FDG-PET/MRI fused data sets for the detection of liver metastases in patients undergoing systemic anticancer treatment

Background: to retrospectively describe imaging characteristics of liver metastases on fused fdg-pet/ mri data sets and to compare the diagnostic accuracy of mri and fused fdg-pet/mri data sets for the detection of liver metastases in patients undergoing systemic anticancer treatment. materials and methods: 43 oncological patients (mean age: 56+/- 11 years) were investigated by fdg-pet/ct and liver mri. fdg-pet data from pet/ct scans were fused with mri. 556 lesions were evaluated. 5 different evaluation algorithms were used for fdg-pet/ mri evaluation. the sensitivity, specifity, ppv, npv and accuracy of mri and fdg-pet/mri data for the detection of liver metastases were calculated. a mean follow-up of 647 days served as reference standard. mcnemar’s test was used to test for statistically significant differences between mri and fdg-pet/mri (p<0.5). results: the sensitivity, specificity, ppv, npv and accuracy of mri for the detection of liver metastases were 86%, 81%, 97%, 47%, and 85% and 50%, 100%, 100%, 22%, and 56%, for fdgpet/ mri. fdg-pet/mri was significantly less accurate than mri alone (p<.001). conclusion: in opposite to patients before systemic anticancer therapy the fusion of fdg-pet data with liver mri cannot be recommended for the detection of liver metastases in patients undergoing systemic oncological therapy.