DQE , NPS and MTF Clearly Explained (Detective Quantum Efficiency)

DQE , NPS and MTF are related quantities to quantify the image quality in medical imaging such as x-ray and CT.
The Detective Quantum Efficiency (DQE) is related to the Modulation Transfer Function (MTF) and the Noise Power Spectrum.
The DQE is more foundationally defined as the SNR_in (signal to noise input) divided by the SNR_out (signal to noise output).

[@sk1la]

Sir, I measured the DQE of IMS Giotto 3DL ( using A-Se) and Planmed 3D (using A-Si) detectors. but Planmed 3D's DQE is bigger. I think the reason is because IMS GIOTTO 3DL is an older generation product. So what exactly could be causing the IMS GIOTTO 3DL to have a lower DQE? what parameters can i see?

[@blake1796]

If there are two detectors, A and B. detector A has peak DQE 70% at frequency 2 lp/mm and detector B has peak DQE 60% but at frequency 1 lp/mm. which one is better?

[@HowRadiologyWorks]

What is the measurement task primarily used on the system? Also are those DQEs measured the same way?

[@blake1796]

I measured mtf, nps and dqe of two different detectors. I wanna know which one is better. I measured them the same way. Does the faster the DQE reach the peak value, which means the lower the frequency, the better the detector? or just see which peak value is bigger?