The Use of Fusion Ultrasound with CT for The Diagnosis and Treatment of Abdominal Region Pathologies: a Systematic Review

Purpose: Fusion ultrasound is a rising technology that allows the combination of two imaging modalities and surmounts the limitations of each single technique. We aimed to systematically evaluate the application of fusion ultrasound with CT for the diagnosis and intervention of abdominal region pathologies.

Methods: We searched the PubMed database and screened the reference lists for original publications. The search included publications up to September 1, 2021. The risk of bias evaluation included the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2).

Results: The search yielded 830 articles. Of those, 33 original articles satisfied the inclusion criteria. Organs inspected were liver (21 studies,1214 patients), kidneys (5 studies, 108 patients), pancreas (3 studies,148 patients), groin (2 studies, 57 patients), aorta (1 study,14 patients), intestine (1 study,20 patients), with various pathologies. Most studies found fusion US to reduce the radiation needed. It was found within a few studies that fusion US is a feasible tool for clinical practice. When comparing fusion-US-guided biopsy with CT-guided biopsy, the diagnostic yields were comparable. However, the average procedure duration for fusion- US was approximately half. Also, fusion-US was found to be a reliable radiological tool. For example, in a study investigating the conspicuity of hepatic lesions, 66.7% of lesions that were invisible on B-mode sonography became visible with fusion-us. However, excluding two studies, all articles were conducted only on a few dozen patients, and none of the studies were blinded. The QUADAS-2 tool identified a high risk of bias in 6/33 (18.1%) studies.

Conclusion: Fusion-US is a rising radiological tool, diagnostic and interventional. However, the literature is still not satisfactory, limited by small patient numbers and type of studies. Hence, there is a need for more well-designed prospective controlled studies that can accurately assess the value and more specific uses of fusion-US for the abdominal region.