Subtle renal duplication as an unrecognized cause of childhood incontinence: diagnosis by magnetic resonance urography

Urinary incontinence in young girls who have been toilet trained may be due to an ectopic ureter inserting below the urinary sphincter. This diagnosis is frequently delayed, is psychologically distressing, and may be missed at physical examination. Findings at ultrasound evaluation may be subtle and imaging with computed tomography or intravenous urography exposes young patients to ionizing radiation. We report two cases of girls with urinary incontinence where magnetic resonance (MR) urography revealed subtle renal duplication which implied the presence of an ectopic duplicated ureter with infrasphincteric insertion. These cases stress the importance of examining the kidneys, rather than the perineum, at MR, ultrasound and intravenous urogram evaluation, and show the value of MR urography as a safe alternative to computed tomography and intravenous urography for making this diagnosis.     

Pediatric hypertension: an approach to imaging

Since 1981, we have made diagnoses of secondary hypertension using state of art imaging equipment in 18 pediatric patients. The most valuable tests were ultrasound in identifying renal parenchymal disease, computed body tomography for adrenal tumors and intra-arterial renal angiography for renovascular disorders. Based on our experience, we have formulated an algorithm for the evaluation of the hypertensive pediatric patient. The initial step is careful clinical and laboratory screening to identify those patients that are likely to have essential hypertension and who should not undergo imaging tests. In the cases where there is a possible secondary etiology, renal ultrasound is usually performed first to identify parenchymal disease. If catecholamines are elevated, then abdominal computed tomography is the initial test. If no etiology is identified from these noninvasive studies, then direct intraarterial renal angiography is performed. The authors do not feel that excretory urography, radionuclide renography, intravenous digital subtraction angiography or selective renal vein sampling for renin are useful or practical screening tests for renovascular hypertension.     

Comparison of ultrasound examination and intravenous urography after a urinary tract infection.

The results of ultrasound examination and intravenous urography after a urinary infection were compared in 100 children. Thirty seven had an abnormality on urography, but in 12 this was not seen on ultrasound. One of these had renal scarring, the remainder only minor abnormalities.     

MR imaging of kidneys: functional evaluation using F-15 perfusion imaging

BACKGROUND: Children with hydronephrosis are typically investigated by a combination of diuretic renal scintigraphy, ultrasound, and voiding cystourethrography. Unfortunately, there is no gold standard to assess obstruction. PURPOSE: The purpose of our study was to evaluate the utility of dynamic contrast enhanced MR urography in the investigation of children with hydronephrosis to define urinary tract anatomy, to calculate differential renal function and to assess urinary tract obstruction. MATERIALS AND METHODS: Dynamic contrast-enhanced MR imaging was performed in 40 children with unilateral hydronephrosis. There were 14 girls and 26 boys with an age range of 1 month to 14 years (mean 1.4 years). The information from traditional imaging modalities was compared to the information obtained from the single MR study. RESULTS: The anatomic imaging with MR urography was superior to other modalities. The split renal function was estimated with MR urography by calculating the volume of enhancing renal parenchyma and was comparable to renal scintigraphy ( r=0.98). By using surgery versus non-surgery as the decision point, with MR urography the sensitivity was 100%, specificity 71%, positive predictive value 86%, negative predictive value 100%, and diagnostic efficiency 90%. For renal scintigraphy the sensitivity was 96%, the specificity 56%, positive predictive value 76%, negative predictive value 90%, and diagnostic efficiency 79%. CONCLUSIONS: Dynamic contrast-enhanced MR urography provides superior anatomic and functional information when compared with ultrasound and diuretic renal scintigraphy. The information is gathered in a single study that does not use ionizing radiation. It is likely that MR urography will replace renal scintigraphy in the evaluation of hydronephrosis in children.     

Ureteroceles in children: an ongoing challenge

The treatment of ureteroceles in children requires an individualised approach. Antenatal diagnosis is the ideal, so that postnatal urinary antibiotic prophylaxis and appropriate investigations can be organised. Postnatal investigations should assess both upper and lower urinary tract. Renal and bladder ultrasound and radiographic micturating cystourethragraphy under antibiotic cover will both detect vesicoureteric reflux and assess any bladder outlet obstruction due to the ureterocele. Renal function, particularly of the upper moiety, is best evaluated by technetium Tc^99m dimercaptosuccinic acid renal scan. Both function and obstruction can be quantitated by the Tc^99m-mercaptoacetyltriglycine isotope scan with intravenous volume expansion (10 ml/kg) and furosemide diuresis (1 mg/kg). Intravenous urography provides the best anatomic information when the upper moiety is functional. The surgical management is based on the clinical situation, which is often variable, and therefore needs to be tailored for each patient. The general principles include restoration of anatomy to as near normal as possible and preservation of functional renal tissue.     

