Abstract
This chapter outlines the physical background of cardiac CT and different scanning approaches including aspects of radiation exposure. Several measures are instrumental for reducing radiation exposure from cardiac CT: prospective ECG triggering of acquisitions, short scan lengths, reduction of tube voltage as much as feasible, and individual adjustment of tube current to each patient. Raw-data-based iterative reconstruction has potential to improve image quality, which can be used to reduce radiation output.
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Notes
- 1.
Physicists measure spatial resolution as the point spread function (PSF) and express the performance of CT scanners with regard to spatial resolution as the full width half maximum (FWHM) of the PSF. The FWHM defines whether or not two adjacent structures will be represented separately in the images; two structures separated by at least one FWHM can in general be distinguished from each other, two structures separated by less than one FWHM are bound to merge together in the reconstructed image.
- 2.
The equivalent dose is the product of absorbed dose (D, mGy) and a radiation weighting factor (wR, mSv/mGy). The radiation weighting factor for X-rays is 1, so absorbed dose and the equivalent dose are numerically equal.
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Geleijns, J., Dewey, M. (2014). Physics Background and Radiation Exposure. In: Cardiac CT. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-41883-9_7
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DOI: https://doi.org/10.1007/978-3-642-41883-9_7
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