Sunday, August 31, 2008

A Bakery Hannibal Lecter Would Love

My spouse and I just finished watching the excellent second season of Dexter. Only minutes later, by interesting coincidence, I ran into this gruesome but fascinating post on the "Body Bakery" in Ratchaburi, Thailand.

This bakery is the studio of Thai artist Kittiwat Unarrom. Therein he sculpts amazingly realistic (and highly edible) replicas of dismembered human body parts out of bread. These are then packaged as food items and sold in the showroom of his gallery.

It's been pretty hard to gross me out since cadaver lab back in med school, but civilians may find Unarrom's work a bit disturbing. The Shape and Colour blog conveys this unease quite articulately.

(via Movin' Meat)

Saturday, August 30, 2008

Jazz and the Art of Medical Presentations

As an ivory tower radiologist, I give and receive a lot of presentations. Over the years, I've really learned to really, really hate presentations that suck. For inspiration and tips on how to avoid presentation suckage myself, I frequently visit Garr Reynolds' excellent Presentation Zen site. Being a musician myself, I found his posting on Jazz and the Art of Connecting particularly interesting. In this post, Reynolds (who paid his way through college playing jazz) shares quotes from jazz greats that are relevant to non-musical presentations. Here's one:

Dizzy Gillespie: It’s taken me all my life to learn what not to play.
Amen. I'm frequently asked to cram way too much information into way too little time, e.g. 4 years of radiology residency into a 75 minute talk. Instead, I spend the time giving my audience a handful of concepts that they can then apply to many different situations.

Leonard Bernstein, on making jazz interesting:
In his book, The Joy of Music, Bernstein maintains that predictability is a key to making jazz interesting. Consider these two extremes:
1. if the audience can predict every note that you're going to play, it will be boring.

2. if they can't predict a single note, it will also be boring because the music now appears completely random.
A good lecture avoids these extremes. We've all seen way too many lectures read verbatim from a stack of PowerPoint bullet-point slides. (Tip: learn how to set off your own pager to help escape this special circle of PowerPoint hell.)

Handouts can be a similar pitfall if they follow the lecture too closely. Most performers instinctively avoid this like the plague. As a musician, I've learned to love the limelight, and am loath to share any of it with any handout -- even one of the excellent ones I create. My personal tactic is to put my handout on the web, and give the audience a URL to download it at the end of my talk.

Sign on wall in Preservation Hall, New Orleans jazz club:
It's easy to overdo even a great tune. I know how this feels -- at some meetings, I'm asked give the same freaking presentation to 9 different audiences. Viewing this as a jazz gig helps to keep me from going nuts. Even though I play the same tune (i.e same concepts and slide set) for each group, I do my best to customize the talk for each group in real-time, based on audience interaction.

Customizing a talk on the fly can be challenging, especially with large groups. Therefore, I use straw polls and audience response systems (ARS) as often as I can. For non-threatening questions, I use the flesh histogram technique, i.e. have them raise their hands. For other questions, I use the ARS, and their replies are summarized anonymously on-screen in a large graph. I find these graphs to be a great diagnostic tool for gauging their comprehension of a topic. Rather than rolling along monolithically through a slide set, I can add or subtract riffs until the ARS shows me that the audience understands a concept.

Charlie Parker: Master your instrument. Master the music. And then forget all that bullshit and just play.
It took me a while to learn to speak at large radiology meetings with an unclenched sphincter. The key, as usual, was lots and lots of practice. In this respect, music gave me a huge advantage over fellow faculty. Weekly musical gigs quickly gave me an order of magnitude more experience working in front of crowds. It has also helped me to practice many different variations of a tune, a talk or a topic. Once you've done that, the appropriate notes or words seem to pop out just when you need them on stage. At that point, as Bird said, you really can forget all that bullshit and just play.

Friday, August 29, 2008

Anatomic Product Names

One wonders how long it can be before we see lap belt editions from the same maker. A company this creative is bound to come up with similar single entendres like PussyCat™ or FreeWilly™ (or worse) any day now...

(via Real Dan Lyons)

Sunday, August 24, 2008

Grand Rounds - Vol 4, no. 48

I'm in back in town from one final week of summer vacation and am belatedly posting a link to this week's edition of Grand Rounds, hosted this week by Kerri at the Six Until Me blog.

My contribution is yet another round of medical dictation errors: Normal Sphincter and Nose Coordination.

Friday, August 22, 2008

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.

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

(via Pharyngula)

Tuesday, August 19, 2008

Shadow Pictures of Pilobolus

I'm a long-time fan of Pilobolus, the wonderful dance group.

