Theoretical performance analysis for CMOS based high resolution detectors.

Area of Science:

• Medical Imaging
• Radiological Physics
• Biomedical Engineering

Background:

• High-resolution imaging is critical for successful endovascular interventions.
• Current X-ray detectors have limitations impacting clinical image quality.
• The micro-angiographic fluoroscope (MAF-CCD) shows good performance but can be improved.

Purpose of the Study:

• To theoretically evaluate the performance of two proposed CMOS detectors as successors to the MAF-CCD.
• To compare the modulation transfer function (MTF) and detective quantum efficiency (DQE) of the proposed detectors.

Main Methods:

• Linear cascade modeling was employed to simulate detector performance.
• Two CMOS detector designs were analyzed: MAF-CMOS (with a 50 μm-pixel CMOS sensor) and MAF-CMOS-LII (with a variable gain light image intensifier).
• Both designs utilized a 300 μm thick HL-type CsI phosphor.

Main Results:

• MAF-CMOS demonstrated slightly superior MTF compared to MAF-CMOS-LII.
• MAF-CMOS-LII exhibited significantly better DQE, particularly at lower exposure levels.
• Both proposed detectors showed potential for improved MTF and DQE over the existing MAF detector.

Conclusions:

• The MAF-CMOS detector performs excellently for angiography but is limited by noise at fluoroscopic levels.
• The MAF-CMOS-LII, with its variable light image intensifier gain, overcomes noise limitations, offering exceptional performance across a wide exposure range.
• While MAF-CMOS-LII is more complex and expensive, its broader applicability makes it a promising candidate for advanced endovascular imaging.