Renal Cortical Scintigraphy Research Articles

Diagnostic role of initial renal cortical scintigraphy in children with the first episode of acute pyelonephritis

Assessment of the first febrile urinary tract infection (UTI) in children has been the subject of debate for many years. Diagnosis of acute pyelonephritis (APN) is usually based on clinical and biological data. The clinical usefulness of early Tc-99m DMSA scintigraphy remains controversial, although it may influence the type and duration of treatment. The aim of this study was to assess the role of initial cortical scintigraphy in the detection of early renal parenchymal damage in children highly suspected of having APN and to compare the scintigraphic findings with selected clinical/laboratory parameters and ultrasonography. A prospective study was conducted in 34 infants and young children (18 boys, 16 girls), aged 1.5-36 months (mean 9.8 ± 8.7 months), hospitalized with a first episode of clinically suspected APN. Within the first 5 days after admission, Tc-99m DMSA renal scintigraphy, ultrasonography (US), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), white blood cell count (WBC) and urine analyses were performed. DMSA scintigraphy showed changes consistent with APN in 27/34 (79%) patients, with a mean age of 10.9 months, including 12 males (44%) and 15 (56%) females. Out of 9 febrile children with negative urine culture and supportive evidence of UTI, scintigraphy showed parenchymal involvement in 8 children (24% in the whole group, 30% in scintigraphically documented APN). There were no statistically significant correlations between the frequency or size of the initial scintigraphic abnormalities and age, sex, body temperature, CRP levels or ESR. A CRP level of >54 mg/L and a WBC of >13,300/mm³ had sensitivities of 56 and 59% and specificities of 86 and 71%, respectively. US showed changes consistent with APN in 7/34 (21%) in the whole group and in 7/27 (26%) patients with positive cortical scan (p < 0.05). Initial DMSA renal scintigraphy is a sensitive method for the early diagnosis of APN in young children and is useful in the assessment of the severity of kidney injury even in patients with negative urine culture. Clinical, biological and ultrasound parameters do not identify children with renal damage. Normal DMSA study, excluding parenchymal involvement and late sequelae, could minimize the use of scintigraphy in the follow-up and reduce the redundancy of cystography.

Predictors of abnormal renal cortical scintigraphy in children with first urinary tract infection: the importance of time factor

We evaluated different factors predicting the development of acute pyelonephritis in Iranian children, with special attention to time factor. One hundred nineteen patients (93 females and 26 males; age = 32.6 ± 30.8 months) with first urinary tract infection (UTI) were evaluated. None had previous urological problems. Prior to antibiotic therapy blood samples were gathered for laboratory evaluation. Vital signs on admission were measured. Clinical and laboratory indices, including therapeutic delay time (TDT) and therapeutic response time (TRT), were measured. Most patients were evaluated with renal ultrasound in the first three days following admission. All patients underwent dimercaptosuccinic acid (DMSA) renal scintigraphy and 71 were assessed for vesicoureteral reflux (VUR). DMSA scans were abnormal in 77 cases, of which 11 cases had bilateral renal involvement. Mean values for TDT, TRT, leukocyte count (LC), absolute neutrophil count (ANC), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) were 74.1 h, 39.6 h, 15725 ± 6682 mm(-3), 10772 ± 6458 mm(-3), 51.9 ± 32.5 mm, and 27.3 ± 25.1 mg l(-1), respectively. VUR was present in 29 of 142 evaluated renal units. TDT ≥ 48 h, TRT ≥ 24 h, axillary temperature ≥ 39°C, LC ≥ 13500 mm(-3), and age ≥ 18 months predicted abnormal DMSA scan in patients with first episode of UTI. Considerably higher TDT and TRT values of the current study compared to previous ones suggests the more important role of time factor in predicting abnormal DMSA findings in a developing country than in developed ones.

