2.1 Chest X-Ray Interpretation

Front 1

What are some overall uses of chest x-ray?

Back 1

Baseline for perioperative care.
Preoperative evaluation.
Diagnosis of disease.
Post-treatment evaluation.
Detection of acute changes.

Front 2

What is the importance of chest x-ray?

Back 2

Essential for anesthetists to understand basic concepts in chest x-ray methods & interpretation.

Front 3

What should you look for in a preoperative chest x-ray?

Back 3

Significant cardiopulmonary changes.
Positioning of invasive monitoring lines (swan, CVL).
Trauma (Chest injuries, pneumothorax. cardiac tamponade.)
Pre-existing chest disorders (tumor).
Reveal new pathology (Emphysema.)

Front 4

What is the diagnosis of pulmonary disease based upon?

Back 4

Known medical history.
Presence of dyspnea.
Physical exam.
Lung biopsy.
PFT’s

note: Up to 10% of normal chest x-rays have chronic infiltrative pulmonary disease

Front 5

Considerations with the "Routine Chest X-ray"

Back 5

Under 40 years old, chest x-ray detects new pathology in <1.5% of population.
Routine preoperative chest x-rays not indicated for patients <60 y/o if no disease is suspected from history or exam.

Front 6

What lesions may affect anesthetic management?

Back 6

Tracheal obstruction.
Pleural effusions.
Cardiac enlargement.
Emphysematous spaces.
Bullous disease.
Infectious abscess.
Infiltrates.

Front 7

What is associated w/ Tracheal obstruction?

Back 7

Deviation
Carina shifts
Mediastinal masses
Aortic aneurysms

Front 8

What are some complications associated w/ tracheal obstruction?

Back 8

Pathology may lead to difficult visualization, intubation, & ventilation.

Front 9

Complications resulting from Pleural effusions.

Back 9

Resulting in decreased vital capacity & functional reserve capacity.

Front 10

Complications resulting from Cardiac Enlargement?

Back 10

Possible cardiopulmonary disease, hypertension, & greater sensitivity to cardio-depressive effects of anesthetic agents.

Front 11

Complications associated w/ Bullous disease.

Back 11

Possibility of rupture & compression of lung tissue with + pressure ventilation.

Front 12

Complications associated w/ Infectious abscess.

Back 12

Air-fluid cavity w/ risk of enlargement.

Front 13

Complications associated w/ Infiltrates.

Back 13

Can be alveolar or interstitial, resulting in shunting & V/Q mismatching & hypoxia.

Front 14

What is the importance of chest x-ray identification?

Back 14

Identification of such lesions through chest x-ray provides the ability to provide appropriate anesthetic management.

Front 15

Why is recognition of infiltrates significant on a chest x-ray?

Back 15

Further evaluation may be necessary from a pulmonologist or cardiologist. Specific detection may indicate medical therapy: antibiotics (Infection) or diuretics (CHF).

Front 16

What is the physics of radiography? How do they work?

Back 16

X-rays have a specific range of radiation darkening photographic film’s emulsion (White to gray.)
Varying densities are produced d/t different absorption of x-rays by body tissues to foreign materials.

Front 17

What are the five densities associated with x-rays from radiopaque to radiolucent?

Back 17

Metal.
Bone.
Muscle.
Fat.
Air.

Front 18

What is radiopaque & example?

Back 18

Significant absorption of x-ray beam thus fewer x-rays strike film.
Bone (White area on film)

Front 19

What is radiolucent & example?

Back 19

Small amount of absorption thus most of x-rays strike film.
Air (Dark area on film)

Front 20

What are some other tissues seen in an x-ray & how do they appear?

Back 20

Tissue, fluid, & foreign material produce varying gray densities.
Muscle, blood, & solid organs appear the same gray density.
Fat is slightly darker.

Front 21

What are some geometric considerations when taking x-rays?

Back 21

Altered image size (D/T distance changes b/n x-ray tube, film plate & pt)
X-ray tube closer to pt (Image size inc.)
X-ray tube moves further from pt (Image size decr.)
If pt rotates against the film plate, image size may enlarge.

Front 22

What distance, from a patient, should a standard chest x-ray be?

Back 22

Six feet from x-ray tube to patient.

