CXR

Question 1

What is an x-ray?

Answer 1

Electromagnetic wave of high energy and very short wavelength – able to pass through many materials

X-rays being absorbed to diff degrees

Question 2

What x-ray dose is given?

Answer 2

0.02mSv (milli severt)

Question 3

What are the projections we can do with a CXR?

Answer 3

AP = anterior posterior (heart closer to the front, will appear magnified), more diff to interpret, performed in unwell pts, cant put x-ray machine behind them

PA = posterior anterior

Question 4

A good x-ray needs to include what?

Answer 4

1st rib

Lateral margin of ribs

Costophrenic angle

Question 5

How is rotation assessed on a CXR?

Answer 5

Alignment of spinous and clavicles

Question 6

How is lung volume assessed on a CXR?

Answer 6

Expect to see anterior ribs 5-7 at the diaphragm

Pt takes deep breath and holds

Flattened hemidiaphragm

Question 7

Where is the costophrenic angle/recess seen?

Answer 7

Angle in the lower corner of the diaphragm

Important when looking for effusions – is the recess filled?

Question 8

When are flat diaphragms seen?

Answer 8

Emphysema

Question 9

How do we know we have an adequate levels of penetration?

Answer 9

Vertebrae just visible through heart

Complete L hemidiaphragm is visible

Question 10

What is an artifact on the x-ray?

Answer 10

External/iatrogenic material which obstructs

Buttons

Hair

Surgical/vascular lines

Pacemaker

Question 11

What anatomy should be seen on a normal CXR?

Answer 11

Trachea

Hilum of lungs (R/L hilar point)

Lungs

Diaphragm

Heart

Aortic knuckle

Ribs

Scapulae

Breasts

Bowel gas

Question 12

How is the lung divided in a CXR?

Answer 12

Upper zone

Middle zone

Lower zone

Question 13

Sometimes a darkened area is seen below the L diaphragm, what is this?

Answer 13

Stomach bubble

Question 14

Describe the cardiac contours

Answer 14

L contour = LV

R contour = RA

Aortic knuckle

Pts with lymphoma have lymph node in aorto-pulmonary window

Para-tracheal stripe should be thin, if not suggestive of pleural abnormality

Question 15

What approach is taken to evaluate a CXR?

Answer 15

Pt demographics

Projection

Adequacy

Airway = trachea, bronchi, hilar point

Breathing = lungs, pleural spaces, lung interfaces

Circulation = aortic arch, pulmonary vessels, R heart border, L heart border

Diaphragm/Dem bones = free has, nodules, fracture, dislocation, mass

Question 16

What is CXR adequacy and how is it assessed?

Answer 16

R = rotation

I = inspiration

P = penetration

Question 17

Pathology in the apices could be what?

Answer 17

Pneumothorax

Question 18

Pathology in the thoracic inlet could be what?

Answer 18

Mass

Question 19

Pathology in the paratracheal stripe could be what?

Answer 19

Mass

Lymph nodes

Question 20

Pathology in the AP window could be what?

Answer 20

Lymph nodes

Question 21

Pathology in the hila could be what?

Answer 21

Mass

Collapse

Question 22

Pathology behind the heart could be what?

Answer 22

Mass

Question 23

Pathology in below the diaphragm could be what?

Answer 23

Pneumoperitoneum – pt must be erect to visualise

Mass

Question 24

Pathology in the bones could be what?

Answer 24

Fracture

Mass

Missing

Question 25

What is the silhouette sign?

Answer 25

Adjacent structure of diff density form a crisp silhouette Loss of this contour can locate pathology

Question 26

If the R heart border is lost what does this indicate?

Answer 26

Pathology in the R middle lobe

Question 27

If the L heart border is lost what does this indicate?

Answer 27

Pathology in the lingula

Question 28

If the paratracheal strip is lost what does this indicate?

Answer 28

Mediastinal disease

Question 29

If the chest wall silhouette is lost what does this indicate?

Answer 29

Lung disease Pleural disease Rib pathology

Question 30

If the aortic knuckle is lost what does this indicate?

Answer 30

Anterior mediastinum pathology Upper lobe disease

Question 31

If the diaphragm silhouette is lost what does this indicate?

Answer 31

Lower lobe pathology

Question 32

If the horizontal fissure cant be seen what does this indicate?

Answer 32

Pathology in the anterior segment of the upper lobe

Question 33

What causes mediastinal shift?

Answer 33

Push = increased volume/pressure Pull = decreased vol/pressure

Question 34

What descriptive terms can be used to describe a CXR?

Answer 34

Size = large, small varied Side = R/L, unilateral/bilateral Number = single, multiple Distribution = focal, widespread Position = anterior, posterior, lung zones Shape = round, crescentic Edge = smooth, irregular, spiculated Pattern = nodular, reticular Density = air, fat, soft-tissue, calcium, metal

Question 35

Describe a pleural effusion and how it appears on a CXR

Answer 35

Collection of fluid in the pleural space Appearance = uniform white area, loss of costophrenic angle, hemidiaphragm obscured, meniscus at upper border Pt needs to the erect for fluid to collect at the bases – beware supine CXR

Question 36

Describe a pneumothorax and how it appears on CXR

Answer 36

Air trapped in pleural space Appearance = visible pleural edge, lung markings not visible beyond this edge Primary = spontaneous Secondary = as a result of underlying lung disease

Question 37

What is a hydropneumothorax?

Answer 37

Fluid and gas in the pleural cavity

Question 38

Describe consolidation and how it appears on CXR

Answer 38

Filling of small airway/alveoli with pus, blood, fluid, cells. Dense opacification

Question 39

Describe cavitation and how it appears on CXR?

Answer 39

Area of central lucency = cavitation Commonly seen in TB, lung infarcts

Question 40

Describe what a space occupying lesion is and how it appears on CXR

Answer 40

Nodule = <3cm Mass = >3cm Causes = malignant, benign, inflam, congenital Appearance = white shadow can be localised or disseminated

Question 41

Describe lung/lobar collapse and how it appears on CXR

Answer 41

Volume loss within the lung Causes = 1) luminal: aspiration, mucous plug, iatrogenic. 2) mural: brochogenic carcinoma. 3) extrinsic: compression by mass Appearance = elevation of ipsilateral hemidiaphragm, crowding of ipsilateral ribs (lung vol declines), shift of mediastinum towards side of atelectasis, crowding of pulmonary vessels, second heart border

Question 42

What is cardiac index and how is it calculated?

Answer 42

Ratio of heart size to horizontal thoracic size Normal = <50% MUST be a PA image