Chun-Chen Lin

Screening Young Children with a First Febrile Urinary Tract Infection for High-grade Vesicoureteral Reflux with Renal Ultrasound Scanning and Technetium-99m-labeled Dimercaptosuccinic Acid Scanning

OBJECTIVE To evaluate the predictive value of renal ultrasound scanning and 99m-Technetium-dimercaptosuccinic acid (DMSA) scintigraphy for high-grade vesicoureteral reflux (VUR) in young children with a first urinary tract infection (UTI). STUDY DESIGN The medical records of children who had been examined with renal ultrasound scanning, DMSA scanning, and voiding cystourethrography (VCUG) were reviewed. The findings of renal ultrasound scanning, DMSA scanning, and their predictive values were evaluated. RESULTS Of 699 children, high-grade VUR (grades III-V) was diagnosed in 119 (17.0%). Signs of renal hypodysplasia (OR, 16.15), cyclic dilatation of pelvicaliceal system (OR, 11.73), hydroureter (OR, 4.00) with renal ultrasound scanning, and renal hypodysplasia (OR, 8.78), acute pyelonephritis (OR, 2.76) with DMSA scanning were associated with high-grade VUR. The sensitivities for high-grade VUR of ultrasound scanning alone (67.2%) or DMSA scanning alone (65.5%) were not as good as that of a both-test strategy, which had a sensitivity rate of 83.2%. The negative predictive value of the both-test strategy was 91.5%. CONCLUSION Renal ultrasound scanning and DMSA scanning both should be routinely performed in children with a first febrile UTI. VCUG is only indicated when abnormalities are apparent on either ultrasound scanning or DMSA scanning or both.

Intermittent hydronephrosis secondary to ureteropelvic junction obstruction: clinical and imaging features.

OBJECTIVE. We sought to assess the clinical and imaging findings in intermittent hydronephrosis secondary to ureteropelvic junction obstruction, with particular emphasis on the characteristic ultrasonographic findings. METHODS. This prospective, longitudinal, observational study included all children who had intermittent ureteropelvic junction obstruction and presented with abdominal pain over 6 years. Renal ultrasound was used as an initial screening tool to detect intermittent hydronephrosis. Renal ultrasonography was repeated every 1 to 2 days to record serial changes from the symptomatic to the asymptomatic stage. Their clinical manifestations and imaging findings were studied. RESULTS. Eighteen patients (14 boys, 4 girls) were studied. Most had sharp pain that began acutely and typically lasted for <2 days. Most of the children (16 of 18) had nausea and vomiting that accompanied the pain. The acute episode generally resolved spontaneously and was followed by a pain-free interval that ranged from days to months. Factors that predisposed to an attack included increased water intake, vigorous exercise, or bladder distention. All patients had clearly demonstrable obstruction of the renal pelvis during an acute attack, a finding that diminished or resolved during the symptom-free intervals. During convalescence, all patients had renal pelvic wall thickening on ultrasonography. This finding appeared on the second or third day after a painful episode subsided, persisted for 6 to 9 days, and then disappeared in the symptom-free stage. Pyeloplasty was performed in 17 patients, none of whom had recurrent pain on follow-up. Extrinsic obstructions were found in 9 patients. CONCLUSIONS. The keys to diagnosis are awareness of the syndrome, a detailed history, and immediate and serial imaging studies during painful crises. A thickened renal pelvic wall during convalescence is an important ultrasonic sign of intermittent hydronephrosis.

Right perinephric abscess: a rare presentation of ruptured retrocecal appendicitis.

Abstract Perinephric abscess commonly arises from rup- ture of an intrarenal abscess into the perinephric space. It rarely results from gastrointestinal pathology. We report two pediatric patients with retrocecal appendicitis that presented with perinephric abscess. A 3-year-old girl presented with high fever and right flank pain for more than 1 week. Ultrasonography showed a right perinephric fluid collection with normal renal parenchyma and collecting system. A perinephric abscess extending from a ruptured retrocecal appendix was diagnosed by ab-dominal computed tomographic (CT) scan. Her hospital course was complicated with empyema, peritonitis, and pericardial effusion. A 6-year-old girl had lower abdominal pain for 3 days and high fever on the day of admission. Ultrasonography showed a right perinephric abscess with a normal renal contour and a fecalith in the enlarged appendix in the right lower quadrant of the abdomen. Appendectomy and drainage of the perinephric abscess were performed in both cases. We suggest that a ruptured retrocecal appendix must be considered in cases of perinephric abscess, especially in patients with gas bubbles in the abscess and a normal urogenital appearance. Ultrasonography and abdominal CT scan are the preferred diagnostic tools. Prolonged antibiotics and drainage of the abscess are mandatory to decrease morbidity and mortality.

Segmental multicystic dysplastic kidney in children: clinical presentation, imaging finding, management, and outcome

PURPOSE The aim of the study was to assess the presentation, imaging findings, management, and outcome of segmental multicystic dysplastic kidney (MCDK) in children. MATERIALS AND METHODS Six patients with segmental MCDK were diagnosed and observed at our hospital. We reviewed the medical records to collect data on initial symptoms, results of imaging studies, associated urinary tract anomalies, operation, and outcome. RESULTS Three patients had abnormal prenatal ultrasound and were diagnosed by further postnatal imaging; they were asymptomatic after birth. The other 3 children presented with a renal mass, recurrent urinary tract infection, or urinary incontinence. Five patients had associated ipsilateral or contralateral urinary tract abnormalities, including vesicoureteral reflux, ureterocele, duplex collecting system, ureteropelvic junction stenosis, and ectopic ureter. Lower tract reconstruction was performed in 3, and open biopsy was done in 1 child. None underwent partial or total nephrectomy, and all had involution of the cysts for a mean of 40 months. CONCLUSIONS Most of the cases occur in the upper pole of a duplex kidney and often involute spontaneously without significant complication. The clinical presentation and imaging findings depend on the associated anomalies and complications. Although the latter may require surgery to resolve, segmental MCDK itself rarely requires resection.

