Imaging of the Chest

Question 1

What is the most common view of the chest taken in clinic or hospital?

Answer 1

a PA view

Question 2

What are 4 things to consider if a film is adequate?

Answer 2

• adequate breath?
• over or under pentrated?
• anything cut off?
• patient rotated?

Question 3

How can you tell if it was an adequate breath?

Answer 3

should have 10-11 ribs visible within the lung fields

Question 4

Why do you need an adequate breath?

Answer 4

inadequate breath will crowd the lung structures and make them look pathologic

Question 5

If a film looks too dark, is it over or under penetrated?

Answer 5

over

Question 6

What should you check the bones for on a CXR?

Answer 6

fractures are most common - old or new

lesions are next - lytic or blastic

Question 7

If you see something that looks like a rib lesion, what is the MOST likely diagnosis?

Answer 7

not a lesion at all - a callous due to a healing fracture - look to see if there are others on the adjacent ribs - it’s almost impossible to break only one rib

Question 8

What are the most common lesions in older age groups?

Answer 8

metastatic lesions

Question 9

What is located in the mediastinum to look at on a CXR?

Answer 9

heart, aorta, pulmonary vessels, trachea and esophagus

Question 10

WHat’s a good rule of thumb for how big the heart should be?

Answer 10

It should be less than half the size of the entire chest

Question 11

What are some non-pathological things that can make a heart look bigger on CXR?

Answer 11

poor inspiration

supine pictures = AP films in general

Question 12

What are three reasons for the heart to actually be enlarged?

Answer 12

hypertrophy due to overuse
cardiomyopathy from CV disease, drugs or infection
fluid around the heart

Question 13

Can you tell what’s making the heart big on CXR?

Answer 13

not really - tissue will look the same as fluid - you need a CT

Question 14

If you see a slight bulge in the left atrium in the context of no cardiomegaly, what does that suggest?

Answer 14

mitral stenosis

Question 15

What are the two main worrisome things with an abnormal aorta?

Answer 15

aneurysm or dissection

Question 16

Can you usually see a diaphragm on a CXR?

Answer 16

You shouldn’t see the diaphragm itself, but you can see where it is based on the lung contour - the only way you’d see it is if there were air under the diaphragm

Question 17

If you don’t have a sharp border showing the diaphragm, what’s something you should check for? How?

Answer 17

diaphragm paralysis

do inspiration and expiration films or a fluoroscopic evaluation with a sniff test. the diaphragm should move down and if it doesn’t, it’s paralyzed

Question 18

What does air trapping due to COPD look like on a CXR?

Answer 18

1. the lungs will look too dark (radiolucent)
2. the lungs will be hyper-expanded
3. Flat diaphragm

Question 19

What’s the most common cause of tracheal deviation?

Answer 19

enlarged thyroid gland

Question 20

Can you usually see lymph nodes on CXR?

Answer 20

nope - only if they’re enlarged. they’re look like fluffy masses

Question 21

What are the possibilities when you see lymph nodes on CXR?

Answer 21

metastatic disease
lymphoma
reactive nodes related to infection - TB
granulomatous disease like sarcoidosis

Question 22

What is the silhouette sign?

Answer 22

basically, you can only see other things on CXR because of the border they make with the air in the lungs. So if there is a border that’s obscured, that means there’s something that’s replaced the air and it also tells you WHERE it is in the lungs

Question 23

Which lung has three lobes and which has two?

Answer 23

right - three

left - two

Question 24

What does the left have in stead of a third lobe?

Answer 24

A lingula…it’s basically another lobe, but it isn’t divided by a fissure

Question 25

If something blurs the left heart border (left ventricle), where is the pneumonia?

Answer 25

lingula

Question 26

If something blurs the left diaphragm, where is the pneumonia?

Answer 26

left lower lobe

Question 27

If something blurs the right diaphragm, where is the pneumonia?

Answer 27

RLL

Question 28

If something blurs the right atrium, where is the pneumonia?

Answer 28

right middle lobe

Question 29

If something blurs the superior vena cava, where is hte pneumonia?

Answer 29

right upper lobe

Question 30

If something obscures the aortic knob, where is the pneumonia?

Answer 30

left upper lobe

Question 31

In addition to the obscured border, what will you often see on CXR in a pneumonia?

