Week 9 (CXR) Flashcards
Air/gas appear
Black
Fat, soft tissues and water appear
Gray
Bone and metal appear
White
Patient and film details consists of
Labels (name, date, MRN)
Orientation
Projection (PA/AP)
Film quality consists of
Exposure
Inspiratory effort
Patient position
Extrathoracic/thoracic consists of
Soft tissues Thoracic cage (bones)
Intrathoracic consists of
Mediastinum (trachea, hila, heart)
Diaphragms (shape, angles, position)
Lung fields (boundaries, markings, fissures, zones)
Lines and attachments consist of
Drips, drains, tubes, foreign bodies
Patient and film details: PA projection
Rays pass from back to front
Patient usually standing
Ideal view
Patient and film details: AP projection
Rays pass from front to back
Patient usually sitting but can be supine
Less ideal view
Magnification of heart and widening of the mediastinum especially supine film
Exposure: correct penetration
Should just see IV discs behind the heart but can see them easily behind the trachea
All air filled structures should have appropriate amount of translucency
Exposure: over penetration
Can see IV discs behind the heart easily
Overall, film is more translucent
May miss problems that should show up as white/opaque
Exposure: under penetration
Can’t see IV discs behind the heart or trachea
Overall, film is more opaque
Might over-diagnose problems
Exposure: inspiratory effort
X-rays are taken at end of full inspiration and extent of inspiration can be measured by counting ant and post ribs. Deep inspiration:
- 6th ant rib intersect diaphragm at mid-clavicular line
- 9-10 post ribs about the diaphragm
Exposure: patient position
Good: medial ends of clavicles should be equidistant from spinous process
Bad position: some rotation of trunk probably evident when film was taken making normal CXR appear abnormal
Extra-thoracic/thoracic structures: soft tissue
- Breast shadows
- Soft tissue: excess adipose, subcutaneous emphysema (air in soft tissues around thorax)
Extra-thoracic/thoracic structures: thoracic cage
Bones of thoracic cavity should be checked for major abnormalities:
- Vertebral column: scoliosis, kyphosis and rib orientation
- Ribs: fractures and osteoporosis (appear more translucent)
Intrathoracic: mediastinum
- Trachea: translucent tube visible initially above clavicles
- Hila: L hilum lies about 1cm higher and slightly smaller than R
- Heart shadow: should not exceed 50% of the diameter of the thorax. 2/3 of the heart should sit L to midline, 1/2 to the R.
Intrathoracic: lung fields
- Lung markings: fine white lines should extend all the way out to the edge of the chest wall from hilar region to periphery
- Horizontal fissure: visible in about 50-60% of normal adults. Seen as white hair like shadow at level of ant 4th rib running towards centre of R hilum
- Rest of lung: upper zone; above 2nd ant rib, mid zone; between 2nd ant rib and 4th ant rib, lower zone; below 4th ant. rib
- Increased translucency: lung fields appear darker
- Increased opacity: lung fields appear whiter
Intrathoracic: lines and attachment
Tracheostomy tube, oxygen tubing, central line, nasogastic tube, chest drains, surgery stables or wires, valve replacements, heart pacemaker box and pacemaker wires, swan ganz catheter, ECG electrodes and leads
Symmetrical hila indicates
Pulmonary hypertension
Shifted/rotated heart shadow indicates
Collapse of adjacent lung tissue
Intrathoracic: diaphragm
- Shape: dome
- Position: L (stomach) lobe slightly lower than R (liver)
- Angles: acute, clear and symmetrical
Elevation of diaphragm indicates
Collapse on affected side, phrenic nerve damage, collection in abdomen, person didn’t/couldn’t take in deep breath
