similarity index for measuring image quality, brightness, global contrast factor (GCF), contrast per pixel (CPP), and blur were used for objective assessment of image quality. Percentage error in split function estimated from compressed and original images was calculated. Wilcoxon signed-rank test was applied to find statistically significant difference between renal split function, blur, GCF, CPP, and brightness of the compressed image and the original image at .

RESULTS

As per NM physicians, compressed images estimated with tol = 0.1 were identical to the original images. Based on image quality metrics, compressed images were significantly less noisy, brighter, and have better contrast compared with its input images. There was insignificant difference in split renal function estimated from compressed RD study at tol = 0.1 and its original study. The SVD computation and percentage compression per study were found to be 0.04725 s and up to 74.53%.

CONCLUSION

The optimized value of tol for compressing Tc-99m LLEC RD study preserving clinical information was found to be 0.1, and SVD computation time: 0.04725 s.

EFFECTIVE DOSE TO ADULT PATIENTS UNDERGOING RENAL SCANS WITH 99MTC (DMSA, DTPA, EC AND MAG3)

Renal scintigraphy plays an important role in the diagnosis of various kidney disorders. This procedure can be performed with different radiopharmaceuticals. The patients undergoing renal scintigraphy receive a radiation dose that should be assessed. In this study, the effective dose of patients due to renal scintigraphy with 99mTc (DMSA, DTPA, EC and MAG3) was calculated for the International Commission on Radiological Protection (ICRP) 110 adult reference phantoms using the Medical Internal Radiation Dose method and the ICRP 60 and 103 tissue weighting factors. The results show that the highest effective dose per unit activity administered is due to 99mTc DMSA. On average, the effective dose per unit activity administered of 99mTc DMSA is almost twice the effective dose per unit activity administered of other radiopharmaceuticals. The effective doses per unit activity administered calculated using the ICRP 103 tissue weighting factors are always lower than that calculated using the ICRP 60 tissue weighting factors and the ICRP 128 data.

The impact of Technetium-99m dimercapto-succinic acid scintigraphy on DNA damage and oxidative stress in children

BACKGROUND

Technetium-99m-dimercapto succinic acid (Tc-99m DMSA) scintigraphy is a commonly used imaging modality in children with urological abnormalities. The radiopharmaceuticals, which have the effects of ionising radiation, are used in this method. This study aimed to investigate the impact of the Tc-99m DMSA scan on renal oxidative stress and mononuclear leukocyte (MNL) DNA damage.

METHODS

Children, who were followed up by paediatric nephrology at Bezmialem Vakif University and underwent Tc-99m DMSA scintigraphy between April 2015 and January 2016 with the indication of detection of renal scars, were included in this study. The exclusion criteria were nephrolithiasis, history of premature birth and recent urinary tract infection 3 months prior to scintigraphy or antibiotic use in the last 1 month. 3 mL heparinised blood samples were obtained just before, immediately after and 1 week after the scintigraphy. MNL DNA damage, total antioxidant status (TAS) and total oxidant status (TOS) were measured in the blood samples. The oxidative stress index (OSI) was calculated. Spot urine samples were obtained from each patient before and within 3 days after performing the scintigraphy. TAS/Creatinine (TAS/Cr), TOS/Creatinine (TOS/Cr) and N-acetyl-glucosaminidase/creatinine (NAG/Cr) levels were measured in the urine samples.

RESULTS

Twenty-seven children were evaluated. The values between TAS, TOS and OSI levels in serum samples at baseline, immediately after and 1 week after the scintigraphy (P = .105, P = .913, and P = .721, respectively) showed no statistically significant difference. The levels of TAS/Cr, TOS/Cr, NAG/Cr ratios and OSI, which were evaluated from urine samples before and within 3 days after the scintigraphy scan were also similar (P = .391, P = .543, P = .819 and P = .179, respectively). The levels of DNA damage only increased following scintigraphy scan and decreased a week later (P < .05).

CONCLUSIONS

The effect of Tc-99m DMSA scintigraphy is insufficient to create oxidative damage, but it can cause DNA damage via the direct impact of ionising radiation which can be repaired again in a short time.

Effect of Ursodeoxycholic Acid on the Biodistribution and Excretion of Technetium-99m Radiopharmaceuticals in Rat: A Potential Image Quality Enhancer

PURPOSE

This study aimed to investigate the effect of ursodeoxycholic acid (UDCA) on the biodistribution and excretion of technetium-99m (Tc-99m)-labeled radiopharmaceuticals.

MATERIALS AND METHODS

Tc-99m hydroxy-methylene-diphosphonate (HDP), Tc-99m pertechnetate, and Tc-99m dimercaptosuccinic acid (DMSA) were injected via the tail vein of rats. After 30 min, the control group was administered saline, and the UDCA group was given UDCA orally. Scintigraphy images were acquired after 30 min and 1, 2, 3, and 4 h. Radioactivity and rate of change were compared. Tc-99m mercaptoacetyltriglycine (MAG₃) imaging was also performed.

RESULTS

In image analysis of Tc-99m HDP, radioactivity of the buttock was lower in the UDCA group at 4 h. Rates of change in the buttock were significantly different at 3 h-30 min and 4 h-30 min, and buttock radioactivity in the UDCA group had decreased more. In analysis of Tc-99m pertechnetate, radioactivity of the buttock was higher in the control group. Rates of change in the thyroid gland and buttock were different at 1 h-30 min, 3 h-30 min, and 4 h-30 min, with radioactivity in the UDCA group decreasing more. In the analysis of Tc-99m DMSA, while the radioactivity of the kidneys in the control group showed little decrease at 1 h-30 min, that in the UDCA group increased. In the analysis of Tc-99m MAG₃ images, radioactivity and radioactivity/total body radioactivity (TBA) values for the kidneys were higher in the UDCA group at 2 min. At 5 and 10 min, radioactivity/TBA values for soft tissue in the UDCA group were lower than those in the control group.

CONCLUSION

This study demonstrated that administration of UDCA increases renal excretion and soft tissue clearance of radiopharmaceuticals. This investigation could contribute to the broadening of applications of UDCA.

Evaluation of the protective effect of paricalcitol and vitamin D3 at doxorubicin nephrotoxicity in rats with 99mTechnetium-dimercaptosuccinic acid renal scintigraphy and biochemical methods

AIM

The present study aimed to examine the effect of paricalcitol (PRC) and vitamin D3 (vit D3) on doxorubicin (DOX)-induced nephrotoxicity in rats.

