ESPR uroradiology task force and ESUR paediatric working group: imaging recommendations in paediatric uroradiology, part IV: Minutes of the ESPR uroradiology task force mini-symposium on imaging in childhood renal hypertension and imaging of renal trauma in children

Imaging of urinary tract in children in different clinical scenarios: a guide for general radiologists

Background

Children are frequently referred to the pediatric radiology department due to complaints related to the urinary tract.

Main body

We aimed to describe common clinical scenarios in paediatric urology practice and their recommended imaging diagnostic algorithms. Practical imaging approach to following common clinical scenarios and the common radiological findings are discussed: (A) perinatal urinary tract dilatation and other congenital anomalies; (B) recurrent urinary tract infection; (C) enuresis and daytime urinary incontinence; (D) abdominal masses; (E) flank pain; (F) hematuria; (G) trauma; (H) nonpalpable testis, ambiguous genitalia and common urogenital sinus anomalies; and I) renovascular hypertension

Conclusions

Imaging investigations should be tailored according to the clinical presentation in a stepwise approach aiming for optimum patients’ care.

Does contrast-enhanced ultrasound have a role in evaluation and management of pediatric renal trauma? A preliminary experience

BACKGROUND

To report our initial experience using intravenous contrast-enhanced ultrasound (CEUS) in pediatric renal trauma with the potential for substantial radiation reduction.

METHODS

A retrospective review of all patients who underwent intravenous CEUS at our institution between May 2015 and January 2018 for the suspicion of blunt renal trauma. CEUS was obtained either as an immediate or short-term comparison to contrast-enhanced computed tomography (CECT), or in outpatient follow-up.

RESULTS

CEUS was performed on 7 patients (9 kidneys) with age range 2 months to 16 years old. CEUS was utilized as a comparison to CECT in 4 of 7 patients for initial evaluation, clinical change, or short-term follow-up. CEUS alone was used in one patient with low suspicion for renal injury. In the remaining two patients, CEUS was obtained as a follow-up study weeks after the initial CECT, following conservative management. All patients with confirmed renal injury by CECT (n = 5) underwent a follow-up CEUS at 1-2 months.

CONCLUSIONS

In an era of conservative management for renal trauma in which operative intervention is dictated more often by the clinical course than radiographic findings, it is reasonable to consider alternative imaging methods such as CEUS in stable patients to decrease radiation exposure.

LEVEL OF EVIDENCE RATING

IV.

Renal ultrasound to evaluate for blunt renal trauma in children: A retrospective comparison to contrast enhanced CT imaging

INTRODUCTION

The standard imaging modality for hemodynamically stable blunt abdominal trauma patients is a contrast enhanced CT scan, which is reflected in the current AUA urotrauma guidelines. This comes, however, with radiation exposure and the potential sequalae of IV contrast administration in the pediatric patient.

OBJECTIVE

We hypothesize that ultrasound imaging would be able to diagnose and rule out clinically significant renal injuries when compared to the gold standard of CT scan in the setting of pediatric blunt abdominal trauma.

STUDY DESIGN

All children <18 years of age who were evaluated for blunt abdominal trauma who had a CT scan and ultrasound imaging of kidneys were identified. The ultrasound images were reviewed by four reviewers who were blinded to CT results and all clinical information. The ability of ultrasound to diagnose and rule out clinically significant renal injury was evaluated by diagnostic test performance characteristics including sensitivity, specificity, negative predictive value and positive predictive value.

RESULTS

There were 76 patients identified, 24 of which had a renal injury (1 bilateral) diagnosed by CT scan for a total of 25 injuries in 152 renal units. There were six grade I-II injuries and 19 grade III-V injuries. The sensitivity of the four blinded reviewers by ultrasound alone to detect the 19 grade III-V injuries ranged from 79 to 100% with NPV between 97 and 100%. Three of the four reviewers identified all 19 grade III-V injuries by ultrasound. When combined with significant hematuria, all 19 grade III-IV injuries were identified. Of note, all patients with a grade III-V injury of the kidney had significant hematuria. Of the grade I-II renal injuries, all reviewers identified 1/5 or 2/5 by ultrasound alone.

DISCUSSION

The limitations of this study include: its retrospective nature, limited number of patients and reviewers, quality of the ultrasound machine. and experience of technologist, radiologist and urologist. A major limitation is the inability to assess other solid organ injuries during this initial study.

CONCLUSIONS

When compared to a CT scan as the gold standard, kidney ultrasound images had a sensitivity of 79-100% to detect grade III-V injuries and NPV of 97-100% by four blinded reviewers. All grade III-V injuries had either an episode of gross hematuria or microscopic hematuria >50 RBC/hpf. A prospective study that includes full abdominal imaging is needed to confirm that ultrasound can safely be used in place of CT scan for evaluation of hemodynamically stable blunt trauma patients.

