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Hi, I'm Marc Gosselin,

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and we're going to continue on with the

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cardiopulmonary imaging sessions.

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This is the introduction,

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session number two.

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And in this one, we're going to cover

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mainly the importance of the morphologic

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abnormalities on imaging and very important.

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Disease distribution, disease distribution

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and morphology together can help us

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come to a probable pathologic process.

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And I'll show you how one way you can do that.

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And also we'll review quickly some of

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the recommended terminology and some

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terminology you really should just avoid.

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So let's quickly look at the

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signs and symptom-based learning.

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One of the issues I've had with medical

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education, and not just in radiology,

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but for clinical, is that we tend to focus

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on disease and etiologic-based learning.

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And if you think about it,

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that's a little backward.

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We try, we really should be focusing on what a

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patient's signs and symptoms are, and developing

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that ability to process through, to come to a

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reasonable differential diagnosis of diseases.

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When we teach the diseases first and

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then we say, well, they can have these

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symptoms, we're kind of going backward.

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And so the diseases, um, we're going to

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do in these series, we're going to focus

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on the morphology and the distribution

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because for us in radiology, that is

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our science and symptoms, really, it is.

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And so we need to work and develop these

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skill sets to go from these imaging

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appearances to a probable pathology.

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All right.

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So imaging concept number

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three, that's really important.

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It's all about morphology of disease.

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And distribution, those

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are our signs and symptoms.

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How do we go from here?

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See, it, that's part of it, is perception

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and then develop the critical thinking

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skills to come to a conclusion. So just quickly,

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try to not use the terms airspace.

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It really doesn't help.

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Pathologists have shown us that almost all pulmonary

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diseases have both airspace and interstitial.

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It's an artificial distinction.

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Reticular nodular, if you say that,

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it's like saying macular papular skin lesion.

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You're just throwing out words here.

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And avoid the term infiltrate.

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It is, it's lowbrow.

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It doesn't help you.

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The other thing that doesn't get

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a lot of focus is distribution.

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It's all real estate,

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location, location, location.

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Only certain diseases can

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develop in the parts of the lung.

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And when you combine the two, along with

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the duration of symptoms, you can come

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up with a pretty reasonable differential.

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So here's the morphology.

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This is the terminology that

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I would encourage you to use.

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There's consolidation, there's ground glass,

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acute or chronic, and acute usually infers

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that the symptoms have been less than a week.

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Reticular, which are lines that don't

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branch, nodule or nodules, you know,

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well-defined or ill-defined, cavitary,

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non-cavitary, peripheral lace-like capacities

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or reticulation, curved reticular, kind of

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the cystic, and the budding tree appearance.

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Okay, again, avoid the terms airspace,

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interstitial, infiltrate, and reticular nodular.

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They really don't help you.

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Um, that's what a consolidation looks like.

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Increased areas of ill-defined

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opacity; cannot see the vessels.

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As opposed to ground glass,

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increased ill-defined opacity.

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The vessels are blurry because the

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density is starting to approach that of

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the vessels, but you can still see them.

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It's kind of like a fog.

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Reticulation or lines, curved reticular,

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peripheral lace-like opacities with these little

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tiny kind of reticulations forming these little

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cysts or honeycomb, and of course, nodules.

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Now, distribution of disease is set

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up so it's sort of upper lobe,

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um, which I have a mnemonic set: PARC.

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I went to school in McGill and

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in French, PARC spelled with a C.

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So I use that,

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uh, and I'll show you what that is.

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Bronchovascular means it

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radiates out from the hilum.

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Peripheral, random, just anywhere,

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uh, perilymphatic and central lobular.

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These are distributions that

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are often discussed in CT.

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Diffuse distribution, which I'm going to cover on

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its own because there's something unique about it.

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Focal, multifocal, and of course

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dependent, which is gravitational.

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So that's kind of what the distribution is.

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Here, this is gravitational

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congestive heart failure.

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Notice how the consolidation is worse

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in the lower lobes, but not as bad here.

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This is random cavitary nodules,

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upper lobe disease, where you can see the hilum

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are pulled up like old man's pants in Florida.

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You got a diffuse distribution here.

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And this is what bronchovascular

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seems to radiate out from the hilum.

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And these distributions can help you

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tremendously when coming to a conclusion.

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So this is the card that

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you'll be able to download.

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And it has the entire cardiopulmonary

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differential, to the best of my ability,

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uh, set up so it's based on morphology,

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acute or chronic, and distribution.

