Contrast-enhanced ultrasound compared with computed tomography, magnetic resonance imaging, and positron emission tomography-computed tomography for diagnosing liver metastases in people with newly diagnosed colorectal cancer

Objectives: This is a protocol for a Cochrane Review (diagnostic). The objectives are as follows:. To determine the diagnostic accuracy of contrast-enhanced ultrasound (CEUS) versus contrast-enhanced computed tomography (CECT), magnetic resonance imaging (MRI), and fluro-18-deoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) for diagnosing liver metastases in people with newly diagnosed colorectal cancer. Secondary objectives We plan to investigate the following potential sources of heterogeneity. Study design (prospective compared to retrospective) Study date (studies conducted before the year 2000 compared to studies conducted after the year 2000) due to advancements in technology and change in diagnostic criteria Participant selection (participants recruited from planned screening programmes compared to clinical setting) Proportion of participants with resectable liver metastasis Maximum diameter of the largest liver lesion Differences in operator skills in CEUS performance, assessed by years of experience Different reference standards (studies using pathology of resected liver compared to studies using histology of hepatic lesion).