Program Information
Evaluation of Image Quality in Fluoroscopic System
M Ahmad*, L Thai , J Feng , The University of Texas Health Sciences Center, Houston, TX
Presentations
MO-RAM-GePD-IT-3 (Monday, July 31, 2017) 9:30 AM - 10:00 AM Room: Imaging ePoster Theater
Purpose: Despite standardization in fluoroscopy equipment testing particularly relating to dose, there is no widely-accepted image quality testing standard. Modern machines contribute many variables affecting image quality, such as protocol settings, automatic exposure rate control (AERC) algorithm, post processing, etc. In this study, we developed simple and repeatable methods to test low contrast detectability (LCD) and spatial resolution on fluoroscopic units.
Methods: Table-top, mobile and stationary C-arm fluoroscopes were tested in this study. Anatomical protocols, if available, were consistently controlled and exposure parameters were recorded. The LCD and spatial resolution were evaluated for multiple field of views (FOVs).To evaluate LCD, the Leeds T0-10 phantom was imaged with four additional 1-mm copper plates attenuation. For each of the 12 different detail sizes, the minimum contrast level was recorded and a contrast-detail curve was generated. To evaluate spatial resolution, the Leeds TVF phantom was imaged with one additional 1-mm copper plate attenuator. The TVF phantom’s line pair patterns were aligned 45 degrees in relation to monitor scan lines. The highest frequency line-pair pattern was recorded. In both tests, the objects and attenuator were placed in the closest vicinity to the image receptor. Room lights were dimmed (or off if possible) and the images were scored on the in-room display monitor during live fluoroscopy from the typical fluoroscopist's position.
Results: Images of the T0-10 and TVF phantoms are shown in the supporting document. Baseline contrast detail curves and limiting spatial resolution were recorded for future comparison for each of the different types of fluoroscopes.
Conclusion: Image quality can be difficult to assess in modern fluoroscopic systems. We have proposed simple and reproducible procedures to track image quality of clinical fluoroscopic systems over time.
Contact Email: