Low radiation coronary calcium scoring by dual-source CT with tube current optimization based on patient body size

Area of Science:

• Radiology
• Medical Imaging
• Cardiovascular Disease

Background:

• Reducing radiation exposure is crucial in medical imaging.
• Previous studies have shown benefits of lowering tube voltage in CT scans.
• Coronary artery calcium scoring is a key diagnostic tool.

Purpose of the Study:

• To evaluate the feasibility of reducing tube current for coronary calcium scoring using multidetector row CT.
• To determine if lower radiation doses impact the accuracy of coronary calcium measurements.
• To assess the correlation between standard and low-dose CT protocols.

Main Methods:

• Sixty-six outpatients underwent dual-source CT (DSCT) scans with both standard (120 kVp, 150 mAs) and reduced tube current protocols.
• Reduced tube current was adjusted based on patient body mass index (BMI) and weight.
• Low-dose scans were analyzed by a blinded, experienced reader.

Main Results:

• Coronary calcium measurements (Agatston scores and volume) showed no significant difference between standard and low-dose scans (P > 0.14).
• Excellent correlation (r = 1.0) was observed between the two protocols.
• Effective radiation dose was significantly reduced by approximately 40% in the low-dose protocol (1.0 mSv vs 1.7 mSv).
• Image noise was higher in low-dose scans but remained within acceptable limits.

Conclusions:

• Optimized, lower tube current CT protocols can effectively measure coronary artery calcium.
• This approach achieves diagnostic equivalence to standard protocols while significantly reducing patient radiation dose.
• Lowering radiation dose for coronary calcium scanning is feasible and recommended.