Optimized radiographic spectra for small animal digital subtraction angiography.
Journal Article (Journal Article)
The increasing use of small animals in basic research has spurred interest in new imaging methodologies. Digital subtraction angiography (DSA) offers a particularly appealing approach to functional imaging in the small animal. This study examines the optimal x-ray, molybdenum (Mo) or tungsten (W) target sources, and technique to produce the highest quality small animal functional subtraction angiograms in terms of contrast and signal-difference-to-noise ratio squared (SdNR2). Two limiting conditions were considered-normalization with respect to dose and normalization against tube loading. Image contrast and SdNR2 were simulated using an established x-ray model. DSA images of live rats were taken at two representative tube potentials for the W and Mo sources. Results show that for small animal DSA, the Mo source provides better contrast. However, with digital detectors, SdNR2 is the more relevant figure of merit. The W source operated at kVps>60 achieved a higher SdNR2. The highest SdNR2 was obtained at voltages above 90kVp. However, operation at the higher potential results in significantly greater dose and tube load and reduced contrast quantization. A reasonable tradeoff can be achieved at tube potentials at the beginning of the performance plateau, around 70kVp, where the relative gain in SdNR2 is the greatest.
- De Lin, M; Samei, E; Badea, CT; Yoshizumi, TT; Allan Johnson, G
- November 2006
Volume / Issue
- 33 / 11
Start / End Page
- 4249 - 4257
Electronic International Standard Serial Number (EISSN)
Digital Object Identifier (DOI)
- United States