Scanner matching (1): find parameter for matching
 
 
- Calculated PARs for all “NRPB” scanners for which CTDI values were available
- Calculated effective doses using CTDOSE software for head and body examinations on “NRPB” scanners
- Input all values into multi-variate analysis software
- Obtained following coefficient values:
	For head scans: a = 0.47; b = 0.80; c = 0.075
	For abdo scans: a = 3.58; b = 0.63; c = -0.090
ImPACT Factor = a. PARc + b. PARp + c
-    Calculated ImPACT Factors for each NRPB scanner
    for a head and body examination