Effects of combining multiple dose reduction techniques on coronary computed tomography angiography.

Background: Coronary computed tomography angiography (CCTA) is the preferred non-invasive examination method for coronary heart disease. However, the radiation from computed tomography has become a concern since public awareness of radiation hazards continue to increase.

Aim: To explore the value of multiple dose reduction techniques for CCTA.

Methods: Consecutive normal and overweight patients were prospectively divided into two groups: Group A₁, patients who received multiple dose reduction scans (n = 82); and group A₂, patients who received conventional scans (n = 39). The scan parameters for group A₁ were as follows: Isocentric scan, tube voltage = 80 kV, and tube current control using 80% smart milliampere. The scan parameters for group A₂ were as follows: Normal position, tube voltage = 100 kV, and smart milliampere.

Results: The average effective doses (EDs) for groups A₁ and A₂ were 1.13 ± 0.35 and 3.36 ± 1.30 mSv, respectively. There was a statistically significant difference in ED between the two groups (P < 0.01). Furthermore, noise was significantly lower, and both signal-to-noise ratio and contrast signal-to-noise ratio were higher in group A₂ when compared to group A₁ (P < 0.01). Moreover, the subjective image quality (IQ) scores were excellent in both groups, in which there was no significant difference in subjective IQ score between the two groups (P = 0.12).

Conclusion: Multiple dose reduction scan techniques can significantly decrease the ED of patients receiving CCTA examinations for clinical diagnosis.