[Kidney trauma in children: state of the art medical imaging]

Point-of-Care Ultrasound to Assess Anuria in Children

Anuria in children may arise from a host of causes and is a frequent concern in the emergency department. This review focuses on differentiating common causes of obstructive and nonobstructive anuria and the role of point-of-care ultrasound in this evaluation. We discuss some indications and basic techniques for bedside ultrasound imaging of the urinary system.

[Ultrasound of the urinary system]

Ultrasound techniques are able to provide a fairly complete examination of the urinary system, achieving a high sensitivity in relevant-pathology detection, especially in the kidney, bladder and prostate. Early detection of pathologies such as tumors or urinary tract obstructions, sometimes even before their clinical manifestation, has improved their management and prognosis in many cases. This, added to its low cost and harmlessness, makes ultrasound ideal for early approaches and follow-up of a wide number of urinary system pathologies. In this article, the ultrasound characteristics of the main urinary system pathologies that can be diagnosed by this technique, are reviewed.

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.

[Outcome of severe closed kidney injuries in children]

AIMS

To analyze the results of treatment of major renal injuries according imaging data in order to determine their function after follow-up.

PATIENTS AND METHODS

This is a retrospective study of 22 cases of fracture of the kidney (grade V) in two pediatric surgical services that were reviewed over a period of 16 years. After initial conservative treatment in 19 patients (86.5%), a scan and/or Uro-MRI were realized in all patients in monitoring evolving. Three children with vascular injury were treated by interventional radiology. The morphology and functional evolution of the injured kidney were determined.

RESULTS

A DMSA scan investigation was performed in 21 patients (95.5%) associated with Uro-MRI in two cases; one patient was only explored with Uro-MRI. A complete restitution of the renal parenchyma was confirmed in 10 children (45.5%), we noted an atrophy of the upper pole in 30%, a lower pole atrophy in 4.5%, two complete renal atrophy in 9%. An urinoma was present in six patients (27%) that required drainage in five cases and declined during the surveillance in one case. Normal function of the injured kidney was noticed in half of grade V (11 of 22 patients) with a mean follow-up of 19 months. None of our patients did present hypertension.

CONCLUSION

Non-operative conservative treatment in severe renal trauma was efficient, morphological and functional sequelae were present in 50% on scintigraphy and/or Uro-MRI.

[Thoracic and abdominal trauma in children]

Knowledge of the characteristics of thoraco-abdominal trauma in children is important to optimize the imaging work up while keeping radiation exposure to a minimum. Because of the plasticity of the pediatric rib cage, rib fractures are infrequent, and severe parenchymal injuries may be present in the absence of rib fracture. Mediastinal injuries are unusual. The increased mobility of solid intraabdominal organs combined with a weaker abdominal wall are specific to pediatric patients. First-line imaging typically includes chest radiograph and abdominal US with Doppler imaging. Contrast-material enhanced CT is used as a second-line technique, with delayed imaging in patients with urinary tract lesions. Dedicated pediatric acquisition protocols are mandatory. Follow-up is obtained mainly with US.