Program Information

Comparison of CCD and CMOS Micro-Angiographic Fluoroscope (MAF) Detector Systems Using Contrast Measurements for Specific Imaging Tasks Related to Neuro-Endovascular Image-Guided Interventional (EIGI) Procedures

R Rana*, A Jain , S Setlur Nagesh , D Bednarek , S Rudin , University at Buffalo, Buffalo, New York

Presentations

SU-E-I-13 Sunday 3:00PM - 6:00PM Room: Exhibit Hall

Purpose: To compare the performance of two high-resolution detector systems for use during neuro-EIGI procedures.

Methods: The task-specific performance of custom high-resolution CCD and CMOS micro-angiographic fluoroscopes (MAF) was compared. To simulate the attenuation of x-rays by a patient in neuro-EIGIs, a modified ANSI head phantom was used. A bar phantom with 0.05-mm thick lead was used to simulate the contrast and size of EIGI devices used in neuro EIGIs. The bar phantom, placed at an angle of 6.5 degrees relative to the pixel rows of both detectors, was imaged for 88kVp using the small 0.3mm focal spot in order to decrease the geometric unsharpness and preserve the high-resolution capabilities of both detectors. The resultant images have a geometric object magnification of 1.25, similar to that of a clinical neuro-EIGI, and a fixed field size was used to keep the scatter the same for both detectors. For images obtained using each detector, we calculated and compared the contrast of the averaged line profiles for the 5.0, 5.6 and 6.3 lp/mm bar pattern groups, which have lead-line widths of 100, 89, and 79 microns, respectively.

Results: For the MAF-CCD, the measured contrasts were 0.020, 0.019 and 0.013 for the 5.0, 5.6 and 6.3 line pair groups, respectively, and for the MAF-CMOS the contrasts were 0.025, 0.019 and 0.014 for the 5.0, 5.6 and 6.3 line pair groups, respectively.

Conclusion: For the very small lines of the bar pattern, the MAF-CMOS appears to provide almost the same contrast as compared to the MAF-CCD, within the measurement error; however, noise and dynamic range characteristics remain to be studied before concluding that the MAF-CMOS can replace the MAF-CCD during task-specific neuro-EIGI procedures where high spatial resolution is required.

Funding Support, Disclosures, and Conflict of Interest: Supported by NIH Grant: 2R01EB002873 and an equipment grant from Toshiba Medical Systems Corporation.

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