How to Interpret a Chest X-Ray (Lesson 7 - Diffuse Lung Processes)

Summary

This educational video delves into the interpretation of chest X-rays, focusing on diffuse lung diseases. It outlines objectives to identify lung volume issues, differentiate pulmonary edema types, classify interstitial processes, and compare alveolar and interstitial findings. The script explains the signs of reduced and increased lung volumes, discusses alveolar opacities, including cardiogenic and non-cardiogenic edema, and explores interstitial opacities' subtypes. It concludes with distinguishing features between alveolar and interstitial patterns, providing a foundation for diagnosing various lung conditions.

Takeaways

• 📚 The video is part of a series on interpreting chest X-rays, focusing on diffuse lung disease.
• 🔍 The learning objectives include identifying reduced lung volumes, distinguishing cardiogenic from non-cardiogenic pulmonary edema, classifying interstitial processes, and comparing alveolar and interstitial findings.
• 🏥 Reduced lung volumes on an X-ray can indicate underlying lung, diaphragm, neuromuscular, or thoracic wall disease, and should not be mislabeled as 'poor inspiratory effort' without direct observation.
• 🌟 Hyperinflation on X-ray is characterized by an increased subjective impression of total lung capacity, often seen in COPD and occasionally in asthma during acute exacerbations.
• 🌫 Alveolar opacities are due to fluid accumulation in the alveoli and terminal bronchioles, and can be caused by edema, pus, or blood.
• 💧 The differential diagnosis for alveolar opacities includes cardiogenic and non-cardiogenic pulmonary edema, with the latter associated with conditions like acute lung injury and ARDS.
• 🔬 Radiographic features to differentiate cardiogenic from non-cardiogenic edema include air bronchograms, peribronchial cuffing, curly lines, cephalization, and the batwing pattern.
• 🌬 Interstitial opacities can present as reticular (excessive lines), nodular (excessive dots or nodules), or reticular nodular patterns on X-rays.
• 🏥 The differential diagnosis for interstitial opacities is extensive, including conditions like pulmonary fibrosis, connective tissue disease, and sarcoidosis.
• 📉 Alveolar opacities can change rapidly and may contain air bronchograms if due to non-cardiogenic edema, while interstitial opacities evolve more slowly and have sharper margins.
• 📈 The next video in the series will cover focal lung processes, providing further insights into lung disease identification.

Q & A

What is the main topic of the seventh video in the series on interpreting chest x-rays?

The main topic of the seventh video is diffuse lung disease.

What are the two primary learning objectives related to lung volumes mentioned in the script?

The two primary learning objectives are to identify and know the differential diagnosis of low lung volumes and hyperinflation, and to describe them specifically without mislabeling them as poor inspiratory effort.

Why is it important to avoid labeling a chest x-ray with reduced lung volumes as 'poor inspiratory effort'?

It is important because unless the interpreter is physically present when the x-ray was taken, they cannot know the patient's actual inspiratory effort. Mislabeling risks missing an early diagnosis of lung, diaphragm, neuromuscular apparatus, or thoracic wall diseases.

What is the most common etiology of reduced lung volume according to the script?

The most common etiology of reduced lung volume may in fact be poor inspiratory effort, but it could also be due to a sub-optimally timed exposure or restrictive lung disease.

What does the term 'hyperinflation' on an x-ray refer to?

Hyperinflation refers to a subjective impression that the total lung capacity is likely increased, based on the number of ribs seen, flattening of the diaphragms, and the diffusely increased lucency of the lungs.

What are the two classic radiographic categories of diffuse lung capacities discussed in the video?

The two classic radiographic categories are alveolar opacities, often referred to as airspace opacities, and interstitial opacities.

How can one differentiate cardiogenic from non-cardiogenic pulmonary edema on an x-ray?

One can differentiate them by looking for five radiographic features: air bronchogram, peribronchial cuffing, curly lines, cephalization, and the bat swing pattern.

What does the term 'cephalization' refer to in the context of pulmonary edema on an x-ray?

Cephalization refers to the increased visibility of pulmonary vessels at the lung apices compared to the bases, which is suggestive of increased left atrial pressure.

What are the two main subtypes of alveolar opacities based on their differential diagnosis?

The two main subtypes are cardiogenic pulmonary edema, associated with elevated pulmonary capillary wedge pressure, and non-cardiogenic pulmonary edema, where the wedge pressure is normal.