The Role of Tc-99m Dimercaptosuccinic Acid Renal Cortical Scintigraphy in Acute and Recurrent Episodes of Renal Infarction in a Patient With a Tendency Toward Thrombosis

Tc-99m dimercaptosuccinic acid (DMSA) renal cortical scintigraphy (RCS) of a 46-year-old man with abdominal and right flank pain who had history of a tendency toward thrombosis revealed extensive renal parenchymal changes secondary to renal infarction and a small size defect in the right kidney in addition to the patient's prior computed tomography results. The patient had Coumadin treatment. Two months later, he was referred to the hospital with the same symptoms. DMSA RCS established that the small defect in the right kidney had enlarged; other scarred areas persisted. This case indicates the value of DMSA RCS for early diagnosis, follow-up of acute/recurrent renal parenchymal scarring in patients with thrombophilia.

Comparison of 99mTc-DMSA Dual-Head SPECT Versus High-Resolution Parallel-Hole Planar Imaging for the Detection of Renal Cortical Defects

Renal cortical scintigraphy with (99m)Tc dimer captosuccinic acid (DMSA) is the standard method to detect acute pyelonephritis and cortical scarring. Different acquisition methods have been used: planar parallel-hole or pinhole collimation and single photon emission tomography (SPECT). Publications support the superiority of each; few comparative studies have been reported, with mixed results. We have compared planar parallel-hole cortical scintigraphy and dual-head SPECT for detection of cortical defects. Forty patients (37 children, 3 adults; 9 male, 31 female) were imaged 3 hours after injection of (99m)Tc-DMSA with dual-head SPECT and planar imaging (posterior, left, and right posterior oblique views with a parallel-hole collimator). For each patient, planar and SPECT images were evaluated at different sittings, in random order, by three independent observers. Twelve cortical segments were scored as normal or reduced uptake. The linear correlation coefficient for the number of abnormal segments detected between readers, techniques, and segments was calculated. No significant difference was seen in the average number of abnormal segments detected by planar versus SPECT imaging; 2.1 for planar imaging and 2.2 for SPECT (p = 0.84, two-tailed). For all observers, the average correlation coefficient for SPECT alone, planar imaging alone, and between techniques (SPECT vs planar imaging) was high (r = 0.93-0.94). Applying nonparametric Spearman's rank analysis, the average correlation remained high (r = 0.70-0.75). Correlation between readers, techniques, and segments for methods and readers was also good (r = 0.69-0.77). (99m)Tc-DMSA renal cortical imaging using dual-head SPECT offers no statistically significant diagnostic advantage over planar imaging for detection of cortical defects.

Interobserver reproducibility in reporting on renal cortical scintigraphy in children: a large collaborative study

To evaluate the interobserver reproducibility in reporting on technetium-99m (99mTc) dimercaptosuccinic acid (DMSA) scan in children. Sixty 99mTc-DMSA scans, issued from three centres, were distributed by e-mail to nuclear medicine physicians from the five continents interested in paediatric nuclear medicine. Observers had to choose, for each kidney, among four answers: normal, abnormal, equivocal or poor quality. An additional question was the location of the lesion if any: upper part, mid part, lower part. The responses had to be returned by e-mail. Sixty-one observers, with an experience of approximately five or more 99mTc-DMSA/month, contributed to the study. Median agreement was 93%. The agreement was less than 80% in 29 kidneys (24%) but only in 13% (16 kidneys) was there disagreement between normality and abnormality, the remaining cases being related to 'equivocal' responses. Disagreement was mainly related to the following patterns: (i) normal variants: pear-shaped kidney, hypoactive poles contrasting with important parenchymal mass, triangular kidney, unusual shape of the columns of Bertin; (ii) congenital abnormalities: hydronephrosis, normal duplex kidney; (iii) small defects. Interobserver reproducibility can be considered as good among a wide number of observers from the five continents. Disagreement among observers could be reduced by taking the normal variants into account.

VESICOURETERAL REFLUX INCIDENCE IN SIBLINGS OF CHILDREN WITH REFLUX: IS SCREENING REQUIRED?