Ultrasound finding of peripelvic urine extravasation in ureteropelvic junction obstruction

Pylosinus backflow is usually associated with acute obstruction and occurs as the result of increased hydrostatic pressure in the renal pelvis. Microruptures or tears occur at the calyceal fornix. The extravasating urine may then be absorbed by lymphatics, rupture into veins, or dissect in the renal sinus [1]. As extravasating urine extends from the peripelvic tissues into the perirenal space, it becomes easily visualized by ultrasound as a perirenal fluid collection. We describe the ultrasound finding of decreased peripelvic echogenicity in an infant with ureteropelvic junction obstruction and peripelvic urine extravasation. To our knowledge this finding on ultrasound has not been previously described. If not for the peripelvic decreased echogenicity, the resulting pelvic decompression may have otherwise mimicked a nonobstructed kidney.     

Ultrasound and the diagnosis of renal and ureteral calculi

We retrospectively compared ultrasound examination with plain film radiography of the abdomen (KUB) in the diagnosis of renal and ureteral calculi in 13 patients. Overall, ultrasound was more sensitive than KUB (84% versus 54%) in detecting calculi. However, KUB was superior for the diagnosis of ureteral stones. No calculi were detected by intravenous urography that were not first seen on either ultrasound or KUB. Our experience suggests that the combination of ultrasound and KUB is less invasive and more sensitive than intravenous urography for the diagnosis of calculi in patients with symptoms and signs suggestive of stone disease or who are at high risk for stone formation.     

儿童肾积水的影像学诊断策略

儿童肾积水最常见的病因是肾盂输尿管连接部(uteropelvic junction,UPJ)狭窄,表现为肾盂肾盏扩张积水。临床上对儿童肾积水的诊断依赖于超声、静脉肾盂造影(intravenous pyelography,IVP)、MR尿路成像(MR urography,MRU)、CT尿路成像(CT urography,CTU)、核素扫描(SPECT肾动态扫描)等多种影像学检查。不同医疗机构设备和技术不尽相同,目前诊断儿童肾积水主要有超声+IVP+MRU、超声+CTU、超声+SPECT+MRU等几种影像学检查组合。本文就儿童肾积水各种影像学诊断方法的优缺点及最佳组合方式进行解读。     

Genitourinary imaging techniques

In the current era of pediatric uroradiology, use of nuclear medicine, ultrasonography, CT, and MRI has been valuable in the identification and management of genitourinary diseases. Excellent information about the renal parenchyma and renal function is currently attainable with current cross-sectional imaging techniques that can identify tissue differentiation of lesions, distinguish dilatation of the pelvocalyceal system, and determine margins of the kidney and perirenal space. Invasive angiography is limited in application specifically to vascular diseases, although they are uncommon in childhood. Because of these newer techniques, intravenous urography has lost its position as the "cornerstone" of urinary tract imaging and is used mainly to identify pathologic conditions of the ureters.     

Renal tuberculosis mimicking xanthogranulomatous pyelonephritis: ultrasonography,computed tomography and magnetic resonance imaging findings

The incidence of tuberculosis has been increasing in recent years, and its treatment has also become challenging. The diagnosis of renal tuberculosis is often difficult and delayed. Early and correct diagnosis of tuberculosis with different organ system involvement is very important and can be easier with ultrasonography, computed tomography and/or magnetic resonance imaging. Although renal tuberculosis is the result of hematogenous spread more commonly from the lungs, less than 5%, of patients with urinary tract tuberculosis have active pulmonary disease. Renal tuberculosis may show variable radiological findings depending on the stage of the infection. Although an end-stage "autonephrectomized" kidey in tuberculosis is classically defined to be small in size, enlargement may on rare occasions be observed, which is the case in our patient. This form greatly mimics diffuse xanthogronulomatous pyelonephritis. Both diseases show thickening of the perirenal fasciae and spread of inflammation into the adjacent organs. Computed tomography and magnetic resonance imaging may show some specific features to differentiate these two entities.     

