Magnetic resonance urography in pediatric urology

Magnetic Resonance Urogram in Pediatric Urology: a Comprehensive Review of Applications and Advances

Magnetic Resonance Urography (MRU) has emerged as a powerful imaging modality in pediatric urology, offering comprehensive anatomical and functional assessment of the urinary tract without exposure to ionizing radiation. This review provides an in-depth analysis of MRU's technical aspects, clinical applications, advantages, and recent advancements. Traditional imaging techniques, such as ultrasound, voiding cystourethrography, and nuclear scintigraphy, have long been utilized for evaluating pediatric urinary tract anomalies; however, these methods have inherent limitations in anatomical resolution and functional assessment. MRU combines high-resolution anatomical imaging with dynamic functional analysis, making it particularly valuable in evaluating conditions such as hydronephrosis, ureteropelvic junction obstruction, and ectopic ureters. Advancements in MRU technology, including the use of 3T MRI for superior spatial resolution, diffusion-weighted imaging, and dynamic contrast-enhanced imaging, have enhanced its diagnostic capabilities. The ability to assess renal transit times and differential renal function allows for precise evaluation of obstructive uropathies and congenital anomalies. Despite requiring sedation in younger children and longer acquisition times, MRU has demonstrated superior accuracy compared to conventional imaging, reducing the need for multiple diagnostic studies. Recent developments in real-time MRI, faster imaging techniques, and AI-based reconstructions have further optimized MRU's efficiency and diagnostic utility. As MRU continues to evolve, its role in pediatric urology is expected to expand, potentially replacing traditional imaging modalities in select cases. This review highlights the growing significance of MRU in pediatric urinary tract evaluation, emphasizing its potential to improve clinical decision-making and patient outcomes.

Surgical validation of functional magnetic resonance urography in the study of ureteral anomalies distal to the uretero-pelvic junction in a pediatric cohort

BACKGROUND

Ureteral anomalies distal to the uretero-pelvic junction (UPJ) belong to the wide spectrum of congenital anomalies of the kidney and urinary tract (CAKUT). They can cause severe obstruction requiring a detailed anatomical depiction to define the surgical approach. Up to date, ultrasonography, voiding cystourethrography and scintigraphy are considered the gold-standard diagnostic tools to study obstructive anomalies of the urinary tract; however, they do not provide accurate ureteral anatomical details. The aim of our study was to evaluate the concordance between functional magnetic resonance urography (fMRU) and intraoperative findings to define ureteral anomalies distal to UPJ.

METHODS

Pediatric patients with ureteral anomalies distal to the UPJ who underwent surgery after performing fMRU were retrospectively collected. Surgical data were compared with radiological results. The concordance was assessed considering both pathological and non-pathological urinary tracts and was calculated by means of the Cohen's kappa coefficient. fMRU diagnostic accuracy was defined by sensitivity, specificity, and binomial exact confidence intervals.

RESULTS

We included 46 patients. The sensitivity and specificity of fMRU were 98.0% and 83.3%; positive predictive value 90.4%, negative predictive value 96.2%. The concordance between surgical findings and fMRU was 92.3%, with a Cohen's k coefficient of 0.83 (excellent).

CONCLUSIONS

Our study demonstrates the excellent agreement between fMRU and surgical findings in the definition of ureteral anomalies distal to the UPJ in children. Thus, it could be considered a valid imaging technique in the preoperative planning as it provides the surgeon with important information regarding the etiology and site of the obstruction.

The Saudi urological association guidelines on urolithiasis

Aims

The Saudi Urolithiasis Guidelines are a set of recommendations for diagnosing, evaluating, and treating urolithiasis in the Saudi population. These guidelines are based on the latest evidence and expert consensus to improve patient outcomes and optimize care delivery. They cover the various aspects of urolithiasis, including risk factors, diagnosis, medical and surgical treatments, and prevention strategies. By following these guidelines, health-care professionals can improve care quality for individuals with urolithiasis in Saudi Arabia.

