Interactive Transcript
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It's worth touching a moment on cabbage to that.
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Cabbage, as you know, stands
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for coronary artery bypass grafting
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and, um, one of the few uses in CT
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to use volume rendered images.
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This is a case from the CAD RADS 2.0 guidelines,
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but um, it's a nice illustration of it.
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Uh, arterial graft, so this is a lima
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and you can see it's tortuous,
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but does touch on the LAD as it usually does.
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And then this case also has, uh,
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aortic coronary bypass grafts
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and they can, any vessel can go anywhere.
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These are, um, looking like venous bypass grafts going
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to a diagonal
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and then further to an obtuse marginal,
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they tend not to cross though they can.
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Um, you can use the Lima left internal mammary artery,
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which comes off of the left subclavian,
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or you can use the right internal mammary artery.
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Uh, and sometimes you use both.
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Uh, you probably are aware that many bypass grafts, uh,
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are tenuous and can go down.
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Um, arterial bypass graft such as a Lima arima
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or even a radial artery
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that's transposed from the arm into the chest, uh,
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tend to be more patent.
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You can even use the gastro lipoic artery from the abdomen.
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So if you do have a case where somebody knows they have a,
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uh, abdominal graft, you'd want to extend the scan
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to cover the abdomen as well.
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Uh, when you do these, uh, you're often looking
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through vessels that are occluded.
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So, uh, you may just say the vessels you see
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and the vessels you don't.
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So if there's history of a saphenous graft,
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but you don't find a saphenous graft, probably occluded.
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In fact, 12% of bypass grafts are down by the morning
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after surgery, um, in older studies.
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So we tend not to do as many bypass grafts these days
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and try to focus on arterial grafts when you can, um,
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and give a durable, uh, result.
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You'll also see that there's a lot of, uh,
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clips along this case.
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Those are metallic clips that the enemy of a, uh,
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CT artifacts, uh, or they cause artifacts.
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So sometimes you miss a touch of the anatomy due to streak
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and we just tend to ignore that.
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You wanna look for the origin and the touchdown
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and then look for any stenosis when the graft,
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and we'll look at a lot of cases of,
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uh, graft abnormalities.
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And you're often using this
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to guide the invasive angiography.
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So here's a and matched invasive coronary
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angiogram, sternotomy wire.
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As you can see, this is an arterial graft.
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The same case actually.
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And so this is a very tortuous lima graft,
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but one of your roles as a CT imager is just
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to find the graft anatomy
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because the invasive angiography has to hunt around.
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For instance, if they're looking
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for a saphenous graft in this patient, they'd have
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to know exactly where it arises from the, uh, aorta,
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but the CT imager can find that very clearly.
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In fact, if it's occluded, no need to do an angiogram.
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Uh, so just some, uh, some basic pointers on bypass grafts.
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Uh, and of course you are gonna look at the curve planar
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reformat and the axial images,
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but you, uh, can illustrate this very nicely for surgeons
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and, and interventional cardiologists
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by using volume rendered images.
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And one other note is most sites scan just the
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Heart for a coronary ct.
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If you know there's a bypass graft,
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you wanna extend the scan up to
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above the first ribbon clavicle junction
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because then you'll cover the origin, uh,
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and the entire course of a lima graft
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to the left control mammary.
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And you wanna make sure you clear the inflow from the
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subclavian, which you'll automatically get if you do that.
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One easy rule of thumb
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that we do at our site is we tell our technologist if you
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see a sternotomy scan, the whole chest,
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'cause it has been a cabbage
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or there's another heart surgery
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and a cabbage is potentially addressable.
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So have a sternotomy scan, the whole chest.