螺旋CT及三维重建尿路成像在肾发育不良诊断中的应用

目的 寻觅诊断小儿肾发育不良最好的检查方法。方法 对7例正常排尿的间歇期有会阴部滴尿的患儿，均经超声、单光子发射计算机断层肾动态显像（SPECT）、静脉尿路造影、（IVU）和CT尿路成像（CTU）检查。并对照术后诊断，比较CTU、IVU、超声、SPECT对肾发育不良的诊断符合率。结果 7例患儿的发育不良肾CTU均清楚显示，左侧3例，右侧4例。增强后实质期图像示病变侧腰大肌前方明显强化的肾样小结节，分泌期图像可显示集合系统及输尿管腔，MPR、3D、4D像直观、立体，显示了发育不良肾的大小、位置、轮廓及其输尿管走行。CTU诊断符合率100％。ECT检查仅1例显示发育不良肾，诊断符合率14.3%(1/7)。IVU、B超均未能显示发育的肾和输尿管。CTU的诊断符合率明显高于SPECT、IVU及B超。结论 如疑有肾发育不良或经超声初步检查仅发现一个肾，应行CTU检查，以明确是否为单侧肾发育不良。CTU是目前诊断肾发育不良最准确的非创伤性影像检查方法。     

Neonatal urinomas: Imaging considerations

Neonatal urinomas can be defined as encapsulated extravasations of urine occuring secondary to congenital obstructive uropathies. Since 1978, four patients with proven urinomas have been studied at the Medical University of South Carolina, three of which had posterior urethral valves and the fourth, a segmental ureteral atresia. They were classified into three major types; subcapsular, diffuse perirenal and localized perirenal. The radiologic and imaging appearances are demonstrated. We found the most efficacious approach for identification of neonatal urinomas to be renal ultrasound, voiding cystourethrography and the Tc-99 m DPTA renal scintigraphy.     

CT尿路成像技术在儿童经皮肾镜碎石术中的应用

目的探讨CT尿路成像技术在小儿B超引导下经皮肾镜碎石术治疗复杂肾结石的术前应用。方法对24例复杂肾结石患者在行经皮肾镜碎石术前,应用CT尿路成像三维重建技术,了解肾结石的部位、形状、结石分支的位置或方向,以及有无。肾盏积水等,确定穿刺点、穿刺角度和深度,以提供最优穿刺路径,并与同期29例未行CTU评估的穿刺患儿比较结石清除率。结果24例使用CTU的患儿因为提供了最优穿刺路径,结石诊断率为100％,穿刺成功率100％,结石总取净率为79．4％,无输血病例,无腹腔脏器及胸膜损伤发生,较未行CTU评估穿刺的患儿结石一期清除率明显提高。结论应用CT尿路成像技术对肾结石进行评估,制定最佳穿刺路径,可减少穿刺损伤周围脏器的风险,减少手术出血。经皮肾镜碎石术前应用CTU能提高穿刺成功率,提高结石清除率,减少和避免术后并发症。     

彩色超声引导联合聚桂醇灌注治疗小儿单纯性肾囊肿

目的 探讨彩色超声引导联合聚桂醇灌注治疗小儿单纯性肾囊肿临床疗效,寻找小儿单纯性肾囊肿有效的治疗方法及合适的应用药物.方法 回顾2011年5月至2014年10月我院经彩色超声、CTU明确诊断为单纯性肾囊肿患儿51例,其中28例为聚桂醇治疗组,采用彩色超声引导下经皮穿刺并注入聚桂醇,无水乙醇灌洗法23例设为对照组,对比两组不良反应发生情况及治疗后1年两组疗效情况.结果 51例患儿均穿刺注药成功,治疗后3个月、6个月、1年均获彩色超声随访,聚桂醇治疗组治愈率为85.7％,有效率为92.9％,均高于无水乙醇组的60.9％和65.2％,差异均有统计学意义(P＜0.05);聚桂醇治疗组患儿异常哭闹及面红例数均明显较对照组少,差异有统计学意义;聚桂醇治疗组无一例肉眼血尿发生,对照组有6例治疗后出现肉眼血尿,辅助应用止血药物后,均在3d之内消失,差异有统计学意义(P＜0.05);聚桂醇治疗组患儿仅1例出现穿刺后发热,对照组治疗后9例出现发热,差异有统计学意义(P＜0.05);治疗组患儿穿刺点渗血及呕吐例数均较对照组少,差异均有统计学意义(P＜0.05).聚桂醇治疗组二次穿刺例数及手术例数均较无水乙醇组少.结论 彩色超声引导联合聚桂醇灌注治疗小儿单纯性肾囊肿疗效确切、副作用小,应作为小儿单纯性肾囊肿首选治疗方案.     

Congenital anterior urethral diverticulum associated with bilateral urinomas and dysplastic kidneys

Congenital anterior urethral diverticulum (AUD) is a rare condition. We report a case of AUD associated with urinary ascites, bilateral urinomas and dysplastic kidneys. The diagnosis of urethral obstruction was established in utero by means of ultrasound. The right perirenal urinoma appeared "septated", and we believe that this is related to its hemorrhagic content. Improvement of the clinical condition and renal function was noted after decompression by bilateral cutaneous loop ureterostomy.     

