CT radiation dose has been one of the top radiology headlines this year due to the publication of several studies linking radiation to cancer risk. But new research offers hope that CT radiation dose can be reduced, even across large healthcare systems.
CT’s link to cancer risk has been controversial, but most established models connect low-level radiation to cancer formation.
- The debate heated up this year with a September study linking radiation to pediatric blood cancers, following research in April claiming CT radiation would account for 5% of all cancers in the U.S. in a year at current dose levels.
There are lots of great technologies for reducing CT radiation dose, from photon-counting CT to adjusting scanner parameters like mA and kVp, while image reconstruction algorithms can upscale noisy low-dose images to look like higher-quality exams.
- But the problem has always been getting these technologies into the hands of clinicians – and then making sure they use them, especially across large multi-center health systems, where dose can vary even within the same network.
Taking a crack at the problem were cardiologists from Lee Health Heart Institute in Fort Myers, Florida, in a new paper in JACC: Case Reports.
- They specifically looked at radiation dose for coronary CT angiography exams, determining that based on the literature an optimal radiation dose for CCTA should be ≤ 4 mSv – lower than the system’s 6.2 mSv median dose.
So they implemented several strategies for reducing CCTA dose…
- Standardizing scanning protocols that emphasized prospective ECG gating, reduced field of view, BMI-tailored tube voltage (kVp), and elimination of redundant imaging phases.
- Setting parameters for single-source CT at 100 kVp for patients with BMI <30 and 120 kVp for BMI ≥30, with prospective scanning for 60-80% of the cardiac cycle.
- Using similar kVp settings for dual-source CT scanners, but implementing systolic imaging between 250-450 milliseconds.
How well did it work? After reviewing the program, researchers found…
- System-wide radiation dose fell 23% (4.8 vs. 6.2 mSv).
- Diagnostic quality improved as measured by the acceptance rate for FFR-CT exams (93% vs. 91%).
- Dose consistency was achieved across locations despite differences in scanner models and practices.
The Takeaway
The new study on CCTA radiation dose shows that dose can be reduced system-wide while maintaining – and even improving – diagnostic image quality. Is it a problem that the research was led by cardiologists and not radiologists? Not if you’re a patient.
