Chest Imaging

Question 1

what colour is air on CXR?

Answer 1

black

Question 2

what colour is fat on CXR?

Answer 2

grey

Question 3

what colour is soft tissue/ muscle on CXR?

Answer 3

grey/ white

Question 4

what colour is bone on CXR?

Answer 4

white

Question 5

what colour is metal on CXR?

Answer 5

bright white

Question 6

what to check when looking at a CXR?

Answer 6

patients name
CHI
side marker
adequate projection

Question 7

how do you tell if there is adequate projection on CXR?

Answer 7

PA
ratio of cardiac diameter to horizontal thoracic diameter is <50%
assess scapula

Question 8

how do you tell if a CXR is adequate inspired?

Answer 8

anterior ends of at least 6 ribs are visible (remember the ribs you can see are posterior)

Question 9

how do you tell if a CXR if adequately rotated?

Answer 9

medial ends of clavicles equidistant from spinous processes of upper thoracic vertebra

Question 10

which hila is higher?

Answer 10

left due to the heart

Question 11

which side of the diaphragm is higher?

Answer 11

right due to the liver

Question 12

what should the hila look like on CXR?

Answer 12

chevrons ><

if not= bilateral hilar lymphadenopathy

Question 13

review areas on CXR

Answer 13

1. lung apices
2. behind the heart
3. below the diaphragm
4. bone and soft tissues

Question 14

why do you need to look at the lung apices on CXR?

Answer 14

masses (Pancoast tumour)

pneumothroax

Question 15

what to look for behind the heart on CXR?

Answer 15

consolidation
masses
hiatus hernia

Question 16

what to look for below the diaphragm on CXR?

Answer 16

free gas
lines
tube e.g. NG
gastric distension
bowel obstruction

Question 17

what to look for in bones and tissues on a CXR?

Answer 17

fractures
masses
mastectomy
subcutaneous emphysema
evidence of previous surgery e.g. axillary clips

Question 18

how many lobes does each lung have?

Answer 18

left= 2 lobes
right= 3 lobes

Question 19

fissure in the right lung

Answer 19

oblique

horizontal

Question 20

what causes a lobar collapse?

Answer 20

obstruction of a lobar bronchus

Question 21

causes of lobar collapse

Answer 21

tumours
aspirated foodstuffs
mucus impacted

Question 22

why does the lobe collaspe?

Answer 22

air is resorbed, loses volume and collapses

Question 23

pleural space abnormalities

Answer 23

1. pleural effusion

2. pneumothorax

Question 24

how does a pleural effusion appear on an erect CXR?

Answer 24

pleural fluid collects at lung bases and forms the curved appearance of a meniscus at lung edges blunting the costophrenic angles

Question 25

what causes a pneumothorax?

Answer 25

rupture of the visceral pleura allows air to rush in from the lungs every time the patient inspires air accumulates impairing respiratory function

Question 26

why is tension pneumothorax an emergency?

Answer 26

displaces heart and diaphragm

Question 27

signs of pulmonary oedema

Answer 27

``` A (alveolar oedema- batwing opacities) B (kerley B lines) C (cardiomegaly) D (dilated upper lobe vessels) E (pleural effusion) ```

Question 28

what is CXR used to confirm the placement of?

Answer 28

``` endotracheal tubes (ET) nasogastric tubes (NG) central venous lines ```

Question 29

where should an endotracheal tube sit?

Answer 29

5cm above carina

Question 30

malposition of endotracheal tube

Answer 30

past carina right main bronchus (more vertical at carina) oesophagus

Question 31

where should NG tubes sit?

Answer 31

subdiaphragmatic position in the stomach (overlying stomach bubble) 10cm beyond gastro-oesphageal junction

Question 32

malpositioning of NG tube

Answer 32

remaining in oesophagus traversing bronchus intracranial insertion (possible in skull base trauma/ surgery)

Question 33

where should central venous catheters be placed?

Answer 33

central lines can be inserted via right and left internal jugular or subclavian veins tip should be at cavoatrial junction

Question 34

how are peripherally inserted central catheters done?

Answer 34

via cephalic, basilic or brachial veins

Question 35

malpositioning of central venous catheters

Answer 35

tip to high in proximal SVC (thrombus risk) tip too low in distal right atrium or ventricle (arrhythmias) coiled/displaced in vein (IJV/azygous vein)

Question 36

when is contrast enhanced CT used for pulmonary masses?

Answer 36

assessing tumour size showing metastases guided biopsy of peripheral lesion

Question 37

what is FDG-PET CT used for pulmonary masses?

Answer 37

nodal and distant mets (not brain)

Question 38

what is a pneumoperitoneum?

Answer 38

perforation of a hollow viscus that results in air in peritoneal cavity

Question 39

diagnosis of pneumoperitoneum?

Answer 39

erect allowing gas to rise up under the diaphragm(black thin line between diaphragm and subdiaphragmatic structures)

Question 40

diagnosis of PE

Answer 40

XR V/Q scan CTPA