The Role of Magnetic Resonance Imaging in Necrotizing Enterocolitis

To the Editor.

The treatment of necrotizing enterocolitis (NEC) is a continuing challenge for neonatalogists and pediatric surgeons. Although many infants are treated successfully without operation, others require surgical intervention for intestinal perforation or necrosis. Determining which infants with NEC require operation is a diagnostic challenge. In a recent issue of Pediatrics, Maalouf et al conclude, “Magnetic resonance imaging (MRI) is likely to be of value in diagnosing intestinal necrosis and determining the need for surgical intervention.”¹

Although the authors have chosen a crucial subject for study and have raised some interesting questions, they have not presented data sufficient to support their conclusions. The major problems of this study include: selection of a study group inappropriate to answer the research question, selection of a control group inappropriate to the research question, retrospective analyses of the results of the MRI scans by unblinded radiologists already aware of the clinical findings, and a sample size far too small to allow results to be generalized.

The authors defined the entry criteria for the study to include patients with clinical and radiographic signs of severe NEC who subsequently underwent operation for NEC. All 6 of the study patients already had a combination of clinical and radiographic abnormalities mandating operation before the MRI scan was obtained. Each had extensive pneumatosis on plain films and at least 2 had intraperitoneal gas.

The authors describe the MRI findings to include dilated bowel loops, mesenteric edema, and thick bowel wall. Each of these findings was present on the plain radiographs, and MRI was not needed to see them. The authors then describe what they believe to be the pivotal finding in their study: “bubble-like appearance.” “Bubble-like appearance” is the term used by the authors to describe the MRI appearance of intramural gas or what is commonly called …