Panel

The Saudi Urolithiasis Guidelines Panel consists of urologists specialized in endourology with expertise in urolithiasis and consultation with a guideline methodologist. All panelists involved in this document have submitted statements disclosing any potential conflicts of interest.

Methods

The Saudi Guidelines on Urolithiasis were developed by relying primarily on established international guidelines to adopt or adapt the most appropriate guidance for the Saudi context. When necessary, the panel modified the phrasing of recommendations from different sources to ensure consistency within the document. To address areas less well covered in existing guidelines, the panel conducted a directed literature search for high quality evidence published in English, including meta analyses, randomized controlled trials, and prospective nonrandomized comparative studies. The panel also searched for locally relevant studies containing information unique to the Saudi Arabian population. The recommendations are formulated with a direction and strength of recommendation based on GRADE terminology and interpretation while relying on existing summaries of evidence from the existing guidelines.

The Emerging Role of MR Urography in Imaging Megaureters in Children

INTRODUCTION

Megaureter, described as ureter dilatation more than 7 mm in diameter, commonly associated with other anomalies, is still a diagnostic and therapeutic challenge. Magnetic resonance urography (MRU) appears as a promising method in urinary tract imaging, providing both anatomical and functional information. There are several postprocessing tools to assess renal function (including differential renal function) and severity of ureteral obstruction based on MRU. Still, the place of this method in the diagnostic algorithm of ureteropelvicalyceal dilatation with megaureter remains underestimated. Analysis of imaging findings in a group of children diagnosed with megaureter was done.

MATERIAL AND METHODS

A retrospective analysis of magnetic resonance urography (MRU) was performed in 142 consecutive patients examined from January 2013 to September 2019. Twenty-five patients meeting the criteria of megaureter (dilatation more than 7 mm) in MRU were included in the further analysis. The MRU, ultrasound (US), and scintigraphy results were compared and analyzed together and compared with clinical data.

RESULTS

The sensitivity and specificity of US was comparable to the MRU in the assessment of upper urinary tract morphology (p > 0.05). In five out of 25 children, megaureter was found in each kidney; in a single case, both poles of a duplex kidney were affected. In the diagnosis of ureter ectopia, the MRU was superior to the US for which sensitivity did not exceed 16%. The US showed limited value in the diagnostics of segmental ureter dysplasia as a cause of primary megaureter when compared with MRU. Four cases were visualized in MRU studies, whereas the US examination was negative (all confirmed during surgery). There was a moderate correlation between relative renal function between fMRU and scintigraphy (t = 0.721, p = 0.477) and in the severity of obstruction assessment between both methods (r = 0.441, p < 0.05). However, in 10 kidneys with megaureter, the results in scintigraphy were inconclusive due to the signal from the megaureter imposing on the renal field.

CONCLUSIONS

MRU seems to be a preferred method in the diagnostic algorithm for megaureter, providing both anatomical and functional information. MRU is superior to US and scintigraphy in diagnosing urinary tract anomalies with megaureter.

Imaging modalities and treatment of paediatric upper tract urolithiasis: A systematic review and update on behalf of the EAU urolithiasis guidelines panel

BACKGROUND

Prompt diagnosis and treatment of paediatric urolithiasis are required to avoid long term sequelae of renal damage.

OBJECTIVE

To systematically review the literature regarding the diagnostic imaging modalities and treatment approaches for paediatric urolithiasis.

STUDY DESIGN

PubMed, Science Direct, Scopus and Web of Science were systematically searched from January 1980-January 2019. 76 full-text articles were included.

