Radiology I - Chest

Question 1

CXR indications

Answer 1

To evaluate suspected abnormalities of heart & lungs

• Chest pain
• SOB
• Cough
• Hemoptysis
• Traumatic injury
• Postive TB test

Question 2

Advantages of CXR

Answer 2

• Excellent eval of heart & lungs
• Quick & cheap
• Low radiation dose

Question 3

Disadvantages of CXR

Answer 3

• Does use radiation
• Challenging in large, uncooperative pts
• Interpretation requires experience

Question 4

U/s

Answer 4

Sound waves sent out by a probe, bounce back, creating an image on a monitor

Question 5

CT scan

Answer 5

X-ray radiation sent out in a 3D fashion & reconstructed by a computer into 3D images

Question 6

MRI

Answer 6

• Magnetic fields & radio frequency emissions combine to create 3D images
• Usually 2-3 planes

Question 7

Nuclear medicine

Answer 7

Broad range of tests - injecting radioactive isotopes into the body & then imaging this

Question 8

Black areas on CXR

Answer 8

More radiation passes through

Question 9

White areas on CXR

Answer 9

More radiation absorbed

Question 10

X-ray densities

Answer 10

From least to most dense:

• Air/lung
• Fat
• Soft tissue density
• Bone/calcification
• Metal

Question 11

Pulmonary TB

Answer 11

• Asymptomatic carriers
• Difficult & long tx
• Developing resistance

Question 12

Primary TB infection

Answer 12

• Can be clinically silent

- Or can look like pneumonia w/ pleural effusion (nonspecific appearance)

Question 13

Post-primary TB

Answer 13

• Aka. reactivation or secondary
• May develop lung cavities in upper lungs
• Often re-ignites due to relative immunocompromised

Question 14

Most common etiologies of lung cavity

Answer 14

• TB
• Valley Fever
• Cancer (esp. squamous cell)
• Inflammatory conditions (Wegener’s Disease)

Question 15

Atelectasis

Answer 15

• Lung collapse
• Difficult to distinguish from pneumonia
• Long term chronic atelectasis = lung scarring

Question 16

Intrinsic causes of atelectasis

Answer 16

• Mucous
• Foreign body
• Poor inspiratory effect, hypoventilation
• Lack of surfactant

Question 17

Extrinsic causes of atelectasis

Answer 17

• Compressing mass
• Compressing adenopathy
• Misplaced ET tube

Question 18

Pleural effusion

Answer 18

Accumulation of fluid in pleural space

- Lateral radiograph has higher sensitivity than frontal

Question 19

Pleural space

Answer 19

Potential space btwn lung & chest wall

Question 20

Pleural effusion ddx

Answer 20

• Transudate
• Exudate
• Air
• Blood
• Infection/pus
• Tumor
• Chronic scarring

Question 21

Pleural plaques

Answer 21

• Soft tissue thickening & calcification

- Can be related to asbestos

Question 22

Pneumothorax

Answer 22

Accumulation of air in pleural space

Question 23

Tension pneumothorax

Answer 23

• Emergency
• Imminent risk of cardiopulmonary collapse
• Tx: Needle thoracotomy at 2nd rib space, mid-clavicular line

Question 24

Pulmonary edema

Answer 24

• Movement of fluid from pulmonary venous system into lungs

- Exists on a spectrum from pulmonary venous HTN (lower pressures) to frank pulmonary edema (higher pressures)

Question 25

Pulmonary edema

Answer 25

- Movement of fluid from pulmonary venous system into lungs | - Exists on a spectrum from pulmonary venous HTN (lower pressures) to frank pulmonary edema (higher pressures)

Question 26

Stages of CHF

Answer 26

1. Cardiomegaly 2. Pulmonary venous HTN 3. Pulmonary interstitial edema 4. Pulmonary alveolar edema

Question 27

PA chest (pathway)

Answer 27

x-ray source --> posterior --> anterior --> detector - Heart shadow is smaller - < 50% of thoracic width

Question 28

AP chest (pathway)

Answer 28

x-ray source --> anterior --> posterior --> detector | - < 55-60% of thoracic width

Question 29

Calcified pulmonary nodule

Answer 29

- Benign, no further f/u | - Calcified nodule = granuloma

Question 30

Non-calcified pulmonary nodule

Answer 30

- < 3cm = nodule - > or = 3cm = mass - Large nodule > 0.8cm or growing --> biopsy &/or PET/CT

Question 31

Chest trauma

Answer 31

- CXR are insensitive to rib fractures | - RIB FILMS are done to evaluate rib fractures

Question 32

Lines & tubes

Answer 32

- CXRs are commonly used to confirm line placement

Question 33

Chest CT advantages

Answer 33

- Excellent eval of most structures of chest | - Fast

Question 34

Chest CT disadvantages

Answer 34

- Higher radiation dose | - Cost

Question 35

Cause of cardiogenic pulmonary edema (true CHF)

Answer 35

- Increased hydrostatic pressure at the pulmonary capillary level - Water is forced from high to low pressure

Question 36

Cause of non-cardiogenic pulmonary edema

Answer 36

- Increased permeability at the pulmonary capillary level - Water is able to leak out * Look identical to true CHF on radiograph