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The first of the congenital lung malformation

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that we will discuss is congenital lobar over inflation.

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It's thought that this occurs as a result

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of early bronchial obstruction, eventually leading

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to a ball valve mechanism

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where in utero fluid can get into the distal airways

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but cannot get out.

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And so distal lung airspace overinflate

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ultimately on imaging postnatally.

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When that fluid is replaced by air, we end up

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with a hyper lucent or hyper expanded lobe.

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Note that this entity used to be called congenital low bar

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emphysema, but now is termed congenital

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lobar over inflation.

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I also mentioned bronch atresia here

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because it's probably on the same spectrum as CLO.

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Ultimately what we can see is a tubular atretic bronchus

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with mucus plugging.

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Sometimes we also see an air-filled bronchae

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or fluid-filled mucus seal.

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And as I mentioned in the introduction,

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these congenital lung malformations probably

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have a common origin.

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So it's not unusual

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that bronchi Atresia is seen in conjunction

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with some other malformations including CPAM

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and VPS, which I'll talk about a little bit later.

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The first case I'll show you has multiple images.

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We will start with the baby on the day that they were born.

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We can see that in the left upper lobe there is

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an opacity that could be mistaken for normal thymus

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because frequently normal thymus does live in that area.

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So it would not be unusual

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that this would be just called normal thymus

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and not distinctly something else.

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However, in this particular patient,

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we'll keep our eye on this area.

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Two days later, a follow-up radiograph shows

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that it's no longer pacified in that region,

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so it's not just thymus.

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In fact, it looks fairly normal.

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However, a couple weeks

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after that, at 18 days of age, we noticed

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that left upper lobe is looking hyper expanded hyper

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lucent compared to other parts of the lung.

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And there's midline shift

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of the mediastinal structures to the right.

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The next day, the same patient underwent ct, which confirms,

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as we can see on this coronal ct, hyper lucency

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hyper expansion of the left upper lobe.

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And this was in fact due to congenital lobar over inflation.

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So it makes sense when we think about it

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because the lung lesion originally is opacified

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because it's not normal lung

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and so it was not replaced with air at the same rate

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as the rest of the lungs.

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But over time, eventually that fluid is replaced by air,

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so it normalizes on the chest radiograph,

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but over time, even further,

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that ball valve mechanism is still occurring now with air.

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And so we get the hyper expanded look

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that we see both on the chest radiograph and on the ct.

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The next case is another patient with multiple images.

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The first image that I'll show you is when they were born

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and we can see this patient is rotated to their right

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and we see sort of vague opacity

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in the left upper lobe region.

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Hard to know what to do with prospectively,

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but something to keep our eye on.

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However, a month later when there were 31 days of age,

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we can see similar to our first case,

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there is hyper expansion, hyper lucency of

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that left upper lobe.

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There's also probably some ectasis of the left lower lobe.

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And on that same day, that patient also underwent a CT scan

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confirming we have hyper expansion of that left upper lobe.

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Notice that this still looks like lung parenchyma,

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but it just looks hyper expanded.

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It still has normal pulmonary vessels

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and bronchials traveling throughout.

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It just looks hyper expanded.

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The final case I'll show is another baby

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with multiple images.

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We'll start with this chest radiograph on the day

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that they were born and we can see again

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increased opacity in the left upper lobe.

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There's normal thymus over here on the right side,

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so it would be difficult

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to distinguish normal thymus from an actual opacity

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if you were reading this prospectively.

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But since we are talking about congenital lung disorders,

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we'll keep our eye on that left upper lobe.

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This patient also actually had a prenatal diagnosis

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of a congenital lung lesion,

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and this was their first postnatal image.

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This patient ended up undergoing surgery

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and it was found that this was a bronchial atresia.

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I'll show you on this CT scan coronal images that

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as we scroll through here,

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I'm gonna change my windows a little bit,

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so the contrast is not quite so bright.

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We can see that there's a soft tissue density

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in the left hilum.

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And then if we change to lung windows, we'll also notice

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that there's hyperinflation of that left upper lobe.

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And if we follow the airway from the distal trachea

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to the left main bronchus,

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we don't see a communicating bronchus going to

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that hyper area area.

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So this turned out to be bronchial.

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Atresia, like I said, is probably on a continuum

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with congenital lobar over inflation,

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but in this case we have that hyper expanded lung.

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We do not see a communicating bronchial since it's a retic.

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And then we do see this soft tissue density,

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which turned out to be a mucus seal, which can be associated

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with bronch regia.

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And then this is a follow-up radiograph when the patient was

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eight years old just to show the hyper aeration

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and slight mass effect on the mediastinum.