MATERIALS AND METHODS

Forty-two Wistar rats were randomly categorized into six groups: control; 2) PRC(0.5 µg/kg) and 3) vit D3(5.000 IU/kg) administered for 14 days; 4) DOX, 18 mg/kg administered on the 12th, 13th and 14th days of the study; 5) PRC (0.5 µg/kg, +DOX(18 mg/kg); vit D3(5.000 IU)+DOX(18 mg/kg). On the 15th day of the experiment, 99mTc-DMSA uptake level and biochemical parameter in serum and tissue were assay.

RESULTS

Activities of 99mTechnetium-Dimercaptosuccinic Acid (99mTc-DMSA) were lower in groups receiving DOX and/or PRC+DOX, vit D3+DOX than in control groups. The 99mTc-DMSA level in the group PRC+DOX and vit D3+DOX were importantly higher than DOX group. DOX caused an important increase in blood urea nitrogen (BUN), creatinine, Tumor Necrosis Factor-α(TNF- α), interleukin-6(IL-6) and nitric oxide(NO) levels compared to control groups. However, PRC and vit D3 pretreatments lowered them. Uptake of 99mTc-DMSA level was higher in groups PRC+DOX than in vit D3+DOX group. Administration of PRC and vit D3 alone did not change alterations all of parameters.

CONCLUSION

The results indicated that PRC administration protects kidney in DOX-induced nephrotoxic rats. In addition, PRC has a stronger nephroprotective effect than vit D3.

Colonic Visualization of 99mTc-DMSA Due to Enterovesical Fistula

A 60-year-old woman with recurrent urinary tract infection who had several operations for colorectal carcinoma underwent Tc-DMSA renal scintigraphy which showed an unexpected accumulation of radiotracer in the colon. When symptoms were reviewed, we noticed that she was suffering from pneumaturia and fecaluria which raised the suspicion of enterovesical fistula. Rectal contrast-enhanced computer tomography of pelvis demonstrated enterovesical and enterovaginal fistulas. Colonic radioactivity was considered to be related to retrograde peristalsis of Tc-DMSA from bladder activity via enterovesical fistula. In patients with pelvic surgeries and radiotherapy, radioactivity in the colon should raise the suspicion of enterovesical fistula.

Clinical relevance of 18F-FDG PET/CT in the postoperative follow-up of patients with history of medullary thyroid cancer

BACKGROUND

The aim of the study was evaluation of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography with computed tomography (PET/CT) in the detection of active disease in the patients with suspected recurrence of the medullary thyroid carcinoma (MTC).

PATIENTS AND METHODS

18F-FDG PET/CT investigation was performed in 67 patients, investigated from 2010 to 2019. _ Follow up was performed from 6 to 116 months after surgery (median 16.5 months, x± SD = 29±28.9 months). Twenty five of 67 patients underwent 99mTc-dimercaptosuccinic acid (99mTc-DMSA) scintigraphy, 11 underwent somatostatin receptor scintigraphy (SRS) with 99mTc-HYNIC TOC while 11 123I-metaiodobenzylguanidine (MIBG) scintigraphy.

RESULTS

From 67 patients, 35 (52.2%) had true positive 18F-FDG PET/CT findings (TP). Average maximal standardized uptake value (SUVmax) for all TP lesions was 5.01+3.6. In 25 (37.3%) patients findings were true negative (TN). Four (6%) patients had false positive (FP) findings while three (4.5%) were false negative (FN). Thus, sensitivity of the 18F-FDG PET/ CT was 92.11%, specificity 86.21%, positive predictive value 89.74%, negative predictive value 89.29% and accuracy 89.55%. In 27 patients (40%) 18F-FDG PET/CT finding influenced further management of the patient.

CONCLUSIONS

18F-FDG PET/CT has high accuracy in the detection of metastases/recurrences of MTC in patients after thyroidectomy as well as in evaluation and the appropriate choice of the therapy.

Evaluation of the protective effect of edaravone on doxorubicin nephrotoxicity by [99mTc]DMSA renal scintigraphy and biochemical methods

To evaluate the nephroprotective effect of edaravone on doxorubicin-induced nephrotoxicity. In this experimental study, twenty-eight Wistar male rats were used. The rats were separated into 4 groups (n = 7); group І (control), rats were treated with saline (4 ml/kg) and group ІІ (doxorubicin), nephrotoxicity was induced by three doses of 18 mg/kg/i.p. doxorubicin, at a 24-h interval on the 12th, 13th, and 14th days. Group ІІІ (edaravone), rats were treated with edaravone (30 mg/kg/for 14 days), and group ІV (edaravone + doxorubicin), rats were treated with edaravone (30 mg/kg/for 14 days) and doxorubicin were injected (18 mg/kg/for 3 days; at a 24-h interval on the 12th, 13th, and 14th days). On the 15th day of the experiment, technetium-99m-labeled dimercaptosuccinic acid ([^99mTc]DMSA) uptake was obtained in both kidneys and biochemical parameters from serum and kidney tissue were measured. Doxorubicin led to nephrotoxicity through elevation of serum blood urea nitrogen (BUN), creatinine and tumor necrosis factor-α (TNF-α), nitric oxide (NO), and interleukin-6 (IL-6) in kidney tissue and decreased [^99mTc]DMSA uptake level in the kidney when compared with control group (p < 0.01). Pretreatment edaravone significantly decreased BUN and creatinine, also kidney tissue TNF-α, IL-6, NO, and increased [^99mTc]DMSA uptake level compared with the doxorubicin. Edaravone has a significant nephroprotective effect through the attenuation of oxidative stress and inflammatory markers during doxorubicin-induced nephrotoxicity in rats.

Effectiveness of the smoothing filter in pediatric 99mTc-dimercaptosuccinic acid renal scintigraphy

The present study aimed to evaluate whether the use of a smoothing filter would improve the image quality in pediatric ^99mTc-dimercaptosuccinic acid (^99mTc-DMSA) scintigraphy. We retrospectively reviewed 31 kidneys in 16 consecutive pediatric patients aged 10 months to 14 years. The administered dose was calculated using a weight-based method. Two reviewers randomly evaluated the original planar posterior images and smoothing filter image; they assessed image quality and performed defect evaluations. The evaluation of visual image quality yielded significantly better results for the smoothing filter images than for the original images. Although the smoothing filter images were slightly inferior to the original images in terms of edge sharpness, no significant difference was observed in the defect evaluation. We confirmed that ^99mTc-DMSA scintigraphy with a smoothing filter yielded reduced image noise, while maintaining defect evaluation performance and improving image quality.

