Single- and dual-energy CT with monochromatic synchrotron x-rays
Abstract
We explored the potential for clinical research of computed tomography (CT) with monochromatic x-rays using the preclinical multiple energy computed tomography (MECT) system at the National Synchrotron Light Source. MECT has a fixed, horizontal fan beam with a subject apparatus rotating about a vertical axis; it will be used for imaging the human head and neck. Two <IMG SRC="http://ej.iop.org/images/0031-9155/42/2/009/img22.gif" ALIGN="TOP"/>-photodiode array detectors with different spatial resolutions were used. A 10.5 cm diameter acrylic phantom was imaged with MECT at 43 keV and with a conventional CT (CCT) at 80 kVp: spatial resolution <IMG SRC="http://ej.iop.org/images/0031-9155/42/2/009/img23.gif" ALIGN="TOP"/> line pairs (lp)/cm for both; slice height, 2.6 mm for MECT against 3.0 mm for CCT; surface dose, 3.1 cGy for MECT against 2.0 cGy for CCT. The resultant image noise was 1.5 HU for MECT against 3 HU for CCT. Computer simulations of the same images with more precisely matched spatial resolution, slice height and dose indicated an image - noise ratio of 1.4:1.0 for CCT against MECT. A 13.5 cm diameter acrylic phantom imaged with MECT at <IMG SRC="http://ej.iop.org/images/0031-9155/42/2/009/img24.gif" ALIGN="TOP"/> above the iodine K edge and with CCT showed, for a <IMG SRC="http://ej.iop.org/images/0031-9155/42/2/009/img25.gif" ALIGN="TOP"/> solution, an image contrast of 26 HU for MECT and 13 and 9 HU for the 80 and 100 kVp CCT, respectively. The corresponding numbers from computer simulation of the same images were 26, 12, and 9 HU, respectively. MECT's potential for use in clinical research is discussed.
- Publication:
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Physics in Medicine and Biology
- Pub Date:
- February 1997
- DOI:
- 10.1088/0031-9155/42/2/009
- Bibcode:
- 1997PMB....42..371D