Vesicoureteral reflux in male and female neonates as detected by voiding ultrasonography.
BACKGROUND: Vesicoureteral reflux (VUR) is assumed to be congenital, and its early diagnosis is desired in order to prevent acquired renal damage. However, the incidence of VUR in neonates remains to be revealed. METHODS: Two thousand newborn babies (1048 boys and 952 girls) underwent voiding ultrasonography (an ultrasound examination of urinary tract during provoked voiding). Those who showed transient renal pelvic dilation during voiding, who had small kidneys, or who subsequently developed urinary infection underwent voiding cystourethrography. RESULTS: Transient renal pelvic dilation was observed in 16 babies (0.8%), including one boy with small kidneys. Among the rest of the babies, one boy had a small kidney, and nine babies subsequently developed urinary infection. Voiding cystourethrography revealed VUR in 24 ureters of 16 children (11 boys and 5 girls). Dimercaptosuccinate renoscintigraphy confirmed small kidneys, with generally reduced tracer uptake in a total of three boys, all having VUR. Voiding ultrasonography detected transient renal pelvic dilation in 17 (71%) of the 24 kidneys with VUR and, strikingly, 16 of the 17 (94%) kidneys with high-grade VUR (grade III or more). CONCLUSION: This study effectively detected VUR in 0.8% of the neonates (mostly of high grades and predominantly in males) and voiding ultrasonography showed a decided usefulness for the detection of VUR. The male preponderance of VUR in neonates was considered to be due to the occurrence of congenitally small kidneys, with reflux found exclusively in males and easier ultrasound detection of VUR in male neonates because the majority of diagnoses are reported to be high grades of VUR. (+info)
Quantitative 99mTc-DMSA uptake in experimental pyelonephritis.
Quantitative 99mTc-dimercaptosuccinic acid (DMSA) renal uptake was studied in unilateral reflux-related pyelonephritis in pigs. The changes to absolute % dose uptake and differential uptake occurring with induction and after treatment of pyelonephritis were correlated with the DMSA images and renal pathology. METHODS: Quantitative uptake in 53 young pigs was obtained from planar images acquired 6 h after injecting the dose. Baseline studies were made (Q1), and studies were made again after urinary infection was established (Q2), when 8 pigs had normal (no defect) renal images (group A), 23 had photon-deficient (reversible) focal defects (group B) and 22 had photon absent (irreversible) focal defects (group C). Q3 studies were made in 21 animals from groups B and C after 3-wk antimicrobial treatment. RESULTS: At Q2 the affected kidney differential uptake was unchanged for group A and reduced for groups B and C (respective mean changes -1.7%, P < 0.01; and -5.5%, P < 0.01). The absolute % dose uptake was unchanged in pyelonephritic kidneys, but increased in the contralateral nondiseased kidneys in groups B and C (respective mean increases +1.4%, P < 0.05; and +5.4%, P < 0.01), while remaining unchanged for group A. In group C, global renal accumulation was actually increased above the Q1 values. After treatment (Q3) the reduced pyelonephritic kidney differential uptake persisted in groups B and C. In group C, however, the increased absolute % dose uptake by the contralateral kidney was less marked and not significantly different from Q1 values in this small group. CONCLUSION: Induction of unilateral pyelonephritis produced a small reduction in diseased kidney differential uptake that was greatest in the group with irreversible imaging defects. The method did not discriminate individuals with reversible and irreversible imaging defects. The decrease in pyelonephritic kidney differential uptake resulted from increased DMSA accumulation (absolute % dose uptake) by the nondiseased contralateral kidney, while that in pyelonephritic kidneys remained unchanged. After treatment, the reduced pyelonephritic kidney differential uptake persisted, but the elevated global DMSA accumulation seen for group C (with irreversible imaging defects) was not sustained and was variable. (+info)
Improved renal cortical SPECT of neonates and young infants using narrow imaging pallets.