RESULTS

Ultrasound and Kidney-Ureter-Bladder radiography are the baseline diagnostic examinations. Non-contrast Computed Tomography (CT) is the second line choice with high sensitivity (97-100%) and specificity (96-100%). Magnetic Resonance Urography accounts only for 2% of pediatric stone imaging studies. Expectant management for single, asymptomatic lower pole renal stones is an acceptable initial approach, especially in patients with non-struvite, non-cystine stones<7 mm. Limited studies exist on medical expulsive therapy as off-label treatment. Extracorporeal shock wave lithotripsy (SWL) is the first-line treatment with overall stone free rates (SFRs) of 70-90%, retreatment rates 4-50% and complication rates up to 15%. Semi-rigid ureteroscopy is effective with SFRs of 81-98%, re-treatment rates of 6.3-10% and complication rates of 1.9-23%. Flexible ureteroscopy has shown SFRs of 76-100%, retreatment rates of 0-19% and complication rates of 0-28%. SFRs after first and second-look percutaneous nephrolithotomy (PNL) are 70.1-97.3% and 84.6-97.5%, respectively with an overall complication rate of 20%. Open surgery is seldom used, while laparoscopy is effective for stones refractory to SWL and PNL. Limited data exist for robot-assisted management.

CONCLUSIONS

In the initial assessment of paediatric urolithiasis, US is recommended as first imaging modality, while non-contrast CT is the second option. SWL is recommended as first line treatment for renal stones <20 mm and for ureteral stones<10 mm. Ureteroscopy is a feasible alternative both for ureteral stones not amenable to SWL as well as for renal stones <20 mm (using flexible). PNL is recommended for renal stones >20 mm.

Evaluation of Congenital Hydronephrosis with Static and Dynamic Magnetic Resonance Urography in Comparation to Dynamic Renal Scintigraphy

Introduction:

Congenital hydronephrosis (CH) is a condition with dilated renal pelvis with or without dilation of renal calyces.

Aim:

To examine the role of magnetic resonance urography in the detection of congenital hydronephrosis in comparison to dynamic renal scintigraphy (DRS).

Patients and methods:

Resarch included 58 (n=58) patients with diagnosis of congenital unilateral or bilateral dilatation of kidney duct system. Each patient had a one-time or multiple hospitalization at the Nephrology Department of the Pediatric Clinic, with performed: ultrasound which confirmed CH, voiding cystourethrography / voiding urosonography was confirmed based on which the vesicoureteral reflux (VUR) was established / excluded, dynamic renal scintigraphy and magnetic urography (analysis was made by CHOP-fMRU software) on the basis of which the uterine anatomy and the relative renal function were evaluated.

Results:

Male patients were represented in 40 cases (69%). The average age was 4.4 ± 4.3 years with the youngest patient at the age of 2 months, and the oldest was 17 years old. According to diagnostic entities, the most common diagnosis was ureteropelvic junction (UPJ) obstruction in over half of cases (30 or 51.7%), followed by subjects with ureterovesical junction (UVJ) obstruction (11 or 19%), VUR was recorded in 9 (15.5%) cases, and pyelon fissus in 7 (12.1%), and one case (1.7%) was recorded with bilateral megaureter. Comparison of the value of the renal function obtained with DRS and CHOP-fMRU methods shows that there were no statistically significant differences between two methods. In the case of right kidney, the mean DRS value was 53.4 ± 18.4% (range 13-100%), while CHOP-fMRU was 51.8 ± 22.4 (range 0-96.7%). In the case of left kidney, the average value according to the DRS method was 46.9 ± 18.9% (range 0-87%) and according to CHOP-fMRU 47.6 ± 21.5% (range 8.3-100%). The correlation coefficients of both right and left kidneys show a highly statistically significant correlation between these two methods.

Conclusion:

Magnetic resonance urography in the pediatric population in CH based on results should be an integral part of the management of these patients, especially in congenital obstructive uropathy, in complex and associated congenital anomalies, as it provides morphological and functional data on the state of the kidneys and urinary tract.

Surgical validation of functional magnetic resonance urography in the study of ureteropelvic junction obstruction in a pediatric cohort

INTRODUCTION

Ureteropelvic junction obstruction (UPJO) is one of the most common urological diseases in children. The etiology can be intrinsic, extrinsic (crossing vessel [CV] or adhesions), or mixed. To date, ultrasonography and scintigraphy are considered gold-standard imaging techniques for the study of UPJO. Functional magnetic resonance urography (fMRU) combines anatomical and functional information and has been recently evaluated for the detection of CVs in UPJO.

