12 Oct To Your Health: CT Scans, Lifesaving Tech — So Let’s Use Them Wisely!
Welcome back to the series which offers a deep dive into the world of health, wellness, and disease prevention with Telluride local Dr. Alan Safdi.
Dr. Alan is a board-certified physician in Internal Medicine and Gastroenterology, a Fellow of the American College of Gastroenterology, and a respected leader in healthcare. His blogs have featured and will continue to showcase the most current information in his fields: health, wellness and longevity. During Covid, Dr. Alan went radio silent. Now Dr. Alan is back in action with “To Your Health.”
In this installment of “To Your Heath, Dr. Alan does a dive deep into CT scans, why they are great tools – when deemed necessary.
Scroll down to read the salient details and listen to the podcast to find out more.
Bottom line: CT scans are fast, powerful tools that often change care on the spot. But because they use ionizing radiation, doing them when they aren’t needed can add small cancer risks that accumulate across millions of scans.
What’s New — And Why People Are Talking About This
A new national analysis estimated that the 93 million CT scans done in the U.S. in 2023 could eventually lead to about 103,000 future cancers—roughly 5% of all new cancer cases if current practices continue. Children face a higher risk per scan, but adults account for most of the projected cases simply because they undergo the majority of CT imaging. The biggest contributor to overall exposure was CT scans of the abdomen and pelvis, which are very common in emergency and hospital settings.
The takeaway: No one is saying “don’t scan.” The message is to scan when it helps, and right-size the dose.
Why CT Is Often Exactly the Right Choice
Speed and accuracy in emergencies: In trauma, stroke, pulmonary embolism, internal bleeding, or bowel obstruction, CT scans can quickly provide lifesaving information that other imaging can’t match.
When other tests fall short: Ultrasound or plain X-rays can miss important findings, especially in deeper tissues or when bone or gas blocks the view.
Safer than before: Modern CT scanners use advanced software and dose-reduction techniques that produce clear images at much lower radiation levels than older machines.
Why CT Can Be Overused
In busy emergency departments, it’s often easier to order a CT “just to be safe.” But that approach has drawbacks.
• Incidental findings: Scans sometimes reveal small, harmless abnormalities that lead to unnecessary tests, biopsies, or worry.
• Additive risk: Each scan adds a small radiation dose, and across the population these add up to a measurable cancer burden.
• Better options exist: For certain conditions, careful physical exams, observation, or other imaging (like MRI or ultrasound) can provide answers without radiation.
How Much Radiation Is in a CT Scan?
It depends on what part of the body is being imaged and how many phases are taken:
• CT of the head: about 2 millisieverts (mSv)
• CT of the abdomen and pelvis: about 7 to 15 mSv
• Chest X-ray: about 0.1 mSv
That means a CT of the abdomen and pelvis gives roughly the same radiation exposure as about 100 chest X-rays, though the exact number depends on the scanner and settings. These are small doses overall, but the key is that they should be used only when truly helpful.
For children and younger adults, the same dose carries a slightly higher lifetime risk because their tissues are more sensitive and they have more years ahead for any radiation-related effects to appear. That’s why pediatric imaging uses lower-dose settings or substitutes like ultrasound or MRI when possible.
Does CT Cause Cancer?
For children and teenagers, studies suggest a small increase in the risk of leukemia and brain tumors after multiple scans, reinforcing the need to minimize exposure.
For adults, direct proof of risk is harder to show because the effects are small and develop decades later. Still, statistical models built from long-term radiation studies suggest that widespread CT use could cause tens of thousands of future cancers if current patterns continue.
Again, the key message is not to avoid scans that are medically necessary—but to ensure that every scan has a clear purpose.
Dr. Alan, more:
Dr. Alan Safdi is board-certified in Internal Medicine and in Gastroenterology and a Fellow of the American College of Gastroenterology. A proven leader in the healthcare arena, he has been featured on the national program, “Medical Crossfire” and authored or co-authored numerous medical articles and abstracts.
Safdi, a long-time Telluride local, has been involved in grant-based and clinical research for four decades. He is passionate about disease prevention and wellness, not just fixing what has gone wrong.
Dr. Alan is an international lecturer on the subjects of wellness, nutrition and gastroenterology and now in partnership on an AI project with Stanford and the Mayo Clinic.
In these cases, CT scans can be the difference between a fast diagnosis and a missed emergency.
• “A typical CT of the abdomen and pelvis is around 7–15 mSv, roughly equivalent to about 100 chest X-rays, depending on the settings.”
• “About 103,000 future cancers could stem from the 93 million CTs done in 2023 if we don’t improve how we use them—but smarter scanning can cut that risk.”
• “CT scans save lives. The goal isn’t to avoid them—it’s to use them wisely.”
Why Atomic Bomb Data Aren’t Comparable to CT Scans
Much of what we know about radiation risk originally came from studies of survivors of the atomic bombings in Japan. But those exposures were instantaneous, extremely high, and involved the entire body—often thousands of times higher than a CT scan. They also occurred under conditions of trauma, starvation, and no medical care, which likely made the effects worse.
In contrast, medical CT scans deliver small, focused doses to specific body regions over time, allowing normal DNA repair processes to work between exposures. While atomic bomb data help shape safety standards, they don’t directly apply to modern medical imaging, which is targeted, controlled, and vastly lower in dose.
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