The Scan That Sees Everything — And What It Can’t Undo

The Scan That Sees Everything — And What It Can’t Undo

Every scan can save a life or quietly shorten one.

“We do not remember days, we remember moments.”
 — Cesare Pavese.

It was 6:03 a.m. when I walked into the hospital.

That liminal hour before the world decides whether it’s still night or already morning.

The halls smelled faintly of coffee, antiseptic, and something else — like metal warmed by old sunlight.

I had a scan that day.

Not for a patient but for myself.

You see, I’m a radiation oncologist. 

I deliver precisely calibrated energy beams into the human body to treat disease.

But I’ve also been on the receiving end.

More than once.

A rare, aggressive pituitary tumor — most likely triggered by radiation exposure — has already taken me to the OR four times, including through the front door of my skull.

So when I read a new study projecting that over 100,000 future cancer cases in the U.S. could stem from CT scans performed in a single year, I felt it like a quiet knock.

Familiar.

Not loud.

But unmistakably personal.

In this piece, I’ll explore what CT scans give us — and what they quietly take.

As a radiation oncologist and a patient with a radiation-induced brain tumor, I’ve come to see these machines through two lenses: precision and consequence.

The Beauty — and Cost — of Clarity

CT scans are beautiful machines.

 They hum. 

They illuminate. 

They help us see what the eye cannot, what touch cannot confirm, and what bloodwork cannot hint at.

In 2023, more than 62 million Americans underwent at least one CT exam. These scans likely saved thousands of lives. 

They caught tumors, clots, fractures, and bleeds. 

CT scans told stories that needed telling.

However, as this recent modeling study reminds us, even clarity has a cost.

What the Data Didn’t Whisper

The study used data from over 121,000 CT exams and projected that nearly 103,000 future cancers are traceable back to radiation from scans done in 2023 alone.

Not directly. Not with a fingerprint. But in probability. 

The risk isn’t distributed evenly:

• Children under one-year-old have the highest per-scan risk.
• Middle-aged adults who receive more scans carry the highest projected burden.
• Abdominal and pelvic CTs were responsible for the greatest share.
• In children, head CTs accounted for more than half the projected cases.

5% Doesn’t Sound Like Much — Until It’s You

“It is not length of life, but depth of life.”
 — Ralph Waldo Emerson.

The authors estimate that if current trends hold, 

CT scans could account for 5% of all new cancer diagnoses annually, on par with risks from alcohol or obesity.

However…

While the numbers are large in aggregate, they translate into a tiny individual risk per scan: a 0.1% lifetime increase per exam. That’s one in a thousand.

Zooming out means a shift from a 50% lifetime cancer risk to 50.1%. 

So, the risk is real but rarely immediate and rarely overwhelming. 

It’s a whisper, not a roar. 

Unless you happen to be the one hearing it.

Balancing the Beam: CT’s Double-Edged Gift

This essay isn’t a warning against CT scans. 

Far from it.

If your doctor recommends one, it’s likely for a good reason.

CT saves lives. 

It caught my tumor. 

It’s helped me monitor its return. 

I owe it as much as I question it.

But here’s what The Scan That Sees Everything — And What It Can’t Undo

It was 6:03 a.m. when I walked into the hospital.

That liminal hour before the world decides whether it’s still night or already morning.

The halls smelled faintly of coffee, antiseptic, and something else — like metal warmed by old sunlight.

I had a scan that day.

Not for a patient but for myself.

You see, I’m a radiation oncologist.

I deliver precisely calibrated energy beams into the human body to treat disease.

But I’ve also been on the receiving end.

More than once.

A rare, aggressive pituitary tumor — most likely triggered by radiation exposure — has already taken me to the OR four times, including through the front door of my skull.

So when I read a new study projecting that over 100,000 future cancer cases in the U.S. could stem from CT scans performed in a single year, I felt it like a quiet knock.

Familiar.

Not loud.

But unmistakably personal.

A Delicate Machine

A CT scan is like turning on the lights in a room you’re afraid to enter. 

You want to see what’s there, but some part of you also knows that seeing changes everything.

CT scans are beautiful machines.

They hum.

They illuminate.

They help us see what the eye cannot, what touch cannot confirm, and what blood work cannot hint at.

In 2023, more than 62 million Americans underwent at least one CT exam. These scans likely saved thousands of lives.

They caught tumors, clots, fractures, and bleeds.

CT scans told stories that needed telling.

However, as this recent modeling study reminds us, even clarity has a cost.

The Numbers

The study used data from over 121,000 CT exams and projected that nearly 103,000 future cancers could be traced back to radiation from scans done in 2023 alone.

Not directly. Not with a fingerprint. But in probability.

The risk isn’t distributed evenly:

• Children under one year old have the highest per-scan risk.
• Middle-aged adults who receive more scans carry the highest projected burden.
• Abdominal and pelvic CTs were responsible for the greatest share.
• In children, head CTs accounted for more than half the projected cases.

What 5% Really Means

The authors estimate that if current trends hold,

CT scans could account for 5% of all new cancer diagnoses annually, on par with risks from alcohol or obesity.

However…

While the numbers are large in aggregate, they translate into a tiny individual risk per scan: a 0.1% lifetime increase per exam. That’s one in a thousand.

Zooming out means a shift from a 50% lifetime cancer risk to 50.1%.

So, the risk is real but rarely immediate and rarely overwhelming. 

It’s a whisper, not a roar.

Unless you happen to be the one hearing it.

Risk, Revisited

This essay isn’t a warning against CT scans.

Far from it.

If your doctor recommends one, it’s likely for a good reason.

CT saves lives.

It caught my tumor.

It’s helped me monitor its return.

I owe it as much as I question it.

But here’s what the data reminds us:

• Use imaging wisely.
• Avoid repeat scans unless truly necessary.
• Opt for the lowest possible dose.
• And if you can order scans, pause, and ask if there’s another way to see.

Because even a soft light can leave a shadow.

The Scan That Sees Everything — And What It Can’t Undo: A Note of Caution: What the Study Doesn’t Show

A few limitations are worth noting — none weaken the message, but add helpful context.

The Doctor, The Patient, and the Quiet Shadow: The Scan That Sees Everything — And What It Can’t Undo

“The saddest aspect of life right now is that science gathers knowledge faster than society gathers wisdom.”
 — Isaac Asimov.

I walk hospital corridors with a doctor’s badge clipped to my coat.

But I also walk with surgical scars hidden behind my hairline.

I carry the knowledge of what we can do with technology — 
 — and what it sometimes does in return.

A scan sees everything.
But it doesn’t see what it leaves behind.
That remains with us in shadow.

Sometimes, CT scans are necessary and invaluable.

If you need one, ask if it is required and whether there are reasonable non-radiation-containing alternatives.

Have you ever faced a decision where technology gave answers but raised new questions?

One more thing:

Your Next Mammogram Could Be a Game Changer: AI Sees What We Miss
medium.com

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