Sacrum

I was reading an article on the role of religion in the secular Turkish state and came across this statement:

It is possible -- such is the argument of Carter Findley in his Turks in World History -- that in doing so it drew on a long Turkish cultural tradition, born in Central Asia and predating conversion to Islam, that figured a sacralisation of the state, which has vested its modern signifier, devlet, with an aura of unusual potency.

You may be wondering what the heck a congenital variant of spinal segmentation has to do with religion. From the always-excellent Online Etymology Dictionary:

Bone at the base of the spine, 1753, from Late Latin os sacrum "sacred bone," from Latin os "bone" + sacrum, neuter of sacer "sacred" (see sacred). Said to be so called because the bone was the part of animals that was offered in sacrifices. Translation of Greek hieron osteon. Greek hieros also can mean "strong," and some sources suggest the Latin is a mistranslation of Galen, who was calling it "the strong bone."

Nerve Root(s)

In season 3, episode 18 of Star Trek: Deep Space Nine Dr. Bashir has to deal with some deep-seated personal issues. One of these is the fact that he graduated second in his medical school class because he mistook a "pre-ganglionic fiber for a post-ganglionic nerve." Spoiler alert: He did it on purpose because he didn't want to deal with the pressure of being first.

Dr. Bashir is not alone. I see this lead to 2 errors every day in our trainees. The clinical implication is zero, because the referring physicians also don't make this distinction (two wrongs do make a right, apparently).

First, take a look at the image below:



Note that there are 2 nerve roots (dorsal and ventral) on each side (left and right). When you say a lumbar disc compresses a nerve root in the central spinal canal, you need to add an "s," because these dorsal and ventral nerve roots travels down together in the cauda equina. Next time you look at an axial T2-WI of the lumbar spine, see if you can see two distinct nerve roots on either side.

Second, note that once we're post-ganglionic, we're dealing with a nerve, not a root. So, if you're talking about a nerve root outside the foramen, you're about as anatomically correct as a Ken doll.


The same goes for the "nerve roots" of the brachial plexus and the famous Randy Travis Drinks Cold Beer mnemonic for the brachial plexus anatomy (sorry, Randy). All is not lost. Just replace Randy Travis with Nikola Tesla.

Reference

• Basic anatomy that everyone ignores.

M.D. = Makes Decisions (unless you're a radiologist)

#
1	This is a cat.	This is a hemangioma.
2	This is most likely a cat.	This is most likely a hemangioma
3	This is consistent with a cat.	This is consistent with a hemangioma.
4	This is most likely a cat, but get a follow-up picture to make sure it wasn't a baby tiger all along.	This is most likely a hemangioma. Recommend follow-up to document stability.
5	This is most likely consistent with a cat.	This is most likely consistent with a hemangioma.
6	This is likely a cat, but can't exclude a tiger hiding behind it way in the distance.	This is likely a hemangioma, but can't exclude malignancy, sarcoid, etc.
7	This is likely a cat. Why don't you take a look for yourself and stop bothering me?	This is likely a hemangioma. Recommend clinical correlation.
8	This is likely a cat, but get a saliva sample and send it in for genetic analysis. Better yet, kill the cat and dissect it.	This is likely a hemangioma. Recommend biopsy. Open biopsy may be required.

In the real world (with the cat), anything other than statement #1 will get you laughed at. In radiology, statement #1 is rare. Instead we teach our residents and fellows, by our own weak examples, to be as non-declarative as possible.

Statements #2 and #3 are as declarative as most radiologists get. "I said most likely. What more do you want from me?!"

Statement #4 just passes the buck to the next radiologist.

Statement #5 combines 2 mild hedge words to produce one super-hedgy sentence.

Statement #6 is the reason Bayes rolls in his grave every time a radiologist signs a report.

Statement #7 is basically saying, "Thanks for the money suckers! This report was useless." We have access to so much patient data these days that it baffles me to see this in reports. Of course, this doesn't apply to cases where we're reading in isolation and when the only history we get from referrings is "pain," or some random ICD code. This negligent absence of data in a requisition borders on (is?) malpractice. I've seen it in imaging referrals my family members get from their doctors and it aggravates me to no end.