Point-of-Care Ultrasound Evaluation of Severe Renal Trauma in an Adolescent

Traumatic renal injuries are more common in pediatrics because of the relatively larger size of the kidneys in the pediatric patient. Although computerized tomography remains the criterion standard for the initial evaluation of blunt renal trauma, there is evidence that renal ultrasound may serve a role in postinjury surveillance. Here, we present a case in which point-of-care ultrasound was used to image severe blunt renal trauma in a 17-year-old adolescent boy. In this case, point-of-care ultrasound identified severely distorted renal parenchyma after a grade 5 renal laceration was identified on computerized tomography scan.

Standardization of pediatric uroradiological terms: a multidisciplinary European glossary

To promote the standardization of nephro-uroradiological terms used in children, the European Society of Paediatric Radiology uroradiology taskforce wrote a detailed glossary. This work has been subsequently submitted to European experts in pediatric urology and nephrology for discussion and acceptance to improve the quality of radiological reports and communication between different clinicians involved in pediatric urology and nephrology.

Standardization of pediatric uroradiological terms: A multidisciplinary European glossary

To promote the standardization of nephro-uroradiological terms used in children, the European Society of Pediatric Radiology uroradiology taskforce wrote a detailed glossary. This work has been subsequently submitted to European experts in pediatric urology and nephrology for discussion and acceptance to improve the quality of radiological reports and communication among different clinicians involved in pediatric urology and nephrology.

Sonographic evaluation of renovascular hypertension in the pediatric population: State-of-the-art

Hypertension in children affects 2-5% of the pediatric population. Identifying secondary causes of hypertension is crucial, as some of these entities may be treatable. Renovascular hypertension accounts for 5-10% of the secondary causes of hypertension in children and is mainly related to fibromuscular dysplasia and neurofibromatosis type 1. Ultrasonographic evaluation of the kidneys, including Doppler interrogation, is the recommended primary screening tool. A comprehensive study of the upper abdomen and retroperitoneum allows for identification of additional underlying etiologies. The purpose of this review is to emphasize the different causes of renovascular hypertension in children one can diagnose during the initial ultrasonographic evaluation. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:282-292, 2017.

Renal trauma: imaging evaluation and implications for clinical management

Severe renal injuries are usually associated with multisystem injuries, may require interventional radiology to control hemorrhage and improve the chances for renal salvage, and are more likely to fail nonoperative management. However, most renal injuries are mild in severity and successfully managed conservatively. The AAST classification is the most widely used system to describe renal injuries and carries management and prognostic implications. CT with intravenous contrast is the imaging test of choice to assess for renal injuries. Contrast extravasation indicating active bleeding should be mentioned as its presence is predictive for failure of nonoperative management. Radiologists play a critical role in identifying renal injuries and should make every effort to describe renal injuries according to the AAST grading scheme to better inform the surgeon's management decisions.

Imaging assessment of renal injuries in children and adolescents: CT or ultrasound?

BACKGROUND

Since the introduction of the ALARA ("as low as reasonably achievable") concept, ultrasound (US) has been progressively advocated for paediatric diagnostic imaging. This study aimed to analyse the role and accuracy of US in paediatric renal trauma.

METHODS

From 1999 to 2009, the tertiary-care-hospital database was retrospectively evaluated for renal trauma with regards to aetiology, type of injury, diagnostics, management and outcome.

RESULTS

Forty-seven patients (29 males, 18 females; median age=14years, range 1-17 years) were identified. US was initially applied in 45 patients with correct results in 86.6%. Computed tomography (CT) was performed in 16 patients in the acute trauma setting - complementary to US in 14 cases, with a diagnostic accuracy of 93%. Most renal injuries were grade I° (n=30), followed by grade III° (n=8), IV° (n=5), and II°/V° (n=2 each). All patients were initially managed conservatively and followed by US. Clinical deterioration necessitated surgery in four patients (2 nephrectomies, 1 partial nephrectomy, 1 urinoma drainage). The outcome was generally favourable with a renal preservation rate of 95%.

CONCLUSION

With respect to the ALARA principle, US can be safely and reliably applied as the first-line diagnostic imaging technique and for follow-up for suspected traumatic paediatric renal injuries.