Front 23

What are the three (3) interpretations from a systematic approach, regarding x-rays?

Back 23

1.) Initial evaluation
2.) Radiographic technique evaluation
3.) Systematic analysis

Front 24

Name considerations w/ Initial evaluation. (1st)

Back 24

INSPECTION
Examine for common errors.
Name, time and date correct?
Film markers (right or left).
Adequate quality.
Artifact (ECG leads, metal snap on gown).

Front 25

Explain radiographic technique evaluation (2nd) w/ position & distance when comparing x-rays.

Back 25

Ensure that position & distance are consistent (May not be realistic in ED, ICU, OR; Was patient able to cooperate?)

Front 26

Explain radiographic technique evaluation (2nd) in ERECT position.

Back 26

1) Examination of normal mediastinum
2) Correct interpretation of fluid & air levels

Front 27

Explain radiographic technique evaluation (2nd) in SUPINE position.

Back 27

1) Flattened mediastinum looks unusually wide
2) Pleural fluid will settle posteriorly to lung (Appear as haziness in hemithorax)
3) Air will rise to anterior surface of lung (Appears more lucent in hemithorax)

Front 28

Explain radiographic technique evaluation (2nd) in POSTEROANTERIOR (PA) position.

Back 28

1) Routine chest x-ray for baseline
2) X-ray beam passes from posterior to the anterior surface of chest & strikes film plate

Front 29

Explain radiographic technique evaluation (2nd) in ANTEROPOSTERIOR (AP) position.

Back 29

1) Portable chest x-rays in OR or at bedside are usually AP
2) X-ray beam passes from anterior to the posterior surface of chest & strikes film plate

Front 30

What are two advantages of the PA position?

Back 30

Yields least distortion.
Gives best view of pulmonary fields.

Front 31

What are some considerations concerning distortion w/ the AP position.

Back 31

AP films make heart & mediastinum appear larger because of their anterior location in the chest (farther from the film)

Front 32

Explain radiographic technique evaluation (2nd) concerning INSPIRATION.

Back 32

1) Was patient able to inhale & hold breath?
2) Should observe 10-11 posterior ribs over lung fields
3) Begin counting with 1st rib (difficult to find, look for anterior end just below mid-clavicle & follow to posterior)

Front 33

Explain radiographic technique evaluation (2nd) concerning EXPIRATION.

Back 33

1) Lung tissue will be compressed making heart & mediastinum appear larger d/t high position of diaphragm.
2) However….identifying pneumothorax (maximal expiration used to compress lung tissue increasing its density in contrast to pleural air aiding in its diagnosis)

Front 34

What is seen w/ proper exposure in x-rays?

Back 34

Soft tissues of lung visible.
Vertebra slightly visible through heart.

Front 35

What is seen when penetration too intense in x-rays?

Back 35

Normal lung markings blacked out.
Vertebrae well visualized.

Front 36

What is seen when penetration too light in x-rays?

Back 36

Radiopaque or washed out.

Front 37

What are some key points when addressing systematic analysis (3rd) & chest x-rays.

Back 37

Assessment of A&P
Begin with chest periphery & progress toward center
If reading film is a non-emergency, save the problem area for last (this avoids a “tunnel-vision” focus on the suspected pathology thus overlooking another situation)

Front 38

WHat are some considerations of Systematic analysis (3rd) pertaining to bony & soft tissue?

Back 38

Find ribs, clavicles, vertebrae, & scapula
Count vertebrae (remembering each corresponding rib is connected posteriorly)
Are they symmetrical? (Kyphosis, degenerative joint disease, FXs)
Presence of SQ air in soft tissues? (Remember air will appear dark & may be localized as lines or beads)

Front 39

What can SQ air be indicative of ?

Back 39

Ventilator trauma, lung or bronchial injury after chest trauma (may be d/t pneumomediastinum from migration of CO2 during laparoscopic nissen fundoplication.)

Front 40

What are some considerations of Systematic analysis pertaining to the Diaphragm?

Back 40

Normally rounded (Rt side slightly higher d/t location of liver)
Bilateral elevation (Pregnancy, obesity, peritoneal fluid)
Flattened (Emphysema, asthma, pleural effusion, tension pneumothorax)
Unilateral L elevation (Perforated ulcer, gastric gas)

Front 41

What are some other pathologies that may cause uni- or bilateral elevation?