Development of visual scoring system with Tc-99m DMSA renal scintigraphy to predict the risk of recurrence of symptomatic urinary tract infections in pediatric patients

OBJECTIVE

Vesicoureteral reflux (VUR) is a major risk factor for recurrent symptomatic urinary tract infection (UTI) in pediatric patients. In addition, dimercaptosuccinic acid renal scintigraphy (DMSA) is an important diagnostic modality of VUR. However, the value of DMSA for predicting recurrent pediatric UTI has not been studied. Therefore, we aimed to develop visual scoring system (VSS) with DMSA to predict the risk of recurrence of symptomatic urinary tract infection in pediatric patient under the age of 24 months.

METHODS

Pediatric UTI patients who visited our tertiary hospital emergency department and underwent DMSA for initial work-up from January 2006 to December 2014 were reviewed retrospectively. We developed a VSS with Tc-99m DMSA renal scintigraphy. We compared sensitivity and specificity between VSS with DMSA and other variables in predicting recurrent symptomatic UTI. Laboratory indices for systemic inflammation, abnormal finding on ultrasonography, VUR on voiding cystourethrogram (VCUG), and the VSS with DMSA were considered as variables. In addition, we used Kaplan-Meier estimator analyses and Cox proportional regression analyses to evaluate the predictive value of each variable for the recurrence of symptomatic UTI.

RESULTS

A total of 338 patients were enrolled. During the follow-up period, 42 patients (12.4%) had UTI recurrence. Visual scoring with DMSA resulted in 69.1% sensitivity and 79.4% specificity with an optimal cut-off value of score 2 (AUC = 0.790, p < 0.001). Significant predictive factors associated with recurrent symptomatic UTI were CRP ≥ 67.0 mg/L, VUR on VCUG and VSS with DMSA ≥ score 2. On multivariate analysis, the visual score with DMSA was the only independent prognostic factor for recurrent symptomatic UTI (p < 0.001; adjusted hazard ratio = 7.522; 95% CI = 2.799-20.224).

CONCLUSION

High scores in VSS with DMSA were associated with frequent recurrence and short recurrence periods in pediatric UTI patients. VSS with DMSA can stratify risk of recurrence in pediatric UTI patients.

PATIENT-SPECIFIC DOSIMETRY FOR PEDIATRIC IMAGING OF 99mTc-DIMERCAPTOSUCCINIC ACID WITH GATE MONTE CARLO CODE

In this study, radiation absorbed dose of 99mTc-dimercaptosuccinic acid (DMSA) in critical organs was calculated using Monte Carlo simulation. Ten child patients with genitourinary abnormalities were imaged using a series of planar, SPECT and MRI, after injection with 99mTc-DMSA. Patient-specific organ segmentation was performed on MRI and used as input in GATE. Organs with substantial uptake included kidneys, bladder and liver. The mean organ absorbed dose coefficients (mGy/MBq) were 0.063, 0.058, 0.018, 0.016, 0.013 and 0.010 for the right kidney, left kidney, bones, urinary bladder wall, liver and gonads, respectively. The absorbed dose coefficients in the remainder of the body was 0.012 mGy/MBq. The authors implemented an image-based Monte Carlo method for patient-specific 3D absorbed dose calculation. This study also demonstrates the possibility to obtain patient-specific attenuation map from MRI to be used for the simulations of radiation transport and energy deposition in phantom using Monte Carlo methods.

Interobserver variability for interpretation of DMSA scans in the RIVUR trial

INTRODUCTION

Technetium-99m dimercaptosuccinic acid (DMSA) renal scans are used in the diagnosis of renal scarring. In the Randomized Intervention for Children with Vesicoureteral Reflux (RIVUR) trial that randomized 607 children, DMSA renal scans were used for evaluating the presence and the severity of renal scarring.

OBJECTIVE

The aim was to determine interobserver variability in reporting of DMSA renal scans in the RIVUR trial.

STUDY DESIGN

We compared DMSA renal scan reports for renal scarring and acute pyelonephritis from all non-reference local radiologists (ALRs) at study sites with adjudicated as well as non-adjudicated reports from two reference radiologists (RRs) of the RIVUR trial. Two-way comparisons of concordant and discrepant responses were analyzed using an unweighted kappa statistic between the ALR and the adjudicated RR interpretations. All analyses were performed using SAS v 9.4 (SAS institute 2015) and significance was determined at the 0.05 level.

RESULTS

Of the 2872 kidneys evaluated, adjudicated RR reports had 119 (4%) kidneys with renal scarring compared with 212 (7%) by the ALRs. For 79% kidneys the grading for scarring reported by ALRs was either upgraded (24%) or downgraded (55%) by RRs. For acute pyelonephritis (n = 2924), adjudicated RR reports had 85 (3%) kidneys with pyelonephritis compared with 151 (5%) by the ALRs. For 85% kidneys, the grading for pyelonephritis reported by the ALRs was either upgraded (28%) or downgraded (57%) by the RRs. A three-way comparison revealed that all three (RR1, RR2, and ALR) agreed over presence of renal scarring in 19% cases and two of the three agreed in 80% cases. The respective numbers for pyelonephritis were 13% and 84%. The agreement rate for all DMSA scan reports between the RRs and the ALRs was 93%.

DISCUSSION

The study revealed significant interobserver variability in the reporting of abnormal DMSA renal scans compared with the previously published studies. A noteworthy limitation was a lack of uniformity in local reporting of the scans.

CONCLUSIONS

Our study highlights the need for optimizing the clinical yield of DMSA renal scans by more specific guidelines, particularly for standardized and uniform interpretation.

Technetium-99m-dimercaptosuccinic acid renal scintigraphy can guide clinical management in congenital hydronephrosis

OBJECTIVE

The purpose of this study was to evaluate damage of the kidney with technetium-99m-dimercaptosuccinic acid (^99mTc-DMSA) scintigraphy in children with congenital hydronephrosis (CH) and the influence of other postnatal associated diagnoses on abnormal ^99mTc-DMSA findings.

