Fig. 7
![Fig. 7](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs40658-022-00452-4/MediaObjects/40658_2022_452_Fig7_HTML.png)
ROI Mean comparison between OSEM, OSEM-PSF, HKEM and FHKEM frozen at the 72nd sub-iteration for the hottest lesion of 4 different patients. The black vertical and horizontal lines represent respectively the CoV and the mean value estimated on the vendor reconstructed image at iteration 2