OBJECTIVE

The objective of the study was to evaluate the concordance between fMRU and surgery in determining the etiology of UPJO and the presence of obstructing/non-obstructing CVs.

STUDY DESIGN

Patients with unilateral hydronephrosis who underwent surgery after an fMRU were included in the sample. Surgical data regarding the etiology of UPJO were compared with radiological results. The etiology was divided into intrinsic, extrinsic due to CV, extrinsic due to adhesions, and mixed or cicatricial (postoperative). The concordance was calculated by means of the Cohen's kappa coefficient.

RESULTS

The observed agreement between fMRU and surgical findings regarding the etiology and the presence of CV were 83.2% and 89.4%, respectively (with substantial Cohen's kappa coefficient). The sensitivity and specificity of fMRU were 0.84 and 0.93, respectively; the positive predictive value (PPV) and negative predictive value (NPV) were 0.889 and 0.897, respectively. The observed agreement regarding the type of vessel was 88.3% with a Cohen's kappa coefficient of 0.787 (substantial).

DISCUSSION

In children with hydronephrosis, it is very important for the surgeon to quantify the extent of dilation, define the etiology of the obstruction, and the presence or absence of CVs. fMRU is a 'one-stop-shop' technique which provides both anatomical and functional information showing a high concordance with surgical findings, avoiding radiation exposure.

CONCLUSIONS

fMRU should be considered a valid imaging technique in the study of pediatric UPJO, as it provides the surgeon with important information regarding the etiology of the obstruction for the preoperative planning.

Computed tomography urography with iterative reconstruction algorithm in congenital urinary tract abnormalities in children - association of radiation dose with image quality

Purpose

To assess the extent to which a radiation dose can be lowered without compromising image quality and diagnostic confidence in congenital urinary tract abnormalities in children by using a CT scanner with an iterative reconstruction algorithm.

Material and methods

120 CT urography image series were analysed retrospectively. Image series were divided into four study groups depending on effective radiation dose (group 1: 0.8-2 mSv; group 2: 2-4 mSv; group 3: 4-6 mSv; group 4: 6-11 mSv). Objective and subjective image quality were investigated. In objective analysis, measurements of attenuation and standard deviation (SD) in five regions of interest (ROIs) were performed in 109 excretory image series, and image noise was evaluated. In subjective analysis, two independent radiologists evaluated 138 kidney units for subjective image quality and diagnostic confidence.

Results

There were no significant differences in image noise in objective evaluation between the following study groups: 2 vs. 3 and 3 vs. 4 in all ROIs (with the only exception in spleen SD measurement between study groups 2 vs. 3), while there was significantly more image noise in group 2 in comparison to group 4. For all other ROIs in all study groups, there was more image noise on lower dose images. There were no significant differences in pairwise comparisons between study groups in subjective image quality. Diagnostic confidence was not significantly different between all study groups.

Conclusions

Low-dose CT urography can be a valuable method in congenital urinary tract abnormalities in children. Despite poorer image quality, diagnostic confidence is not significantly compromised in examinations performed with lower radiation doses.

Patterns and frequency of renal abnormalities in Fanconi anaemia: implications for long-term management

BACKGROUND

Fanconi anaemia (FA) is an inherited disease with bone marrow failure, variable congenital and developmental abnormalities, and cancer predisposition. With improved survival, non-haematological manifestations of FA become increasingly important for long-term management. While renal abnormalities are recognized, detailed data on patterns and frequency and implications for long-term management are sparse.

METHODS

We reviewed clinical course and imaging findings of FA patients with respect to renal complications in our centre over a 25-year period to formulate some practical suggestions for guidelines for management of renal problems associated with FA.