SUBJECTS AND METHODS

^99mTc-DMSA scintigraphy in 54 children (17 girls and 37 boys), aged from 2 months to 5 years (median 11 months) with 66 congenital hydronephrotic renal units (RU) (42 unilateral hydronephrosis-29 boys and 13 girls; 12 bilateral hydronephrosis-8 boys and 4 girls) was performed. Male/female ratio was 2,2:1, unilateral/bilateral hydronephrosis ratio was 4:1. Hydronephrosis classified into three groups according to ultrasound measurement of the antero-posterior pelvic diameter APD): mild (APD 5-9.9mm) was present in 13/66RU, moderate (APD 10-14.9mm) in 25/66RU, and severe (APD≥15mm) in 28/66RU. Simple hydronephrosis was present in 15RU, and the postnatal associated clinical diagnosis were vesicoureteric reflux (VUR) in 21, pelviureteric junction (PUJ) obstruction in 7, pyelon et ureter duplex in 11, megaureter in 11 and posterior urethra valves in 1RU, respectively. Static renal scintigraphy was performed 2 to 3 hours after intravenous (iv) injection of ^99mTc-DMSA using a dose of 50μCi/kg (1.85MBq/kg; minimal dose: 300μCi). Four views (posterior, left and right posterior oblique and anterior) were obtained with a head gamma camera "Orbiter" filtered with high resolution parallel whole collimator. All images were stored in an Pegasys computer with a matrix size of 256×256. The relative kidney uptake (RKU) between the left and right kidney was calculated as an average number counts from anterior and posterior view. Renal pathology was defined as inhomogenous or focal/multifocal uptake defects of radiopharmaceutical in hydronephrotic kidney or as split renal uptake of <40%, and poor kidney function was defined as split renal uptake <10%. Descriptive and analytical statistics (SPSS version 20.0) was performed. Analytical statistics implied the non-parametric Mann-Whitney test for determination of statistically significant difference between the normal and pathological findings on ^99mTc-DMS scan. The default level of significance was P<.05.

RESULTS

Our ^99mTc-DMSA scintigraphy findings in children with ANH were: decreased or enlarged kidney with inhomogeneous kidney uptake radiopharmaceutical in 22, irregular shape kidney with inhomogeneous accumulation of radiopharmaceutical in 3, connected (fused) kidney in 1 patient, and poorly or nonvisual kidney in 14RU respectively (total 40/66RU with pathological ^99mTc-DMSA finding, 60,6%). Relative accumulation in hydronephrotic kidney was less or equal to 40% in 17RU, less than 10% in 14RU and inhomogeneous radiopharmaceutical uptake with relative accumulation over 40% was detected in 9RU. Regular kidney morphology with homogeneous accumulation of radiopharmaceutical (normal DMSA scintigraphy finding) were found in 26/66RU (39,4%). Statistically significant correlation between the degree of the hydronephrosis (APD) and ^99mTc-DMSA scan findings (P<0.001) and between the degree of the VUR and DMSA scan finding (P=0.002) was established. In our study, other associated diagnosis were not statistically correlated with pathological findings on ^99mTc-DMSA scan due to low number of patients.

CONCLUSION

On the basis of these results (60% pathological findings) we recommend DMSA scintigraphy in the evaluation renal pathology in children with congenital hydronephrosis. Greater number of patients is needed for the estimation of the associated diagnosis (other than VUR) influence on the renal parenchymal damage in children with CH.

Dimercaptosuccinic acid scan challenges in childhood urinary tract infection, vesicoureteral reflux and renal scarring investigation and management

Vesicoureteral reflux (VUR) is a precipitating factor in acute pyelonephritis (APN), and a risk factor for renal scar formation, even if VUR and APN occur independently. There is no scientific evidence on a specific diagnostic evaluation of children after a febrile urinary tract infection (UTI). Based on recent literature and our clinical experience, we reviewed the role of 99mTc dimercaptosuccinic acid (DMSA) renal scan in UTI/VUR imaging. We also reviewed the DMSA challenges and controversies in UTI/VUR management. A DMSA renal scan is the most reliable tool for the establishment of the diagnosis of APN during febrile UTIs acute phase. The "top-down" approach focuses on kidney involvement during UTI rather than on VUR existence, with a goal of diagnosing APN and/or renal dysplasia. Therefore, DMSA is performed before void cysteourethrography (VCUG). Late DMSA scanning should be performed to evaluate the presence of permanent renal scars. DMSA may be considered valuable in the follow-up of children with VUR, in order to detect new renal scarring after breakthrough or recurrent UTIs. An abnormal DMSA scan comprises a risk factor for VUR identification after UTI, for recurrent UTIs, renal damage/scarring, renal function deterioration, and a negative predictive risk factor for VUR improvement and/or spontaneous resolution. An individualized DMSA risk-based dynamic approach may assist physicians on VUR management decisions. DMSA could play an important role in selecting children with UTI/VUR who would benefit from close monitoring and/or early intervention. However, more data are needed for evidence-based guidelines.

Delayed Therapeutic Response Time Predicts Renal Damage in the First Episode of Febrile Urinary Tract Infection

OBJECTIVE

To evaluate the relationship of therapeutic delay time (TDT) and therapeutic response time (TRT) with renal damage in the first episode of febrile urinary tract infection (UTI).

MATERIAL AND METHOD

A prospective study was conducted in 67 children with the first episode of UTI at the Department of Pediatrics, Faculty of Medicine Siriraj Hospital between 2008 and 2010. To assess for renal damage, dimercaptosuccinic acid (DMSA) renal scintigraphy was performed at one and six months after the acute episode.

RESULTS

Abnormal DMSA renal scintigraphy was detected in 20 (29.9%) patients. There was no difference in TDT but TRT was different between the patients with normal and abnormal DMSA renal scintigraphy at p-value 0.001. The area under receiver operating characteristic (ROC) curve for TRT was 0.76 (95% confidence interval (CI) 0.64-0.86) at p-value 0.001. The optimal cut-off value for TRT was 22 hours with sensitivity 80.0% (56.3-94.1) and specificity 63.6% (47.8-77.6). In 50 patients with no vesicoureteral reflux (VUR), there was difference in TRT at p-value 0.002. The area under ROC curve for TRT was 0.82 (95% CI 0.69-0.96) at p-value 0.004. The optimal cut-off value for TRT was 25 hours with sensitivity 88.9% (95% CI 51.7-98.2) and specificity 68.4% (95% CI 51.3- 82.5).

CONCLUSION

TRT at or more than 22 hours predicts renal damage after first episode of UTI. In patients with no VUR, TRT at or more than 25 hours predicts renal damage. DMSA renal scintigraphy in the first episode of UTI should be considered in these patients.

Dimercaptosuccinic acid scan or ultrasound in screening for vesicoureteral reflux among children with urinary tract infections

BACKGROUND

There is considerable interest in detecting vesicoureteral reflux (VUR) because its presence, especially when severe, has been linked to an increased risk of urinary tract infections and renal scarring. Voiding cystourethrography (VCUG), also known as micturating cystourethrography, is the gold standard for the diagnosis of VUR, and the grading of its severity. Because VCUG requires bladder catheterisation and exposes children to radiation, there has been a growing interest in other screening strategies that could identify at-risk children without the risks and discomfort associated with VCUG.

OBJECTIVES

The objective of this review is to evaluate the accuracy of two alternative imaging tests - the dimercaptosuccinic acid renal scan (DMSA) and renal-bladder ultrasound (RBUS) - in diagnosing VUR and high-grade VUR (Grade III-V VUR).

