Applying PSF on small lesions may result in what effect on SUV max?

Applying Point Spread Function (PSF) modeling on small lesions in Positron Emission Tomography (PET) imaging can significantly affect the calculated Standardized Uptake Value maximum (SUV max) for several reasons.

When PSF is applied, it accounts for the spatial resolution of the imaging system, effectively compensating for the blurring that typically occurs due to factors such as detector performance and patient motion. For small lesions, which inherently have a limited number of counts and may not be optimally resolved, the use of PSF enhances the delineation of these lesions from surrounding tissue.

As a result of this improved resolution and contrast, the SUV max—which reflects the peak uptake of the radiotracer within a lesion—can be increased. The PSF helps in more accurately portraying the activity concentrated in smaller lesions, leading to a higher value for SUV max compared to images processed without PSF correction. This increase in SUV max is particularly important for diagnostic purposes, as it can provide better insight into the aggressiveness of lesions and aid in treatment planning.

Ultimately, the application of PSF can lead to a more accurate representation of lesion uptake, which is critical in assessing the presence and severity of disease.