What is the significance of the bat wing pattern in differentiating cardiogenic from non-cardiogenic pulmonary edema?

The bat wing pattern is most consistent with cardiogenic edema, though it may be seen with some specific aetiologies of non-cardiogenic edema, and it refers to bilateral, predominantly higher concentration of opacification.

How do alveolar and interstitial opacities differ in terms of their appearance and progression on an x-ray?

Alveolar opacities have hazy margins, may contain air bronchograms if caused by non-cardiogenic pulmonary edema, and can change rapidly over time. Interstitial opacities have sharp margins, do not contain air bronchograms, and evolve more slowly.

What are some examples of diseases that can cause both alveolar and interstitial changes on an x-ray?

Diseases such as pulmonary edema and sarcoidosis can cause both alveolar and interstitial changes, demonstrating the complexity of distinguishing between the two categories.

What is the differential diagnosis for diffuse interstitial opacities that cause a predominantly reticular pattern?

Diseases that cause a predominantly reticular pattern include idiopathic pulmonary fibrosis, connective tissue disease, atypical pneumonia, asbestosis, chronic aspiration, pulmonary drug toxicity, sarcoidosis, and others.

How does the presence of nodules in interstitial opacities help differentiate between various lung diseases?

The size of the nodules can help differentiate; diseases causing small nodules under two centimeters include miliary tuberculosis, fungal infections, silicosis, and sarcoidosis, while those causing medium and large nodules include metastatic cancer, lymphoma, and rheumatoid nodules.

What does the script mention as a common manifestation of sarcoidosis in the lung?

Sarcoidosis can manifest in various ways in the lung, including causing either reticular or nodular interstitial patterns, alveolar opacities, and is best known radiographically as a cause of prominent hilar lymphadenopathy.

What is the final topic covered in the script before concluding the video?

The final topic covered is a summary of the comparison between alveolar and interstitial opacities, highlighting their differences in terms of distribution, margin clarity, presence of air bronchograms, rate of change, and descriptive terms.

Outlines

00:00

📚 Introduction to Diffuse Lung Disease in Chest X-rays

This paragraph introduces the seventh video in a series focused on interpreting chest X-rays, specifically addressing diffuse lung disease. The learning objectives include identifying and differentiating lung volumes and hyperinflation, recognizing pulmonary edema, distinguishing between cardiogenic and non-cardiogenic causes, classifying interstitial processes, and comparing alveolar and interstitial findings. The speaker emphasizes the importance of accurately identifying reduced lung volumes, avoiding mislabeling due to poor inspiratory effort, and recognizing the potential early signs of lung disease. The paragraph also touches on hyperinflation, its subjective nature, and its common association with COPD and asthma.

05:00

🔍 Differentiating Cardiogenic and Non-Cardiogenic Pulmonary Edema

The second paragraph delves into the differentiation between cardiogenic and non-cardiogenic pulmonary edema. It outlines the causes of cardiogenic edema, such as heart failure and various cardiac conditions, and non-cardiogenic edema, which is associated with conditions like severe sepsis and pneumonia. The speaker discusses five radiographic features that aid in this differentiation: air bronchogram, peribronchial cuffing, curly lines, cephalization, and the bat-wing pattern. Each feature is explained with examples and its significance in identifying the type of pulmonary edema is highlighted.

10:01

🌟 Understanding Alveolar and Interstitial Opacities

This paragraph discusses alveolar and interstitial opacities in the context of diffuse lung disease. Alveolar opacities result from fluid accumulation and can be caused by edema, pus, or blood. The paragraph differentiates between cardiogenic and non-cardiogenic causes of alveolar opacities and mentions additional causes such as multilobar pneumonia and diffuse alveolar hemorrhage. Interstitial opacities are then introduced, with subtypes including reticular, nodular, and reticulonodular patterns. The speaker provides examples of diseases that cause these patterns and notes the difficulty in distinguishing between them on plain radiographs.

15:03

📈 Comparing Alveolar and Interstitial Opacities

The final paragraph provides a comparative summary of alveolar and interstitial opacities. It contrasts their distribution, margins, presence of air bronchograms, rate of change, and descriptive terms. Alveolar opacities are described as having a hazy margin, rapid change, and subjective descriptions, while interstitial opacities have a sharp margin, evolve slowly, and are described with more objective terms. The paragraph concludes with a preview of the next video in the series, which will cover focal lung processes.

