Chest Radiology Flashcards
What is shown on the radiograph on the right?
Enlarged right ventricle
What is the silhouette sign? (e.g. where is the disease when the right and left heart borders are obscured? the hemidiaphragms?)
The absence of a silhouette suggests a disease process
e.g.
- when you can’t see the left heart border, there is disease in the lingula
- when you can’t see the right heart border there is disease in the right middle lobe
- when you can’t see the hemidiaphragms there is disease in the lower lobes
What makes up the technical quality of a radiograph?
- Rotation: spinous processes should be equidistant from clavicular heads
- Inspiration: diaphragm crosses 6th interspace anteriorly or 10th interspace posteriorly in the midclavicular line
- Penetration (exposure): should be able to see vertebral disks through the heart
Also, make sure you can see everything (nothing is cut off)
What is the suggested approach for reviewing a chest radiograph?
- Technical factors
- written data
- chest wall/soft tissues
- abdomen
- diaphragm
- pleura
- heart
- mediastinum
- hila
- lung parenchyma
What to pay attention to in written data?
- Name (ethinicity?)
- Sex
- Ward (ICU, CCU?)
What to check for when you check soft tissues?
Clavicles
vetebrae
- become more lucent inferiorly
ribs
- should be able to see 10 posterior ribs on inspiration
breast shadows
- absence of one indicates masectomy
soft tissue masses
On a lateral film, does the lucency of the veterbrae change?
inferior vertebrae should become more lucent compared to superior vertebrae
What do you check when you check the abdomen?
gastric bubble
liver shadow
bowel distention
calcifications (?gall stones)
What do you check for when you check the diaphragm?
Convexity (vs. flat in emphysema)
Costophrenic angle
Right should be higher than left
Is it easier to detect pleural effusion on lateral or PA films?
Lateral (need 75 cc of fluid) vs. PA (need 200 cc fluid)
What are you checking when you check the pleura?
separation of the two pleura (pneumothorax)
pleural effusions (will see a meniscus)
pleural calcifications (e.g. asbestos)
pleural thickening (e.g. mesothelioma from asbestos exposure)
Where does the pleura extend in the midclavicular, midaxillary lines and posteriorly?
8th rib, 10th rib and 12th rib
What are you checking for when you check the mediastinum?
masses (need lateral view to localize)
retrosternal space (as in emphysema)
What are you checking for when you check the heart
Cardiomegaly (<0.5 is PA or 0.6 AP is normal)
visible heart borders
What are you checking for when you check the hila?
Left side is normally higher than right
check for enlargement (lymph nodes, arteries, veins…)
Check for masses
What do the blue and orange arrows show?
Enlarged pulmonary arteries (blue) with peripheral pruning of arteries (orange). Pulmonary hypertension.
What are you checking when you check the lung parenchyma?
Air space disease (fluid in the alveoli)
- diffuse, confluent opacities with air bronchogram sign
- ground glass opacity if combined with interstitial disease.
Interstitial disease
- reticulation/lace-work
- ground glass opacity if combined with air space disease
Nodular disease
- e.g. miliary TB
Lucent lung disease
- emphysema- flat diaphragm and increased AP diameter
What is the air bronchogram sign?
It indicates that alvoeli are filling up with something (pus,
What does ground glass opacity signify?
A combination of alveolar and interstitial disease.
It is increased density that doesn’t obscure the vessels
What is this lung filled with?
cystic spaces ( >1cm)
What does this lung have?
Honeycombing: peripheral stacked, small cystic spaces
What does this lung have?
some kind of micro-nodular process (e.g. miliary TB, silicosis)
*can also have macronodular (>8mm) where nodules can cavitate
Advantages and disadvantages of CXR vs. CT vs. MRI vs US vs. PET
(when they are good to use)
CXR
- cheap
- low-dose
- 2D representation
CT
- expensive
- higher radiation
- excellent spatial resolution
- good for bone, lung
MRI
- expensive
- no radiation
- slow
- good spatial resolution
- good for soft tissue (lung neoplasm, cardiac)
US
- no radiation
- cheap
- portable
- user-dependent
- cannot see through air or bone
- can see pneumothorax and pleural effusion better than CXR
PET
- low resolution
- neoplasm
- pulmonary embolism assessment