Aim: The purpose of this study was to evaluate prospectively the age-related incidence and severity of primary vesicoureteral reflux (VUR) in siblings of children with reflux and to conclude whether screening of this group is required or not. Methods: A total of 71 siblings (32 boys, 39 girls) of reflux patients, aged less than 15 years (mean age, 8.4 years) were included in the study. Examination methods including urinalysis, urine culture, renal ultrasonography, and voiding cystourethrography were performed in all of the siblings. Additionally, 99m technetium (Tc)-dimercaptosuccinic acid (DMSA) renal cortical scintigraphy was performed in siblings with VUR. Results: Primary VUR was found in 10 (14%) of the siblings, and the incidence for girls and boys were 41.7% and 9.3%, respectively. The reflux incidence in siblings aged less than 6 years was 40%, whereas in siblings older than 6 years it was found 60%. DMSA scintigraphy was performed on all the siblings with VUR, of whom 5 had normal and 5 had abnormal findings. Conclusion: The incidence of primary VUR in siblings of affected children was found higher compared to the siblings of children without the disease, supporting the necessity to screen this population.

Vesicoureteric reflux deterioration in monozygotic twins

Primary vesicoureteric reflux (VUR) is the most common inherited structural urinary tract disorder, conforming closely to autosomal dominant transmission. A pair of monozygotic siblings is described exhibiting a remarkably parallel clinical course. VUR grade II was diagnosed in girl A during urinary tract infection at the age of 2 yr; screening of her asymptomatic sister (girl B) revealed the same. Renal cortical scintigraphy unveiled unilateral hypo-dysplasia in both the twins. Despite trimethoprime-sulfamethoxazole prophylaxis, infection recurred in girl A after 7 months, while girl B had a first episode 2 months later that prompted regimen switch to nitrofurantoin. Follow-up at the age of 4 depicted bilateral reflux deterioration; an urodynamics study that followed revealed functional bladder instability in both girls and the oral antispasmodic oxybutynin was initiated with good results. Evaluation for reflux should be prompt in infants with urinary infection. Patient siblings display a higher relative reflux risk, being highest in identical twins. Heredity issues, the impact of age and dysfunctional voiding in the clinical course, and the contribution of nuclear medicine in VUR management are discussed.

18 Motion correction in renal cortical scintigraphy (DMSA) in children

18 Motion correction in renal cortical scintigraphy (DMSA) in children

The role of 99mTc DMSA renal scintigraphy in Joubert syndrome

Joubert syndrome is a severe autosomal recessive disorder, which is characterized by hypotonia, impaired psychomotor development, retinal dystrophy with abnormal ocular movements and cerebellar vermis agenesis with dilatation of the fourth ventricle. Joubert syndrome type B is a developmental disorder of the nephronophtisis complex with multiple organ involvement. Although this syndrome is rare, since first described by Joubert et al in 1969, there have been several cases about the components and the chromosomal abnormalities related with it. Here we report 2 patients with Joubert syndrome in whom renal involvement was demonstrated by ultrasonography as renal cystic disorders which represented nephronophtisis. For each patient we performed renal cortical scintigraphy with 99mTc-DMSA ( 99mtechnetium-dimercaptosuccinic acid) which showed bilaterally decreased radiopharmaceutical uptake in kidneys due to tubulointerstitial nephropathy. Scintigraphy may have a great value in the diagnosis and evaluation of the presence and severity of renal involvement in Joubert syndrome since it can evaluate kidney parenchyma and functioning renal tissue.

Megaureter visualization on Tc-99m DMSA scintigraphy

We present a patient with left-sided obstructed megaureter secondary to neuropathic bladder. He was referred for technetium-99m dimercaptosuccinic acid ((99m)Tc-DMSA) renal cortical scintigraphy to evaluate renal cortical function. Images obtained 4 hr after injection showed significant activity in the dilated left ureter. When the ureter is visualized on DMSA scan, obstructive megaureter should be considered in the differential diagnosis.

