Field Notes #14
Pricier, questionable bone-density scan, new COVID-19 breath test, creative notes from an illustrator, and an easy way to help your brain wake up
Hello there! Happy Wednesday. This week’s Field Notes is quite a mix — a bit of medical procedure sleuthing, a new COVID testing invention, a video about the power of your eyes, and a wonderful illustrator who writes a creative newsletter. I hope you find something here for you. If you find spy something helpful — maybe a tip for your favorite octogenarian? —please feel free to forward it along. You’ll help this little newsletter grow, too.
1} Pricier, questionable QCT Bone-density scans
Bone-density scans measure how strong your bones are, which can help diagnosis or predict osteoporosis or osteopenia. Broken bones are usually not a big deal for kids and young adults, but as we age, broken bones can precipitate a dramatic decline in health. So it’s a marker to watch.
Recommendations vary, but most professional and health organizations agree that all women 65 years of age and older should get a bone-mass density scan every 2 years or more, and some recommend men over 70 or 75 should be scanned, too. People who are at higher risk should be evaluated earlier. (Here’s a chart of recommendations by various organizations, and the latest guidance from the U.S. Preventive Services Task Force.)
I’ve had a few bone-density scans in my life, because I’ve been on particular drugs in the past. One common, vexing drug is prednisone, a corticosteroid used to treat asthma, inflammatory bowel disease, and many other conditions.
Prednisone always seemed to work like magic for me — debilitating symptoms, including severe pain, disappeared, and my energy levels and appetite soared. But prednisone comes with its own set of troubles, including difficulty getting off the drug and long-term risk to bone and eye health. I’m grateful I haven’t been on prednisone in years.
Still, I watch my bone health. The gold standard for bone scans is the dual-energy x-ray absorptiometry (DXA) scan, which is the one I’ve always had.
So I was especially interested in a recent MedPage Today article about a new bone scan that has been popping up, called the quantitative computed tomography (QCT) scan. As the article reports:
“Experts told MedPage Today QCT can exaggerate fracture risk in the lumbar spine by as much as 1.5 standard deviations, can be almost three times as expensive, and delivers between 1,000 and 3,000 times the radiation of DXA, according to some estimates.”
Yikes!
The reporter, Cheryl Clark, discovered this issue when her own doctor wanted to check her bone health and ordered a QCT scan. The results showed her lumbar spine T-score at -2.87, worse than the report’s range for osteopenia, though better than her 70-something peers. Did she have osteoporosis? “This was scary,” she wrote.
She started researching and learned that QCT results are often exaggerated in the spine. So she asked for a DXA scan, a less expensive option, with much lower radiation exposure. The DXA reported that her spine was fine, but her hips were worse off! What? (She wrote a separate article on her experience: Two Bone Scans Three Weeks Apart, Results in Reverse — Discordant QCT, DXA results confuse patients and doctors, "How can they both be right?")
More digging revealed that QCTs seem to be ordered in small pockets in the nation, a very uneven distribution. It sounded like some health systems may have discovered they can get higher Medicare reimbursement for QCT scans, even though these scans have much higher radiation exposure and are not necessarily more accurate.
If a doctor ever recommends a QCT scan for me in the future, I’ll be asking questions, mainly: Why not do a DXA scan, instead?
Read the article Pricier, Questionable Bone Density Scan Growing in Use — QCT delivers far more radiation and exaggerates spinal bone loss, so why is it on the rise? and the reporter’s own story.
2} New COVID-19 breath test
Here’s a fascinating and hopeful news alert: FDA authorizes first COVID-19 breath test. This newly approved machine, about the size of a carry-on luggage, can deliver COVID-19 result in 3 minutes from a patient breathing in a disposable straw connected to the device. (See a photo of the InspectIR COVID-19 Breathalyzer in this article.) No nose swab needed.

The device was validated in a study of 2,409 people, showing a “91.2% sensitivity (the percent of positive samples the test correctly identified) and 99.3% specificity (the percent of negative samples the test correctly identified). The study also showed that, in a population with only 4.2% of individuals who are positive for the virus, the test had a negative predictive value of 99.6%, meaning that people who receive a negative test result are likely truly negative in areas of low disease prevalence.”
I wonder if we’ll see technology like this in use in future pandemics, if checking our breath for dangerous germs becomes routine one day, especially if a future virus is even deadlier than COVID-19.
3} How to give your brain an easy wakefulness signal
Thanks to illustrator Adam Ming for sharing this video. I subscribe to Adam’s newsletter, Adam’s Notes, which is a delightful mix of whimsical art, tips for illustrators and other artists, and thoughts on the creative process. (Here’s his most recent post, on 20 minutes of exercise a day.)
And in one of his newsletters, he mentioned this video, a clip of neuroscientist Dr. Andrew Huberman describing how our eyes work, and how looking upward helps send a signal of alertness to our brain.
“If you are feeling tired, it actually can be beneficial to the wakefulness systems of the brain — including the locas coeruleus and the areas that release norepinephrine — to actually look up to the ceiling … to raise your eyes up toward the ceiling, and to try and hold that for 10 to 15 seconds,” explains Dr. Huberman.
I’ve found myself paying more attention to when I’m looking down and when I’m looking up, and using this simple tip to counter that mid-afternoon energy lag.
(Taking a short walk while gazing upward at the cinematic clouds is even more effective, according to my personal research.)
Here are a few charming pieces of artwork by Adam, just for fun. (Shared with permission — thanks, Adam!)



Adam will also be illustrating an upcoming children’s book, titled Down the Hole: “The tale follows a suspiciously polite fox who tries to coax his next meal out of the burrow—but is met with a clever rabbit who has been plotting with his warren to arrange a different meal than the fox expects.”
You can follow Adam on Instagram or subscribe to his newsletter, Adam’s Notes.
I hope you have a lovely rest of the week full of joyful moments and gazes upward for a burst of energy. I’ll see you back here on Sunday!
To our journeys and healthier days ahead,
Brianne