Keywords

💡Diffuse lung disease

Diffuse lung disease refers to a group of disorders that affect the lungs in a widespread or 'diffuse' pattern, rather than being localized to a specific area. In the video, this term is central to the discussion as it sets the stage for understanding various lung conditions that present with widespread symptoms and patterns on chest X-rays.

💡Lung volumes

Lung volumes are measures of the air within the lungs, including total lung capacity and residual volume. Reduced lung volumes are mentioned in the script as a potential sign of underlying lung disease, while hyperinflation refers to an increase in lung volume, often seen in conditions like COPD. These concepts are integral to diagnosing and understanding lung function.

💡Pulmonary edema

Pulmonary edema is a condition where fluid accumulates in the lungs, causing difficulty in breathing. The video distinguishes between cardiogenic and non-cardiogenic pulmonary edema, which are types of edema caused by heart failure and other conditions, respectively. Recognizing the type of edema is crucial for determining appropriate treatment.

💡Cardiogenic

Cardiogenic refers to conditions that originate from the heart. In the context of pulmonary edema, cardiogenic edema is caused by heart failure and is associated with an elevated pulmonary capillary wedge pressure. The video explains how to identify cardiogenic edema on X-rays, which is important for diagnosis.

💡Non-cardiogenic

Non-cardiogenic conditions are not caused by the heart. Non-cardiogenic pulmonary edema is mentioned in the script as a type of edema with a normal wedge pressure, often associated with conditions like severe sepsis or pneumonia. Differentiating between cardiogenic and non-cardiogenic edema is essential for proper patient management.

💡Interstitial processes

Interstitial processes refer to conditions affecting the interstitial spaces of the lungs, which include the tissue and fluid between the air sacs. The video discusses classifying these processes based on radiographic features, which is important for diagnosing conditions like fibrosis or sarcoidosis.

💡Alveolar opacities

Alveolar opacities are abnormalities seen on X-rays that indicate fluid accumulation within the alveoli (air sacs) and terminal bronchioles. The script explains that these can be caused by edema, pus, or blood, and are characterized by hazy margins. Differentiating between alveolar and interstitial opacities is key to diagnosing various lung diseases.

💡Air Bronchogram

An air bronchogram is a radiographic sign seen on X-rays where the bronchi are visible against a background of opacified lung tissue. The script uses this term to describe a finding in alveolar opacities, particularly in cases of pulmonary edema, and it helps in distinguishing between cardiogenic and non-cardiogenic edema.

💡Cephalization

Cephalization refers to the increased visibility of pulmonary vessels at the lung apices compared to the bases, suggesting increased left atrial pressure. The script mentions this as a radiographic feature that can help distinguish between types of pulmonary edema, although its subjectivity limits its diagnostic utility.

💡Batwing pattern

The batwing pattern, also known as the butterfly pattern, describes a specific distribution of opacities on chest X-rays, typically seen in cardiogenic pulmonary edema. The script uses this term to illustrate a radiographic sign that can help differentiate between cardiogenic and non-cardiogenic causes of pulmonary edema.

💡Reticular opacities

Reticular opacities are seen on X-rays as an increased number of lines, creating a lace-like or net-like appearance, indicating interstitial lung disease. The script discusses this pattern in the context of interstitial processes and its differential diagnosis, which includes various lung diseases that affect the interstitial spaces.

💡Nodular opacities

Nodular opacities are radiographic findings that appear as small dots or nodules, often less than one centimeter in size, indicating a diffuse interstitial lung disease. The script differentiates between nodular opacities based on size, such as miliary pattern for nodules less than two millimeters, and relates them to various lung diseases like tuberculosis or sarcoidosis.

💡Sarcoidosis

Sarcoidosis is a systemic disease characterized by the formation of granulomas in various organs, including the lungs. The script mentions sarcoidosis as a condition that can present with both alveolar and interstitial opacities, as well as with nodular patterns, highlighting its varied radiographic manifestations.

Highlights

Seventh video in a series on interpreting chest x-rays with a focus on diffuse lung disease.

Learning objectives include identifying differential diagnosis of lung volumes and hyperinflation, distinguishing cardiogenic from non-cardiogenic pulmonary edema, classifying interstitial processes, and comparing findings in alveolar and interstitial processes.

Importance of accurately describing reduced lung volumes to avoid mislabeling and missing early diagnosis opportunities.

