The role of non-invasive imaging techniques in detecting intra-abdominal adhesions: a systematic review

BACKGROUND: Intra-abdominal adhesions after surgery are highly prevalent. Adhesions implicate complications during subsequent surgery and can cause chronic abdominal pain. The objective of this review was to investigate the usefulness of non-invasive diagnostic methods for detection of adhesions.

METHODS: We searched the electronic databases: MEDLINE, Embase, and The Cochrane Central Register of Controlled Trials for studies investigating the use of non-invasive diagnostic imaging techniques for detecting adhesions. Main outcome was the sensitivity and specificity of each technique. We used the Quality Assessment of Diagnostic Accuracy studies tool to assess bias.

RESULTS: In total, 25 studies were included: 18 using ultrasound (US), 5 using magnetic resonance imaging (MRI), 1 using computed tomography (CT), and 1 using both US and MRI. A total of 2195 patients were included. Overall accuracy ranged between 76 and 100% for US studies and between 79 and 90% for MRI and was 66% for CT. Sensitivity ranged between 21 and 100% for US and between 22 and 93% for MRI and was 61% for CT. Specificity was 32-100% for US, 25-93% for MRI, and 63% for CT. Bias analysis revealed that in most studies, investigators were blinded to the reference standard but not to the index test and 11 of 25 studies had a high risk of selection bias.

CONCLUSIONS: Currently, abdominal US can be used to determine the presence of adhesions between bowel and the abdominal wall. MRI is also an accurate diagnostic modality and can in addition visualize adhesions between viscera, however, with a tendency to over diagnose adhesions. There is insufficient evidence to support CT as a diagnostic modality for adhesions.