Evaluation of a High Concentrated Contrast Media Injection Protocol in Combination with Low Tube Current for Dose Reduction in Coronary Computed Tomography Angiography

Publication date: Available online 8 August 2017
Source:Academic Radiology
Author(s): Yibo Sun, Yanqing Hua, Mingpeng Wang, Dingbiao Mao, Xiu Jin, Cheng Li, Kailei Shi, Jianrong Xu
Rationale and ObjectivesThe study aimed to prospectively evaluate the radiation dose reduction potential and image quality (IQ) of a high-concentration contrast media (HCCM) injection protocol in combination with a low tube current (mAs) in coronary computed tomography angiography.Materials and MethodsEighty-one consecutive patients (mean age: 62 years; 34 females; body mass index: 18–31) were included and randomized-assigned into two groups. All computed tomography (CT) examinations were performed in two groups with the same tube voltage (100 kV), flow rate of contrast medium (5.0 mL/s), and iodine dose (22.8 g). An automatic mAs and low concentration contrast medium (300 mgI/mL) were used in group A, whereas effective mAs was reduced by a factor 0.6 along with HCCM (400 mgI/mL) in group B. Radiation dose was assessed (CT dose index [CTDIvol] and dose length product), and vessel-based objective IQ for various regions of interest (enhancement, noise, signal-to-noise ratio, and contrast-to-noise ratio), subjective IQ, noise, and motion artifacts were analyzed overall and vessel-based with a 5-point Likert scale.ResultsThe CT attenuation of coronary arteries and image noise in group B were significantly higher than those in group A (ranges: 507.5–548.1 Hounsfield units vs 407.5–444.5 Hounsfield units; and 20.3 ± 8.6 vs 17.7 ± 8.0) (P ≤ 0.0166). There was no significant difference between the two groups in signal-to-noise ratio, contrast-to-noise ratio, and subjective IQ of coronary arteries (29.4–31.7, 30.0–37.0, and medium score of 5 in group A vs 29.4–32.4, 27.7–36.3, and medium score of 5 in group B, respectively, P ≥ 0.1859). Both mean CTDIvol and dose length product in group B were 58% of those of group A.ConclusionsHCCM combined with low tube current allows dose reduction in coronary computed tomography angiography and does not compromise IQ.



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