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And you look to see which diseases are in which.

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Notice how you don't say,

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have to say airspace, you know, say

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interstitial, just what is the pattern?

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What's the distribution?

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Here are the possibilities.

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Patient with a radiograph has got some perihilar

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ground glass and upper lobe ground glass.

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There are curved reticular opacities.

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All right, ground glass acute, because the

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patient's symptoms were over the last week.

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You notice there's your differential, blood pus

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or water, the curved reticular pattern, we look

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at that differential, upper lobe disease, we look

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at the differential, any of these in all three.

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Yeah, PCP, PCP, and PCP.

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What does this person have?

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They have pneumocystis pneumonia.

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They have HIV.

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Do you need a CT?

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Patient with a consolidation upper lobe anterior

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segment because it abides the minor fissure.

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It's got a cavity in it.

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Cough for two weeks.

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This is most consistent with a

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consolidation and a necrotizing component.

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Over two weeks we start to get

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in the subacute or chronic.

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It's upper lobe.

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You look in the, uh, chronic consolidation,

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upper lobe, you'll notice that TB

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and fungal are both there, and this

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turned out to be coccidioidomycosis.

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But you could say, you know, maybe an

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aspiration, anaerobic infection or something,

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if you wanted to round out a differential.

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Patient with lots of sort of the budding

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tree appearance, coalescing here,

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this is airway-centered, and notice

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the distribution is gravitational

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this video.

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What is this most likely to be?

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Aspiration.

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The patient has an aspiration

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pneumonitis or possible pneumonia.

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It's a gravitational process, airway-related

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budding tree, and that's how you work it through.

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Last imaging concept here that

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I'm going to talk about is your approach.

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Many approaches that are

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taught are overly complicated.

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We separate things too much and it

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leads to a less flexible approach.

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And I like flexibility when I approach imaging.

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So I kind of divide it into three areas.

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The lungs, between the lungs,

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which is the heart, hilum, and superior

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mediastinum, and outside the lungs,

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which is the pleura, bones, and upper abdomen.

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You can go in whatever order you want.

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But before you give a differential,

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you have to at least gotten through all three.

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This is very helpful because when I give

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cases to residents or so, and I've got an

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obvious abnormality in the lung, and they

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start talking about the bones and soft

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tissues first, that just seems ridiculous.

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I mean, when a clinician, when you present a

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case to a clinician, you don't start with the

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review of systems and family history, right?

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You go with the chief complaint,

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and then you work your way down.

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And then you give your

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differential after you've finished.

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So this is a patient who's got a large mass.

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Well, let's start with that.

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Uh, where is it?

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Well, it's not inside the lung because

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you, it's got the incomplete border

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sign here, like a ball under the carpet.

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That tells me it's chest wall.

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And I see that the rib is actually destroyed.

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So this is a rib lesion.

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Uh, when I look at the lungs, they look clear.

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The heart looks okay.

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Hilum is not dense or large, thoracic aorta

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looks fine, there's some scoliosis there,

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uh, no pleural effusion, so I'm done.

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This is going to most likely be primary

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rib lesion, mass, or more likely,

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metastases or melanoma, or myeloma.

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So, in this case, the patient did have renal

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cell carcinoma, And this was a metastasis.

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How about this one?

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We take a look.

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The lungs have reticulation.

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The reticulation is asymmetric.

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Hmm, reticular capacities we've covered.

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Well, it could be pulmonary

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edema, but it's asymmetric.

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Let's keep looking.

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Heart looks okay.

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And then we get in the mediastinum, convex

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and dense, AP recess, aortic pulmonary recess, convex.

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What does that tell you?

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Probably enlarged lymph nodes.

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Okay.

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Well, let's finish it up.

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No, there's no pleural effusion.

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And then we look and wait a minute,

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well, outside the lung, there's a

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right breast, but no left breast.

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Okay, all three areas had something abnormal.

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Now I'm ready for my differential.

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Patient likely has breast cancer with

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metastatic adenopathy and lymphogenic

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spread of tumor given the asymmetry.

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That's it.

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So with that, session two, approach

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by looking at the morphologic

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abnormalities, disease distribution,

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try using a card, see if it works for you.

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Use the recommended terminology,

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avoid airspace, infiltrate, nonspecific,

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and try to develop a more flexible approach.

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The problem is to say you have

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to make sure you cover everything before you move

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on to your differential. With that, I thank you

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for your time, and I hope you found it helpful.