Intestinal imaging of children with acute rotavirus gastroenteritis

OBJECTIVE

To examine the morphology and motility of the distal small bowel of infants with rotavirus gastroenteritis using non-invasive/non-ionizing imaging technology.

METHODS

Prospective, non-randomized observational study of five infants with symptomatic rotavirus infection. Infants were imaged by real-time magnetic resonance imaging (MRI) and ultrasound within 5 days of onset of gastroenteritis symptoms. Imaging studies were repeated in the convalescent period 5 to 9 weeks later.

RESULTS

Three of five infants had a significant increase in the ileal wall thickness visualized by ultrasound during acute rotavirus infection compared with convalescence. The number and size of mesenteric lymph nodes visualized by ultrasound appeared similar in the acute and convalescent phases, as did peristaltic activity assessed by MRI.

CONCLUSION

Abdominal ultrasound can detect changes in ileal wall thickness in infants with rotavirus infection. These changes may reflect ileal inflammation elicited by viral infection. Such studies may prove useful in evaluating morphologic response to attenuated rotavirus vaccines.

Evaluation of anatomic changes in young children with natural rotavirus infection: is intussusception biologically plausible?

BACKGROUND

Several studies have shown an association between vaccination with the rotavirus vaccine and the development of intussusception. We evaluated the plausibility of a causal association between natural rotavirus infection and intussusception.

METHODS

We performed ultrasound measurements, in infants with confirmed rotavirus infection and in healthy control subjects, of the ileum wall thickness and mesenteric lymph nodes, at enrollment and 1 month later.

RESULTS

Thirteen pairs of patients with rotavirus infection and control subjects were enrolled. The mean distal ileum wall thickness at the first examination was 3.0 mm in patients with rotavirus infection and 2.0 mm in control subjects (P = .037). The maximum lymph node size in patients with rotavirus infection was 11.6 mm at the first examination and 7.4 mm at the second examination (P = .017). Nodal aggregates and free fluid were also observed more commonly among patients with rotavirus infection (54% vs. 9%; P = .033 for both).

CONCLUSION

Rotavirus infection was associated with increased distal ileum wall thickness and lymphadenopathy during the illness period. These changes suggest a plausible mechanism by which rotavirus infection could cause intussusception.

Ultrasonographic assessment of Salmonella enterocolitis in children

BACKGROUND

Salmonella enterocolitis (SE) is one of the important causes of acute infectious diarrhoea. Imaging studies are rarely performed on these patients. Consequently, ultrasound (US) features of SE are controversial.

OBJECTIVE

To identify the clinical significance of US in the evaluation of SE.

MATERIAL AND METHODS

Abdominal US was performed in 15 patients with SE and 9 patients with Rotavirus enterocolitis (RE).

RESULTS

Ascites was present in 60 % and mural thickening of the colon in 40 % of patients with SE on abdominal US, whereas we could not identify these features in patients with RE. In patients with SE, colonic wall thickening; and ascites, the levels of C-reactive protein (CRP) were significantly higher as compared to patients with SE and no colonic wall thickening or ascites. Also, the stool occult blood test was positive more often in patients with colonic wall thickening and ascites on US than in patients without these findings. The colonic wall thickness significantly correlated with CRP and stool occult blood level.

CONCLUSIONS

US is able to identify pathological changes in bowel and intra-abdominal spaces. The US findings of ascites and colonic wall thickening may be useful for determining the severity of SE.

Differences in the clinical and radiologic patterns of rotavirus and non-rotavirus necrotizing enterocolitis

We analyzed retrospectively 32 successive infants who developed necrotizing enterocolitis (NEC), 13 with rotavirus (RV) infection (RV+) and 19 RV-negative (RV-). All patients showed at least pneumatosis intestinalis. All patients except one had risk factors for perinatal asphyxia. Our study demonstrated significant differences between RV+ NEC and RV- NEC cases: RV+ NEC infants had a higher birth weight and were born at a later gestational age. Oral feeding was started earlier and symptoms developed later and more insidiously in RV+ patients than in RV- NEC babies. Radiology revealed a less severe and more distal colon involvement in RV+ NEC infants, whereas the RV- NEC patients mostly had small intestinal or ileocecal changes and more frequent complications of pneumoportogram and intestinal perforations. These latter infants often had a rapidly deteriorating clinical course; 84% needed surgical treatment. In conclusion RV may be a cause of NEC in susceptible infants. Historic and clinical data and a more distal colonic pneumatosis allow a differentiation of RV+ NEC from other forms of NEC.

[The diagnostic value of the plain abdominal radiogram in differentiating rotavirus-negative and rotavirus-positive necrotizing enterocolitis]

Clinical data and radiographic findings of 32 newborn suffering from necrotising enterocolitis were analysed [12 patients with rotavirus-positive necrotising enterocolitis (RV + NEC), 20 patients with rotavirus-negative necrotising enterocolitis (RV-NEC)]. The presence and degree of pneumatosis intestinalis, portal venous gas and pneumoperitoneum on abdominal radiographs were graded after Kosloske et al. according to "mild, moderate, and severe". Pneumatosis intestinalis occurred twice as often in the ascending colon in RV-NEC compared to RV + NEC, whereas the transverse colon was involved nearly as frequently as the descending colon in both groups. Portal venous gas was present in 10% of the cases with RV-NEC and was absent in RV + NEC. Pneumoperitoneum only occurred in 8% of RV + NEC but in 20% of RV-NEC. Radiographic findings are helpful in the differentiation between both groups of NEC. Conservative therapy is preferable especially in mainly distal colon distribution of pneumatosis intestinalis without pneumoperitoneum.

Chest radiography in infant cardiac allotransplantation

Heart transplants were performed in seven infants at Loma Linda University Medical Center from 1985 to 1987. Five of these seven patients survived. In this report, the radiographic appearance of the chest is presented before surgery, immediately after surgery, and during a documented episode of rejection. The most current available chest radiograph is also presented. Acute rejection was confirmed by clinical, echocardiographic, and ECG findings. The only pulmonary infection encountered was mycoplasma pneumonitis. Four patients developed gastrointestinal rotavirus infections and were shown to have dilated proximal small-bowel folds on upper gastrointestinal studies. At the time of this writing, the prognosis for the five surviving infants is good. We conclude that the radiographs of infants who have received heart transplants show an unusual cardiac contour and slight cardiomegaly. Increasing cardiomegaly can alert one to early rejection. Prominent folds in the small bowel are of uncertain origin and significance, but they may be related to infection resulting from immunosuppression.

The radiographic findings in severe rotavirus-induced colitis

Rotavirus infections are a common cause of childhood gastroenteritis but are rarely severe enough to justify radiographs. However, there appears to be a small subset of children in whom a rotavirus-induced diarrheal illness accompanied by bloody stools is sufficiently severe and protracted to warrant barium studies. We have observed spasm and minute mucosal ulcerations of the colon in three of these children. These findings, under other circumstances, would have prompted the diagnosis of ulcerative colitis. These children also had a variety of other findings, such as osteomyelitis, intraocular mycetoma, and positive blood cultures. We suggest that when bloody diarrhea follows or accompanies a typical viral illness, rotavirus particles or antibodies be sought. This may prevent misdiagnosis of ulcerative colitis and unnecessary treatment with steroids.