AbstractID: 9834 Title: Digital Fluoroscopic Imaging: Acquisition, Processing and
Display
Abstract
Title: Digital Fluoroscopic Imaging: Acquisition, Processing, and Display
Presenter: J. Anthony Seibert, Ph.D.
Acquisition, processing, and display of digital imaging sequences are a major part of a
modern fluoroscopic system that can optimize the use of information at the lowest
possible radiation dose. Acquisition includes signal amplification, sampling frequency,
and bit depth requirements of analog to digital conversion to minimize quantization
errors, define spatial resolution, and avoid signal aliasing. Image processing algorithms
reduce quantum noise by temporal data averaging or low-pass filtering, enhance contrast
using look-up-table adjustments of the display image data, and emphasize detail with
high-pass filtering algorithms. Digital subtraction angiography (DSA) is a common
procedure whereby pre and post-contrast subtraction algorithms isolate temporally
dependent iodine attenuation in the vasculature to improve conspicuity and to lower the
volume of contrast agent needed. Motion compensation with re-masking and/or subpixel shifting is crucial for DSA image quality. Accurate quantitative measurements
(e.g., relative stenosis, volumetric densitometry) necessitate compensation of geometric
and non-linear degradations inherent in the detector design and acceptance of x-ray and
light scatter. Fluoroscopic C-arm tomography requires additional corrections for
rotational variability. Image display requirements, contrast / brightness adjustments, and
data archiving issues conclude the presentation.
Objectives:
1. Review recent advances in equipment technology for fluoro image acquisition
2. Illustrate acquisition requirements in terms of analog to digital conversion
3. Discuss image processing techniques used in fluoroscopic and interventional
procedures
4. Describe display requirements and storage needs necessary for a fully
functional digital fluoroscopy system