How to use abdominal X-rays in preterm infants suspected of developing necrotising enterocolitis

Acute abdomen in pediatric radiology

BACKGROUND

 Imaging is a common part of the workup for acute abdomen in childhood and adolescence. Rapid diagnosis is crucial for adequate therapy, especially in young children.

METHOD

 This review is intended to provide an overview of the typical causes of acute abdomen in children and adolescents and is specifically aimed at radiologists who do not regularly work in pediatric radiology.

RESULTS AND CONCLUSION

 Age-specific peculiarities make a division into three age groups useful: Newborns, infants and toddlers, and schoolchildren. Possible causes of acute abdomen in children range from congenital lesions, particularly in newborns, to entities well known in adult radiology, more commonly in school-aged children. Since younger children have a higher sensitivity to radiation and often a limited ability to cooperate, sonography and conventional X-ray are the primary imaging modalities used. Decisive advantages of sonography, especially in younger children, include its widespread availability, the lack of need for sedation, and the possibility of bedside examination. Supplementary cross-sectional imaging, usually MRI, is reserved for special clinical questions. Close interdisciplinary cooperation between attending clinicians and radiologists is essential for efficient diagnostics in this patient group.

KEY POINTS

  · Age-specific features must be observed. · Sonography and radiography are the most important modalities. · Both congenital and acquired pathologies play a role. · Good interdisciplinary cooperation is essential in this patient group.

CITATION FORMAT

· Lochbühler N, Bölle P, Müller-Abt P. Acute abdomen in pediatric radiology. Fortschr Röntgenstr 2024; 196: 451 - 462.

Neonatologist-performed point-of-care abdominal ultrasound: What have we learned so far?

This review describes the sonographic appearances of the neonatal bowel in Necrotising enterocolitis. It compares these findings to those seen in midgut-Volvulus, obstructive intestinal conditions such as milk-curd obstruction, and slow gut motility in preterm infants on continuous positive airway pressure (CPAP)-CPAP belly syndrome. Point-of-care bowel ultrasound is also helpful in ruling out severe and active intestinal conditions, reassuring clinicians when the diagnosis is unclear in a non-specific clinical presentation where NEC cannot be excluded. As NEC is a severe disease, it is often over-diagnosed, mainly due to a lack of reliable biomarkers and clinical presentation similar to sepsis in neonates. Thus, the assessment of the bowel in real-time would allow clinicians to determine the timing of re-initiation of feeds and would also be reassuring based on specific typical bowel characteristics visualised on the ultrasound.

Bubbles in the belly: How well do radiology trainees recognize pneumatosis in pediatric patients on plain film?

OBJECTIVES

Pneumatosis intestinalis is a radiographic finding that refers to the presence of gas within the walls of the small or large bowel. This sign is diagnostic in the setting of premature infants with suspected necrotizing enterocolitis. Earlier detection of NEC on X-ray is vital to improve the overall management in these infants. The identification of pneumatosis intestinalis concerning for necrotizing enterocolitis by the "on-call" trainee is critical in the care of the preterm infant. Our objective was to study trainees' ability to identify pneumatosis on an emergent overnight film.

METHODS

The Emergent/Critical Care Imaging SIMulation (WIDI SIM) is a strategically designed computer-aided simulation of an emergency imaging experience that has been rigorously tested and proven to be a reliable means for assessing radiology trainee preparedness to competently and independently cover radiology call. One test case each year included requires the trainee to accurately identify pneumatosis on a plain radiograph of the abdomen in a neonate.

RESULTS

A total of 463 radiology trainees from 32 distinct training programs across the country were given a case of pneumatosis using the WIDI simulation web-based testing platform. On average only 28% of radiology trainees were able to correctly identify pneumatosis intestinalis on plain film. Although the sample sizes in the upper-level trainees were smaller, those with greater number years of training performed better.

CONCLUSIONS

Further training must be given to radiology trainees to accurately recognize pneumatosis and report concerns for necrotizing enterocolitis.

ADVANCES IN KNOWLEDGE

This paper is the first to describe and assess the ability of the "on-call" radiology trainee to accurately recognize pneumatosis and report concerns for necrotizing enterocolitis. Our paper includes the largest cohort of radiology trainees evaluated to this date.

Imaging for Diagnosis and Assessment of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is inflammatory bowel necrosis of preterm and critically ill infants. The disease is seen in 6-10% of preterm infants who weigh less than 1500 g at birth and carries considerable morbidity, mortality, and healthcare cost burden. Efforts focused on timely mitigation remain restricted due to challenges in early diagnosis as clinical features, and available laboratory tests remain nonspecific until late in the disease. There is renewed interest in the radiological and sonographic assessment of intestinal diseases due to technological advances making them safe, cost-efficient, and supporting Web-based transmission of images, thereby reducing time to diagnosis by disease experts. Most of our experience has been with plain abdominal radiography, which shows characteristic features such as pneumatosis intestinalis in up to 50-60% of patients. Many patients with advanced disease may also show features such as portal venous gas and pneumoperitoneum. Unfortunately, these features are not seen consistently in patients with early, treatable conditions, and hence, there has been an unfulfilled need for additional imaging modalities. In recent years, abdominal ultrasound (AUS) has emerged as a readily available, noninvasive imaging tool that may be a valuable adjunct to plain radiographs for evaluating NEC. AUS can allow real-time assessment of vascular perfusion, bowel wall thickness, with higher sensitivity in detecting pneumatosis, altered peristalsis, and characteristics of the peritoneal fluid. Several other modalities, such as contrast-enhanced ultrasound (CEUS), magnetic resonance imaging (MRI), and near-infrared spectroscopy (NIRS), are also emerging. In this article, we have reviewed the available imaging options for NEC evaluation.