Histogram analysis reveals a better delineation of tumor volume from background in 18F-FET PET compared to CBV maps in a hybrid PET-MR studie in gliomas

Measuring the intersection of tumor and reference tissue histograms in 18F-FET PET and rCBV maps based on identical VOIs defined in anatomical images with tumor marked by contrast enhancement in T1-weighted images can easily be performed and indicates that tumor volume can better be discriminated from background in 18F-FET PET compared to rCBV in MRI. With this approach artefacts (e.g. blood vessels) impair the results to a lesser degree compared to the mean and especially maximal TBRs which are often used when comparing these two image modalities.