A Prototype Micro-Angiographic Fluoroscope and Its Application in Animal Studies

Area of Science:

• Medical Imaging
• Biomedical Engineering
• Radiology

Background:

• Neurovascular image-guided interventional (IGI) procedures demand high-resolution imaging.
• Existing fluoroscopy systems may not fully meet these demanding resolution and frame rate requirements.

Purpose of the Study:

• To develop and characterize a micro-angiographic fluoroscope (MAF) for high-resolution neurovascular IGI procedures.
• To enable both rapid sequence angiography and high frame rate, low exposure fluoroscopy.

Main Methods:

• A prototype MAF utilizing a CsI(Tl) scintillator, fiber-optical taper, microchannel plate (MCP) image intensifier, and a CCD camera was constructed.
• Image quality metrics including Modulation Transfer Function (MTF), Noise Power Spectrum (NPS), and Detective Quantum Efficiency (DQE) were measured.
• Acquisition software was developed for real-time image processing and small animal IGI procedures.

Main Results:

• The MAF achieved high resolution (up to 10 cycles/mm) with MTF of 14% at 4 cycles/mm and DQE(0) of 60%.
• It supports rapid sequence angiography at 15 fps and fluoroscopy at 30 fps with low exposure levels (5-23 microR/frame).
• First frame lag was below 0.8% in fluoroscopic mode.

Conclusions:

• The developed MAF prototype demonstrates capability for high-resolution neurovascular imaging.
• The system's performance in angiography and fluoroscopy modes is suitable for image-guided interventions.
• Future work includes expanding the field of view for enhanced clinical utility.