Economic evaluation of contrast-enhanced liver MRI in the characterisation of suspected liver lesions

Objectives To determine the cost effectiveness of contrast enhanced (CE) liver magnetic resonance imaging (MRI) compared to multi-phase computed tomography (CT) scan to characterise suspected liver lesions in patients with known extra-hepatic cancer. Methods A decision analytic economic model was built to link diagnostic accuracy to health outcomes in patients with colorectal carcinoma. The model assumed that CE-MRI is diagnostically more accurate, in terms of superior sensitivity and equivalent specificity to CE CT, and patients with a colorectal liver metastasis could be eligible for curative surgery or chemotherapy and palliation. Disutilities were included to capture the impacts of delayed diagnosis (false-negative) or misdiagnosis (false-positive). The cost effectiveness was calculated as the incremental cost relative to the incremental benefit, in which the benefit was estimated using quality-adjusted life-years (QALYs). Sensitivity analyses were conducted to test the robustness of the results. Results The clinical evidence supports the increased sensitivity of CE-MRI compared to CT (0.943 versus 0.768). In the base case analysis, CE-MRI was more effective and more costly than CT. The incremental cost effectiveness ratio (ICER) was estimated to be $40,548 per QALY gained. The model is most sensitive to the cost of MRI and palliative treatment and the disutility associated with delayed palliative care in the false negative group. Conclusions The results of this paper provide evidence of potential benefits associated with CE-MRI for the diagnosis of liver metastases in patients with identified colorectal carcinoma. CE-MRI can be recommended as cost effective provided that improved diagnostic accuracy results in earlier, curative, disease management.