Common etiology of reduced lung volume includes poor inspiratory effort and restrictive lung disease.

Hyperinflation is less common on x-ray, indicated by increased total lung capacity and subjective impression.

Hyperinflation commonly seen in COPD and occasionally in asthma during acute exacerbations.

Radiographic categories of diffuse lung capacities include alveolar opacities and interstitial opacities.

Difficulty in distinguishing alveolar and interstitial opacities due to subjectivity and experience required.

Alveolar opacities result from fluid accumulation within alveoli and terminal bronchioles, such as edema, pus, or blood.

Cardiogenic pulmonary edema associated with elevated pulmonary capillary wedge pressure and left-sided heart pressures.

Non-cardiogenic pulmonary edema with normal wedge pressure, related to acute lung injury and ARDS.

Five radiographic features to differentiate cardiogenic from non-cardiogenic edema: air bronchograms, peribronchial cuffing, curly lines, cephalization, and batwing pattern.

Cephalization suggests increased left atrial pressure but is subjective and has poor interobserver agreement.

Batwing pattern consistent with cardiogenic edema but may also be seen with specific non-cardiogenic edema ideologies.

Diseases causing diffuse alveolar opacities without edema include multifocal pneumonia and diffuse alveolar hemorrhage.

Interstitial opacities categorized into reticular, nodular, and reticular nodular patterns based on radiographic appearance.

Difficulties in diagnosing diffuse interstitial opacities due to a large differential diagnosis and lack of distinguishing features on plain radiographs.

Sarcoidosis manifests in various lung patterns, including reticular, nodular, and alveolar opacities, and is known for prominent hilar lymphadenopathy.

Comparison between alveolar and interstitial opacities in terms of distribution, margin clarity, presence of air bronchograms, rate of change, and descriptive terms.

Upcoming video in the series will cover focal lung processes.

