Scott Alexander’s article on altruistic kidney donation weighed the initial CT scan as a heavy negative, like an incremental 1 in 650 risk of death. Shocking to me at the time, but the number seemed to check out, at least as a first order estimate.
What's interesting is I needed surgery to remove the most recent stones, and I've not had a CT-scan since- the urologist uses ultrasound.
On the other hand, I've had fluoroscopy.. probably worse than even CT-scans.