Comparison of MRI and renal cortical scintigraphy findings in childhood acute pyelonephritis: preliminary experience

Comparison of MRI and renal cortical scintigraphy findings in childhood acute pyelonephritis: preliminary experience

Comparison of MRI and renal cortical scintigraphy findings in childhood acute pyelonephritis: preliminary experience

Comparison of MRI and renal cortical scintigraphy findings in childhood acute pyelonephritis: preliminary experience

Persistent renal cortical scintigram defects in children 2 years after urinary tract infection.

Renal cortical scintigraphic studies challenge the role of vesicoureteric reflux in renal scar development, emphasizing instead the part played by acute pyelonephritis. To determine the prevalence of renal cortical defects in a child cohort 2 years after the child's first diagnosed urinary tract infection and to analyze the relationship of these defects with acute illness variables, primary vesicoureteric reflux and recurrent infections. In a prospective cohort study, 193 children younger than 5 years with their first proven urinary tract infection underwent renal sonography, voiding cystourethrogram, and renal cortical scintigraphy within 15 days of diagnosis. Two years later, 150 of the 193 children, or 77.7%, had a further renal cortical scintigram, including 75, or 86.2%, of the 87 children who had acute scintigraphic defects. The relationship of cortical defects to age, gender, pre-treatment symptom duration, hospitalization, presence and grade of vesicoureteric reflux, and recurrent urinary tract infections was evaluated. Overall, 20 of the 150 (13.3%; 95% confidence interval (CI) 8.3, 19.8) children had persistent defects 2 years after infection. This included 20 of 75 (26.7%; 95% CI 17.1, 38.1) with initially abnormal scintigrams. No new defects were detected. Although acute defects were more common in the young, those with persistent defects were older (median ages 16.4 vs. 6.8 months, P=0.004) than those with transient abnormalities. After adjustment for age, persistent defects were no longer associated with gender and were not predicted by acute illness variables, primary vesicoureteric reflux or recurrent infections. Renal cortical scintigraphic defects persisted in approximately one-quarter of young children after their first proven urinary tract infection. The associated clinical features, however, failed to predict scar formation. It is possible that some of the scintigraphic defects preceded the infection by arising from either previously undiagnosed acute pyelonephritis or from underlying congenital dysplasia. The etiology of scars may be best addressed by determining whether prevention of urinary tract infections from birth avoids post-natal scar acquisition or extension.

Comparison of MRI and renal cortical scintigraphy findings in childhood acute pyelonephritis: preliminary experience

Objective: The diagnosis of acute pyelonephritis in children remains a clinical challenge. It may cause permanent renal scar formation and results in the chronic renal failure if prompt diagnosis and treatment are delayed. The purpose of this study is to compare magnetic resonance imaging (MRI) and renal cortical scintigraphy (RCS) findings in childhood acute pyelonephritis and to determine pyelonephritic foci in the acute phase. Materials and method: Twenty children (15 females and five males) with symptoms dysuria, enuresis, costovertebral pain, fever of 37.5 °C or more and/or positive urine culture were imaged by unenhanced turbo spin echo T2, spin echo T1-weighted, pre- and post-gadolinium inversion recovery MRI and RCS. Both imaging techniques were read independently by two radiologists and nuclear medicine specialists. Sensitivity and specificity of MRI in detecting acute pyelonephritic foci and scar lesions were calculated. Furthermore, in order to calculate the reliability of MRI over RCS in differentiating scar tissue and acute pyelonephritic foci, follow-up MRI studies were done in six patients after treatment of acute pyelonephritis. Results: Sensitivity and specificity of MRI in the detection of pyelonephritic lesions were found to be 90.9 and 88.8%, respectively. There is no statistically significant difference in lesion detection between the two diagnostic modalities ( P>0.05). Conclusion: Post-gadolinium MR images show significant correlation with RCS in the determination of renal pathology. Moreover, the ability of discriminating acute pyelonephritic foci and renal scar in early stages of disease is the superiority of MRI.

