D. Grönemeyer,B. Brandts,C. Lehrenfeld,F. Metz,Marietta Garmer,O. Klein-Wiele,
False-Positive Calcifications and Radiation Dose in Coronary Artery Calcium Scoring Using Iterative Reconstruction on The Basis of a Noise Threshold
Radiology and Medical Diagnostic Imaging
2019
2613-7836
http://dx.doi.org/10.31487/j.RDI.2019.04.01
https://www.sciencerepository.org/false-positive-calcifications-and-radiation-dose-in-coronary-artery-calcium-scoring-using-iterative-reconstruction-on-the-basis-of-a-noise-thr_RDI-2019-4-101 
Abstract: Radiation dose from cardiac CT seems to be underestimated. To determine the effect of iterative
reconstruction in coronary artery calcium (CAC) scoring on false positive lesions and radiation dose using
a noise threshold. Noise-based thresholds have been previously suggested to reduce false positive lesions in
lower dose protocols. In 388 matched pairs of patients we performed CAC scoring using a 320-row CTscanner with standard dose filtered backprojection (FBP) and lower dose iterative reconstruction (IR). Dose
modulation was based on a noise threshold. Radiation dose, image quality and extent of false-positive
calcifications were obtained. IR versus FBP showed a reduced dose length product (median 61 versus 74;
p< 0.001), less noise (median SD 14.71 versus 18.07; p< 0.001) and higher signal-to-noise ratio (median
4.01 versus 3.14; p< 0.001). Using IR in 388 patients, a low quantity of false-positive calcifications was
found in 302 patients, a moderate quantity in 76 patients and a high quantity in 10 patients, while using
FBP, the corresponding distribution of patients was 79, 175 and 134 (p<0.001). In this clinical setting we
confirm the observation of a phantom study that CAC scoring using iterative reconstruction and a noise
threshold is effective for the reduction of radiation dose.Keywords: Coronary artery disease, vascular calcification, radiation exposure, image reconstruction, cardiac imaging techniques