CM- Radiology Flashcards

1
Q

What are Dr. Reynolds’ nine steps to reaching a chest radiograph?

A
  1. Check identity of the patient
  2. General symmetry
  3. lung fields
  4. mediastinum and hila
  5. diaphragm and costophrenic angles
  6. Outside the chest (abdomen, neck)
  7. ribs and chest wall
  8. “sneaky places” - apex and retrocardium
  9. Look at the lateral view
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2
Q

What 2 views make up the standard x-ray examination?

What are circumstances when you would have to stray from these views?

A
  1. PA (posterior anterior where the patient has the plate on their front and the xray goes back to front
  2. lateral view (beam shot to the left)

AP must be done instead of PA if the patient cannot stand. To do a PA, the person MUST be erect.

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3
Q

How do you verify the identity of the patient on Xray?

A
  1. verify the tag on the film that states the name
  2. look at patients gender and habitus
  3. compare to prior xrays from the patients file
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4
Q

How do you verify left from right on a PA film?

A
  1. see which side the tech labeled L and R
  2. if there is NO marker, use anatomy:
    - cardiac apex is left
    - stomach gas bubble is left just below hemidiaphragm
    - aortic knob protrudes from the left of the spine
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5
Q

What is one way the erroneous impression of cardiomegaly can happen?

A

If the film is AP instead of PA.
In a PA film (normal) the heart is far anterior and very close to the film so it is not magnified.
In an AP film, the heart is 10-15cm from the film and greatly magnified.

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6
Q

The ___________ and object is from the film, the more it is magnified.

A

further

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7
Q

How can you determine whether a film is PA or AP?

A
  1. look at air-fluid level in the gastric fundus below the left hemidiaphragm. If you see a horizontal line separating gas/liquid the patient is upright (most frequently PA are upright and AP are supine)
  2. If there is not enough gas/fluid in the stomach to make a fluid air level, look for dependent breast shadows
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8
Q

How do you know if the film was taken in inspiration or expiration? Why is that important?

A

If the diaphragm lies below the ninth rib, the person is inspiring and there should be no significant anatomic distortion and the film can be read.

If the person is expiring, the diaphragm will be elevated compressing the lower lungs and heart distorting the anatomy giving the appearance of cardiomegaly or basal density for infiltration in the lower lung fields

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9
Q

What are the 2 steps for evaluating the lungs on xray?

A
  1. look at the big picture and compare one whole lung field to the other for symmetrical density, size, shape. (lack of symmetry generally = pathology)
  2. Scan the lungs for focal areas of disease or small lesions like early tumors (Hold the film 18” from your face so fovea centralis can focus and look at 6 9cm circles on the film)
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10
Q

If you have already determined that the film is PA, what is the next step for assessing whether cardiomegaly is present?

A

Measure the greatest transverse diameter of the heart and the greatest transverse diameter of the thoracic cavity (from inner aspects of rib cage).

If the cardio-thoracic ratio of these 2 measurements is greater than 50%, the heart is enlarged.

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11
Q

What are the left mediastinal borders from cephalic to caudal?
What film view do you see these best?

A
  1. aortic knob
  2. pulmonary artery- enlarged in cor pulmonale
  3. LA appendage -normal is flat, bulging =pathologic
  4. LV- should be rounded

PA or AP

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12
Q

What are the right mediastinal borders from cephalic to caudal?
What film view do you see this best?

A

It is pretty much all right atrium.

Seen best on PA or AP

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13
Q

What are the anterior borders of the mediastinum?

What film view do you see this best?

A

Right ventricle best seen with a lateral chest radiograph

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14
Q

What are the posterior borders of the mediastinum?

What film view do you see this best?

A

Left atrium best seen with a lateral chest radiograph

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15
Q

Where would you find the azygous vein on a chest xray?

What are 2 caveats for identifying this structure?