As someone who works all day long in the land of shadows, I am especially fond of these three routines:

Saturday, August 16, 2008

Normal Sphincter and Nose Coordination

More medical malaprops courtesy of a friendly mole in the world of medical transcription:
Normal sphincter and nose coordination bilaterally. (finger-to-nose)

We will place him at bed rest with his eggs elevated.

The patient's gray cat with white paws and crossed eyes is still living in Prague with friends.

Last summer, she had an injury to her right knee when her left knee was on a boat.

Blood pressure elevated by the nurse at 160/96 today.

Patient respiratory Martian artifact degrades image quality. (motion artifact)

This patient from a small town in Alaska with no history of cardiac disease developed severe recurrent chest pain on the day of admission

Past Medical History: Spleen apnea. (sleep apnea).

Upon awakening, he removed all his extremities. (moved)

Works as a night-stalker in a grocery store. (night stocker)

Patient has one sister and three brothers who are all diseased. (deceased)

Chief complaint: Foreign body in esophaguts. (esophagus)

Next is history of, uh . . . next is history of, uh . . . next is history of, uh . . . next is history of, uh . . . . . learning disability.

Last Hurrah of Summer

My family and I are heading off later today to the wilds of northern Idaho for a last hurrah of summer. We'll spend the week there camping, swimming, fiddling and folk dancing with pals from multiple states.

While I'm gone, several posts will automatically appear here via the ghostly hand of Google.

Have a great week!

Thursday, August 14, 2008

Berne Building Bashed by Brobdingnagian Bupkis

Apparently art can indeed change the world.

A Swiss children's home in Berne was abruptly changed on July 31st when a large piece of art dropped from the sky and broke one of its windows.

The Guardian has the whole "scoop": "Giant dog turd wreaks havoc at Swiss museum".

Just for scale, the brown objects above are the size of a house.

As Orac notes in his Respectful Insolence blog , you can't make shit like this up.

Wednesday, August 13, 2008

Predictive Text Swearing

I use voice dictation systems to transcribe all of my radiology reports these days. The system I use at one hospital works quite well, and saves me lots of time. The one chosen by our other hospital is about the worst piece of software I've ever been forced to use.

The following video clip probably explains why the words "ducking piece of pigt" appear in the second system's transcriptions so frequently...

(via Daring Fireball)

Tuesday, August 12, 2008

Grand Rounds - Vol 4, No. 47

The latest edition of Grand Rounds is now on display at the Medical Humanities Blog, featuring the latest round of keen medical blogging.

My contribution to the menu is A Call for Randomized Clinical Trials of Parachutes.

Monday, August 11, 2008

The Fascist Octopus Has Sung Its Swan Song

Jeepers, two George Orwell posts in two days.

The lurid phrase above comes from
Politics and the English Language, a short but excellent essay by Orwell on the art of writing clearly in English. He has particular censure for buzzwords.

This essay is from 1946, but contains many wise words for anyone putting quill to parchment or post to blog.

A summary in Orwell's words:
But one can often be in doubt about the effect of a word or a phrase, and one needs rules that one can rely on when instinct fails. I think the following rules will cover most cases:

i. Never use a metaphor, simile or other figure of speech which you are used to seeing in print.

ii. Never use a long word where a short one will do.

iii. If it is possible to cut a word out, always cut it out.

iv. Never use the passive where you can use the active.

v. Never use a foreign phrase, a scientific word or a jargon word if you can think of an everyday English equivalent.

vi. Break any of these rules sooner than say anything outright barbarous.
I especially like rule vi, and plan to (ab)use it with great profligacy.

(via 43 Folders)

Sunday, August 10, 2008

Magnets Inside the Body

A fair amount of my work time is spent inflicting intense external magnetic fields on patients. This is otherwise known as magnetic resonance imaging (MRI).

I therefore found it very interesting to read this interview with Quinn Norton, in the Canadian Medicine blog. Norton, a San Francisco journalist describes her experience with having a small rare earth magnet implanted into her fingertip.

Due to complications, she eventually had to have the magnet removed. In the meantime, she claimed it gave her a "sixth sense" that allowed her to detect electromagnetic fields from a distance.

As her story suggests, such implants are not not quite ready for prime time. However, it would be cool to be able to sense magnetism directly.

Anyone who has worked around MRI for very long has eventually forgotten to remove sensitive objects before entering the scanner room. At minimum, this results in having the magnetic stripe wiped on all your credit cards. Other objects, such as metal pens or nail clippers can suddenly turn into dangerous projectiles. If my finger twitched whenever I entered the scanner room, it would be a great reminder to be sure that my pockets were clear.