RESULTS

Thirty patients including four sibling sets were reviewed. On imaging, 14 had evidence of anatomical abnormalities of the kidneys. Two cases with severe phenotype, including renal abnormalities, had chronic kidney disease (CKD) at diagnosis. Haematopoietic stem cell transplantation was complicated by significant acute kidney injury (AKI) in three cases. In three patients, there was CKD at long-term follow-up. All patients had normal blood pressure.

CONCLUSIONS

Evaluation of renal anatomy with ultrasound imaging is important at diagnostic workup of FA. While CKD is uncommon at diagnosis, our data suggests that the incidence of CKD increases with age, in particular after haematopoietic stem cell transplantation. Monitoring of renal function is essential for management of FA. Based on these long-term clinical observations, we formulate some practical guidelines for assessment and management of renal abnormalities in FA.

Imaging in the diagnosis of pediatric urolithiasis

Pediatric urolithiasis is an important and increasingly prevalent cause of pediatric morbidity and hospital admission. Ultrasound (US) is the recommended primary imaging modality for suspected urolithiasis in children. There is, however, widespread use of CT as a first-line study for abdominal pain in many institutions involved in pediatric care. The objective of this review is to outline state-of-the-art imaging modalities and methods for diagnosing urolithiasis in children. The pediatric radiologist plays a key role in ensuring that the appropriate imaging modality is performed in the setting of suspected pediatric urolithiasis. Our proposed imaging algorithm starts with US, and describes the optimal technique and indications for the use of CT. We emphasize the importance of improved communication with a greater collaborative approach between pediatric and general radiology departments so children undergo the appropriate imaging evaluation.

Diagnostic and Surgical Approach to Prenatally Detected Urinary Tract Anomalies

Regular ultrasound examinations carried out in the second trimester of pregnancy help in detecting many anomalies in the fetal urinary tract. Their percentage ranges from 1% to 3% of all controlled pregnancies. There is a wide spectrum of anomalies that affect the urinary tract, but the most significant are: uretero/hydronephrosis (unilateral or bilateral), kidney agenesis, dysplastic kidney, polycystic and multicystic kidneys, anomalies of ascent, anomalies of kidney rotation or fusion, bladder exstrophy, posterior urethra valve etc. Many of these anomalies do not have impact either on urine flow or on kidney function and hence they can be qualified rather as a condition than as a disease. At the same time, most of the hydronephroses that are seen prenatally are being resolved spontaneously, and they are not detected neither presented postnatally as uretero/hydronephroses of unobstructed type and do not require surgical treatment. Only one tenth of these anomalies are subject to active surgical treatment. Therefore, the assessment of these conditions should be done by a specialized team, who will make adequate therapeutic decisions based on clinical guidelines, as well as will advise the parents on the future clinical implications of the detected anomaly.

Magnetic resonance urography in the pediatric population: a clinical perspective

Diagnostic imaging in pediatric urology has traditionally relied upon multiple modalities based on availability, use of ionizing radiation, and invasiveness to evaluate urological anomalies. These modalities include ultrasonography, voiding cystourethrography, fluoroscopy and radionuclide scintigraphy. Magnetic resonance urography (MRU) has become increasingly useful in depicting more detailed abdominal and pelvic anatomy, specifically in duplex collecting systems, ectopic ureter, ureteropelvic junction (UPJ) obstruction, megaureter and congenital pelvic anomalies. Here we discuss the clinical role of MRU in the pediatric population and its future direction.

Evaluation and management of hydronephrosis in the neonate

PURPOSE OF REVIEW

The prenatal detection of congenital anomalies of the kidney and urinary tract (CAKUT) has permitted the early management of these conditions. The aim of this review is to provide an overview of the management of neonates with antenatal hydronephrosis (ANH).

RECENT FINDINGS

In spite of the continuous advances in the understanding of the genetic basis, clinical course, and outcomes of CAKUT, there are still many controversies regarding the clinical significance, postnatal evaluation, and management of neonates with ANH. Mild ANH will often resolve spontaneously, whereas moderate to severe ANH is frequently associated with CAKUT.

