Diagnostic imaging features of necrotizing enterocolitis: a narrative review.

Necrotizing enterocolitis (NEC) is an inflammatory process, characterized by intestinal necrosis of variable extension, leading to perforation, generalized peritonitis and death. The classical pathogenetic theory focuses on mucosal damage related to a stress induced intestinal ischemia leading to mucosal injury and bacterial colonization of the wall. A more recent hypothesis emphasizes the role of immaturity of gastrointestinal and immune system, particularly of the premature, responsible of bowel wall vulnerability and suffering. NEC is the most common gastrointestinal emergency in the newborn, with a higher incidence in the preterm; improvement of neonatal resuscitation techniques enables the survival of premature of very low birth weight (VLBW) with prolongation of hospital stay for perinatal and neonatal care and a higher risk of NEC. Clinical presentation of NEC in newborn ranges from mild forms with moderate gastrointestinal tract disorder and that can heal spontaneously, to very serious forms with fulminant course characterized by perforation, peritonitis, sepsis, disseminated intravascular coagulation (DIC) and shock. Imaging modality in the diagnosis of NEC is historically represented by the plain-film abdominal radiographs which can be performed every 6 hours because of the rapid evolution that may occur in the patient's clinical condition. However ultrasound (US), in recent years, is playing an increasingly important role in the evaluation of early stages of the disease as it provides images in real time of the abdominal structures being able to assess the presence and validity of peristalsis of the bowel loops, detect the thickness of the intestinal wall and the presence of minimal amounts of fluid in the peritoneal cavity. In this paper we review the pathogenesis, clinical presentation and imaging of NEC with a particular attention to the emergent role of US in the diagnosis of the disease.

Atypical presentation of sacrococcygeal yolk sac tumor in infant: beware of the injuries of the gluteal region.

Malignant sacrococcygeal yolk sac tumor is a rare extra-gonadal germ cell tumor of infancy and childhood. We report the case of a 14-month-old white female infant with a rapidly growing supra-gluteal mass at first misdiagnosed as hemangioma after a clinical assessment. The lesion was then classified as extra-gonadal yolk sac tumor due to alarming ultrasound features, later confirmed at MRI and pathology. This report remarks the need of a rigorous methodology in the ultrasound exploration of the gluteal region.

Chronic peritoneal dialysis in children: the role of ultrasound in the diagnosis of peritoneal catheter obstruction.

PURPOSE: Over the past two decades, continuous ambulatory peritoneal dialysis has emerged as the first-choice dialysis modality in children awaiting for transplantation. Despite the improvements observed in catheter survival over the past several years, the obstruction is one of the reasons for immediate catheter non-function. This study assessed usefulness of ultrasound (US) in visualizing the obstruction of chronic peritoneal dialysis (CPD) catheter and identifying the etiology. MATERIALS AND METHODS: Between January 2000 and November 2012, 38 patients (20 M, 18 F) were treated with CPD and examined with US. The type of catheter in all subjects was the straight two-cuff Tenckhoff catheter. We evaluated the typical sonographic signs of the most common CPD catheter complications. RESULTS: We had 12/38 cases with catheter malfunction due to its obstruction. In eight patients, US showed the presence of echogenic material fragmented into the lumen and around the distal tip of the catheter. In the other four patients, US demonstrated the displacement of catheter in bowel loops and an amorphous material as homogeneous echoic area around the distal tip. CONCLUSIONS: Our results confirm the effectiveness of US in the assessment of the complications related to intraperitoneal catheters. US is able to identify the catheter obstruction and recognize the etiology (endoluminal strands of fibrin, other materials or the omental wrapping), facilitating a correct therapeutic approach.

Fluoroscopy-guided hydrostatic reduction of intussusception in infancy: role of pharmacological premedication.

PURPOSE: Intussusception is one of the most common causes of paediatric emergency. Fluoroscopy-guided hydrostatic reduction is a common nonoperative management strategy for the treatment of intussusception. The role of pharmacological premedication in increasing the success rate of hydrostatic reduction is still controversial. The purpose of this study was to verify the presence of a possible correlation between pharmacological premedication and the percentage of hydrostatic reduction of intussusception in paediatric patients. MATERIALS AND METHODS: This study considered children with a diagnosis of idiopathic intussusception treated at our hospital between January 2007 and June 2013. One group of patients underwent hydrostatic reduction by barium enema without any preliminary therapy. A second group of patients received pharmacological premedication with both a sedative and an anti-oedematous agent before the procedure. RESULTS: A total of 398 patients were treated with barium enema for therapeutic purposes. In the group of patients who received no premedication (n = 254), 165 (65 %) children achieved hydrostatic reduction of the intussusception. Among the patients who received pharmacological premedication prior to barium enema (n = 144), 122 (85 %) children achieved resolution of the intussusception. CONCLUSIONS: Our study shows that the use of pharmacological premedication is effective for the reduction of the intussusception, as its limit patient stress, fluoroscopic time and radiation dose.

Ultrasonographic diagnosis of midgut volvulus with malrotation in children.

OBJECTIVES: Midgut volvulus with malrotation is typical in newborns. We present our experience to emphasize the importance of suspecting midgut volvulus as a cause of abdominal pain also beyond infancy, particularly in relation to malrotation, and the relevance of ultrasonographic (US) signs in its diagnosis. METHODS: A total of 34 patients (10 boys, 24 girls; ages between 1 day and 12 years) diagnosed as having malrotation or malrotation with volvulus, surgically confirmed, between 2006 and 2013 were retrospectively selected among all of the patients referred to our institution for acute abdomen and bilious vomiting. All of them underwent US and color Doppler examination before surgery. The US examinations were performed with 6 to 10 MHz microconvex and 7.5 to 10 Mhz linear transducer. The transducer was placed under xiphoid, and, with axial projection, the presence of anatomic position reversed between superior mesenteric vein (SMV) and superior mesenteric artery (SMA), as a sign of malrotation, and the presence of "whirlpool sign" (WS) (wrapping of the SMV and the mesentery around the SMA), as a sign of midgut volvulus, were evaluated. RESULTS: In 27 of these 34 patients, midgut volvulus was present; 7 patients had intestinal malrotation. In 2 of 7 (28%) patients with malrotation, SMA and SMV were inverted. Among the patients with volvulus, 2 showed reversed vessel position and 22 patients presented the WS in association with SMA/SMV inversion (22/27, 81%). CONCLUSIONS: Midgut volvulus with malrotation can appear beyond the neonatal age group as demonstrated in our case. The WS sign is sufficiently sensitive for its diagnosis and should be routinely researched at all ages of pediatric population. Anatomic inversion between SMV and SMA seems to be not enough sensitive in isolated malrotation diagnosis.