The researchers used the validated GE Noise Injection software to modify existing spine and chest CT scans from 10 patients retrospectively to create CT images that stimulate the standard dose of 100 percent, 50 percent dose and 25 percent dose scans. There were four orthopedic surgeons and a pediatric radiologist blinded to the doses that measured the medial-lateral pedicle width and maximum anterior-posterior bony length along the axis of presumed pedicle screw placement.
The researchers found:
1. There wasn’t clinically relevant differences between measurements at the different dose levels.
2. There wasn’t an apparent degeneration in the precision at the different dose levels.
3. There was consistent variation between raters, likely because of individual differences in the measurement.
4. The researchers concluded the spinal CT scans done for preoperative planning can be performed at 25 percent of the current radiation dose and speicalists won’t lose the surgical planning measurement accuracy or precision. The 25 percent dose-reduction had an average CT Dose Index volume dose levels of around 1.0 to 2.5 mGy.
5. The size-specific dose estimates for the spinal CT scans at 25 percent dose-reduced is around 2.5 mGy, a substantial dose savings compared to the current practice.