Transcripts

this is the seventh video in this series

on interpreting chest x-rays and the

topic is diffuse lung disease the

learning objectives are first to be able

to identify and know the differential

diagnosis of Load lung volumes and

hyperinflation second to be able to

identify pulmonary edema as well as

specific features that can help

distinguish cardiogenic from non

cardiogenic ideologies third to be able

to classify interstitial processes based

on their radiographic features and

finally to be able to compare typical

findings in alveolar and interstitial

processes the first topic in this video

will be a very brief discussion of lung

volumes so here is an x-ray which shows

an example of reduced lung volumes we

know this because when we count ribs

there are only seven full posterior ribs

seen above the diaphragm where normally

there should be nine to ten when

describing an x-ray with reduced lung

volumes it is important to describe it

specifically as such and never as quote

poor inspiratory effort which is

frequently done the reason for this is

that as the x-ray interpreter unless you

are physically present when the x-ray

was taken you have no idea what the

patient's inspiratory effort was like

low lung volumes may be the first sign

of otherwise occult disease of the lung

interstitial of the diaphragms

neuromuscular apparatus or thoracic wall

mislabeling this x-ray as poor

inspiratory effort risks missing an

opportunity at an early diagnosis of

these conditions having said that the

most common etiology of reduced lung

volume may in fact be poor inspiratory

effort it may also be the consequence of

a sub-optimally timed exposure it can

obviously be seen in restrictive lung

disease due to any of the aforementioned

general mechanisms and finally it can be

the consequence of unappreciated

subharmonic effusions which were

discussed in the last

video in this series in contrast to low

lung volumes we can instead see

hyperinflation which in my experience is

less common

there is no widely applied precise

definition of hyperinflation on x-ray

instead the term refers to a subjective

impression that the total lung capacity

is likely increased if measured by

pulmonary function tests this subjective

impression is based upon the number of

ribs seen flattening of the diaphragms

and the diffusely increased lucency of

the lungs hyperinflation has a very

short and specific differential

diagnosis it is most commonly seen in

COPD it can also occur occasionally in

asthma but only during acute

exacerbations for the remainder of this

video I'll be referring to the two

classic radiographic categories of

diffused lung capacities they are

alveolar opacities often referred to as

airspace capacities and interstitial

opacities while I will be discussing the

features which distinguish one category

from another and discussing the subtypes

of each in practice the distinction

between alveolar and interstitial

opacities is not easy it is a skill that

entails much subjectivity requires much

experience and typically shows

significant interrelation a large part

of these issues stems from the fact that

few diffused lung diseases are

completely limited to only the air

spaces or to the interstitial many

diseases which are classically alveolar

such as pulmonary edema may also

demonstrate typical interstitial changes

and many diseases which are classically

interstitial such as sarcoidosis may

also demonstrate typical alveolar

changes as a consequence many of the

distinctions discussed during the rest

of this video are not always obvious and

they may be a source of disagreement

even between experienced healthcare

professionals

alveolar opacities are due to fluid

accumulation within the alveoli and

terminal bronchioles this fluid may be

edema pus or blood opacities are hazy

with poorly defined margins but can

respect low bar boundaries unless

diffuse differential diagnosis for most

alveolar opacities can be divided into

two main subtypes first is cardiogenic

pulmonary edema which is that associated

with an elevated pulmonary capillary

wedge pressure which is a surrogate for

elevated left-sided heart pressures in

general this type of pulmonary edema can

be seen in any cause of congestive heart

failure this includes exacerbations of

long-standing cardiomyopathy acute MI

arrhythmia myocarditis or acute aortic

or mitral regurgitation secondary to

endocarditis then there is non

cardiogenic pulmonary edema in which the

wedge pressure is normal the clinical

correlate to diffuse non cardiogenic

pulmonary edema is the spectrum between

acute lung injury and acute respiratory

distress syndrome the distinction

between these two is largely arbitrary

and is based on the severity of a

patient's hypoxemia as with heart

failure a li and ARDS are not ideologies

themselves but can be caused by a long

and diverse list of pathologic

conditions these include severe sepsis

pneumonia including viral pneumonia from

things like influenza aspiration

pneumonitis pancreatitis severe burns

post transfusion reaction near-drowning

extreme elevation CNS catastrophe and

inhalational injury

in order to differentiate cardiogenic

from non cardiogenic edema on x-ray

there are five radiographic features

which one can look for they are air

Branca Graham's peribronchial cuffing

curly lines cephalization and the bat

swing pattern I'll talk about each one

at a time first up our air Bronco

Grahams

since bronchi are relatively thin walled

air filled structures surrounded by air

filled alveoli they are usually not

visible on x-ray however a pacification

of alveoli adjacent to a bronchus

results in the dark air field bronchi

becoming identifiable against a white

background in this example the patient

has a pacification of the right lower

lung zone probably the right middle lobe

as we will discuss in the next video if

we zoom in on the pacification we can

see an outline of a dark branching

structure which are the bronchi visible

bronchi are not only a manifestation of

air Branca grams but also of

peribronchial cuffing interstitial edema

can accumulate a round bronchi making

the bronchial walls thick this appears

like a ring when seen in cross-section

and like tram tracks when seen

longitudinally here is an x-ray with a

number of different findings if we zoom

in again on the right mid-long zone we

can see two ring shaped structures

adjacent to one another which are

bronchi seen in cross-section next are

curly a and B lines curly a lines are

diagonal on branching lines two to six

centimeters long extending from the

hilum they represent channels between

peripheral and central lymphatics curly

B lines are faint thin horizontal lines

