Low-Pass High-Pass Filters

Hi All, I am working on vessel segmentation for my ultrasound images, I have tried VMTK but it didn’t work so now I am annotating the vessels manually and to eliminate the high noise signal for sharper and finer detailed segmentation I wanna apply simple filter such as Low pass High Pass filters or try to find the background noise intensity and filter it later using a tool you would recommend. I added some images for the noise signal and its overlap with the vessel segmentation at the top right of the image where you can see the noise effect and greyness of the image.

Thank you again all and I hope I would get some help from your forum to overcome this problem in processing my data using 3D Slicer