SEARCH METHODS

We searched MEDLINE, EMBASE, BIOSIS, and the Cochrane Register of Diagnostic Test Accuracy Studies from 1985 to 31 March 2016. The reference lists of relevant review articles were searched to identify additional studies not found through the electronic search.

SELECTION CRITERIA

We considered published cross-sectional or cohort studies that compared the results of the index tests (DMSA scan or RBUS) with the results of radiographic VCUG in children less than 19 years of age with a culture-confirmed urinary tract infection.

DATA COLLECTION AND ANALYSIS

Two authors independently applied the selection criteria to all citations and independently abstracted data. We used the bivariate model to calculate summary sensitivity and specificity values.

MAIN RESULTS

A total of 42 studies met our inclusion criteria. Twenty studies reported data on the test performance of RBUS in detecting VUR; the summary sensitivity and specificity estimates were 0.44 (95% CI 0.34 to 0.54) and 0.78 (95% CI 0.68 to 0.86), respectively. A total of 11 studies reported data on the test performance of RBUS in detecting high-grade VUR; the summary sensitivity and specificity estimates were 0.59 (95% CI 0.45 to 0.72) and 0.79 (95% CI 0.65 to 0.87), respectively. A total of 19 studies reported data on the test performance of DMSA in detecting VUR; the summary sensitivity and specificity estimates were 0.75 (95% CI 0.67 to 0.81) and 0.48 (95% CI 0.38 to 0.57), respectively. A total of 10 studies reported data on the accuracy of DMSA in detecting high-grade VUR. The summary sensitivity and specificity estimates were 0.93 (95% CI 0.77 to 0.98) and 0.44 (95% CI 0.33 to 0.56), respectively.

AUTHORS' CONCLUSIONS

Neither the renal ultrasound nor the DMSA scan is accurate enough to detect VUR (of all grades). Although a child with a negative DMSA test has an < 1% probability of having high-grade VUR, performing a screening DMSA will result in a large number of children falsely labelled as being at risk for high-grade VUR. Accordingly, the usefulness of the DMSA as a screening test for high-grade VUR should be questioned.

Usefulness of analytical parameters in the management of paediatric patients with suspicion of acute pyelonephritis. Is procalcitonin reliable?

OBJECTIVE

To investigate the usefulness of procalcitonin (PCT) and other analytical parameters (white blood cell count [WBC], C-reactive protein [CRP]) as markers of acute renal damage in children after a first febrile or afebrile urinary tract infection (UTI).

METHODS

A retrospective study was conducted on children with a first episode of UTI admitted between January 2009 to December 2011, and in whom serum PCT, CRP and white blood cell count were measured, as well as assessing the acute renal damage with renal scintigraphy with ^99mTc-DMSA (DMSA) within the first 72h after referral. A descriptive study was performed and ROC curves were plotted, with optimal cut-off points calculated for each parameter.

RESULTS

The 101 enrolled patients were divided into two groups according to DMSA scintigraphy results, with 64 patients being classified with acute pyelonephritis (APN), and 37 with UTI. The mean WBC, CRP and PCT values were significantly higher in patients with APN with respect to normal acute DMSA. The area under the ROC curve was 0.862 for PCR, 0.774 for WBC, and 0.731 for PCT. The optimum statistical cut-off value for PCT was 0.285ng/ml (sensitivity 71.4% and specificity 75%).

CONCLUSION

Although the mean levels of fever, WBC, CRP, and PCT were significantly increased in patients with APN than in those who had UTI, the sensitivity and specificity of these analytical parameters are unable to predict the existence of acute renal damage, making the contribution by renal DMSA scintigraphy essential.

Prediction of High-grade Vesicoureteral Reflux in Children Younger Than 2 Years Using Renal Sonography

OBJECTIVES

To investigate the predictive value of renal sonography for vesicoureteral reflux (VUR) and the efficacy of renal sonography, technetium Tc 99m–labeled dimercaptosuccinic acid (DMSA) scanning, and a combination of the two for VUR screening in children younger than 2 years with a first episode of febrile urinary tract infection.

METHODS

Thirty-eight patients younger than 2 years with a first febrile urinary tract infection were included in our study, which was conducted from April through October 2014. Each kidney was considered a separate renal unit. A retrospective review of clinical information and images (renal sonography, DMSA scanning, and voiding cystourethrography) was performed.

RESULTS

Of the 14 renal units (18.4%) with VUR, 4 (28.5%) had high-grade VUR. Among single findings, dilatation of the renal collecting system, wall thickening of the renal collecting system, and DMSA scans significantly predicted VUR (P= .038, .027, and .01, respectively). Dilatation was the most common single finding (46 of 76 renal units). The sensitivity values for dilatation, wall thickening, and DMSA scans were 85.7%, 64.2%, and 50.0%, and the negative predictive values were 93.3%, 89.7%, and 87.9%.

CONCLUSIONS

The negative predictive values indicate that normal renal sonographic and DMSA findings can predict the absence of high-grade VUR. We propose that renal sonographic findings of wall thickening as well as dilatation of the renal collecting system should be considered predictive of high-grade VUR.

Prediction of Cortical Defect Using C-Reactive Protein and Urine Sodium to Potassium Ratio in Infants with Febrile Urinary Tract Infection

PURPOSE

We investigated whether C-reactive protein (CRP) levels, urine protein-creatinine ratio (uProt/Cr), and urine electrolytes can be useful for discriminating acute pyelonephritis (APN) from other febrile illnesses or the presence of a cortical defect on 99mTc dimercaptosuccinic acid (DMSA) scanning (true APN) from its absence in infants with febrile urinary tract infection (UTI).

MATERIALS AND METHODS

We examined 150 infants experiencing their first febrile UTI and 100 controls with other febrile illnesses consecutively admitted to our hospital from January 2010 to December 2012. Blood (CRP, electrolytes, Cr) and urine tests [uProt/Cr, electrolytes, and sodium-potassium ratio (uNa/K)] were performed upon admission. All infants with UTI underwent DMSA scans during admission. All data were compared between infants with UTI and controls and between infants with or without a cortical defect on DMSA scans. Using multiple logistic regression analysis, the ability of the parameters to predict true APN was analyzed.

RESULTS

CRP levels and uProt/Cr were significantly higher in infants with true APN than in controls. uNa levels and uNa/K were significantly lower in infants with true APN than in controls. CRP levels and uNa/K were relevant factors for predicting true APN. The method using CRP levels, u-Prot/Cr, u-Na levels, and uNa/K had a sensitivity of 94%, specificity of 65%, positive predictive value of 60%, and negative predictive value of 95% for predicting true APN.