Back 41

pneumonia, pulmonary infection, mass or distension of abdomen.

Front 42

What are some considerations of Systematic analysis pertaining to the Breasts?

Back 42

Breasts may alter density in lower lung fields producing contour line above diaphragm.
If one breast removed, may mimic pulmonary disease d/t increased radiopacity (scar tissue.)

Front 43

What are some considerations of Systematic analysis pertaining to Lung Fields?

Back 43

With inspiration, air will appear Radiolucent.
Pulmonary vessels give distinct pattern decreasing in size from medial to lateral.
Find the visceral pleural border next to radiopaque thoracic cage (Point of contact b/w pulmonary & parietal pleura)

Front 44

What are some landmarks associated w/ Lung Fields?

Back 44

Find visceral pleural border.
Diaphragm higher on right than left.
Find costophrenic angles (lateral border of rib cage & diaphragm)

Front 45

What could be present if the costophrenic angles are not sharp & well-defined?

Back 45

Air or fluid.

Front 46

What could be indicated if the border of lung is seen separate from chest wall w/ an abnormal density?

Back 46

Pneumothorax (air), hemothorax (blood).
Air will be darker than fluid.

Front 47

What are some key points pertaining to Systematic analysis
w/ the Trachea?

Back 47

Translucent air column.
Should be midline w/ slight Rt deviation at level of aortic arch.
May be straight in children (deviated in tension pneumo, atelectasis, effusion, tumor, or pneumonia consolidation)
Mass pushes trachea away & collapse pulls trachea toward abnormality.

Front 48

What will you see when systematic analysis deals w/ the tracheal bifurcation?

Back 48

R & L main bronchi (barely visible)
Enhance their view by holding film at 45 degree angle to light.

Front 49

What are some points w/ Systematic analysis associated w/ Vascular or hilar shadows?

Back 49

Hila w/ major bronchi & pulmonary vessels.
Above heart w/ Lt higher than Rt extending 1/3 into lung fields.

Front 50

What are key points when Systematic analysis pertains to the Mediastinum?

Back 50

B/n lungs containing heart, great vessels, trachea, esophagus, & lymph nodes.
Trachea will be seen as slightly lucent stripe down center.
Is it widened? (Cancer, hemorrhage, aneurysm, cor pulmonale, mediastinitis, recent CABG)
Is it shifted? (Tension pneumo, atelectasis, effusion)

Front 51

What should you do if an NGT is placed in the patient?

Back 51

Follow radiopaque stripe down esophagus & compare to trachea

Front 52

What key points of Systematic analysis are associated w/ the Cardiac silhouette?

Back 52

Heart visible lower Lt w/ 1/3 located to Rt of midline.
Normal size if < 50% of width of chest.
Cardiac tamponade or pericardial effusion will give “water bottle” round appearance.

Front 53

When evaluating invasive devices such as ETT, what are some considerations?

Back 53

Positioned w/ tip straight 4-6cm above carina in adult (located b/w 5th & 7th thoracic vertebrae).
Flexion of neck produces upward carina shift causing ETT to descend 2-3cm.
Extension of neck produces downward carina shift causing ETT to ascend up to 5cm.
Rotation can elevate ETT tip 1-2cm.

Front 54

What does this tell you about manipulation of patient’s head w/ ETT or Tracheostomy?

Back 54

Poss Rt mainstem w/ subsequent improper ventilation w/ ETT.
Neck movement in trach pt has little effect on tube position (usually @ T3)

Front 55

When evaluating invasive devices such as CVL what are some considerations?

Back 55

Proper placement shows catheter extending into Rt or Lt brachiocephalic vein in the SVC.
Tip should be in SVC at Rt lateral border T5-T6.
Should be medial to anterior aspect of 1st rib. (If tip has perforated into pericardial sac, fluid can be infused leading to pericardial effusion & tamponade).

Front 56

When evaluating invasive devices such as SWAN, what are some considerations?