A

In a normal PA chest Xray, you shouldn’t see the vein. It is seen when it is abnormally distended.
If it is distended it is:
1. to the right of the spine at the same level of the aortic knob
2. It is a water-dense oval in the angle between the air-filled trachea and right stem bronchi

Caveats:

  1. there is a lymph node in the same area that if enlarged mimics the vein
  2. AP film shows enlarged azygous in a normal patient
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16
Q

What are conditions where the azygous vein will be dilated?

A
  1. Right heart failure

2. pericardial tamponade

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17
Q

Where is the trachea air column normally located on x-ray?

What causes deviation?

A

It is a lucent, midline structure that has a slightly indented left side due to the adjacent aortic arch.
It can be displaced by enlargement of adjacent structures (like the thyroid) or decreased/increased pressure from one lobe of the lung

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18
Q

What structures make up the hilus of the lung?

A
  1. branching air-filled bronchi
  2. branching pulmonary arteries - changed in cardiac pathology or lung pathology
  3. lymph nodes - enlarged in neoplasm, infection
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19
Q

How do the right and left hilum differ?

What can displace the hilum upward? downward?

A

The left hilum is slightly higher up (1 cm) than the right due to displacement from the heart (right hand, make a V, finger tips should touch the hila)

Upward:
faint unilateral apical scar retraction
Downward:
lower lobe collapse

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20
Q

How does the hemidiaphragm differ from left to right? Why?

A

The right hemidiaphragm is higher than the left by half of an intercostal space due to displacement by the liver.
They should both appear well-defined bc they are adjacent to the air-filled lungs. The costophrenic angle should be sharp

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21
Q

What forms the angles of the costophrenic sulcus?

What should it look like?

A

It is the formed by the chest wall and the periphery of the diaphragm. In the sulcus should be radiolucent lung tissue.
If the costophrenic angle is not sharp and the area becomes opaque, that means there is pulmonary disease in the peripheral lung base or pleural disease.

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22
Q

In a PA film, how will pleural effusion appear?

What other pathological process can give the appearance of pleural effusion?

A

It will be meniscus shaped because the fluid is being pulled down by gravity but attracted upward by capillaries in the narrow pleural space surrounding the lateral lung.

pleural fibrosis by old hemorrhage or empyema will thicken pleura blunting the costophrenic angle and appearing like the meniscus of pleural effusion

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23
Q

How much of a chest x-ray is typically sub-diaphragm?

What positive findings are most commonly encountered in this area?

A

1/4 to 1/3

  1. calcifications of spleen, gallbladder, kidneys
  2. pneumoperitoneum from perforated bowel
24
Q

In a typical good quality PA x-ray only the ________ aspect of the ribs ar well seen. The _________ are too thin to form a good image and the ________ aspects are not shown in profile in this projection.

A

Posterior is well seen, anterior are too thin for a good image and the lateral aspects are not shown in profile of this projection.

25
Q

What are the 2 “sneaky areas” on PA chest x-rays?

A
  1. lung apex- due to the bony structures (ribs and clavicle) crossing in from and obscuring the view
  2. retrocardiac region- look “through” the solid heart to see pulmonary vessels coursing downward from the left hilus and some ribs, and the descending aorta
26
Q

What region of the lung often requires lordortic view?

How must the x-ray be taken?

A

The apex of the lungs- this projection gets an unobstructed view by looking between rather than through the anterior ribs.
The patient or the beam is tilted (leaned back= lordotic) so it passes between the gaps of the ribs

27
Q

What 6 spaces are better seen on a lateral view?

A
  1. posterior costophrenic angle
  2. retrocardiac
  3. restrosternal
  4. anterior/posterior heart contours
  5. spine
  6. sternum
28
Q

Where are pleural effusions best seen on x-ray?