1 to 2 centimeters long at the long

periphery usually at the bases they

represent inter lobular septa

in general curly be lines are much more

commonly seen and commonly referred to

than curly a lines in this example if we

zoom way in at the right lung base we

can see the tiny faint horizontal curly

B lines specifically indicating this

patient may have mild heart failure the

term cephalization refers to increase

the visibility of pulmonary vessels at

the lung apices as compared to the basis

it is suggestive of increased left

atrial pressure in this example if we

compare the average density of the

pulmonary vessels in the apices to the

middling zones we can see that they are

more prominent in the apices

unfortunately cephalization is highly

subjective and has relatively poor

interobserver agreement limiting its

utility as a radiographic distinguishing

feature of pulmonary edema lastly is the

so called bat swing pattern of a

pacification sometimes referred to

alternatively as a butterfly pattern or

angel's wings this refers to bilateral

parry higher concentration of a

pacification this is seen predominantly

in cardiogenic pulmonary edema but also

in some types of pneumonia particularly

viral pcp and aspiration it can be seen

in inhalational injury pulmonary alveoli

proptosis and in pulmonary hemorrhage so

how do these radiographic features help

distinguish cardiogenic from non

cardiogenic pulmonary edema in

cardiogenic edema the cardiac size is

typically enlarged while in non

cardiogenic edema

it is typically normal in cardiogenic

edema the regional distribution of

opacities is relatively homogeneous

while it is relatively patchy and non

cardiogenic edema air Branca Graham's

are common only in non cardiogenic edema

while peribronchial cuffing is common

only in cardiogenic edema

and concurrent pleural effusions and

curly be lines are more common in

cardiogenic although not listed

explicitly in this chart a batwing

pattern to the pasady s is most

consistent with cardiogenic edema though

it may be seen with some specific

ideologies of non cardiogenic edema as

listed on the previous slide finally

cephalization has historically been

associated with cardiogenic edema

however the subjectivity and lack of

interest regarding this finding limits

its usefulness if you recall back to

near the beginning of this video you may

remember that alveolar opacities can be

caused not just by edema in the alveoli

but also by pus or blood

therefore ideologies that diffuse

alveolar opacities without edema include

multi lowbar pneumonia and diffuse

alveolar hemorrhage I'll now move on to

discuss interstitial opacities there are

several subtypes of interstitial

opacities based upon radiographic

appearance the first are reticular

opacities which essentially means there

are too many lines this can create a

lace-like

or net-like appearance another subtype

is nodular opacities which means there

are too many dots or nodules for diffuse

interstitial disease the nodules are

almost always less than one centimeter

in size if the nodules are all less than

two millimeters it is sometimes referred

to as a miliary pattern due to the fact

that someone a long time ago thought the

nodules look like millet seeds

finally our reticular nodular opacities

which means there are too many lines and

too many dots so here's an example of a

reticular pattern that is too many lines

and here is a nodular one

and the last here are diffused

particular nodular capacities the

differential diagnosis of diffused

interstitial opacities is very large and

is generally difficult to place into

categories of groups other than those

diagnoses which cause a predominant

reticular pattern and those which cause

a predominant nodular pattern almost any

cause of interstitial opacities can lead

to a reticular nodular pattern those

diseases which cause a predominantly

reticular pattern of the fuchsia pass

''tis include idiopathic pulmonary

fibrosis connective tissue disease

atypical pneumonia such as that caused

by mycoplasma the idiopathic

interstitial pneumonias of which there

are several histologic subtypes which

cannot be distinguished on plain

radiographs asbestosis chronic

aspiration pulmonary drug toxicity

sarcoidosis chronic hypersensitivity

pneumonitis Langerhans cell

histiocytosis and lymphangitis

carcinomatosis as I said the

differential diagnosis is very long in

some cases there may be subtle clues

pointing towards one diagnosis over

others such as the presence of pleural

plaques suggesting a particular pattern

is due to a space no sis

however for the most part most of these

diseases are indistinguishable from one

another on plain radiographs when it

comes to the causes of diffused

interstitial opacities that cause a

predominantly nodular pattern these can

be broken down into those with nodules

under two centimetres and those with

nodules over two centimetres provided

one realizes that this cutoff is far

from absolute those diseases causing

small nodules include miliary

tuberculosis fungal infections silicosis

coal workers pneumoconiosis and

sarcoidosis

those which caused medium and large

nodules include metastatic cancer

subacute hypersensitivity pneumonitis

lymphoma sarcoidosis granulomatosis with

polyangiitis and rheumatoid nodules you

probably notice that sarcoidosis has

shown up on all three lists which is

because sarcoidosis has a wide variety

of manifestations in the lung

along with causing either reticular or

nodular interstitial patterns

sarcoidosis can also cause alveolar

opacities and is best known

radiographically as a cause of prominent

hilar lymph adenopathy I'll close this

video with a summary of a comparison

between alveolar and interstitial

opacities alveolar opacities showed low

bar or segmental distribution unless

they are diffuse or in the bats wing

pattern while interstitial opacities do

not respect low bar or segmental

boundaries the margin of alveolar

opacities is relatively hazy while

interstitial opacities have a relatively

sharp margin alveolar opacities may

contain air Branca Graham's if they are

caused by non cardiogenic pulmonary

edema while interstitial opacities are

generally devoid of them alveolar

opacities can change rapidly over time

with an ability to appear and disappear

within hours while interstitial

opacities generally evolve much more

slowly and finally alveolar opacities

are often described in highly subjective

terms such as fluffy cotton wool like or

cloud like interstitial opacities are

described in the semi objective terms a

particular nodular or reticular nodular

that concludes this video on diffused

lung processes the next video in this

series will cover focal lung processes

you