Wednesday, 17 October 2012

Technology

If you're looking for a stupid patient story, you'll be disappointed by this update, and I apologise in advance.  If you're looking for a really cool picture, you're in the right place.

If you were in a car accident 25 years ago, chances are very good you have a little scar above your belly button where the trauma surgeon performed a DPL - Diagnostic Peritoneal Lavage.  A small incision was made, a catheter was inserted into the abdomen, and a liter saline was instilled.  That saline was then immediately drained out, and if blood, bile, or stool came out with it, you would have gone straight to the operating room for an exploratory laparotomy where the surgeon makes a much larger incision to get into the abdomen to take a look around.  A very large number of these operations turned out to be unnecessary, because if it was the spleen or liver bleeding (which it usually is), that bleeding almost always stops by itself (over 90% of the time). 

The trauma world has been vastly changed in the past 20 years by the advent of CT scans.  "CT" stands for "computerised tomography", and it's essentially a cross-sectional X-ray.  In the 1990's, a CT scan of the head alone used to take about 30 minutes, since the machine was only able to take one picture at a time.  But we were able to see inside the head for the first time.  These days, a full body scan only takes about 20 seconds because the machine takes 64 or 128 pictures at a time.  The best part is that the really fancy (read: expensive) machines automatically reformat the raw data into 3-D pictures.  But CT scans aren't just for looking at the brain or the guts.  They are also great at finding broken bones, and they are much more sensitive than regular X-rays.  Plus, the pictures just look cool.

In case you don't believe me, here's some proof.  This is an actual 3-D rendering of a patient of mine this past week who was jumped by a gang of misfits who punched and kicked him repeatedly in the face:


In case you don't see it immediately, look at the mandible (that's the jaw bone) on the lower left side of the picture just behind the last molar.  There's a second fracture on the right lower side of the picture just next to the midportion of the mandible. 

Getting all these scans may be a bit more expensive (ok, a LOT more expensive), but it has also enabled us to find a lot of injuries that plain X-rays just can't see.  It has also saved patients from a lot of unnecessary operations.  If I see a bleeding liver or spleen, I know that patient will most likely not need surgery.

Hey, wait a second...I'm operating less than before because of these damned CT scans!  But I love doing surgery!  I'm supposed to hate that, right?  But I just can't...they're just too cool.

10 comments:

  1. I cringed at the X-Ray, God knows the visible damage was brutal. Quick question:

    Do doctors still use morphine as a pain killer, or are there other, less addictive alternatives used now?

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    Replies
    1. I still use morphine as my first-line analgesic in most situations. Some doctors will use hydromorphone (which is several times stronger), but it gives a more euphoric feeling, and that's an undesirable side effect as far as I'm concerned. Patients tend to love it for exactly that reason, and that's exactly why I don't use it unless morphine is ineffective.

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    2. i got morphine for my kidney infection once. it didnt lessen the pain one bit, but it did make me feel like im on clouds.
      =\

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  2. So if a CT scan can be done in a matter of seconds, what is it about the technology and process of an MRI that causes that to take several minutes? I fel like I was in that machine forever when I needed an MRI of my head done a couple year ago.

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    Replies
    1. They are completely different processes.
      CT scans use X-rays, that are like high energy light and get absorbed in different amounts by different tissues. It's essentially like a photo, only it uses more powerful light and the computer puts a bunch of them together to make a 3D model.

      MRI is a magnetic process (hence Magnetic Resonance Imaging). What happens in that is that they put you inside a massive magnet (seriously, these use some of the strongest magnets in the world) which makes the hydrogen in the water in your tissues line up like tiny magnets. They then tip those magnets over using radio waves and detect the waves produced as they tip back again. The amount of signal they get depends upon how strong the magnet is and how much water is in a tissue*. You can imagine the signal is absolutely tiny and it takes a while to collect enough signal to be useful.

      As magnets get stronger and detectors get more sensitive, the process gets faster. Maybe one day these things will improve enough that they will be able to do it in seconds but even now, it's pretty amazing that anyone even thought you could get an image of the inside of a person that way.

      Isn't science amazing.

      *If you add certain other materials to a tissue then you get an enhanced signal, so it's not always just the water. These are called "contrast agents" and act like a dye would in a normal photo.

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  3. Wow, I thought my jaw hurt from TMJ! That's one unlucky patient.

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  4. That's an amazing picture. I love the way you can see the difference between the teeth and the bone. Did you need to do anything about that little chip of bone out on the left?

    And Doc - you know you don't want to operate just to find that you didn't need to! You operate to fix people, not to waste your time that could be better spent opening up someone who really needs it.

    Hope your patient is recovering well.

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  5. That image is incredible! God damn I love medical imaging and how far it's come! My mother still thinks it's weird that I kept her MRIs for myself. I just can't wait to work in medicine :D

    Good luck to the patient as well! That certainly doesn't look like fun to have a mandible in so many pieces.

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  6. When I saw this on FML, I thought it was just a regular picture of a skull. The truth is way more amazing... and painful. Kind of reminds me of Nick Veasey.

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  7. I've been reading your blog for a while now and it truly is incredible to see how much effort you put in to help your patients.

    As I was reading an article I saw a scan of another man's face (after a severe beating from a drunken idiot) that reminded me a lot of this one. The quality isn't as good, but you can still see the damage.

    http://www.stuff.co.nz/national/health/7916270/Face-pieced-together-like-a-jigsaw-puzzle

    I couldn't imagine how difficult it would be to piece somebody back together, in any situation. Anyone is this field should get a hell of a lot more recognition than what they do currently.

    ReplyDelete

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