Radiation dose threshold for coronary artery calcium score with MDCT: How low can you go?
- نوع فایل : کتاب
- زبان : انگلیسی
- مؤلف : Tom D. Newton & Hatem Mehrez & Kelly Wong & Ravi Menezes & Bernd J. Wintersperger & Andrew Crean & Elsie Nguyen & Narinder Paul
- چاپ و سال / کشور: 2011
Description
Objectives To evaluate the lowest radiation exposure threshold at which coronary calcium scoring (CCS) remains accurate. Methods A prospective study of 43 consecutive eligible patients referred for CCS underwent imaging in accordance with the manufacturer’s recommended protocol. Dedicated software was used to generate 8 series of images simulating tube currents ranging from 20 to 300 mA. These images were randomised and read in blinded fashion to determine the lowest tube current at which the CCS remained accurate. The minimum mA was correlated with 6 different patients’ biometric parameters: bodyweight, body mass index, AP and lateral thoracic diameters, average thoracic diameter and the scout attenuation coefficient (SAC). The 95% confidence interval for each parameter was used to calculate tube current threshold levels and hence stratified CCS protocols were derived. Results Spearman’s correlation coefficients of the minimum tube current for the 6 parameters were: 0.66, 0.63, 0.65, 0.74, 0.77 and 0.86 respectively (p<0.001). SAC offered the largest potential reduction in mean effective dose from 1.86 mSv to 0.88 mSv. Conclusion CCS with at least 50% reduction in radiation exposure and below 1 mSv is feasible if CT scout projections are utilised effectively.
Eur Radiol DOI 10.1007/s00330-011-2159-6 Received: 15 December 2010 / Revised: 16 February 2011 / Accepted: 17 March 2011
