Tumor detection by diffusion-weighted MRI and ADC-mapping--initial clinical experiences in comparison to PET-CT.
OBJECTIVE
To evaluate the clinical potential of diffusion-weighted-imaging (DWI) with apparent diffusion coefficient (ADC)-mapping for tumor detection.


METHODS
A single-shot echo-planar-imaging DWI sequence with fat suppression and ability for navigator-based respiratory triggering was implemented. Nineteen patients (11 melanoma, 4 prostate cancer, 1 non-Hodgkin lymphoma, and 3 lung cancer) were examined by positron emission tomography (PET) with an integrated computed tomography scanner (PET-CT) and DWI. Images at b = 0, 400, and 1000 s/mm2 were acquired and ADC maps were generated. PET examinations were used as a reference for tumor detection. Four hundred twenty-four regions of interest were used for DWI and 73 for PET data evaluation.


RESULTS
DWI and ADC maps were of diagnostic quality. Metastases with increased tracer uptake were clearly visualized at b = 1000 s/mm2 with the exception of mediastinal lymph node metastases in cases of lung cancer. ADC mapping did not improve detection rates.


CONCLUSIONS
DWI is a feasible clinical technique, improving the assessment of metastatic spread in routine magnetic resonance imaging examinations.
Lichy
Matthias P
MP
Department of Diagnostic Radiology, Medical Solutions, Erlangen, Germany. matthias.lichy@med.uni-tuebingen.de
Aschoff
Philip
P
Plathow
Christian
C
Stemmer
Alto
A
Horger
Wilhelm
W
Mueller-Horvat
Christian
C
Steidle
Gunter
G
Horger
Marius
M
Schafer
Jurgen
J
Eschmann
Susanne M
SM
Kiefer
Berthold
B
Claussen
Claus D
CD
Pfannenberg
Christina
C
Schlemmer
Heinz-Peter
HP
D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000175:diagnosis*; D010865:Pilot Projects; D049268:Positron-Emission Tomography / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D014057:Tomography, X-Ray Computed / Q000379:methods*