Alveolar Infiltrate – Diagnostic Imaging

00:01 Let's talk about the alveolar infiltrate.

00:04 On this CT of the chest, you'll notice – well, you tell me where these arrows are pointing to.

00:12 Tell me about positioning. Is this the right lung or the left lung? Good. It's the right lung.

00:18 Next, what are these arrows actually pointing to? It's pointing to the very end or the distal most portion of your lung or in other words referring to alveolar duct and sacs.

00:32 Now that alveoli as you see here with these arrows and what it's pointing to is the fact that it seems quite opaque.

00:38 Now what does that mean to you? What that means is the fact that it's filled with fluid.

00:43 Now what that fluid is, well you didn't have to go back to the history of your patient.

00:50 For example, if it was congested heart failure on the left side, then at some point maybe it's filled with fluid and water like and it would be protein poor transudate.

01:02 However at some point with congestive heart failure, especially if it was secondary to motor stenosis, then not only could it be transited but maybe perhaps it's filled with blood and hemorrhage.

01:13 You've heard of alveolar hemorrhage, keep that in mind. What else could it be? Well maybe that alveoli is – your patient is suffering from atypical pneumonia and the type of sputum that's coming up might be rusty colored or maybe a little yellowish.

01:30 Maybe a staphylococcal type of Streptococcus pneumonia. Are we clear? So maybe therefore that alveoli might be filled with pus.

01:38 Now as far as the blood and it being proteinaceous, well there, you're thinking more along the lines of, once again, pneumonia.

01:46 Remember, if it was pus, that's one thing.

01:47 But then in addition, keep in mind that you are increasing your vascular permeability so therefore there is every opportunity for protein to leak between your endothelial cells.

01:58 And when it does so it might then traverse into the interstitial and maybe perhaps even fill up your alveoli that would be protein rich.

02:06 So Dr. Raj you're telling me that it could be more than one type of fluid in your alveoli? Correct.

02:11 And with the same disease it could be multiple types of fluids? That is correct.

02:16 All depends on timeline. Is that clear? Remember CHF early on, pulmonary edema that would be transudate, no doubt increase hydrostatic pressure.

02:25 But please understand, if there's enough damage taking place to the pulmonary capillaries, you could easily push out blood into the interstition and perhaps into the alveoli as well.

02:36 Now as we go through here, I'm gonna give you more test in which you can then figure out as to whether or not it's hemorrhage or maybe if it's just fluid.

02:46 Now, an air broncogram, an airway running through the consolidation helps you know that it's an alveolar pattern.

02:55 And that becomes important to us as we get into more of a pneumonia type of issues.

02:58 I'll give you a description of what's in, it's an air broncogram and this will then help you think about lobar pneumonia.

03:05 Why do we call it a lobar pneumonia? Because the entire load won't be affected.

03:09 Think of this as being a huge brick in your lung.

03:13 So if there's a "brick in the lung" and then you try to percuss it then what happens to the percussion? It will be extremely dull upon percussion.

03:22 Imagine about – imagine percussing about a rock. That's lobar.

03:26 And so therefore here, another description is air broncogram.

03:33 Interstitial infiltrate is where we are here. In the previous discussion, we talked about the alveoli in great detail or the alveoli being affected.

03:41 If it is a type of pneumonia then it'd be typical. But here, things get rather messy.

03:46 And by that, we mean the interstition.

03:48 I'd like you to first take a look at the x-ray on top, there's a chest x-ray.

03:54 And what you're noticing here is that my goodness, the parenchyma and it looks like the lung basis and it looks like it's quite cloudy.

04:05 So this to you should indicate, oh maybe the interstition is being affected.

04:09 Especially if your patient is suffering from mycoplasma pneumonia, then you know no doubt those are the interstition then you would call this pattern as being reticular.

04:17 Reticular, in other words meshwork.

04:20 Whereas if you take a look at the picture at the bottom that's not an x-ray, that is a CT scan.

04:25 So chest CT here is then going to show you, well, why would you wanna use this? Might wanna use this to identify the pleura, maybe lymph nodes.

04:34 And if it is lymph nodes, maybe you're thinking contrast.

04:37 But then also your CT is extremely effective for you to then identify the changes in diseases in the parenchyma.

04:45 What do we mean by – as being the parenchyma? It's those areas that you're seeing being black or dark and on the right side.

04:54 You know where I am right now? The right side, posteriorly – you'll find an area with the posterior by the vertebrae you'll find an area in which you find interstitial infiltrates.

05:07 When you're thinking interstitial diseases then occurs interstitial lung disease maybe early on in CHF because of that transitate type of tissue in the interstitium.

05:16 Are we clear? Certain pneumonia such as atypical, cancer that is spreading and which is referred to atypical.