ESPR uroradiology task force imaging recommendations in paediatric uroradiology, part VII: standardised terminology, impact of existing recommendations, and update on contrast-enhanced ultrasound of the paediatric urogenital tract

Our purpose is to harmonise and standardise terminology in paediatric uroradiology, to provide and update recommendations for contrast-enhanced US to standardise imaging and encourage further research, and to assess the impact of the existing recommendations in paediatric urogenital imaging. Based on thorough review of literature and variable practice at several centres and after discussion within urogenital imaging groups as well as with other subspecialties, we propose a standardisation of terminology in urogenital imaging. An update with recommendations on paediatric contrast-enhanced US has been issued based on available literature and reports. Finally, a questionnaire has been used to assess the knowledge, applicability and usefulness of, and the adherence to existing recommendations of the European Society of Paediatric Radiology (ESPR) Uroradiology Task Force. In conclusion, the ESPR is working to improve patient safety and optimise paediatric urogenital imaging. Standardisation of terminology and provision of updated knowledge on contrast-enhanced US in childhood will contribute to this task, ideally reducing the need for invasive or radiating imaging. Not all existing recommendations are commonly known, which limits adherence to these recommendations and the availability of comparable data and evidence for future adaptation of imaging strategies in paediatric uroradiology.

The utility of initial and follow-up ultrasound reevaluation for blunt renal trauma in children and adolescents

OBJECTIVE

To discover if renal ultrasound (RUS) can be utilized as the primary follow-up imaging modality in the management of blunt renal injuries in children and adolescents.

METHODS

We initiated a protocol utilizing RUS reevaluations for children and adolescents treated for blunt renal injuries. Patients following this protocol (Post) had initial computerized tomography (CT) with RUS reevaluation at day 2 and 2 weeks. We retrospectively compared this group to a 2-year cohort treated between 2007 and 2009 (Pre).

RESULTS

In our study, 28 Post protocol patients were retrospectively compared with 22 Pre cohort patients. No significant differences were observed in age, length of stay (LOS), injury severity score (ISS), and utilization of CT reevaluation. Follow-up reevaluation was obtained in 13 Pre patients versus 21 Post patients (p = 0.231). No patients had any evidence of long-term complications in either cohort.

CONCLUSION

Our results suggest that RUS can be utilized as the primary surveillance imaging modality in the management of blunt renal injuries in children and adolescents. The lack of benefit of usage of RUS demonstrated in the acute post-injury surveillance period calls into question the benefit of RUS immediately following the blunt trauma.

Magnetic resonance and computed tomography in pediatric urology: an imaging overview for current and future daily practice

The main imaging modality of the urinary tract in children is ultrasound. When further cross-sectional morphologic examination and/or functional evaluation is required, magnetic resonance (MR) imaging is the logical and optimal second step, particularly in pediatric patients. There are two main exceptions to this. The first one is when after an ultrasound, additional diagnostic imaging for urolithiasis is needed. The second one involves severe polytrauma, including blunt abdominal trauma. In this review, an overview of the MR imaging and computed tomography examinations important for current and future daily pediatric uroradiologic practice is presented.

Different imaging strategies in febrile urinary tract infection in childhood. What, when, why?

Urinary tract infections (UTIs) are a common problem in childhood. During the last decade, published papers led to a deep revision in the use and usefulness of imaging tools in children with febrile UTIs. This new body of knowledge was partially endorsed by the guidelines published in 2007 by the UK's National Institute for Clinical Excellence and in 2011 by the American Academy of Pediatrics. Nevertheless, new data continuously arise and the scientific debate always revives. Recommendations of published guidelines and strengths and weaknesses of the available biochemical and imaging tools are here critically analysed for giving to the reader a complete, up-to-date and flexible overview on this hot topic.

Multi-detector CT in the paediatric urinary tract

The use of paediatric multi-slice CT (MSCT) is rapidly increasing worldwide. As technology advances its application in paediatric care is constantly expanding with an increasing need for radiation dose control and appropriate utilization. Recommendations on how and when to use CT for assessment of the paediatric urinary tract appear to be an important issue. Therefore the European Society of Paediatric Radiology (ESPR) uroradiology task force and European Society of Urogenital Radiology (ESUR) paediatric working groups created a proposal for performing renal CT in children that has recently been published. The objective of this paper is to discuss paediatric urinary tract CT (uro-CT) in more detail and depth. The specific aim is not only to offer general recommendations on clinical indications and optimization processes of paediatric CT examination, but also to address various childhood characteristics and phenomena that facilitate understanding the different approach and use of uro-CT in children compared to adults. According to ALARA principles, paediatric uro-CT should only be considered for selected indications provided high-level comprehensive US is not conclusive and alternative non-ionizing techniques such as MR are not available or appropriate. Optimization of paediatric uro-CT protocols (considering lower age-adapted kV and mAs) is mandatory, and the number of phases and acquisition series should be kept as few as possible.