OBJECTIVE: The widths of most commercially-made imaging pallets limit the resolution of 99mTc DMSA SPECT imaging in neonates and young infants. We constructed a pediatric imaging pallet for 99mTc DMSA SPECT of neonates and young infants designed to allow close apposition of the camera to these patients during the entire orbit. METHODS: We designed the imaging pallet to replace the standard removable pallet on the imaging stand of a commercial gamma camera. The device consisted of two parts: a steel bracket attached to the imaging stand and a polyvinyl chloride imaging pallet. The imaging pallet consisted of interchangeable 15.24-cm (6-in) or 20.32-cm (8-in) diameter, 6.35-mm (1/4-in) thick polyvinyl chloride plumbing pipes cut in half lengthwise. RESULTS: The pallets were mechanically stable with loads 3 times that expected in clinical practice. Attenuation was acceptable and comparable to commercial pallets. The hemicylindrical shape provided side support and reduced patient motion, as well as allowing closer apposition of the camera head to the patient. The quality of these 99mTc DMSA SPECT images compared favorably with those obtainable in older children and adults. Specifically, the renal cortices were well delineated from the collecting systems and anatomic detail of normal cortex could be readily distinguished from abnormal cortex. CONCLUSION: Custom pediatric imaging pallets optimized for use in neonates and small children can be constructed inexpensively. These pallets are easy to use and are stable. Use of these pallets can optimize 99mTc DMSA SPECT images of neonates and young infants. (+info)
Quantitative SPECT of 99mTc-DMSA uptake in kidneys of infants with unilateral ureteropelvic junction obstruction: assessment of structural and functional abnormalities.
We evaluated individual renal function using quantitative SPECT of dimercaptosuccinic acid (DMSA) uptake by the kidneys (QDMSA) in infants with unilateral ureteropelvic junction (UPJ) obstruction and compared our findings with infants without obstruction. METHODS: QDMSA was performed on 13 infants (mean age of 2.8 +/- 2.8 mo) with unilateral UPJ obstruction and on 15 age-matched controls without obstruction. RESULTS: Control kidneys (n = 30) had a volume of 43.5 +/- 8.8 mL, a percentage injected dose (%ID)/mL 0.62 +/- 0.12 and uptake of 26.1% +/- 3.9%. Kidneys with UPJ obstruction (n = 13) had a volume of 61.2 +/- 19.3 mL, a %ID/mL of 0.42 +/- 0.11 and uptake of 25.4% +/- 8.2%. Contralateral kidneys (n = 13) had a volume of 44.0 +/- 11.9 mL, a %ID/mL of 0.57 +/- 0.16 and uptake of 24.2% +/- 4.6%. The uptake in obstructed kidneys was similar to that observed in contralateral and control kidneys (t = -0.77, P = 0.45; t = -0.37, P = 0.71; respectively). UPJ kidneys had a statistically significant increased volume and decreased %ID/mL, compared with contralateral kidneys (t = 3.35, P < 0.006 and t = 3.75, P < 0.003, respectively) and control kidneys (t = -4.2, P < 0.001 and t = 4.7, P < 0.001, respectively). There was no significant difference between contralateral kidneys and control kidneys regarding volume (t = -0.16, P = 0.87), %ID/mL (t = 0.98, P = 0.33) and uptake (t = -1.41, P = 0.16). Of 13 infants, 11 (85%) showed large kidneys with thinning of the renal cortex. In 1 infant, there was no difference between the obstructed and contralateral kidneys regarding volume, %ID/mL and uptake, and 1 infant showed significant decreased uptake in the UPJ kidney compared with the contralateral kidney. CONCLUSION: Although the overall renal function of the obstructed kidneys remained unchanged, there was a statistically significant decrease in the %ID/mL of renal tissue in UPJ kidneys, which may represent renal dysfunction. Increased functional volume with a thin cortex may represent a compensatory mechanism of the obstructed kidney. Such changes may contribute to the understanding of pathophysiologic mechanisms and may be an early sign of obstruction in infants with hydronephrosis. Further longitudinal studies with an extended number of infants and serial measurements of kidney volumes and %ID/mL are warranted to assess the significance of QDMSA in the management of infants with asymptomatic unilateral renal pelvic dilatation. (+info)
Increased urine interleukin-6 concentrations correlate with pyelonephritic changes on 99mTc-dimercaptosuccinic acid scans in neonates with urinary tract infections.
Interleukin (IL)-6 and -8 are important inflammatory cytokines in bacterial infections. Their serum and urine concentrations were measured in 27 neonates with urinary tract infection (UTI) at onset and the second week of therapy, as well as in 23 control neonates. Escherichia coli was isolated in 89% of cases. 99mTc-dimercaptosuccinic acid (99mTc-DMSA) scans were performed between the 10th and 90th days after UTI and showed pyelonephritic changes in 15 neonates (56%). Increased IL-6 and IL-8 concentrations were found in urine but not in serum within the first 24 h after presumptive diagnosis of UTI (P=.036 and.010, respectively), suggesting that the neonatal urinary tract can respond to uropathogens by producing inflammatory cytokines. Urine concentrations of IL-6 correlated with findings of renal changes in 99mTc-DMSA scans (P=.012) and thus may serve as a marker of renal parenchymal outcome. All neonates exhibited undetectable urine cytokine levels during the second week of therapy. (+info)
Renal function after tumor enucleation: assessment by quantitative SPECT of 99mTc-dimercaptosuccinic acid uptake by the kidneys.