Internal Magnets Placed by Physicians

I don't know of any reputable physician who would implant magnets in a patient for body modification purposes. However, a cursory search of PubMed for "internal magnets" did bring up a few cases of magnets implanted for other reasons.

I found two reports (this one and this one) in which permanent magnets were implanted in the sternum to provide postoperative traction following pectus excavatum surgery.

Some cochlear implants employ an internal magnet.

I was interested to learn that total shoulder replacement by a magnetic arthroplasty has been tried in a patient with a destroyed rotator cuff. These investigators hoped that the strong samarium-cobalt magnet in the prosthetic humeral head would prevent the components from dislocating.

An anus, with homage to Kurt Vonnegut

Another group of investigators has proposed implanting strong magnets in the wall of the anal canal to prevent fecal incontinence. Their preliminary work in pigs suggests that such magnets would be strong enough to keep the anus sealed. My main worry with a magnet this strong would be how to get it open again.

Internal Magnets Removed by Physicians

What happens if you ingest a magnet? It depends.

If it's the right size, it should pass right through your system and eventually drop out in the toilet with no worries.

However, you never, ever want to ingest more than one magnet at a time. See this case report of a child who developed small bowel obstruction due to ingestion of two small (8 mm) magnets from a Polly Pocket doll (Mattel, Inc. El Segundo, CA). The obstruction was caused by the fact that when these two magnets passed by each other in adjacent loops of bowel, they were strong enough to pull these loops together. Said magnets had to be removed surgically. Eek.

Cow Magnets

I first saw the term "cow magnets" in a Gary Larson cartoon, showing several of his classic cows stuck together out in a field. I only learned much, much later that cow magnets are a veterinary device used to prevent hardware disease - bovine traumatic gastritis due to ingestion of metal objects.

Cow magnets

The idea is that after you feed one of these to an calf, it settles in the animal's rumen or reticulum and remains there for the life of the animal. The hope is that bits of ingested metal crud will stick to this magnet in a sort of a ferromagnetic bezoar, rather than causing obstruction elsewhere or perforating the animal's bowel.

George Orwell, Blogger

Jeebus -- as if the competition for eyeballs in the blogosphere weren't already Darwinian enough. Now mere mortal bloggers will have to duke it out with the likes of George Orwell.
The Orwell Prize, Britain’s pre-eminent prize for political writing, is publishing George Orwell’s diaries as a blog. From 9th August 2008, Orwell’s domestic and political diaries (from 9th August 1938 until October 1942) will be posted in real-time, exactly 70 years after the entries were written.
Although his grasp of internet lingo and issues may lag behind the times a bit, Orwell's observations on life and politics during a difficult period of world history should be well worth following.

(via The Loom)

Safer Sex - the Sequel

In the interests of fair and balanced posting, I must point out two U.S. condom manufacturers whose ads are not totally lame...

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.

Friday, August 8, 2008

A Tale of Two Brains

One of my lifelong quests is to learn to give presentations that don't suck.

One tactic in this quest is to learn from people who give exceptional talks. A great source for awesome presentations is the TED conference, which hosts the best speakers in the world and shares them on the web.

In the following TED video, neuroscientist Jill Bolte Taylor gives a play by play account of her own stroke. There's a lot to learn here. Her insights from this devastating event are quite compelling. Equally compelling are the techniques she uses to tell this gripping tale of two brains.

A Call for Randomized Clinical Trials of Parachutes

In the tight-sphinctered world of academic medicine, it's always delightful to find a journal that still has a sense of humor. The following satirical paper from the British Journal of Medicine made me laugh and laugh.

ResearchBlogging.orgSmith GCS, Pell JP. (2003). Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomised controlled trials. BMJ, 327(7429), 1459-1461. DOI: 10.1136/bmj.327.7429.1459

In a nutshell, this paper rightfully points out that no one has ever done a randomized, controlled trial (RCT) on the efficacy of parachutes. Furthermore,
Advocates of evidence-based medicine have criticised the adoption of interventions evaluated by using only observational data.
To be funny, satire has to contain enough truth about its subject to properly skewer its underlying fallacies. Smith and Pell's excellent paper carries the concept of parachute efficacy through the usual machinery of evidence-based medicine, all the way to the following hilarious reductio ad absurdum conclusion:
We think that everyone might benefit if the most radical protagonists of evidence-based medicine organised and participated in a double-blind, randomised, placebo-controlled, crossover trial of the parachute.
From skimming through the comments stimulated by this paper, it seems that not all of the BMJ readers recognized it as satire, even though the article concludes with the following contributors' statement:
GCSS had the original idea. JPP tried to talk him out of it. JPP did the first literature search but GCSS lost it. GCSS drafted the manuscript but JPP deleted all the best jokes. GCSS is the guarantor, and JPP says it serves him right.
A Bit More on Evidence-Based Medicine

The formal term "evidence-based medicine" (EBM), is a relative newcomer on the medical research scene, and is based on early publications by Cochrane in 1972 and Sackett and Guyatt in the early 1990's. Their idea is a simple one: make clinical decisions based on a synthesis of the best available evidence about a treatment.

