Frequency of duodenal anatomical variants in neonatal and pediatric upper gastrointestinal tract series (UGI) and the influence of exam quality on diagnostic reporting of these

Ultrasound for infantile midgut malrotation: Techniques, pearls, and pitfalls

Midgut malrotation with volvulus is a surgical emergency with potentially devastating outcomes which include short gut syndrome necessitating long-term parenteral nutrition, overwhelming sepsis, and death. The clinical presentation is most frequently with bilious vomiting in the first days-weeks of life, which is non-specific and common. Timely imaging investigation is therefore crucial to prevent delays to diagnosis and treatment and avoid unnecessary surgical exploration in infants with non-surgical bilious vomiting. Fluoroscopic upper gastrointestinal contrast series (UGI) has been the first-line imaging modality to investigate midgut malrotation at pediatric surgical centers worldwide. However, there is a growing body of evidence to indicate that ultrasound (US) has greater diagnostic accuracy than UGI in this context. Furthermore, US offers the benefits of accessibility, portability, lack of ionizing radiation, and the ability to identify alternative diagnoses, and is beginning to attract significant attention and consideration in the literature. Over the last 3 years, we have transitioned to an "US-first" pathway for the investigation of midgut malrotation in infants with bilious vomiting. This pictorial essay illustrates our comprehensive approach, describes unique troubleshooting techniques, and highlights the variably published pitfalls we have encountered with the aim of encouraging wider adoption.

Quality and Diagnosis on the Lateral View of Pediatric Upper Gastro-Intestinal Series

BACKGROUND

The standard imaging technique for the diagnosis of intestinal malrotation remains the upper gastro-intestinal series (UGIS). The lateral view is promoted as important for making a diagnosis. For this, the lateral view should be of adequate quality, and radiologists must know the normal appearance as well as the appearance of duodenal variants, as misdiagnosis may lead to unnecessary surgery.

OBJECTIVE

We aimed to evaluate the quality, findings including the prevalence of the "descending staircase" configuration and its correspondence to a diagnosis of duodenum redundum.

MATERIALS AND METHODS

This was a retrospective study and was conducted in a large tertiary children's hospital in the United States. A retrospective review of UGI fluoroscopy exams in children aged ≤ 18 years between January and December 2018 was performed by a pediatric radiologist. First, the lateral view images/cine-loops were assessed independently, followed by the anteroposterior (AP) view. The studies which were designated to have an adequate lateral view were evaluated for configuration of the duodenum and recorded as: normal, abnormal, or normal variant. Also, the presence of a descending staircase configuration was correlated with an AP view for a diagnosis of duodenum redundum.

RESULTS

A total of 26 children (26%) (males:16; females:10) with age range 0 to 16 years had adequate lateral views during UGI exams for inclusion. Of the 26, 18 (69%) were reported as normal, 7 (27%) were reported as having a descending staircase and 1 (4%) was reported as abnormal. The AP view demonstrated 2 abnormal studies (1 malrotation and 1 non-rotation), 6 duodenum redundum and 18 normal exams. The one abnormal lateral duodenum was confirmed as a non-rotation on AP view; the second patient with an abnormal AP view had a normal appearance on the lateral view.

CONCLUSIONS

A total of 26% of UGI studies had adequate lateral views for interpretation. Of these, nearly a quarter (23%) demonstrated the descending stair-case sign corresponding to a diagnosis of duodenum redundum on the AP view. If the lateral view had been used alone, there would have been a missed diagnosis in one patient.

Magnetic resonance urography: a practical approach to preparation, protocol and interpretation

Magnetic resonance urography (MRU) is an important MRI application that provides noninvasive comprehensive morphological and functional evaluation of the kidneys and urinary tract. It can be used to assess congenital anomalies of the kidney and urinary tract, which often present as urinary tract dilation. In children, MRU allows for high tissue contrast and high spatial resolution without requiring ionizing radiation. Magnetic resonance urography requires patient preparation in the form of pre-examination intravenous hydration, placement of a urinary catheter, and the administration of diuretics at the time of the exam. The imaging protocol is based on T2-weighted images for anatomical assessment and dynamic post-contrast images for functional evaluation. These images are then used to generate quantitative and graphic results including contrast transit and excretion time as well as to calculate differential renal function. This review focuses on a simple approach to pediatric MRU acquisition and interpretation based on clinical cases and the authors' experience.