Scanning slit chest radiography: a practical and efficient scatter control design.
OBJECTIVE
To design a chest radiography unit that eliminates scatter.


METHODS
A scanning slit radiography unit that also incorporates a conventional grid was designed. The scanning slit geometry defined a 10-mm-wide beam at the image receptor.


RESULTS
With a typical heavy-duty radiographic tube, the proposed system was capable of delivering an entrance skin exposure of up to 32 microC/kg for a 1-second scan. Monte Carlo simulations indicated that the scatter-to-primary ratio (S/P) imaged with the scanning slit system alone was 0.125 for a 35 x 43-cm, 23-cm-thick Lucite phantom imaged at 140 kVp. When the system was coupled with 4:1, 8:1, and 12:1 grids, S/P decreased to 0.063, 0.055, and 0.054, respectively.


CONCLUSIONS
A scanning slit system coupled with a conventional grid is a practical and highly efficient method of controlling scatter and will result in minimal soft-tissue and bone measurement errors in dual-energy chest radiography.
Barnes
G T
GT
Department of Radiology, University of Alabama Hospitals and Clinics, Birmingham.
Wu
X
X
Sanders
P C
PC
D006801:Humans; D009010:Monte Carlo Method; D013902:Radiography, Thoracic / Q000295:instrumentation / Q000379:methods*; D012542:Scattering, Radiation; D013679:Technology, Radiologic