Is radiography or ultrasonography superior at detecting intestinal obstructions in dogs with acute abdominal signs?
Authors: Corrick Josephine 
Published: June 2023

PICO question
In dogs with acute abdominal signs is radiography or ultrasonography superior at detecting surgical patients with intestinal obstructions?

Clinical bottom line
Category of research
Diagnosis.
Number and type of study designs reviewed
Six relevant studies were identified and reviewed, all diagnostic validity studies. Four had cross sectional designs in place and two have a prospective cohort study design.
Strength of evidence
Moderate.
Outcomes reported
All studies showed that ultrasound and radiography were useful in the diagnosis of small intestinal obstruction in dogs. One study with moderate evidence showed that ultrasound is superior to three-view abdominal radiography for diagnosing small intestinal mechanical obstructions in dogs with acute vomiting (p = 0.013). Most of the studies suggested that ultrasound might be more accurate than radiography at detecting surgical patients with intestinal obstructions, but no sufficient evidence was reported. In some studies, the results are too similar for a statistically significant difference to be claimed without further investigation. All studies suggest that the experience of the person who performs or estimates the diagnostic imaging studies can affect the accuracy of each technique, but no statistical comparisons were made to support this hypothesis.
Conclusion
The results of these studies suggest that both techniques are helpful in the diagnosis of small intestinal obstructions in dogs. There are limitations on each technique and factors that can affect accuracy, like the level of training and expertise but more studies are needed to estimate that. Future studies should focus on the comparison of results when ultrasonography is performed in a general practice setting and knowledge base rather than specialists. The majority of studies included in this summary suggest that ultrasound is generally superior if only one modality can be used, but this is mostly based on weak evidence and further investigations to confirm statistical significance are needed. Considering that all studies were performed by diagnostic imaging experts, the only conclusion that can be safely made is that abdominal ultrasound is superior to three-view abdominal radiographs for diagnosing small intestinal mechanical obstructions in dogs with acute vomiting. Additionally it suggests this modality combined with a good level of training on ultrasonography interpretation or, if possible, cooperation with an expert to get the most out of this tool while treating future patients with relevant issues.

How to apply this evidence in practice
The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient’s circumstances and owners’ values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources.
Knowledge Summaries are a resource to help reinforce or inform decision making. They do not override the responsibility or judgement of the practitioner to do what is best for the animal in their care.