Monday, May 25, 2015

Will Watson Compete For Radiology Jobs?

IBM recently released an ad from the Ogilvy Group agency currently airing on national TV that directly addresses how Watson, IBM's ongoing supercomputing research project popularized by its star turn on the TV show 'Jeopardy!, may one day play a role in diagnostic imaging:

Is this realistic, or just some far off pipe dream? Technological aspirations often tend to outstrip technical reality. For example, computer-aided diagnosis (CAD) in mammography has not become a panacea for screening mammograms, and ultimately does not appear to have had a significant impact on the labor demand for mammographers. Anecdotally, mammographers I have spoken with regard CAD as too sensitive, and a potential liability. Sure, the software will pick up the subtle lesion occasionally, but it will pick up many more that are merely normal tissue, but nonetheless force the radiologist to make an active decision to dismiss. What happens if the mammographer decides a positive finding on CAD is negative, but cancer develops later anyway? Unless the software can improve both sensitivity *and* specificity, it may create as many problems as it solves.

For argument's sake though, let's say the new technology can improve both sensitivity and specificity.  Several open questions come to mind: will the software aid radiologists? Does it seek to replace radiologists? If it does, who takes on liability if the software 'misses' a lesion, as it inevitably will? And who pays for it all? It is hard to see these questions being answered in the affirmative in the current healthcare system, but after seeing ACA pass, it is clear that the environment is not static. If costs start to rise again, and IBM and similar software vendors market themselves well, one could see hospitals giving such systems a try. The tl;dr - money talks and BS walks: if these systems can do the job better than radiologists, they will be used.

How can radiologists operate under such potential uncertainty? Instead of ducking the issue, radiologists should work towards simultaneously figuring out how best to employ these systems while also demonstrating the value-add of a physician diagnostic imager both to referring clinicians and to patients. If the face of the radiologist is merely the report they generate, very soon that face may take a very Big Blue complexion.

Monday, May 18, 2015

How To Perform An IVC Filter Placement

IVC filters can be placed surgically but the vast majority are placed percutaneously.

Pre Procedure

  • Indications
    • New clot or clot progression on therapeutic anticoagulation.
    • Pre-op for patient who cannot be anticoagulated
  • Can be placed from a transjugular or transfemoral approach.
  • Ideal location is infra-renal.
  • Make sure to check a CT beforehand for variant renal vein anatomy.


  • Access the venous system either via a jugular or femoral approach. If femoral, the vein is 1 cm medial to the artery.
  • Insert a Pig cava catheter, and perform an angiogram (Usually 15 ccs / min for 30 cvs)
  • Exchange the catheter for the filter sheath, after dilation of the tract.
  • Gunther-Tulip Jugular
    • Insert the filter until the feet are at the end of the sheath. Unsheath the filter. Press the button to deploy.
  • Gunther-Tulip Femoral
    • Insert the filter until the tip is at the end of the sheet. Unsheath the filter. Bring the red and white torquers together and twist to deploy.
  • Option
    • Make sure the correct end is facing the catheter

Post Procedure

  • If retrievable, can be retrieved up to 3 weeks before the filter epithelializes
  • Complications: fragmentation, migration, perforation

Sunday, May 17, 2015

Radiology Gifts at Raditudes

Ever look for a gift for that special radiologist in your life? Or just the one you want to tease a little? Check out Raditudes! The store is specifically aimed at radiology and diagnostic imaging related gifts, including t-shirts, coffee mugs, and more!


Have feedback or a design idea you would like to see? Let us know!

Monday, May 11, 2015

How To Perform An IVC Filter Retrieval

Certain types of IVC filters are retrievable within a 3 to 8 week window after placement. Typically, these were placed for a patient who had a short term need for anticoagulation, but could not be medically anti coagulated. For example, a trauma patient with a head bleed and a long bone fracture going to the OR with orthopedics. The procedure is very similar to IVC filter placement.


  • Access the venous system via a jugular approach. Filters can only be retrieved via the jugular vein. 
  • Insert a Pig cava catheter, and perform an angiogram (Usually 15 ccs/sec for 30 cvs) 
  • Exchange the catheter for the sheath, after dilation of the tract. 
  • Extend the snare from the tip of the sheath and capture the filter's hook under fluoro.
  • With gentle back tension on the snare, advanced the sheath over the filter so until the filter is fully within the sheath. 
  • Retrieve the entire system and withdraw it from the neck. Be careful as you cross through the right atrium 
  • Hold gentle manual pressure over the neck venotomy site.

Retrievable IVC Filter
Source: Wikipedia

Monday, May 4, 2015

Dynamic MRI of a Knuckle Cracking

From the medical oddities file, researchers from the University of Alberta have *finally* captured a knuckle popping on MRI in order to explain what goes on during when one "pops a knuckle" and where the sound comes from. Per the Wired article:
First, researchers at the University of Alberta found someone who could crack his knuckles over and over again, without the long refractory period most people have. Yup, he was multiply crackasmic. 
Then the scientists put this crack-addict’s fingers into a magnetic resonance imager, watching cracking events as they took place. That’s what’s in the GIF we made you from the researchers’ video. As the bones in the joint separate, negative pressure means gas (likely nitrogen) in the synovial fluid gathers together, resulting in the sudden formation of bubbles—the scientific term for that is tribonucleation. And with that comes the pop.
The GIF of the knuckle pop looks like this:
Source: Gregory Kawchuk, University of Alberta/PLOS Media via Wired

The actual research article has the more staid title of "Real-Time Visualization of Joint Cavitation" but honestly, the authors must have known that is not the source of interest in their work. If you want to know why exactly the sound occurs, the authors state:
Our results offer direct experimental evidence that joint cracking is associated with cavity inception rather than collapse of a pre-existing bubble. These observations are consistent with tribonucleation, a known process where opposing surfaces resist separation until a critical point where they then separate rapidly creating sustained gas cavities.
The work also goes a long way towards explaining this video from the 1980s:

The research leads one to wonder: what other phenomenon have we been missing on MRI? If a patient has vacuum disc phenomenon in their lower lumbar spine, are they simply in need of a good back massage? Speaking of which, why do massages feel good? Clearly, we need to get a metal-free masseuse into a scanner and see what happens!