Diagnostic accuracy of whole-body MRI/DWI image fusion for detection of malignant tumours: a comparison with PET/CT.
OBJECTIVE
To prospectively evaluate the diagnostic accuracy of whole-body T2-weighted (wbT2), whole-body diffusion-weighted imaging (wbDWI) and wbT2/wbDWI image fusion for malignant tumour detection compared with PET/CT.


METHODS
Sixty-eight patients (44 men; 60 ± 14 years) underwent PET/CT for staging of malignancy and were consecutively examined by 1.5-Tesla MRI including wbT2 and wbDWI. Two radiologists independently assessed wbDWI, wbT2, wbT2 + wbDWI (side-by-side) and wbT2 + wbDWI + wbT2/wbDWI image fusion for the presence of malignancy. PET/CT served as a reference standard.


RESULTS
PET/CT revealed 374 malignant lesions in 48/64 (75%) patients. Detection rates and positive predictive value (PPV) of wbT2 and wbDWI alone were 64% and 84%, and 57% and 93%, respectively. Detection rates and PPV of wbT2 and wbDWI for side-by-side analysis without and with fused images were 72% and 89%, and 74% and 91%, respectively. The detection rate was significantly higher with side-by-side analysis and fused image analysis compared with wbT2 and wbDWI alone (p = .0159; p < .0001). There was no significant difference between fused image interpretation and side-by-side analysis.


CONCLUSIONS
WbDWI allows detection of malignant lesions with a similar detection rate to wbT2. Side-by-side analysis of wbT2 and wbDWI significantly improves the overall detection rate and fused image data provides no added value.
Fischer
Michael A
MA
Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland.
Nanz
Daniel
D
Hany
Thomas
T
Reiner
Caecilia S
CS
Stolzmann
Paul
P
Donati
Olivio F
OF
Breitenstein
Stefan
S
Schneider
Paul
P
Weishaupt
Dominik
D
von Schulthess
Gustav K
GK
Scheffel
Hans
H
D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000175:diagnosis*; D049268:Positron-Emission Tomography; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D014057:Tomography, X-Ray Computed; D051598:Whole Body Imaging