Serendipitous diagnosis of childhood xanthogranulomatous pyelonephritis in a child with osteomyelitis

Xanthogranulomatous pyelonephritis (XGP), a rare chronic renal infection in children, usually presents as high fever, pyuria and an abdominal mass. This child with clinical and radiologic evidence of osteomyelitis was not suspected of renal disease until a non-functioning kidney was discovered during a bone scan. The pathologic proven diagnosis of XGP could have been made by correlative imaging using renal ultrasound, a renal scan and a gallium scan. Computed tomography and voiding cystourethrography provided additional information as to the nature and extent of the disease process.     

Evaluation of renal parenchyma in children by DMSA scintigraphy, X-ray computed tomography and intravenous urography

The demonstration of diminished or scarred renal parenchyma in children is often the decisive factor in determining the future management of children with urinary tract malformations. Renal scintigraphy using technetium 99m-labelled dimercaptosuccinic acid (DMSA), computed tomography (CT) and intravenous urography (IU) were used to evaluate the renal parenchyma prior to ureter re-implantation in a series of 13 children. Their ages ranged from 5 months to 3 years 8 months. The indication for operation was ureteric reflux in 8 children and distal ureteric stenosis in 5. CT was performed on a Toshiba TCT-80 scanner. Renal scintigraphy was performed 3 hours after intravenous injection of DMSA. Compared with IU, DMSA imaging gave more information about the renal parenchyma in 6 children, gave equal information in 6 and less in 1. Compared with CT, DMSA imaging gave more information in 2 children, was equally informative in 8 and less so in 3. Accordingly, DMSA imaging was judged to be more sensitive than IU and as sensitive as CT. DMSA imaging can be used both for the initial evaluation and for follow-up assessment of renal parenchymal damage.     

Evaluation of Renal Parenchyma in Children by DMSA Scientigraphy, X-ray Computed Tomography and Intravenous Urography

ABSTRACT. The demonstration of diminished or scarred renal parenchyma in children is often the decisive factor in determining the future management of children with urinary tract malformations. Renal scintigraphy using technetium 99m-labelled dimercaptosuccinic acid (DMSA), computed tomography (CT) and intravenous urography (IU) were used to evaluate the renal parenchyma prior to ureter re-implantation in a series of 13 children. Their ages ranged from 5 months to 3 years 8 months. The indication for operation was ureteric reflux in 8 children and distal ureteric stenosis in 5. CT was performed on a Toshiba TCT-80 scanner. Renal scintigraphy was performed 3 hours after intravenous injection of DMSA. Compared with IU, DMSA imaging gave more information about the renal parenchyma in 6 children, gave equal information in 6 and less in 1. Compared with CT, DMSA imaging gave more information in 2 children, was equally informative in 8 and less so in 3. Accordingly, DMSA imaging was judged to be more sensitive than IU and as sensitive as CT. DMSA imaging can be used both for the initial evaluation and for follow-up assessment of renal parenchymal damage.     

Giant Hydroureteronephrosis Associated with Primary Obstructed Megaureter

The case is presented of a four year old boy with a large left abdominal mass. The patient was diagnosed as having a left giant hydroureteronephrosis due to a primary obstructed megaureter, based on the findings of ultrasonography, micturating cystourethrography, excretion urography, computed tomography and percutaneous antegrade pyeloureterography. Diuretic renography showed that the obstruction was partial. Since a static renal scintigram indicated that renal function on the affected side was moderately well preserved, ureteroplasty is planned.     

Single-system ectopic ureters associated with renal dysplasia

The purpose of this study was to inquire into the clinical features and methods for the diagnosis and therapy of single-system ectopic ureters associated with renal dysplasia. Intravenous urography (IVP), diuretic B-mode ultrasound (B-US), and, in four cases, computerized tomography (CT) were performed in twelve female patients with renal dysplasia-seven on the left and five on the right-and the clinical records were retrospectively summarized and analyzed. The main presentation was droplet urinary incontinence. IVP and B-US showed that in all in whom the affected kidneys did not function, the contralateral kidneys had undergone compensatory hypertrophy. Only in four cases were the dysplastic renal tissues displayed in the pelvic cavity on B-US. In eight cases, the affected kidneys were not found. Of the four patients who had CT scanning, the dysplastic kidneys were explored in the pelvis in two cases. All patients underwent ureteronephrectomy, and the urinary incontinence disappeared after operation. Single-system ectopic ureters associated with renal dysplasia mainly affect female children, and most present with droplet urinary incontinence; the affected kidney may not be displayed on ultrasonography and IVP, but the contralateral kidney may display compensatory hypertrophy on IVP and can easily be misdiagnosed as a solitary kidney. The curative effect of ureteronephrectomy is definite.