The purpose of this study was to evaluate the amount of functioning renal mass removed and the amount of remaining individual renal function after tumor enucleation. METHODS: Renal functional volume, percentage injected dose (%ID) per cubic centimeter of renal tissue and individual renal uptake of 24 operated and 24 contralateral kidneys were studied by two sequential SPECT quantitations of 99mTc-dimercaptosuccinic acid (DMSA) uptake by the kidneys (QDMSA). The first study was before surgery and the second study was 1 to 6 mo (mean 3.5 mo) after surgery. Mean tumor size was 3.4 +/- 0.99 cm and all tumors were confined to the renal parenchyma (stages pT1 and pT2). RESULTS: In the operated kidneys, there was a statistically significant decrease in renal cortical volume (170 +/- 46 mL after surgery versus 207 +/- 45 mL before surgery, t = 6.2, P < 0.001) and individual renal uptake (10.3% +/- 3.0% after surgery versus 13.0% +/- 2.9% before surgery, t = 5.4, P < 0.001). There was no statistically significant change after surgery compared with before surgery in the %ID per cubic centimeter of renal tissue of the operated kidneys, and in the volume, %ID per cubic centimeter and uptake of the contralateral normal kidneys. CONCLUSION: The results suggest that QDMSA is a noninvasive method able to assess changes in separate renal function. The limited functioning parenchymal loss after tumor enucleation had no effect on the opposite kidneys. (+info)
Relative 99mTc-MAG3 renal uptake: reproducibility and accuracy.
The aim of this study was to estimate the reproducibility and accuracy of 99mTc-mercaptoacetyltriglycine (MAG3) relative percentage uptake. METHODS: Reproducibility was evaluated on healthy volunteers who were submitted twice to a 99mTc-MAG3 renographic study, which used different uptake algorithms, different background corrections and different time intervals. Accuracy was evaluated in a group of patients with symmetrical or asymmetrical relative renal function, who underwent both 99mTc-dimercaptosuccinic acid (DMSA) and 99mTc-MAG3 studies, using the DMSA relative percentage uptake as a reference. RESULTS AND CONCLUSION: The methods that combined the best reproducibility and accuracy for estimating 99mTc-MAG3 left-to-right uptake ratio were the integral method, with subrenal or perirenal background correction, and the Patlak-Rutland plot. The use of the integral method without background correction introduced a systematic bias, whereas the slope method resulted in high variability. Therefore these methods cannot be recommended. (+info)
A multicenter trial on interobserver reproducibility in reporting on 99mTc-DMSA planar scintigraphy: a Belgian survey.
Conflicting opinions have been expressed regarding reproducibility in 99mTc-dimercaptosuccinic acid (DMSA) planar renal image interpretation. The purpose of this investigation was to determine the level of interobserver variability among a large group of Belgian nuclear medicine physicians who evaluated a randomly selected series of DMSA planar scintigraphic examinations performed on children and adults. METHODS: All Belgian nuclear medicine centers (n = 82) were invited to participate in a reproducibility study on 99mTc-DMSA scintigraphy. 99mTc-DMSA scans obtained on 10 adults and 40 children were randomly selected from the databases of 2 hospitals. Those participating in this investigation (65 centers = 79%) received a series of computer disks containing 50 99mTc-DMSA studies. To avoid potential problems related to unfamiliar display, the disks were formatted to be interpretable using the participants' own computer systems. Each participant was then free to use his or her usual display (hard copies, contrast enhancement, color scale, gray scale, and so forth). For each kidney, the observers had to choose between the following answers: normal, abnormal, equivocal, and lack of quality. RESULTS: Forty-two responses were obtained from a wide variety of institutions and from observers with different levels of experience in interpreting 99mTc-DMSA scintigraphy. Altogether, the following data were obtained: 60.8% normal, 25.2% abnormal, 7.0% equivocal, and 3.2% lack of quality. The median percentage of agreement (overall reproducibility) for the 42 observers was 92%. When the results of all 42 observers were compared, the median agreements on normality and abnormality were 93.5% and 90.5%, respectively. In a small number (n = 4) of kidneys, reproducibility was poor and ranged from 51% to 70%. Except for 2 outliers, all observers had almost the same level of performance. CONCLUSION: A large number of Belgian nuclear medicine physicians participated in evaluating a large randomly selected sample of 99mTc-DMSA studies, and excellent interobserver agreement was found. (+info)