Back 56

Should be seen through Rt heart & into large interlobar pulmonary artery 3-4cm beyond vertebral midline at T7 level. (If it is wedged into a smaller pulmonary artery, a pulmonary infarction may be seen as patchy infiltrate or consolidation around tip.)

Front 57

When evaluating invasive devices such as NGT, what are some considerations?

Back 57

Follow down esophagus through mediastinal shadow.
Should extend into stomach below Lt hemidiaphragm.
Watch for coiling in pharyngeal cavity or placement in pulmonary tree.

Front 58

When evaluating invasive devices such as CHEST TUBE, what are some considerations?

Back 58

Should be straight (unkinked).
Ensure all ports of tube (breaks in radiopaque stripe) are located w/n pleural cavity.

Front 59

When evaluating invasive devices such as IABP, what are some considerations?

Back 59

Usually contains 30-40 ml & is 8.5-10"
Should be in descending aorta b/w Lt subclavian artery & renal arteries.
Counterpulsation balloon used to enhance CO & coronary artery perfusion in weak hearts.

Front 60

What are some common Chest pathologies seen?

Back 60

Air bronchograms.
Silhouette sign.
Pleural effusion.
Atelectasis.
Pneumonia.
ARDS (Acute respiratory distress syndrome).
Cardiogenic pulmonary edema.
Aspiration pneumonitis.
COPD or emphysema.

Front 61

What is the significance of common chest pathologies associated w/ x-rays?

Back 61

Pulmonary disease x-ray findings are similar in appearance & non-specific
thus a history & exam are mandatory.

Front 62

What can air filled bronchi visible d/t surrounding infiltrated or consolidated lung tissue indicate? Examples?

Back 62

Air bronchograms.
Pulmonary edema, pneumonia, pulmonary infarct, lung lesions.

Front 63

What can a loss of normally sharp edge of air-filled lung against dense tissue indicate?

Back 63

Silhouette sign

Front 64

What can accumulation of fluid in pleural space indicate?

Back 64

Pleural effusion

Front 65

What are some causes of Pleural Effusion? Give examples of each type.

Back 65

Exudate (inflammation). [Pneumonia, TB, pulmonary infarction, malignancy]

Transudate (elevation in vascular pressure).
[CHF, liver cirrhosis, Meig’s syndrome (ovarian tumors complicated by pleural effusions)]

Front 66

What is common following surgery
resulting in air or fluid collapsing lung parenchyma (pneumothorax)?

Back 66

Atelectasis (lungs will look increasingly opaque as it progresses)

Front 67

What are the classifications of & important factors when dealing w/ Pneumonia?

Back 67

Bacterial, viral, mycoplasmal, or parasitic (Early pneumonia chest x-ray may look normal).
Pulmonary infiltrate slowly progressing.
May include tracheal or mediastinal shifting.

Front 68

What are indications/significance of ARDS?

Back 68

Rapidly progresses from perhilar edema to patchy consolidation.
Atelectasis 2nd to destruction of surfactant.
Can be d/t shock, post-trauma resuscitation, pneumonia, sepsis.

Front 69

What is seen in Cardiogenic pulmonary edema?

Back 69

1st (Pulmonary venous congestion
Upper lobe vessels dilate)
2nd (Increase in Lt atrial pressure
Interstitial pulmonary linear densities between alveoli looking hazy).
3rd (Symmetrical opacities like a butterfly distribution from interstitial fluid in air spaces).

Front 70

What causes & may be seen in Aspiration pneumonitis?

Back 70

Irritating acidic substance (gastric).
X-ray changes can be immediate, delayed or non-existant.
Hypoxemia &/or bronchospasm.
Atelectasis from destruction of surfactant.

Front 71

What can be seen in COPD or Emphysema?

Back 71

Can be present w/o x-ray evidence.
Usually both lungs are extremely radiolucent d/t excess air & vessel compression.
Ribs wide & horizontal (barrel-chest).
Diaphragm low & flat.
Heart narrow & vertical d/t lung overinflation.

Front 72

What is essential to anesthesia practice & why?

Back 72

Knowledge of basic chest x-ray recognition.
Often you will view film first w/ latter confirmation by radiologist, esp. during on-call hours (emergency intubation)

Front 73

What is Dextracardia?

Back 73

refers to the heart being situated on the right side of the body.