Too many scans is bad medicine


A medical diagnostic company recently posted the following tweet: “The best way to beat cancer is early detection. A full-body scan will provide you with a look inside your body and peace of mind.”

I wanted to type a reply, but I like to tell stories, and Twitter will only allow 280 characters.


A young woman sits on the examining table. Texting. As I approach her, she dangles her legs and checks her watch. She notices me and turns to the woman standing beside her. The woman is starched — not a single joint flexed. She snaps back at her daughter, who once again turns her attention to her phone.

“Hi,” I say to the young woman. “What brings you in today?”

Her mother speaks: “She’s home from university … half-way across the country. She’s only here for the weekend, so I need this taken care of.”

The young lady sighs.

The mother holds up a scolding finger. “I’m going to do the talking, OK? You’ve called me twice this week.” She turns to me. “Crying. She called me crying.”

I confirm the patient’s age on the chart. Twenty-one.

“You’re Jennifer?” She nods. “So, what brings you in today?”

“Headaches,” she says, turning off the phone. Her eyes bright, her movements animated, she frowns:

“Like someone’s churning a knife inside my head. More than two weeks.”

“Do they come and go?”

“They’re always there. Sometimes worse.”

I search for clues. She has no past medical history. She’s never had surgery, doesn’t smoke and drinks, as expected — heavily on weekends. “Were you able to go out this past weekend?”

“Only on Saturday,” she says. “I couldn’t on Sunday. The headaches were too bad.”

I know better than to make a connection between an all-nighter and the Sunday morning throb behind her temples. I won’t have a chance, anyway. Her mother is about to take control:

“She needs a CT scan before I can send her back to school.”

“OK,” I say. “Just hold that thought for a second.”

I ask Jennifer several more questions, then move on to the physical exam.

She is physiologically and neurologically perfect — excellent vital signs, normal blood pressure, heart rate, and temperature.

But moreover, she simply looks well. She’s in no distress. Ten feet away, a baby wails. The lights are bright, and the department is buzzing. None of this bothers her. After I finish my exam, she reaches into her pocket, silences her ringing phone, and smirks at the display.

I explain all of this to Jennifer and her mother. I also suggest that she try discontinuing her contraceptive pill, which she had started shortly before the onset of her headaches.

“If things haven’t settled down in a week or two,” I say, “she could be re-examined at school.”

Suddenly, her mother is irate. “Why are you so difficult?” she asks me. “All I’m asking for is a CT scan.”

“A CT scan is just a test,” I say. “It’s a useful tool in conjunction with the history, physical exam, and other tests if needed. But on its own, it’s just a foggy look at the brain. It also means exposure to radiation, which isn’t really justifiable at this point.”

She raises her voice, looking for an audience among the patients waiting in chairs. “This is ridiculous,” she says. “How can you guarantee that there is nothing wrong inside her head without a CT scan.”

“There’s no reason to believe that there is anything wrong inside her head,” I say.

“Is there anyone I can speak to?” she says, stepping out of the examining bay and looking around. “I didn’t have any trouble getting my other three kids their CT scans when they needed them.”

“Were any of them abnormal?”

“No,” she says. “Thank God.”

I know then that there will be no resolution until the young woman and her mother receive the test that’s been requested.

She’ll simply be back tomorrow, or the next day, until the young woman’s head is under the ring, and a grey-and-white picture tells her everything is OK. And if she can’t get her scan at this hospital, she’ll get it somewhere else.

I turn to the patient: “Jennifer, you haven’t said anything, but you’re here, and you’re letting your mother talk for you.”

“Well, another doctor also said I needed the scan,” she says.

“Why didn’t they order it?”

She shrugs and turns back to her phone.

I give in and order the scan.

This is bad medicine.

CT scans, like most tests, are useful adjuncts to the big picture – the history, the physical exam, other tests if indicated. And Jennifer’s history and physical exam suggest a very, very low pretest probability of a positive finding on a scan. And what if there is something on the scan that has no clinical significance? What if there’s an artifact — something that seems abnormal that really isn’t.

Two hours later, the results are back, and there’s a shadow on the scan.

This young woman who is active, alert, and jumps on and off the exam table has an abnormality on her scan. She’s able to party on weekends, play sports after class, and has an excellent academic record.

But, because of a fuzzy shadow, more expensive testing — an MRI — is suggested. Her mother is in tears as I explain this to her and try to reassure her. I know she will worry daily in the next few weeks, as she waits for her daughter to have another test.

In 2014, The New Yorker published an opinion piece called “We Are Giving Ourselves Cancer,” by cardiologist Rita F. Redberg, and radiologist Rebecca-Smith Bindman. It explains that the radiation doses for CT scans are 100 to 1000 times higher than X-rays and that radiation, from medical sources, is the leading environmental cause of breast cancer.

I followed Jennifer’s course as she had further, more precise imaging. In the end, after great expense, and I’m certain — great anxiety to both patient and mother — everything was normal. Through it all, I wonder if Jennifer, or her mother, even remembered the suggestion of stopping her birth control. Or whether they were just happy that the tests they wanted told them everything was OK.


And about the company selling full-body scans?

A fellow physician posted the following beautiful, succinct and accurate response to the medical company selling full-body scans: Indiscriminate testing (including imaging) without adequate consideration of pretest probabilities or predictive value results in an obscene number of false positives, unnecessary follow-up testing, and procedures that carry their own risks.

Raj Waghmare is an emergency physician who blogs at

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