A

If the patient is erect, the best space to look for pleural effusion would be the:
POSTERIOR COSTOPHRENIC ANGLE
This is because it is much deeper than the lateral sulcus so pleural fluid will accumulate here first due to the pull of gravity. You will be able to catch smaller effusions before they become a bigger problem

29
Q

Where are anterior mediastinal masses and aneurysms of the ascending aorta likely to be seen on x-ray?

A

They will be seen on a lateral x-ray in the retrosternal space.

30
Q

What is the most common cause of a solitary pulmonary nodule?

What are other causes that are less common but should be included in the differential?

A

1 - primary bronchogenic carcinoma (lung cancer)

Others:

  • infection (granulomatous, calcified)
  • solitary metastatic nodule (more often multiple)
  • pulmonary laceration
  • pulmonary infarct
  • AV malformation
  • inflammatory conditions (Wegeners, rheumatoid- more often multiple nodules)
31
Q

What re the radiographic findings for a single pulmonary nodule?

A
  1. solitary in #
  2. surrounded on all sides by lung or if it touches chest wall it makes acute angles
  3. ranges from very small to very large
32
Q

What are the radiographic findings for multiple pulmonary nodules?

A
  1. multiple in #
  2. surrounded on all sides by lung or if they touch the chest wall they form acute angles
  3. variable in size
33
Q

What is the “most worrisome” cause of multiple pulmonary nodules?
What should all be included in the differential diagnosis?

A

1 - metastases [colon, breast, renal]

Differential:

  • infections/septic emboli
  • rheumatoid nodules
  • wegener’s granulomatosis
  • multiple infarcts
  • multiple AV malformations
34
Q

What is a pneumothorax? What are the 4 most common causes?

A

It is air accumulation in the pleural space (between the parietal and visceral pleural surfaces)

Causes:

  1. chest trauma
  2. asthma
  3. ruptured lunge bullae (cysts that formed due to decreased elasticity)
  4. iatrogenic (post-thoracentesis)
35
Q

Where will the pneumothorax be seen on a standard PA film? Decubitus film:?

A

Air will accumulate in non-dependent regions of the pleural space.
PA- the patient is upright so the pneumothorax will be seen at the apex
Decubitus- pneumothorax will be seen in the upper portion of the side that is up

36
Q

To detect a small pneumothorax on CXR, what do you look for?

What should the patient do to make it more apparent?

A
  1. accumulation in non-dependent area
  2. visualization of visceral pleural line
  3. lack of lung markings beyond the line
  4. increased lucency on the side of the pneumothorax
  5. collapsed lung

Expiratory chest films decrease lung volume and make the pneumothorax more visible.

37
Q

What is a tension pneumothorax? What are the 2 major CXR signs?
What must be done if a patient has a tension pneumothorax?

A

When the pneumothorax is so large that it exerts mass effect on adjacent structures.

  1. mediastinum pushed away from the pneumothorax
  2. flattened or inverted diaphragm on the side of the pneumothorax

Tension pneumothorax is an emergency situation that requires immediate tube placement to relieve the pressure from the excess air

38
Q

What is lobar pneumonia? What is the typical cause?

A

It is infection of the lung parenchyma that is confined to a pulmonary lobe.

The cause is often bacterial where the infection spreads to the alveoli and fill them with purulent material and edema causing opacity on CXR.

39
Q

What is an air bronchogram?

When it is usually seen?

A

It is when the bronchi remain patent and the opacity of pus-filled alveoli outline the air filled bronchi.

It is most commonly seen with pneumonia.

40
Q

What are the 5 standard chest radiograph findings for lobar pneumonia?

A
  1. pulmonary opacity
  2. air bronchograms
  3. shaped like a pulmonary lobe
  4. may obscure heart or diaphragm margins
  5. may be ill-defined
41
Q

What are the two “classic” ways a M. tuberculosis infection can appear on CXR?

A
  1. upper lobe cavitary lung disease (large lucent cavities)

2. miliary pattern (tiny 1-3mm, sharply defined nodules)

42
Q

Why do you see upper lobe predominance in m. tuberculosis infections?
What causes the “cavitary appearance”?

