Table 3.

Sonographic evaluation of SBO.

Author	Design	N	Findings	Conclusion
Ünlüer et al. [7]	Prospective US versus CT and XR	174	No significant difference between EM and radiology residents in diagnosing BO using US.	With proper training of EM residents, their diagnostic accuracy of BO using US can be comparable to those done by radiology residents.
Jang et al. [8]	Prospective US versus CT and XR	76	US showed that the presence of dilated loop of bowel had a sensitivity and specificity of 90.9% and 83.7%, respectively, and the presence of absent peristalsis had a sensitivity and specificity of 27.3% and 97.7%, respectively.	US showed superiority over plain radiographs in detecting SBO.
Musoke et al. [10]	Prospective	70	US showed a sensitivity of 93%, specificity of 100%, PPV of 100%, and NPV of 73%.	Not only does US show promises in diagnosis, but it may play a role in detecting patients who need emergent intervention such as those with strangulation.
Ko et al. [12]	Retrospective	54	US is better than plain radiographs in diagnosing SBO and in detecting the level and cause of obstruction.	US can be helpful in diagnosing SBO when other modalities are not readily available.
Grassi et al. [13]	Retrospective	150	US not only detects the obstruction, but it can detect if this obstruction is caused by a functional or obstructive cause, and it can detect the level of severity.	Using US can detect findings of a worsening obstruction. This may reduce the wait time for a more detailed imaging study (such as CT) before deciding between conservative and surgical management.