Abstract
Background
The major concerns with coronary computed tomography angiography (CCTA) is the amount of contrast media (CM) injected and the radiation dose.
Purpose
To establish low radiation CCTA with low amount of contrast media.
Methods
Consecutive 60 patients (body weight ≤70mg or less and Agatston score ≤400) who were scheduled coronary computed tomography angiography were enrolled. Dual-source scanner (SOMATOM Force, Siemens, Germany) was used and CM used was Iopamidol 370mg/I (Bayer, Germany). Coronary CT angiography was performed with Turbo Flash Spiral and Sinogram Affirmed Iterative Reconstruction was done. The dose of contrast media was decided according to our original predicting system for 300HU. This study was approved by the local ethics committee and all patients gave written, informed consent. Exclusion criteria for CCTA were low Agatston score (<50), atrial fibrillation, allergy to CM, renal insufficiency (glomerular filtration rate <60 mL/min/1.73 mm2), pregnancy, congenital heart disease, low left ventricular function, and coronary artery bypass graft. All segments were evaluated using a 5-point scale: 5, excellent and easily assessable,; 4, good, mild artifacts at 1 segment and assessable; 3, evaluable, moderate artifacts on a few segments; 2, evaluable, diagnostic combined with axial images; and 1, not assessable.
Results
All patients successfully performed CCTA. Age averaged 46±15 yo (mean±S.D.) and body mass index averaged 22.5±3.0. Used CM was 12±7ml and intracoronary CT number 329±28HU. Dose-length product averaged 21.7±15.0 mGy cm and effective dose averaged 0.30±0.21mSv. Image quality averaged 4.8±0.7. CCTA with the lowest effective dose was 0.04mSv and CCTA with the lowest CM was 4ml.
Conclusions
Ultra-low dose 70kV-CCTA with low dose of contrast media can be performed using dual source computed tomography in patients with body weight ≤70mg or less and Agatston score ≤400.
The optimal monoenergetic spectral image level of coronary computed tomography (CT) angiography on a dual-layer spectral detector CT with half-dose contrast media