Just a few decades later, there are way many EBM advocates who are way too ready to blindly wield EBM like a mighty sword without understanding its limitations. IMHO, one of its biggest limitations is the current EBM definition of "best available evidence". For example, consider the Oxford Centre for Evidence-based Medicine Levels of Evidence (May 2001):

LevelTherapy/Prevention, Aetiology/Harm
1asystematic review (with homogeneity*) of RCTs
1bIndividual RCT (with narrow Confidence Interval‡)
1cAll or none§
2asystematic review (with homogeneity*) of cohort studies
2bIndividual cohort study (including low quality RCT; e.g., <80% follow-up)
2c“Outcomes” Research; Ecological studies
3asystematic review (with homogeneity*) of case-control studies
3bIndividual Case-Control Study
4Case-series (and poor quality cohort and case-control studies§§)
5Expert opinion without explicit critical appraisal, or based on physiology, bench research or “first principles”

I agree with the idea that all evidence is not created equal. However, there is something fundamentally wrong with the hierarchical list above. For one thing, it puts the principles of physics, chemistry and physiology down at the bottom of the heap in category 5, below even "poor quality case-control studies" in category 4. According to this table, a crappy case-series showing nerve conduction velocities faster than the speed of light would trump Albert Einstein's thoughts on the subject. I find this a bit troubling.

This is only one of the wacky conclusions that can arise from blindly following the precepts of EBM. I highly recommend Kimball Atwood's great Evidence-Based Medicine Primer on the excellent Science-Based Medicine blog. Therein he ably shows some of the limitations of EBM, and why it is not up to the task of evaluating highly implausible claims such as, say, homeopathy.

A Better Alternative: Science-Based Medicine

IMHO, EBM is a decent start, but is still a work in progress. The next logical step would be move to science-based medicine (SBM), wherein basic science is placed a lot higher on the food chain of evidence. This lets us start with this basic concept:
Therapeutic claims require evidence.
and come up with a somewhat more refined version:
Exceptional claims require exceptional evidence.
In other words, when we evaluate some intervention, basic science can help us determine if there is a reasonable scientific mechanism that supports it. If not, why do the study? And, if someone does the study anyway (it happens), the scientific plausibility (or implausibility) of the mechanism can help us decide how credible are the results.

Let's look at two brief examples: homeopathy and parachutes.
Homeopathy claims therapeutic benefits from extremely dilute solutions of various agents (e.g. Oscillococcinum). However, the solutions usually employed are so dilute there is not a single molecule left of the original agent. Scientific likelihood of any benefit over that of plain water = zip.

Homeopathy counters this with the claim that the diluting water has a "memory" of the original agent, even though it's all gone. However, there is no scientific evidence of such a "memory" effect. Besides, when one considers how much of our planet's water passes through human kidneys, it seems likely that any possible "memory" of Oscillococcinum would be swamped by just the "memory" of used beer.

Bottom line: scientific likelihood of any benefit of homeopathy over that of plain water again = zero/zed/zip.

In this case, the basic science is so overwhelmingly against any benefit that it seems ridiculous to perform an RCT of homeopathic claims. Even if a marginally weak effect were suggested by a clinical trial, the a priori implausibility of homeopathy makes it hard to put much confidence in the result.
The physics of falling bodies, on the other hand, has been understood for a long time, particularly when there is atmospheric drag. The terminal velocity of a falling human in air is about 55 m/s (120 mph). Scientific likelihood of survival = almost 0% (a few fluke cases have been reported of lucky folks surviving parachute failures).

A properly designed parachute can decrease this falling speed to as little as 2.1 m/s, about the speed you'd develop by jumping off a 9 inch stool. Scientific likelihood of survival = virtually 100%.

In this case, the basic science is overwhelmingly in favor of survival. Therefore, I'm willing to take my chances with a parachute during my next plunge from a height -- RCT or no RCT.

Wednesday, August 6, 2008

iPhone 3G: Rational or Rationalization?