Answer 31

air bronchograms - they're air-filled bronchoa nd bronchioles that are outlined by disease int he adjacent alveoli, so you'll see black tubes in the white stuff

Question 32

Can a CXR tell what's filling up the alveoli and making them look dense?

Answer 32

nope - pus, fluid and blood all look the same on CXR

Question 33

What are the two general areas infiltrates can develop in the lungs?

Answer 33

interstiail - between the alvolei or in the alveoli themselves

Question 34

What does an interstitial infiltrate look like?

Answer 34

lacy, reticular (linear) pattern

Question 35

What is an interstitial infiltrate associated with?

Answer 35

atypical pneumonia, early CSF and fibrosis

Question 36

What do alveolar infiltrates look like?

Answer 36

fluffy consolidating patterns, usually with air bronchograms

Question 37

What is an alveolar infiltrate associated with?

Answer 37

bacterial pneumonia, late CSF or acute respiratory distress syndrome

Question 38

What are some common CXR findings in CHF?

Answer 38

early pulmonary is intersitial while late pulmonary edema is alveolar pleural effusions cardiomegaly Kerley's B lines (septal lines)

Question 39

What will pleural effusions appear as on CXR?

Answer 39

blunting of the costophrenic angles

Question 40

How can you tell if costophrenic angle blunting is from scarring or from effusion?

Answer 40

do a decubitus view and see if the fluid layers out.

Question 41

WHat's the difference between a lung nodule and lung mass?

Answer 41

nodules are less than 3 cm, masses are greater than 3cm

Question 42

What is the number one thing to do if you're trying to rule out cancer with a newly found lung mass?

Answer 42

check old films - stability over 2-3 years suggests a benign process

Question 43

What else can you look for to rule out cancer?

Answer 43

calcifications - coarse, central calcifications suggest a benign process

Question 44

What should be on your differential when you see multiple nodules in the lungs?

Answer 44

metastatic disease infeciton granulomatous disease

Question 45

What should be on yoru differential when you see a solitary nodule in the lungs?

Answer 45

``` lung cancer abscess infection - TB or blasto AV malformation Granulomatous disease Benign Granuloma ```

Question 46

When you have a patient presenting with chest pain, what is the number one thing on the DDx?

Answer 46

acute coronary syndrome - MI or angina

Question 47

How is the diagnosis of an acute coronary syndrome made?

Answer 47

EKG and enzymes - not really with imaging

Question 48

What is the second thing to have on your DDx with chest pain?

Answer 48

pneumothorax

Question 49

Pneumothorax puts air between what?

Answer 49

hte parietal and visceral pleura

Question 50

Which PTX is life threatening?

Answer 50

tension - air accumulates and can't get out, causing increased pressure and vena cava compression/impaired venous return

Question 51

What will you see on CXR with PTX?

Answer 51

you'll see a sharp line in the mid lung field, which is the visceral pleura no lung markings lateral to that line

Question 52

What percentage of PE are diagnosed before death? What percentage of those diagnosed with PE actually ahve one?

Answer 52

only 30% | less than 35%

Question 53

What are the non specific signs of PE on CXR?

Answer 53

Hamptom's hump - a wedge-shaped opacity corresponding to lung infarct Westermark's sign - a translucent area

Question 54

What scans can be used to diagnose PE?

Answer 54

A VQ Scan - nuclear medicine scan with ventrilation and perfusion components; perfusion abnormality with normal ventilation suggests PE Chest CT angiography is more common now

Question 55

What is the most common aortic emergency requiring immediate surgery?

Answer 55

aortic dissection

Question 56

What happens in aortic dissection?

Answer 56

you get a tear in the intimal layer of the vessel, which separates the intima from the media or the adventitia on the outside, which causes a false channel to form in the aorta

Question 57

What do people present with when they have an aortic dissection?

Answer 57

severe pain with tearing or ripping quality

Question 58

What are the risk factors for aortic dissection?

Answer 58

HTN is the main one marfans or ehler-danlos cocaine use pregnancy

Question 59

What will a dissection look like on CXR?

Answer 59

a wide mediastinum abnormal arch configuration - it will bow way out pleural effusion L>R

Question 60

What is the study of choice for diagnosing dissection?

Answer 60

CT

Question 61

How does CT help in determining treatment for dissection?

Answer 61

If it involves the ascending aorta, they need immediate surgery if it's just the descending, the patient can be treated medically - lower HTN and it will often heal on its own