Early treatment of urinary infection prevents renal damage on cortical scintigraphy.

Diagnosis of urinary infection in young children is often delayed, which may result in renal damage. However, it remains to be clarified how soon the treatment should be started to prevent renal changes. The present study prospectively enrolled young children with diagnosis of their first febrile urinary infection who underwent technetium-99m dimercaptosuccinate renal cortical scintigraphy within 120 h of initiation of treatment. Patients with abnormal renoscintigraphy received antibiotics for 2 weeks and scintigraphy was repeated 1 year later. Twenty-two children were enrolled from July 1995 through March 2000. Acute-phase renoscintigraphy identified focal defects in 0 of the 14 children who were treated within 24 h of the disease, 1 of the 3 treated in 24-48 h, and 2 of the 5 treated in 48-72 h. Repeat renoscintigraphy showed disappearance of the focal defects in all 3 children. The present study has shown that early treatment within 24 h of onset of the fever due to urinary infection should deter renal changes. Fever for more than 24 h prior to diagnosis indicates a high risk for renal changes and needs an immediate effective treatment to avoid renal damage.

Acute renal cortical scintigraphy in children with a first urinary tract infection.

This prospective study, performed in 101 children with a first symptomatic urinary tract infection (UTI), evaluates the diagnostic value of clinical, biological, and ultrasound parameters in detecting children with acute renal infection documented by dimercaptosuccinic acid (DMSA) scintigraphy. In children with a positive DMSA scan, mean C-reactive protein (CRP) was higher than in children with a normal DMSA scan (114+/-64 vs. 67+/-38 mg/dl, mean+/-SD, P=0.0002). The sensitivity and specificity of CRP was 64% and 68%, respectively. In children with severe kidney involvement, mean CRP and white blood count (WBC) were higher than in children with mild/moderate disease (151+/-83 vs. 92+/-55 mg/dl for CRP, P=0.0149; 20,100+/-6,854 vs. 15,023+/-6,145 WBC/ mm3 for WBC, P=0.0131). The sensitivity and specificity was 85% and 20% for CRP, and 77% and 18% for WBC, respectively. One or more areas of abnormal cortical echogenicity were documented in 3% of kidneys with positive DMSA scans. Dilatation of the collecting system was observed in 24% of kidneys. The sensitivity and specificity of ultrasonography was 27% and 89%, respectively. In conclusion, clinical, biological, and ultrasound parameters do not accurately distinguish cystitis from pyelonephritis in children with UTI and do not identify children with severe renal damage. Accordingly, we recommend that DMSA scan should be added to the initial work-up of children with UTI.

Consensus on renal cortical scintigraphy in children with urinary tract infection

A questionnaire related to cortical scintigraphy in children with urinary tract infection was submitted to 30 experts. A wide consensus was reached on several issues related to planar images: 99mTc dimercapto succinic acid (DMSA) appears as the most appropriate tracer for renal imaging; dynamic tracers are considered to be inferior, in particular 99mTc diethylenetriaminepentaacetate, which is not recommended. The general opinion is that DMSA scintigraphy is not feasible with a minimal dose below 15 MBq, whereas the maximum dose should not be higher than 110 MBq. The dose schedule generally is based on body surface area, and sedation is only exceptionally given to children. Images are obtained 2 to 3 hours after injection, preferably with high resolution collimators; pinhole images are used by only half of the experts. Posterior and posterior oblique views are used by most of the experts, and the posterior view is acquired in supine positions. At least 200.000 kcounts or 5 minute acquisition is required for nonzoomed images. As a quality control, experts check the presence of blurred or double outlines on the DMSA images. Color images are not used and experts report on film or directly on the computer screen. As far as normal DMSA images are concerned, most experts agree on several normal variants. Hydronephrosis is not a contraindication for DMSA scintigraphy but constitutes a pitfall. Differential renal function generally is measured, but no consensus is reached whether or not background should be subtracted. Most of the experts consider 45% as the lowest normal value. A consensus is reached on some scintigraphic aspects that are likely to improve and on some others that probably represent persistent sequelae. There is a wide consensus for the systematic use of DMSA scintigraphy for detection of renal sequelae, whereas only 58% of the experts are systematically performing this examination during the acute phase of infection.

