Accuracy of [18F]FDG PET/MRI for the Detection of Liver Metastases.
BACKGROUND
The aim of this study was to compare the diagnostic accuracy of [18F]FDG-PET/MRI with PET/CT for the detection of liver metastases.


METHODS
32 patients with solid malignancies underwent [18F]FDG-PET/CT and subsequent PET/MRI of the liver. Two readers assessed both datasets regarding lesion characterization (benign, indeterminate, malignant), conspicuity and diagnostic confidence. An imaging follow-up (mean interval: 185±92 days) and/-or histopathological specimen served as standards of reference. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for both modalities. Accuracy was determined by calculating the area under the receiver operating characteristic (ROC) curve. Values of conspicuity and diagnostic confidence were compared using Wilcoxon-signed-rank test.


RESULTS
The standard of reference revealed 113 liver lesions in 26 patients (malignant: n = 45; benign: n = 68). For PET/MRI a higher accuracy (PET/CT: 82.4%; PET/MRI: 96.1%; p<0.001) as well as sensitivity (67.8% vs. 92.2%, p<0.01) and NPV (82.0% vs. 95.1%, p<0.05) were observed. PET/MRI offered higher lesion conspicuity (PET/CT: 2.0±1.1 [median: 2; range 0-3]; PET/MRI: 2.8±0.5 [median: 3; range 0-3]; p<0.001) and diagnostic confidence (PET/CT: 2.0±0.8 [median: 2; range: 1-3]; PET/MRI 2.6±0.6 [median: 3; range: 1-3]; p<0.001). Furthermore, PET/MRI enabled the detection of additional PET-negative metastases (reader 1: 10; reader 2: 12).


CONCLUSIONS
PET/MRI offers higher diagnostic accuracy compared to PET/CT for the detection of liver metastases.
Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
Karsten
K
Beiderwellen
Department of Nuclear Medicine, University Hospital Santa Creu i Sant Pau, Barcelona, Spain.
Llanos
L
Geraldo
Clinic for Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
Verena
V
Ruhlmann
Department of Diagnostic and Interventional Radiology, University of Duesseldorf, Duesseldorf, Germany.
Philipp
P
Heusch
Clinic for Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
Benedikt
B
Gomez
Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
Felix
F
Nensa
Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
Lale
L
Umutlu
Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
Thomas C
TC
Lauenstein
D000328:Adult; D000368:Aged; D019540:Area Under Curve; D002277:Carcinoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000556:secondary*; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000556:secondary*; D008279:Magnetic Resonance Imaging; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000556:secondary*; D008875:Middle Aged; D064847:Multimodal Imaging / Q000592:standards; D015588:Observer Variation; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D012372:ROC Curve; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed