Hello Dr. Fishman, I was looking at your axial head protocol for the LS16 in 2.5mm. I wanted to get your opinion on acquiring those images in an 8i mode vs the 4i made described in your protocol. The reason would be to try to shorten the overall scan time.
Would this affect image quality if the other factors remained the same?
The main reason that is recommended for scanning that way is twofold: 1)
Neurological detail and 2) Beam Collimation. Utilizing 2.5 in 4i mode
uses only 10 mm in the "Z" axis (scan direction) and provides more
detail to the tissue as well as the edges of the data set while at the
same time reducing the potential for over beaming at either end of the
scan set. Some Radiologists have no issue with the data from an 8i data
set, but that would be their call and you should use it only at their
direction. Newer systems that have 20 mm and 40 mm beam collimation are
generally set to the 20 mm configuration for head scans. Again, 40 mm
would work as long as the person making the diagnosis from the images
says it is okay. Good luck and please remember to use the ALARA
principle as much as possible in directing your scan considerations.
CT Clinical Product Specialist