SUMMARY

ANH is a surrogate marker of potential congenital renal anomalies, but usually cannot identify a specific disease. A multidisciplinary team approach is required to diagnose and treat these complex disorders. Currently nonsurgical management of CAKUT should be considered whenever possible for infants with ANH.

Agreement between static magnetic resonance urography and diuretic renal scintigraphy in patients with ureteropelvic junction obstruction after pyeloplasty

BACKGROUND

Ureteropelvic junction obstruction (UPJO) is the most common cause of hydronephrosis within childhood that usually treat by surgery. According to anatomical variations in different individuals, scheduling similar procedures for all patients is not suitable, and thus the best decision for an appropriate surgical technique should be considered separately for each patient. Regardless of the type of applied technique, creating a funnel-shape UPJ with a suitable size is a successful treatment. In this context, the assessment of a successful surgical treatment in a short-term follow-up means repairing revealed anatomical defects. The present study aimed to compare the diagnostic value of static magnetic resonance urography (MRU) and diuretic-based renalscintigraphy (DRS) in patients with UPJO after pyeloplasty.

MATERIALS AND METHODS

A total of 30 consecutive patients with UPJO, who underwent unilateral pyeloplasty between 2012 and 2013 were assessed. All subjects underwent DRS and also MRU about 1-month after the former procedure.

RESULTS

The Kendall's tau correlation showed a very strong correlation between results of MRU and diuretic renal scintigraphy (r = 0.932, P < 0.001). This strong correlation was also shown by Somers'd test (r = 0.932, P < 0.001) similarly.

CONCLUSIONS

Our study shows a strong agreement between DRS and MRU to assess UPJO. MRU static fluid has a high accuracy for assessment of renal system anatomy. Due to the lack of dangerous consequences of contrast materials, MRU can be the best option instead of DRS.

Acute focal bacterial nephritis, pyonephrosis and renal abscess in children

BACKGROUND-AIM

Acute focal bacterial nephritis (AFBN), renal abscess and pyonephrosis are uncommon and not fully addressed forms of urinary tract infection (UTI) which may be underdiagnosed without the appropriate imaging studies. Here, we review the characteristics and outcome of these renal entities in children managed at a single medial centre.

PATIENTS AND METHODS

The medical files of all children hospitalized for episodes of AFBN, renal abscess and pyonephrosis during a 10-year period (2003-2012) were reviewed.

RESULTS

Among the 602 children hospitalized for UTI, 21 presented with AFBN, one with abscess and three with pyonephrosis. All 25 children (13 girls), ranging in age from 0.06 to 13.4 years, were admitted with fever and an impaired clinical condition, and 18 had urological abnormalities. More than one lesion, often of different types, were identified in 11 episodes. Urine cultures from 13 episodes grew non-Escherichia coli pathogens and those from two episodes were negative. Antibiotics were administered for 14-60 days, and emergency surgery was required in three cases. During follow-up, 13 patients underwent corrective surgery. Permanent renal lesions were identified in 16 patients.

CONCLUSIONS

AFBN, renal abscess and pyonephrosis should be suspected in children with severe presentation and urological history. Appropriate imaging is crucial for management planning. Prognosis is often guarded despite appropriate treatment. Based on the results of this study we propose a management algorithm.

A rare case of congenital distal renal tubular acidosis combined with medullary sponge kidney

Distal renal tubular acidosis combined with medullary sponge kidney (MSK) is not uncommon in adults, but is rare in infants. We report a 13-month-old boy with MSK who had features of distal renal tubular acidosis (nephrocalcinosis, hypercalciuria, hypocitraturia) and failed to thrive. Renal ultrasound revealed bilateral increased medullary echogenicity and nephrocalcinosis. Bilateral medullary nephrocalcinosis in the ultrasound was the first sign that alerted our pediatrician to the presence of MSK in infants. Earlier treatment may increase efficacy.