Childhood Pyelonephritis: Comparison of Gadolinium-Enhanced MR Imaging and Renal Cortical Scintigraphy for Diagnosis

PURPOSE: To compare gadolinium-enhanced inversion-recovery magnetic resonance (MR) imaging with renal cortical scintigraphy in the diagnosis of childhood pyelonephritis. MATERIALS AND METHODS: Thirty-seven patients with fever-producing urinary tract infection underwent gadolinium-enhanced inversion-recovery MR imaging and technetium-99m renal cortical scintigraphy. Each study was read in double-blind fashion by two radiologists. The kidney was divided into three zones, and each was graded as positive, equivocal, or negative for pyelonephritis. RESULTS: Seventy kidneys (210 zones) were imaged. Twenty-six kidneys (54 zones) had evidence of pyelonephritis at both MR imaging and scintigraphy. Twenty-four kidneys (100 zones) were negative on both studies. Twelve kidneys (42 zones) were positive at MR imaging but negative at scintigraphy, and four kidneys (seven zones) were negative at MR imaging but positive at scintigraphy. The results of MR imaging for pyelonephritis were not equivalent to the results of sci...

URINARY TRACT INFECTIONS IN CHILDREN: EPIDEMIOLOGY, EVALUATION, AND MANAGEMENT

Accurate documentation of UTIs in children is essential for proper evaluation and management. Urine cultures with multiple organisms or colony counts less than 50,000 to 100,000 CFU/ml should be considered suspect and require confirmation, particularly with clean-catch specimens. Children with well-documented UTIs should be evaluated based on their age and presenting symptoms. Infants and young children require imaging, usually with a cystogram and sonogram of the kidneys and bladder. Older girls with febrile UTIs and boys at any age should also be considered for urinary tract imaging. Renal cortical scintigraphy with 99mTc-DMSA has emerged as the imaging study of choice for acute pyelonephritis and renal scarring in children with UTIs. Treatment of UTIs in children ideally commences with culture-specific antimicrobial therapy, although treatment may be started in sick children before culture results are available. Short-course treatment (3-5 days) is sufficient for children with acute uncomplicated lower UTIs. Children with acute pyelonephritis require 10 to 14 days of antibiotics, which can be administered on an outpatient basis in older infants and children who are not toxic, as long as good compliance is expected. Patients with first-time UTIs who require imaging should be maintained on low-dose antibiotic prophylaxis until their workup is completed. Treatment of ABU does not seem necessary if the urinary tract is otherwise normal. Long-term antibiotic prophylaxis is indicated for children with frequent symptomatic recurrences of UTI and for those with known VUR. Diagnosis and treatment of underlying voiding dysfunction and constipation is an essential component of the successful management of UTIs in children.

The renal axes in spina bifida: issues of confusion and fusion.

The occurrence of horseshoe kidneys in myelodysplasia has been suggested to be overestimated because of the concurrent prevalence of kyphotic spine in the spina bifida population. Pseudohorseshoe kidneys result from the actual medial migration and apposition of the lower renal poles in the deep fossa created by the gibbus deformity. The presence of a lumbosacral kyphosis, however, does not imply there is not a true horseshoe kidney. In our myelodysplasia population of 189 patients, occurrence of true horseshoe kidneys (13 patients) and pseudohorseshoe kidneys (14 patients) was increased. The finding of lumbosacral kyphosis was twice as common in the pseudohorseshoe population as in the true horseshoe population. True horseshoe kidneys were three times more commonly seen in association with congenital vertebral anomalies cephalad to the dysraphic spine. Diagnosis in this study was predominantly based on renal cortical scintigraphy with the posterior pin-hole magnification technique.