The application of image quality measurements for digital angiography.
The image quality (IQ) evaluation of a charge-coupled device (CCD)-based digital angiography system was assessed with respect to modulation transfer function and noise power spectrum. These values were used to calculate the system's frequency-dependent detective quantum efficiency (DQE). The X-ray image detector was an image intensifier (II) lens coupled to a CCD camera. Two measurement setups were used. Setup A is standard IQ assessment, while Setup B more closely represented clinical conditions (polymethyl methacrylate (PMMA) of varying thickness placed between the X-ray tube and II, with test object positioned between PMMA slices 30 cm from the II). Exposure parameters varied according to automatic brightness control settings. Setup B included X-ray radiation scattered by the patient-PMMA. A clinical DQE, describing the transmission of the input signal-to-noise ratio associated with both primary and secondary X-ray spectra, was defined.
Peterzol
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A
Dipartimento di Fisica, Università di Trieste, Via Valerio 2, 34100 Trieste, Italy. angela.peterzol@insa-lyon.fr
Padovani
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R
Quai
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E
Vano
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E
Prieto
C
C
Aviles
P
P
D000792:Angiography / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D019904:Polymethyl Methacrylate / Q000737:chemistry; D011786:Quality Control; D011856:Radiographic Image Enhancement / Q000379:methods; D013679:Technology, Radiologic; D014963:X-Ray Intensifying Screens; D014965:X-Rays
D019904:Polymethyl Methacrylate