The effect of adaptive iterative dose reduction on image quality in 320-detector row CT coronary angiography

Abstract

The use of AIDR reduces image noise and improves image quality in 320-detector row CTCA.

Feasibility of radiation dose reduction using AIDR-3D in dynamic pulmonary CT perfusion

“…This differs from a study by Negi et al, 22 which reported similar perfusion values in parametric perfusion maps in both low- and high-dose groups. 20 In the present study, a significant reduction in radiodensity was demonstrated at a tube current of 12.5 mAs in the pulmonary artery (but not in the lung tissue), which is thought to be CT number bias related to the increased percentage of non-positive raw data projection sinogram values at very low tube currents. 23 This effect can be expected to be greater for structures with higher attenuation.…”

“…In a comparison of AIDR-3D and FBP in coronary CT angiography, AIDR-3D was demonstrated to reduce noise by an additional 22% compared to FBP. 20 In a lung CT study, AIDR-3D allowed for a dose reduction of 64.5% whilst still reducing noise when compared to FBP filtration in higher-dose scans. 21 A recent study into the effectiveness of a previous version of the iterative algorithm, AIDR, in hepatic perfusion showed that AIDR was significantly better at reducing noise than the FBP method, but not significantly better than QDSþ in either a standard-dose group or a low-dose (approximately 45% lower dose) group.…”

Image quality in coronary CT angiography: challenges and technical solutions

“…5 Although no standard cut-off values of image noise have been reported, some authors suggested values of #30 HU for improved coronary CTA image quality. [6][7][8] Besides image noise, image interpretability is further influenced by the degree of vascular enhancement. Previous reports have suggested that a vascular attenuation value of .400 HU in the aorta is required for coronary CTA image interpretability.…”

“…Previous reports have suggested that a vascular attenuation value of .400 HU in the aorta is required for coronary CTA image interpretability. [6][7][8][9][10] While vascular enhancement and image noise both are defining parameters in determining image quality, in practical terms it is more useful to use the signal-to-noise ratio. Signalto-noise ratio is a generic term to indicate how much signal vs how much noise a particular image has.…”

Iterative reconstruction in cardiac CT

“…The original highnoise images experience multiple iterative loops to achieve the appropriate noise levels. 32,33 This technique has been replaced by a new technique using a 3-dimensional processing algorithm (AIDR-3D). 34 This allows for a morphing of this reconstruction algorithm from the image domain to the raw data space.…”