Bone Scans and DNA Testing by Major League Baseball

The New York Times published a very interesting piece a few days ago called Baseball's Use of DNA Raises Questions.

The impetus for these tests:

Dozens of Latin American prospects in recent years have been caught purporting to be younger than they actually were as a way to make themselves more enticing to major league teams.

Apparently, such players have been able to borrow the birth certificate of a younger child from some other family.

Can these tests actually reveal one's age? In the case of DNA, no. However, it can be used to check whether a given player is actually related to the parents listed on the birth certificate. According to the Times, this alone was enough to void the signing of a Yankee prospect last year from the Dominican Republic.

In the case of a bone "scan", I presume the Times actually means a bone age study, in which an X-ray of a subject's hand and wrist (and sometimes other body parts) is compared to a standardized atlas of age-matched X-rays for various ages. How reliable is a bone age study? Not very.

I interpret these occasionally in my practice. When I give my estimate of someone's skeletal age, it is accompanied with considerable variation -- usually one standard deviation equals about a year. In the specific case of a boy with a chronological age of exactly 16 years (192 months), the mean of the expected skeletal age is 195.3 months, where one standard deviation = 12.9 months. From these figures, we can calculate that 95 % of 16 year old boys should have a skeletal age varying between 169.2 and 220.8 months, i.e. 14.1 and 18.4 years old. This 95 % confidence interval of 4.3 years makes a bone age study pretty darned unreliable.

While bone age studies may be of dubious value, they don't lead to a lot of ethical dilemmas. DNA testing, on the other hand, does.

So far, MLB only seems to be using DNA testing to help verify a player's age. However, it's not hard to imagine how they might use other genetic information as well.

Mark Rothstein, a professor of bioethics at the University of Louisville School of Medicine, said: “The funny thing about this all is that the most famous baseball player with a genetic disorder was Lou Gehrig. Would they have signed him if they knew he was predisposed to A.L.S.?”

Autostitching the Big Apple v 3.0

I hope it doesn't seem as if I've gone completely off the deep end about Autostich here in NYC. It never came up at all during most of the things we did today, including several tasty meals, the Hayden Planetarium show or the Broadway production (Westside Story) we saw this evening.

However, we also spent the afternoon at the wonderful American Museum of Natural History, where there were way too many large photogenic objects that were beyond my ability to resist. Here are my favorites, along with the number of images I used to create them.

Ginormous Northwest Native American dugout canoe, 6 images:


Same canoe, different angle, 3 images:


Views from both ends of the Hall of Biodiversity -- a stunning way to convey the concept of just how many species we have on this planet, 4 and 5 images, respectively:



Beryl exhibit in Hall of Minerals. Stills like this are easy to get with the iPhone even in low light -- pasting the phone against the glass case steadies it as well as any tripod -- 7 images:


Ichthyosaurus skeleton, 2 images:


Pterodactyl skeleton, 2 images:


Brontosaurus, 8 images:


Tyrannosaurus rex, 8 images:


Stegosaurus, 12 images:


Triceratops skull, 4 images:


Triceratops skeleton, 4 images:


Mammoth and mastodon skeletons, 4 images:

Tomorrow, Autostitch meets the new Yankee Stadium!

Happy Halloween!

One of my co-workers is a Jedi of balloon art. She graciously allowed me to post one of her latest works:

I spend a lot of my work time looking at skeletons, and appreciate the extra details she put into the lumbar spine and sacroiliac joints (as seen from behind).

In Vivo Paleontology

Some of the medical images sent to me for interpretation come with so little patient history that I feel a paleontologist.

At times like these it's nice to be reminded of how much tougher my job would be if my patients actually had been dead for 9000 years, with no medical record left other than their bones.

The National Geographic video below shows skeletons from a wonderful find in Northern Niger.

Figure 5. Mid-Holocene burials and skull.
(doi:10.1371/journal.pone.0002995.g005)

See the original paper in PLoSOne by Sereno et al. for many more details on this find.

(via Pharyngula)

Safer Sex - Even After Death

Argentina condom manufacturer Tulipán has got some of the coolest ads on the planet.





Also see this "Sex After Death" series on the excellent Street Anatomy site.

However, my favorite Tulipán ads of all time are these two soccer-themed ads featured on the AdFreak site.

If we were really serious about reducing STD rates in the U.S., I'd suggest putting Tulipán in charge of our national safe-sex education efforts. We could do (and have done) a lot worse.