MR imaging of the abdomen and pelvis in infants, children, and adolescents

Recent developments in magnetic resonance (MR) imaging have profoundly changed the investigation of abdominal and pelvic disease in pediatrics. Motion reduction techniques, such periodically rotated overlapping parallel lines with enhanced reconstruction, or PROPELLER, have resulted in reliable imaging with quiet breathing. Faster imaging sequences minimize artifact and allow for more efficient studies. Diffusion-weighted imaging has become increasingly important in the evaluation of neoplastic disease, depicting disease with increased cellularity and helping to differentiate benign from malignant masses. MR enterography helps visualize intra- and extraluminal bowel pathologic conditions. MR cholangiopancreatography can depict congenital and acquired causes of pancreatic and biliary abnormalities. MR urography is an effective technique for a one-stop-shop evaluation of structural urinary tract abnormality and renal function. Three-dimensional acquisitions allow volumetric display of structures from multiple angles. Specialized techniques allow quantification of iron and fat in the viscera in children with hemolytic anemia and obesity, respectively. This article covers current techniques and strategies to perform and optimize MR imaging of the abdomen and pelvis in infants, children, and adolescents and describes important practical applications.

Imaging of the urinary tract: the role of CT and MRI

Computed tomography (CT) and magnetic resonance imaging (MRI) are increasingly valuable tools for assessing the urinary tract in adults and children. However, their imaging capabilities, while overlapping in some respects, should be considered as complementary, as each technique offers specific advantages and disadvantages both in actual inherent qualities of the technique and in specific patients and with a specific diagnostic question. The use of CT and MRI should therefore be tailored to the patient and the clinical question. For the scope of this article, the advantages and disadvantages of these techniques in children will be considered; different considerations will apply in adult practice.

Implications of ionizing radiation in the pediatric urology patient

PURPOSE

We reviewed the literature on the effects of ionizing radiation in pediatric patients, and discuss current recommendations and challenges facing radiologists and pediatric urologists.

MATERIALS AND METHODS

We performed a MEDLINE(R) search to identify articles evaluating the risk of ionizing radiation in pediatric patients. Particular attention was focused on computerized tomography. Standard radiography, fluoroscopy and nuclear imaging were also evaluated.

RESULTS

To date the literature relating radiation exposure to imaging has primarily focused on the role of the pediatrician and radiologist as decision makers. However, these imaging modalities are important to treat and monitor many conditions treated by the pediatric urologist. Conflicting reports have made clinical decision making and patient education challenging.

CONCLUSIONS

A lack of consensus on the risk of radiation exposure in pediatric patients increases the need for heightened awareness by the urologist requesting radiographic evaluation. Monitoring future studies is required to better understand the impact of radiation on children and ensure prompt implementation of appropriate guidelines for patient care.

Imaging chronic renal disease and renal transplant in children

At Great Ormond Street Hospital we have the highest number of paediatric renal transplant patients in Europe, taking cases from across the United Kingdom and abroad. Our caseload includes many children with rare complicating medical problems and chronic renal failure related morbidity. This review aims to provide an overview of our experience of imaging children with chronic renal failure and transplants.

Functional analysis in MR urography - made simple

MR urography (MRU) has proved to be a most advantageous imaging modality of the urinary tract in children, providing one-stop comprehensive morphological and functional information, without the utilization of ionizing radiation. The functional analysis of the MRU scan still requires external post-processing using relatively complex software. This has proved to be a limiting factor in widespread routine implementation of MRU functional analysis and use of MRU functional parameters similar to nuclear medicine. We present software, developed in a pediatric radiology department, that not only enables comprehensive automated functional analysis, but is also very user-friendly, fast, easily operated by the average radiologist or MR technician and freely downloadable at www.chop-fmru.com . A copy of IDL Virtual Machine is required for the installation, which is obtained at no charge at www.ittvis.com . The analysis software, known as "CHOP-fMRU," has the potential to help overcome the obstacles to widespread use of functional MRU in children.