CONCLUSION

We conclude that these parameters are useful for discriminating APN from other febrile illnesses or discriminating true APN in infants with febrile UTI.

Comparison of renal ultrasonography and dimercaptosuccinic acid renal scintigraphy in febrile urinary tract infection

Accurate and early diagnosis and appropriate treatment of patient with urinary tract infection (UTI) are essential for the prevention or restriction of permanent damage to the kidneys in children. The aim of this study was to compare renal ultrasonography (US) and dimercaptosuccinic acid (DMSA) renal scan in the diagnosis of patients with febrile urinary tract infection. This study involved the medical records of children with febrile urinary tract infection who were admitted to the children's hospital in Qazvin, Iran. Pyelonephritis was diagnosed on the basis of clinical symptoms, laboratory tests and abnormal DMSA renal scans. The criteria for abnormality of renal US were an increase or a decrease in diffuse or focal parenchymal echogenicity, loss of corticomedullary differentiation, kidney position irregularities, parenchymal reduction and increased kidney size. Of the 100 study patients, 23% had an abnormal US and 46% had an abnormal DMSA renal scan. Of the latter patients, 15 had concurrent abnormal US (P value ≤ 0.03, concordance rate: 18%). Renal US had a sensitivity of 32%, specificity of 85%, positive predictive value of 65% and negative predictive value of 60%. Of the 77 patients with normal US, 31 (40.2%) had an abnormal DMSA renal scan. Despite the benefits and accessibility of renal US, its value in the diagnosis of pyelonephritis is limited.

Follow-up (99m)Tc EC renal dynamic scintigraphy and DMSA-III SPECT/CT in unmasking a masqueraded case of Horseshoe kidney

Hydronephrosis is a common finding in urinary tract outflow obstruction. Chronically obstructed hydronephrotic system may be associated with parenchymal changes. Ultrasound, intravenous urography, micturating cysto-urethrogram and scintigraphy are commonly performed to evaluate the cause of obstruction. In childhood, pelviureteric junction obstruction is a common cause of the hydronephrosis. Hydronephrosis can also be present in horseshoe kidneys due to poor drainage. However, a large sized hydronephrotic cavity may obscure the finding of horseshoe kidney. A case was reported, and it was diagnosed as horseshoe kidney on follow-up renal dynamic scan and confirmed with the help of dimercaptosuccinic acid SPECT/CT.

Urodynamic disorders and renal scarring in pediatric patients with nonmonosymptomatic nocturnal enuresis

BACKGROUND/AIM

In nonmonosymptomatic nocturnal enuresis (NMNE), the incidence of organic abnormality and urodynamic disorder is more frequent than the general population. The aim of this study is to identify urodynamic disorders and renal scarring in children with NMNE.

MATERIALS AND METHODS

This study evaluated the urodynamic disorders and renal scarring of a total of 30 patients who were diagnosed with NMNE. A video-urodynamic test and Tc-99m dimercaptosuccinic acid renal scintigraphy were applied.

RESULTS

Records of 605 patients who had been diagnosed with enuresis were analyzed, and 215 (33.5%) of them had been diagnosed with NMNE. Thirty patients older than 6 years old with NMNE were included in the study. Detrusor overactivity was identified in 10 patients. Bladder capacity was low in 5 patients and bladder compliance was low in 2 patients. Renal scarring was identified in 1 patient. Unilateral vesicoureteral reflux was found in 4 patients.

CONCLUSION

Bladder function disorder is also a significant risk factor for the development of renal scarring, besides other risk factors. Organic abnormalities are seen more often in patients with NMNE than patients with monosymptomatic nocturnal enuresis, so urodynamic studies should be remembered for patients with NMNE.

Recurrent urinary tract infections in young children: role of DMSA scintigraphy in detecting vesicoureteric reflux

BACKGROUND

Performing micturiting cystourethrography (MCUG) in young children with recurrent urinary tract infections is controversial with discrepancy among the major guidelines.

OBJECTIVE

Previous studies have shown that a normal dimercaptosuccinic acid (DMSA) scintigraphy may avoid the need of performing MCUG for detecting vesicoureteric reflux in children with first febrile urinary tract infection. However, the role of DMSA for ruling out vesicoureteric reflux in children with recurrent urinary tract infections has not been studied.

MATERIALS AND METHODS

Approval from institutional ethical review committee was sought and the requirement of informed consent was waived. A total of 50 children under the age of 10 years with recurrent urinary tract infections underwent MCUG scan within 3 months of DMSA scan from January 2011 to September 2012 at our institution. Diagnosis of recurrent urinary tract infections and grading of vesicoureteric reflux was according to previously established standards. Abnormalities on DMSA scan - scarring, hydronephrosis and reduced differential renal function - were compared with presence of vesicoureteric reflux on MCUG.

RESULTS

High-grade vesicoureteric reflux was noted on MCUG in 22 (44%) cases. The findings on DMSA included hydronephrosis and scarring in 25 (50%) and 25 (50%) cases, respectively. Abnormalities on DMSA scan for detecting the presence of high-grade vesicoureteric reflux on MCUG examination had sensitivity, specificity, positive and negative predictive values of 95.45%, 35.71%, 53.85% and 90.91%, respectively. The positive and negative likelihood ratios were 1.48 and 0.13 respectively.

CONCLUSION

DMSA scan had high overall sensitivity and negative predictive value with a low negative likelihood ratio for ruling out high-grade vesicoureteric reflux on MCUG, which may obviate the need of invasive MCUG along with its associated drawbacks.

Correlation between serum level of fibroblast growth factor 2 and severity of reflux nephropathy

INTRODUCTION

Fibroblast growth factor 2 (FGF2) is a potent mitogenic factor of cortical fibroblasts and induces kidney fibrosis. We hypothesized that serum levels of FGF2 has an association with the severity of vesicoureteral reflux (VUR) and renal parenchymal scar.

MATERIALS AND METHODS

Between 2007 and 2009, a total of 28 children with VUR were enrolled in this study and were compared with 52 healthy children. All children with VUR underwent technetium Tc 99m dimercaptosuccinic acid renal scintigraphy. Fibroblast growth factor 2 was measured in both groups.

RESULTS

The mean level of FGF2 was 65.0 ± 19.0 pg/mL in the VUR group and 62.5 ± 15.3 pg/mL in the control group (P > .05). There was no correlation between serum levels of FGF2 and sex, age, or the grade of VUR. Of the 28 children with VUR, 19 had renal parenchymal scar on dimercaptosuccinic acid renal scintigraphy. The mean serum level of FGF2 was not significantly different in the children with and without renal parenchymal scar.

CONCLUSIONS

This study showed no correlation between serum FGF2 and renal parenchymal scar or grade of VUR.

