'Intensity diffusion' is a better description than 'partial volume effect'.
Skretting
Arne
A
D006801:Humans; D021621:Imaging, Three-Dimensional; D049268:Positron-Emission Tomography / Q000706:statistics & numerical data*; D009626:Terminology as Topic; D015899:Tomography, Emission-Computed, Single-Photon / Q000706:statistics & numerical data*