Consider the following lines from The Big Chill:
Michael: I don't know anyone who could get through the day without two or three juicy rationalizations. They're more important than sex.

Sam Weber: Ah, come on. Nothing's more important than sex.

Michael: Oh yeah? Ever gone a week without a rationalization?
This quote is brought to you courtesy of my brother, who has watched me buy gadgets for most of our lives.  As he has pointed out many times, I can always cite reasons for buying them, but I really don't need most of them.

This more or less leads right to the point of this posting: I bought an iPhone 3G this past weekend.

Why? After months of reading about it and mulling over the pros and cons, it all essentially came down to:
  1. Bright
  2. Shiny
For the back story and my many rationalizations, read on.

Rationalization 1: my old phone stopped working

Last Wednesday, my venerable iPhone stopped making calls. With the new 3G phone out there, this timing seemed providential. Since it was still in warranty, the top question on my mind was:
Will Apple replace my old phone with a new 3G phone?
Alas, no.

It turns out that Apple currently still has big bags of the original 2G phones around. They don't sell them, but use them to replace defective 2G phones, such as mine. They tested my old phone, and immediately gave me a shiny new 2G replacement unit at no extra charge.

Rationalization 2: there is an easy upgrade path from the 2G to the 3G iPhone

Alas, again. The only migration path is to buy a 3G, move your phone number to it, and then sell your 2G phone.

Rationalization 3: I can use the extra memory

This one has some merit to it.

On the one hand, my old 8 GB 2G phone held more stuff than I could listen to in weeks of commuting.

However, every plane trip required an hour of iPhone prep work -- shuffling stuff on and off the phone so that I had enough room for a few trip movies and podcasts. This will be a lot easier to do with the extra 8 GB on the new 16 GB phone.

Also, even in these early days of iPhone applications, I can already see how easy it would be to fill up my phone with apps alone.

Rationalization 4: the extra 3G speed will be great

When I use it, it is nice. I live in a town with decent 3G availability, and web pages and e-mail downloads feel a lot zipper than with 2G. However, when I'm at home or work, I have much faster WiFi connections. 3G is therefore probably only useful to me for about 5% of the time. The rest of the time, it seems to suck the battery down at a sometimes appalling rate.

Rationalization 5: the built-in GPS will be awesome

We are still in the early days of location-based phone services. However, I am already convinced that these apps are a killer reason to buy a 3G. I'm guessing that 20 - 40% of my visits to the web for information require me to tell the site where I am (movie times, weather, bus and ferry schedules, dining, etc.). As I posted here before, iPhone apps like Loopt and Urbanspoon are already automating this process for me. Other apps such as HereIAm, BoxOffice and one showing my local bus routes have been equally useful. It's impressive just how much time is liberated by having the iPhone enter this information instead of me.

For the most part, the built-in GPS seems to work quite well, other than in a drugstore parking lot in my neighborhood, where the GPS repeatedly thinks I am near a cemetery in Jersey City, NJ, zillions of miles away.

Rationalization 6: I can sell the 2G phone on eBay

This is true. One current bid there for a locked mint 2G phone was $365.

Rationalization 7: 3G's are in stock right now -- who knows when they will have them again?

This is not very convincing locally, since all of our stores seem to have all models in stock every day.

The feeding frenzy seems to have died down considerably. While there are lines locally, they are short. This past weekend, I didn't get in line until about 11:30 am on Saturday morning. I had a voucher for a 16 GB phone about 20 minutes later, and had an activated phone in hand 30 minutes after that.

Rationalization 8: I can just use my old SIM card in the new 3G

Alas, no. However, a new SIM card comes with the 3G, and it only took a few minutes to transfer my old number to the new phone.

Rationalization 9: all of my email accounts, photos, etc. will transfer over to the new phone

This was true for me. However, I first read this article from the Apple support site and followed its advice closely:
This article explains how to replace an original iPhone with an iPhone 3G using the same carrier. If you follow these steps to backup your original iPhone first, and then restore the backup to your iPhone 3G, your saved SMS messages, email accounts, photos, notes, and other personal settings will be present on your iPhone 3G.
Rationalization 10: the 3G phone has plenty of battery life

I think the battery life is fine. However, with the phone, GPS, 3G and WiFi all enabled, it is pretty daunting just how quickly that battery level can drop down to 20%. However, if I run on phone and WiFi alone at work (GPS and 3G off), my battery seems to last all day with no problems.

However, the following Twitter quote by Rands (via The Macalope) really hits the nail on the head:

PEOPLE the battery life appears less because YOU CAN'T PUT THE DAMNED THING DOWN.