Use of a ray-based reconstruction algorithm to accurately quantify preclinical microSPECT images

This work aimed to measure the in vivo quantification errors obtained when ray-based iterative reconstruction is used in micro-single-photon emission computed tomography (SPECT). This was investigated with an extensive phantom-based evaluation and two typical in vivo studies using 99mTc and 111In, measured on a commercially available cadmium zinc telluride (CZT)-based small-animal scanner. Iterative reconstruction was implemented on the GPU using ray tracing, including (1) scatter correction, (2) computed tomography-based attenuation correction, (3) resolution recovery, and (4) edge-preserving smoothing. It was validated using a National Electrical Manufacturers Association (NEMA) phantom. The in vivo quantification error was determined for two radiotracers: [99mTc]DMSA in naive mice (n  =  10 kidneys) and [111In]octreotide in mice (n  =  6) inoculated with a xenograft neuroendocrine tumor (NCI-H727). The measured energy resolution is 5.3% for 140.51 keV (99mTc), 4.8% for 171.30 keV, and 3.3% for 245.39 keV (111In). For 99mTc, an uncorrected quantification error of 28 ± 3% is reduced to 8 ± 3%. For 111In, the error reduces from 26 ± 14% to 6 ± 22%. The in vivo error obtained with 99mTc-dimercaptosuccinic acid ([99mTc]DMSA) is reduced from 16.2 ± 2.8% to -0.3 ± 2.1% and from 16.7 ± 10.1% to 2.2 ± 10.6% with [111In]octreotide. Absolute quantitative in vivo SPECT is possible without explicit system matrix measurements. An absolute in vivo quantification error smaller than 5% was achieved and exemplified for both [99mTc]DMSA and [111In]octreotide.

Urinoma secondary to ureteropelvic junction obstruction in the neonate. Presentation of a case and bibliographic review

OBJECTIVE

To analyze the management of prenatal urinoma and ureteropelvic junction obstruction (UPJO) postnatally by a case report and literature review.

METHODS

We report a case of an UPJO and urinoma in a newborn. After birth, renal function was absent, and nephrectomy was performed. The literature from 1985 to date has been reviewed.

DISCUSSION

By the analysis of the literature, we can observe mainly, that prenatally diagnosed urinoma and UPJO are managed conservatively. After birth, different attitudes have been carried out, independently of residual renal function, such as radical or reconstructive surgery, or conservative treatment.

CONCLUSION

Intrauterine management is not indicated. Urinary diversion is indicated in symptomatic cases secondary to renal trauma or endoscopic procedure. In non-functional kidney, nephrectomy is indicated.

Scintigraphic features of duplex kidneys on DMSA renal cortical scans

The spectrum of manifestations of duplex kidneys on (99m)Tc-dimercaptosuccinic acid (DMSA) renal cortical scans and correlating findings on other imaging modalities are presented. Relevant embryology of the duplex systems and technical aspects of DMSA scintigraphy are reviewed.

Scintigraphy with 99mTc(V)-DMSA in monitoring patients with inflammatory bowel disease

The clinical significance of pentavalent technetium-99m dimercaptosuccinic acid (99mTc(V)-DMSA) scintigraphy in diagnosing inflammatory bowel disease (IBD) has not yet been fully elucidated. The aim of this prospective paper was to study the above. This study included 54 patients, 22 females and 32 males (mean age: 36.68±11.49; range: 18-63 years) with IBD who came to our clinics for follow-up and were examined clinically by colonoscopy and 99mTc(V)-DMSA scintigraphy. On the follow-up studies, five patients (9.25%) relapsed, and 49 (90.74%) remained at a steady condition. There was a good correlation between the scintigraphic results and the clinical and colonoscopy data of the patients (P<0.05). In conclusion, our results indicated that 99mTc(V)DMSA scintigraphy can be complementary to colonoscopy for the diagnostic evaluation of IBD.

Predisposing factors for renal scarring in children with urinary tract infection

This study was undertaken to determine the predisposing factors for renal scarring in children with urinary tract infection. In this prospective cohort study, 176 children with documented urinary tract infection were categorized into four groups: ≤1 year old, 1-2 years old, 2-7 years and 7-14 years old. Ultrasonography and Technetium-99 m-DMSA scan were used to detect the possible abnormalities. Infants under 12 months old presented as the most common group for renal scarring (27 cases, 52.9%), and vesicoureteral reflux (VUR) was diagnosed in 29 cases (56.8%). Fifteen (41.67%) children between the ages of one and two years had renal scar, and VUR was detected in half of the patients. In the third group, 36.3%, and in fourth group, 41.6% of the patients had renal scar. Also, 38.6% in group three and 50% in the final group had VUR. A co-incidental finding that was observed in this study was the high incidence of pseudohypoaldesteronism (PHA) in our patients: in 39.2% of the children in group one, 22.2% in group two and 4% in group three. In group four however, none of the patients had PHA. Risk of scar formation with urinary tract infection (UTI) was higher in the younger age group and in those with recurrent UTIs.

Is a routine voiding cystourethrogram necessary in children after the first febrile urinary tract infection?

AIM

The aim of this study was to estimate the value of identifying vesicoureteral reflux (VUR) on a voiding cystourethrogram (VCUG) and the benefit of VUR management according to imaging strategies at the first febrile urinary tract infection (UTI).

METHODS

Children aged 1-144 months (n = 618) with the first febrile UTI admitted at our hospital from 2000 to 2009 were enrolled. In all patients, renal sonogram (US), (99m) Tc-dimercaptosuccinic acid (DMSA) renal scanning and VCUG were performed. Retrospective analyses per patient and per renal unit were performed.

RESULTS

Abnormal US or DMSA scans had a sensitivity of 100% and a negative predictive value (NPV) of 100% to detect high-grade reflux. In hydronephrotic kidneys, DMSA scanning had a sensitivity of 88.2% and a NPV of 97.1% to detect high-grade reflux.

CONCLUSION

Routine VCUG is not required after the first febrile UTI in patients with normal US or normal DMSA scan. Even if the US reveals hydronephrosis, routine VCUG is not necessary if the DMSA findings are normal. It is recommended that children who did not receive both a DMSA scan and VCUG after the first febrile UTI should be followed up over the long term.

[Partial elective nephrectomy]

INTRODUCTION

Partial nephrectomy is widely accepted as a therapeutic modality in renal cell carcinoma (RCC) in patients with single kidney, bilateral tumor or deteriorated renal function. Currently, long-term survival studies have consolidated partial nephrectomy as the treatment of choice for RCC in selected patients with normal contralateral kidney.

