The MTF, NNPS, and DQE are standard linear system metrics used to characterize intrinsic detector performance.
To evaluate total system performance for actual clinical conditions, generalized linear system metrics (GMTF,
GNNPS and GDQE) that include the effect of the focal spot distribution, scattered radiation, and geometric
unsharpness are more meaningful and appropriate. In this study, a two-dimensional (2D) generalized linear system
analysis was carried out for a standard flat panel detector (FPD) (194-micron pixel pitch and 600-micron thick CsI)
and a newly-developed, high-resolution, micro-angiographic fluoroscope (MAF) (35-micron pixel pitch and 300-
micron thick CsI). Realistic clinical parameters and x-ray spectra were used. The 2D detector MTFs were calculated
using the new Noise Response method and slanted edge method and 2D focal spot distribution measurements were
done using a pin-hole assembly. The scatter fraction, generated for a uniform head equivalent phantom, was
measured and the scatter MTF was simulated with a theoretical model. Different magnifications and scatter fractions
were used to estimate the 2D GMTF, GNNPS and GDQE for both detectors. Results show spatial non-isotropy for
the 2D generalized metrics which provide a quantitative description of the performance of the complete imaging
system for both detectors. This generalized analysis demonstrated that the MAF and FPD have similar capabilities at
lower spatial frequencies, but that the MAF has superior performance over the FPD at higher frequencies even when
considering focal spot blurring and scatter. This 2D generalized performance analysis is a valuable tool to evaluate
total system capabilities and to enable optimized design for specific imaging tasks.