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Impact of iodine concentration and scan parameters on image quality, contrast enhancement and radiation dose in thoracic CT.
- Source :
-
European radiology experimental [Eur Radiol Exp] 2020 Sep 11; Vol. 4 (1), pp. 57. Date of Electronic Publication: 2020 Sep 11. - Publication Year :
- 2020
-
Abstract
- Background: We investigated the impact of varying contrast medium (CM) densities and x-ray tube potentials on contrast enhancement (CE), image quality and radiation dose in thoracic computed tomography (CT) using two different scanning techniques.<br />Methods: Seven plastic tubes containing seven different CM densities ranging from of 0 to 600 HU were positioned inside a commercial chest phantom with padding, representing three different patient sizes. Helical scans of the phantom in single-source mode were obtained with varying tube potentials from 70 to 140 kVp. A constant volume CT dose index (CTDIvol) depending on phantom size and automatic dose modulation was tested. CE (HU) and image quality (contrast-to-noise ratio, CNR) were measured for all combinations of CM density and tube potential. A reference threshold of CE and kVp was defined as ≥ 200 HU and 120 kVp.<br />Results: For the medium-sized phantom, with a specific CE of 100-600 HU, the diagnostic CE (200 HU) at 70 kVp was ~ 90% higher than at 120 kVp, for both scan techniques (p < 0.001). Changes in CM density/specific HU together with lower kVp resulted in significantly higher CE and CNR (p < 0.001). When changing only the kVp, no statistically significant differences were observed in CE or CNR (p ≥ 0.094), using both dose modulation and constant CTDIvol.<br />Conclusions: For thoracic CT, diagnostic CE (≥ 200 HU) and maintained CNR were achieved by using lower CM density in combination with lower tube potential (< 120 kVp), independently of phantom size.
Details
- Language :
- English
- ISSN :
- 2509-9280
- Volume :
- 4
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- European radiology experimental
- Publication Type :
- Academic Journal
- Accession number :
- 32915405
- Full Text :
- https://doi.org/10.1186/s41747-020-00184-z