MATERIAL AND METHODS

Between July 1990 and January 2008, a total of 102 partial nephrectomy were performed on 100 patients with pre-operative ultrasonography diagnosis of renal carcinoma in 94 cases and complex renal cysts in 6 cases. The pre-operative ultrasonography size varied from 1.5 to 10 cm with an average of 4.85 cm.

RESULTS

Tumor size was correlated with the pathological stage, finding tumors in stage pT1 with sizes less than and greater than 4 cm in 74% and 64%, respectively, and in stage pT2 of 3.7% and 5.4%. Tumor size measured by pre-operative CT scan was compared with the definitive size of the pathology specimen in 93 cases (56<4 cm and 37>4 cm, according to the CT scan). We found high concordance, however in the larger tumors, there was a tendency of the CT scan to overestimate the size. A post-operative gamma scintigraphy with DMSA was performed in 40 patients. The values in the tumors <4 cm (21 patients) were 12-77% (average 43.3%). In tumors between 4 and 7 cm (17 patients), the values were 13.8-53.3% (average 37.6%) and in 2 cases of tumors >7 cm the post-operative DMSA showed 47.5 and 51%.

CONCLUSIONS

Partial nephrectomy is currently accepted as elective treatment in incidental kidney tumors less than 4 cm and it is indicated increasingly more frequently in larger tumors and of central localization. The finding of benign pathology in the anatomic-pathology specimen in up to 20% of the incidental renal tumors and low potential of malignancy of the possible satellite lesions in the remnant kidney also support nephron-sparing surgery in these tumors.

Risk factors of renal scars in children with acute pyelonephritis

OBJECTIVE

The aim of this study was to determine the association between previously documented risk factors such as recurrent pyelonephritis with the incidence of renal scarring after acute pyelonephritis in children.

MATERIAL AND METHODS

Children with acute pyelonephritis who were admitted to the Department of Pediatrics of a teaching hospital during 2007-2009 were enrolled in this study. DMSA scans were obtained 4-6 months after the last episode of pyelonephritis in all patients.

RESULTS

A total of 80 children with acute pyelonephritis were enrolled in this study. Most of them were girls (77.5%), with a median age of 12 months. Nearly half of the children (n = 44; 55%) had one or more renal scars. The distribution of gender, CRP level and leukocytosis did not differ significantly regarding the absence or presence of renal scars (p > 0.05). Most of the scars occurred in children who had presented with bilateral pyelonephritis (69.4% vs. 18.2%, p = 0.001). Most of the patients with renal scars had a positive history of vesicoureteral reflux (VUR) (75% vs.13.6%, p = 0.001). The significant roles of recurrent pyelonephritis and presence of VUR were further confirmed by multivariate analysis.

CONCLUSIONS

According to our findings, presence of VUR and recurrent pyelonephritis are independently associated with a higher incidence of renal scarring.

Doppler ultrasonography as a predictive tool for permanent kidney damage following acute pyelonephritis: comparison with dimercaptosuccinic acid scintigraphy

INTRODUCTION

The aim of this study was to investigate power Doppler ultrasonography for diagnosis and prediction of scarring compared with technetium Tc 99m dimercaptosuccinic acid scintigraphy in acute pyelonephritis.

MATERIALS AND METHODS

Sixty-six children, aged 2 months to 6 years old, admitted with clinical and biological signs of their first febrile urinary tract infection were studied. All of the children underwent PDU and technetium Tc 99m dimercaptosuccinic acid scintigraphy within 7 days after diagnosis and repeat scintigraphy at least 6 months later, if results of the first study were abnormal. Scintigraphic and Doppler studies were interpreted and compared.

RESULTS

Dimercaptosuccinic acid scintigraphy demonstrated scar in 7.6% of renal units, 3.1% of patients without reflux and 66.7% of those with high-grade reflux. Kidneys with permanent kidney damage had a mean resistive index (RI) of 0.71 ± 0.06, while the RI value for nonscarred kidneys was 0.66 ± 0.06 (P = .02). The best cutoff point of RI value was 0.715, with a sensitivity of 70%, a specificity of 87.7%, and positive and negative predictive values of 32% and 97%, respectively. These values significantly increased when grey-scale ultrasonography findings were brought into account. Reflux was observed in 19.7% of renal units, which were associated with significantly higher RI values (P = .05).

CONCLUSIONS

Power Doppler ultrasonography with a cutoff value of 0.715 has a reasonable sensitivity and specificity for prediction of renal scarring in young children with febrile urinary tract infection.

Role of vitamin A in preventing renal scarring after acute pyelonephritis

INTRODUCTION

The role of vitamin A in re-epithelialization of the damaged mucosal surfaces has been documented. The aim of this study was to evaluate the role of vitamin A in preventing renal scaring after acute pyelonephritis in children.

MATERIALS AND METHODS

This clinical trial study was conducted in children with acute pyelonephritis in Mofid Children Hospital (Tehran, Iran). Patients were randomly divided into two groups to receive ceftriaxone and vitamin A or ceftriaxone only. Dimercaptosuccinic acid (DMSA) renal scintigraphy was performed before the start of the treatment and 6 months later. Results were compared for renal scaring between the two groups.

RESULTS

Seventy-six patients (11 boys and 65 girls) were enrolled. The mean age was 25 ± 24 months and 54 patients (71.1%) were under 2 years old. The average vitamin A level was 71 ± 24 microg/dL in the treatment group and it was 62 ± 18 µg/dL in the control group. Baseline DMSA scans were comparable between the two groups in terms of scarring (P = .53), but the second DMSA scans showed a significant change in progression of the renal injury and scaring in the control group compared to those treated with vitamin A as well as antibiotic (P < .001).

CONCLUSIONS

We found administration of the vitamin A was useful in decreasing the amount of the injury and scarring following the pyelonephritis. Based on our study, vitamin A can be used in conjunction with other treatments in the management of acute pyelonephritis in children.

(99m)Tc-DMSA scintigraphy diagnosing crossed renal ectopia with fusion in a three years old boy

A 3 years old boy with a history of surgery for orchidopexy was admitted to our hospital with fever and abdominal pain. Clinical examination and laboratory investigations revealed urinary tract infection with renal involvement. Ultrasonography demonstrated a solitary left kidney and raised the suspicion of a fusion anomaly. Voiding cystography disclosed grade III vesicoureteral reflux and technetium-99m dimercaptosuccinic acid scintigraphy revealed right to left crossed renal ectopia with fusion (L-shaped kidney). The patient is undergoing standard follow-up for the early detection of possible renal complications. In conclusion, L-shaped kidney is a rare entity and the (99m)Tc-DMSA scintigraphy played an important role on timely diagnosis.