Paecilomyces Lilacinus Peritonitis Complicating Peritoneal Dialysis Cured by Oral Voriconazole and Terbinafine Combination Therapy

Fungal peritonitis (FP) is a serious complication in patients on continuous ambulatory peritoneal dialysis (CAPD). We report a case of CAPD-related FP caused by Paecilomyces lilacinus in a 15-year-old uraemic boy. The infection was successfully treated by combination therapy consisting of oral voriconazole and terbinafine, which has not been previously reported in the treatment of FP.

Why is hypercalciuria absent at diagnosis in some children with ATP6V1B1 mutation

We try to explain why hypercalciuria is absent at diagnosis in some children with an ATP6V1B1 mutation. A 5-month-old girl presented with distal renal tubular acidosis (dRTA) and sensorineural hearing loss. Direct sequencing of the ATP6V1B1 genes disclosed a new homozygous mutation (452 delT) in exon 13. In particular, an absence of hypercalciuria and a normal level of parathyroid hormones were noted. After alkaline therapy, the signs of nephrocalcinosis improved on ultrasound during follow-up. After a review of the literature regarding patients with ATP6V1B1 gene mutations, a young age seemed to be an important factor for normocalciuria. The probable mechanism of normocalciuria and a dynamic mode of calcium excretion in patients with dRTA is proposed. The determinant factors include the degree of systemic acidosis, urine pH, genetic polymorphisms, age, dietary factors, and volume status. Low sodium intake may be a major determinant of normocalciuria in these patients. It is suggested that hypercalciuria is usually absent at diagnosis of dRTA in young infants. Blood pH, plasma bicarbonate concentration, urinary citrate levels, and growth catch-up may be better indicators of adequate alkali therapy in normocalciuric children. Volume contraction, low salt content in infant formula, and alkaline urine in young infants are likely to account for the increased calcium reabsorption.

Hemolytic Uremic Syndrome Caused by Enteroviral Infection

A 4-year-old boy presented with enteroviral infection complicated with atypical hemolytic uremic syndrome (aHUS). Enterovirus RNA was detected by reverse transcription polymerase chain reaction (RT-PCR) of both blood and kidney biopsy specimens. A survey of the complement system did not reveal a specific complement defect. Supportive therapy with blood components transfusion, plasma therapy, and immunosuppressants was administered, however, renal function did not recover. The results of this report demonstrate that the enterovirus is the cause of aHUS.

Renal Microabscesses: A Presentation of Cat Scratch Disease

A previously healthy 5-year-old girl was referred following a spiking fever for 8 days accompanied by abdominal pain, fatigue, and headache. Physical examination was unremarkable. Initial laboratory evaluation revealed a white blood cell count of 12 100/mm (normal ranges, 4000-10 000/mm3) and C-reactive protein of 12.06 mg/dL (normal value, < 0.8 mg/dL). Urinalysis showed 33 white cells/high-power field. Liver and renal functions were within normal limits. Empiric antibiotics were given but spiking fever persisted. Bacterial and fungal cultures of blood, urine, and bone marrow yielded no growth. Contrast-enhanced computerized tomography revealed multiple small hypodense lesions scattered throughout the cortex of both kidneys consistent with microabscesses (Figure 1). In addition, multiple enlarged lymph nodes were found at mesenteric root and para-aortic regions (Figure 2; available at www.jpeds.com). No abnormalities of the liver and spleen were seen. All studies for fever of unknown origin were negative. However, a careful history revealed she had close contact with kittens at home and that she had been scratched by a cat. Indirect immunofluorescence antibodies for Bartonella henselae were positive for Immunoglobulin G (1: 2048) and Immunoglobulin M (1: 320). Therefore, renal cat scratch disease (CSD) was diagnosed. The fever gradually subsided during 4 weeks of tetracycline and

Potential Role of Tc-99m DTPA Diuretic Renal Scan in the Diagnosis of Calyceal Diverticulum in Children.

AbstractThe aim of the study was to assess the usefulness of Technetium-99m diethylene triamine pentaacetic acid (Tc-99m DTPA) diuretic scan to diagnose calyceal diverticulum (CD).From January 2000 to June 2014, children with evidence of renal cystic lesions of undetermined diagnosis on ultrasound were enrolled. Computed tomography urography (CTU) and Tc-99m DTPA diuretic scan were performed to characterize the precise anatomy. The diagnosis of CD depended on visualization of a renal cystic lesion with filling of contrast material or radiotracer from the collecting system on CTU or diuretic renal scan. Children who had positive findings of CD on 1 or both imaging studies were selected and analyzed.Both CTU and Tc-99m DTPA diuretic renal scan were performed in 39 children. A total of 9 (23.1 %) children with CD were diagnosed. All 9 children had positive diagnosis of CD on diuretic renal scan. Only 6 (66.7%) children could be diagnosed by CTU, and CD was missed by CTU in 3 subjects. The differential renal functions in patients with CD were 46% to 55%. The time of radiotracer appearance in the CD ranged from the 8th to the 24th minute. Seven patients had persistent accumulation of radiotracer in their CD at the end of the study.Tc-99m DTPA diuretic renal scan seems to be more sensitive than CTU in diagnosing CD. The possible reasons of higher sensitivity are discussed. Additional advantages that Tc-99m DTPA diuretic renal scan provides include the following: continuous monitoring, less radiation doses, and information on renal function, making it an attractive alternative to CTU for diagnosis of CD.