Plain abdominal radiography is the current standard imaging modality for evaluation of necrotizing enterocolitis (NEC). Sonography is still not routinely used for diagnosis and follow-up, as it is not widely recognized that it can provide information that is not provided by plain abdominal radiography and that may affect the management of NEC. Like plain abdominal radiography, sonography can depict intramural gas, portal venous gas, and free intraperitoneal gas. However, the major advantages of abdominal sonography over plain abdominal radiography are that it can depict intraabdominal fluid, bowel wall thickness, and bowel wall perfusion. Sonography may depict changes consistent with NEC when the plain abdominal radiographic findings are nonspecific and inconclusive. Thinning of the bowel wall and lack of perfusion at sonography are highly suggestive of nonviable bowel and may be seen before visualization of pneumoperitoneum at plain abdominal radiography. The mortality rate is higher after perforation; thus, earlier detection of severely ischemic or necrotic bowel loops, before perforation occurs, could potentially improve the morbidity and mortality in NEC. The information provided by sonography allows a more complete understanding of the state of the bowel in patients with NEC and may thus make management decisions easier and potentially change outcome.

Color Doppler US is more accurate than abdominal radiography in depicting bowel necrosis in NEC.

Torsion of the testis and torsion of the testicular appendages have similar presenting features, namely, acute testicular pain and swelling. The former condition requires urgent surgical intervention to save the testis; the latter condition can be treated conservatively. Despite the frequency of torsion of the appendix testis, which is the most common cause of acute hemiscrotum in the child, only occasional references to this entity are found in the radiological literature. We describe five cases in which an enlarged, homogeneously echogenic appendix testis was seen medial or posterior to the head of the epididymis. All cases were accompanied by hydrocele and thickening of the scrotal wall. Among the five cases, enlargement of the head of the epididymis was seen in four and increased testicular blood flow in two. Scanning in the coronal and transverse planes above the testis was useful in locating the enlarged, twisted appendix.