Ultrasonography and Doppler Sonography in the Diagnosis of Necrotizing Enterocolitis

Abstract

Despite improvements in ultrasound equipment, ultrasound examination is not widely used for diagnosing necrotizing enterocolitis (NEC) in newborns. The objective of the research was to generalize own experience of using ultrasonography and Doppler sonography for the diagnosis of NEC. The research is based on the results of ultrasound examination of 69 newborns with NEC of varying degrees of severity using diagnostic ultrasound machines “Aloka 600” and “Voluson 730 Pro” (General Electric Healthcare, Austria) with 5-15 MHz linear and curved transducers. According to the results of color Doppler imaging 3 types of blood circulation within the intestinal wall - normal, increased, and absent – were observed in newborns with NEC. Normal blood flow was detected in 20.3% of children with initial stages of the disease. The increased blood flow which was observed in 60.9% of children was characterized by circulatory patterns of blood flow around the intestinal wall (21.7% of children), U-shaped pattern of blood flow in distal mesenteric and subserosal vessels (23.2%) and multiple parallel color Doppler signals which characterized blood flow within hyperemic mucosal folds (15.9%). Blood flow in the intestinal wall was absent in 19 (95%) children with stage III B NEC and 19 (82.6%) children with stage III A NEC; no color Doppler signals were detected. The sensitivity of USG and Doppler sonography regarding the diagnosis of NEC severity, detection of intestinal necrosis in particular was 88.4% and its specificity was 93.9%. The nature of changes in intramural and magistral blood flow depended on the duration of the disease and severity of the pathological process. The obtained results revealed that there was a clear correlation between the indicators of peak systolic velocity and the resistance index in all patients regardless of disease severity. Hemodynamic changes in distal vessels correlated with the decrease in intramural blood flow or its complete absence in the intestinal wall which was typical for newborns with stage III B NEC. Ultrasonography and Doppler sonography allows us to detect necrotic changes in the intestinal wall before perforation occurs and perform required surgical intervention preventing the development of peritonitis that improves the results of treatment of children with necrotizing enterocolitis.