Abstract
Objectives To assess the impact of combining low-tube voltage acquisition with iterative reconstruction (IR) techniques on the iodine dose in coronary CTA. Methods Three minipigs underwent CCTA to compare a standard of care protocol with two alternative study protocols combining low-tube voltage and low iodine dose with IR. Image quality was evaluated objectively by the CT value, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) in the main coronary arteries and aorta and subjectively by expert reading. Statistics were performed by Mann–Whitney U test and Chi-square analysis. Results Despite reduced iodine dose, both study protocols maintained CT values, SNR, and CNR compared to the standard of care protocol. Expert readings confirmed these findings; all scans were perceived to be of at least diagnostically acceptable quality on all evaluated parameters allowing image interpretation. No statistical differences were observed (all p values > 0.11), except for streak artifacts (p = 0.02) which were considered to be more severe, although acceptable, with the 80 kVp protocol. Conclusions Reduced tube voltage in combination with IR allows a total iodine dose reduction between 37 and 50%, by using contrast media with low iodine concentrations of 200 and 160 mg I/mL, while maintaining image quality.
Highlights
Iodine based contrast agents, such as those used in CT and angiography, can cause contrast-induced nephropathy (CIN), which is associated with increased mortality in atrisk patients with renal insufficiency
Several studies demonstrated that CIN incidence is related to the administered iodine load, which motivates the aim for the reduction of the total iodine dose (TID) [1,2,3,4,5,6]
Several studies have demonstrated that contrast-induced nephropathy (CIN) incidence is related to the administered iodine dose
Summary
Iodine based contrast agents, such as those used in CT and angiography, can cause contrast-induced nephropathy (CIN), which is associated with increased mortality in atrisk patients with renal insufficiency. By decreasing the acquisition tube voltage, the attenuation difference between enhanced and nonenhanced tissues increases because the X-ray output energy approaches the iodine k-edge of 33 keV. This increase in image contrast opens up the opportunity to decrease the required iodine dose [7,8,9]. Scanning at lower photon energies, introduces more noise into the images, since X-rays of lower energies are more absorbed and less photons reach the detector [10, 11] This noise increase could be tackled by increasing the tube current, resulting in an increased radiation dose, which is unfavourable considering patient safety. Instead of using an idealised imaging model like in traditional filtered back-projection (FBP), these IR
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