Statement #8, I don't even... For a cat/hemangioma?

Look, sometimes we have to hedge. Sometimes we are no better than Plato's cave captives, squinting at shadows with no idea of what's behind us. We know that two or more widely disparate entities can have identical imaging features. But when you know something can only be one thing, just say so. Save the patient some anxiety. And, save the rest of us some money by reducing unnecessary imaging.

What are some of your favorite radiology hedges?

Costochondritis

Costochondritis, as its implies, is a nonspecific term for inflammation of the costal cartilage. The problem with this definition is that it implies a non-specific process, where inflammation can be caused by any number of pathological processes, including trauma, infection, or radiation.

The clinical entity of costochondritis, on the other hand, has specific features:

• Self-limited
• Usually multiple affected levels
• Can occur at the costochondral junction or at the chondrosternal joints
• No swelling or induration on physical examination
• Pain that is reproduced by palpation and may radiate on the chest wall

This definition differentiates costochondritis from the much rarer Tietze syndrome (TS). In TS, the inflammatory process causes visible enlargement of the costochondral junction(s) and is most commonly isolated to a single rib (usually the 2nd, but can also involve the 3rd rib). TS can be caused by infectious, rheumatologic, and neoplastic processes. The infection is usually associated with trauma (e.g., stab wounds, iatrogenic) or with intravenous drug use.

Costochondritis is relatively common, and can be seen is as many as 14% of adolescents and 13 to 36% of adults with chest pain.

References

Proulx AM, Zryd TW. Costochondritis: diagnosis and treatment. Am Fam Physician. 2009 15;80(6):617-20.

"You keep using that word. I do not think it means what you think it means."

This post is futile. Language is an evolving process. Words have been joining, splitting, and changing meaning for as long as we've had language. The advent of printing helped slow down the process by disseminating "correct" definitions, but words will continue to evolve in spite of dictionaries and curmudgeons like me. That's a good thing.

The definitions of the words below will soon change to match their current "incorrect" usage, first as alternative meanings, and then as the accepted definition. This will happen as surely as ask is changing to aks/axe before our eyes, a continuation of the battle between āscian and āxian in Old English and asken and axen in Middle English.

Having said all that, the following is a list of incorrectly used words that you should feel free to ignore:

• Epicenter: This refers to a point on the Earth's surface directly above the focus of an earthquake or some other rumble down below. We have appropriated the term to replace plain old center. If we were to correctly use the term in radiology, we'd use epicenter to refer to the skin on top of a deep lesion: "The epicenter of the femoral lesion is on the skin of the medial thigh." See also penultimate.
  
  
• Serpiginous: Serpiginous (from serpere-to creep) is the term that is used to describe creeping and advancing skin diseases, such as ringworm or noduloulcerative cutaneous syphilis. This term is incorrectly used to describe snaky (serpentine) things like vessels or borders of bone infarctions. The person who is responsible for introducing serpiginous into the radiology literature in 1967 issued a correction in 1988, begging us to use serpentine instead. But the damage had been done. By then, the error had serpiginously crept its way into our mouths, and now spills out daily into millions of microphones and reports.
  
  
• Shotty: This refers to small lymph nodes that feel like buckshot under the skin. You must have serious palpation skills if you can feel shotty mediastinal or retroperitoneal lymph nodes! Bonus activity: Do a poll of your colleagues and trainees and see how many think (or thought) the word is actually shoddy. Bonus activity 2: Ask them what shotty/shoddy means in the context of lymph nodes.

References

• Di Chiro G, Doppman J, Ommaya AK. Selective arteriography of arteriovenous aneurysms of spinal cord. Radiology. 1967 Jun;88(6):1065-77.
• Di Chiro G. Serpentine (not serpiginous) vessels in spinal arteriovenous malformations. Radiology. 1988 Jan;166(1 Pt 1):286.