A

There is a higher oxygen concentration in the upper lobes so it is a more favorable environment for the aerobic bacteria.
The cavitary appearance is due to the fact that tuberculosis has caseating necrosis which leads to cavitation.

43
Q

What causes the miliary appearance associated with tuberculosis?

A

Widespread hematogenous dissemination of the organism results in a pattern of multiple tiny well-marginated nodules

44
Q

In addition to miliary pattern and upper lobe cavitary lung disease, what non-specific finding can be associated with tuberculosis?

A
  1. presentation similar to lobar pneumonia
  2. diffuse bilateral pneumonia
  3. enlarged hilar/ mediastinal lymph nodes
45
Q

What 4 structures are in the mediastinum?

A
  1. heart
  2. trachea
  3. esophagus
  4. great vessels
46
Q

What does the anterior mediastinum include?

A
The area anterior to the trachea and anterior to a line extending behind the heart. 
Contains:
1. heart
2. ascending aorta
3. retrosternal clear space
47
Q

What is the differential diagnoses for an anterior mediastinal mass?

A
  1. thyroid lesion
  2. teratoma
  3. thymoma
  4. aneurysm of ascending aorta
  5. “terrible” lymphoma
48
Q

What changes are noted on a PA film for an anterior mediastinal mass?
What changes are noted on lateral film?

A
PA:
1. alternation of normal contour- trachea, aortic knob
Lateral:
1. anterior to trachea
2. may bow trachea backward
3. filled retrosternal space
49
Q

What is the progression of changes on CXR for CHF?

A
  1. heart enlarges (cardiothoracic ratio is >.45)
  2. cephalization in the upper lobes (vessels are more prominent)
  3. interstitial edema leads to indistinct pulmonary vessels and thickened peribronchial tissue
  4. alveolar edema
  5. pleural effusion (common with right-sided)
50
Q

What are the 7 major findings on a chest radiograph of CHF?

A
  1. enlarged heart
  2. prominent upper lobe vessels
  3. prominent hilar vessels with indistinct margins
  4. intersitital edema (linear network)
  5. Kerley B lines (thick interlobar septum)
  6. alveolar edema
  7. pleural effusion (sometimes)
51
Q

What is pleural effusion?

What are the 4 major causes of pleural effusion?

A

It is fluid that accumulates in the pleural space.

Causes:

  1. pneumonia
  2. tumors
  3. CHF
  4. pulmonary emboli
52
Q

The fluid that accumulates in a pleural effusion is most often __________ meaning that it is highly dependent on _______. More rarely they can be __________.

A

Usually they are free-flowing and dependent on gravity.

More rarely they can be loculated.

53
Q

Where will the pleural effusion be seen in a traditional PA?
What view shows pleural effusion the best?
Where will the pleural effusion be seen in a decubitus position?
Which view is best for determining whether the fluid is free-flowing or loculated?

A

PA- it will be located in the costophrenic sulci. The sulci are deeper posteriorly so the fluid will be best seen on a lateral CXR (although they can also be seen on the lateral costophrenic angles on the PA)

In a decubitus film, the fluid mores to the dependent side (downward side). This is the best view for determining whether the fluid is free flowing or loculated.

54
Q

Both pleural effusions that take up the entire hemothorax and massive atelectasis (lung collapse) can opacify and entire hemothorax. How do you tell the difference?

A

If it is a massive pleural effusion, the mediastinum will deviate away from the opaque side.
If it is a massive telectasis, the mediastinum will deviate toward the opaque side.

55
Q

What are the lateral and anterior findings of pleural effusion?

A

Lateral-
1. blunting of costophrenic angle, meniscus shape
Anterior-
1. blunting of lateral costophrenic angle
2. meniscus
3. thickening of fissures due to fluid in the fissure
4. complete opaque hemithorax in severe cases