MIdterm2 Notes Flashcards
PA chest specifics
High kVp 100+ Full inspiration 72+ FFD frontal view PA Grid or non-grid (film or CR) - DR=grid
Thoracic spine specifics
70-80 kVp Suspend breathing 40inch FFD Frontal view AP Grid
Most common x-ray in humans
Chest x-ray
Most 911 emergencies in your office are on conditions involving
Chest anatomy
Controls density
KVp
15% increase in kVp
Doubles the density
Cut mAs by 1/2
Going from 80-90 kVp is about a
15% increase
Higher ___ = more grays = longer scale of contrast
KVp
C-spine kVp
70-80 kVp
T-spine kVp
70-80 kvp
L-spine kvp
80 kvp
Lat lumbar kvp
85/90 kvp
We determine if the patient is at full inspiration by
Rib count - right hemi-thorax usually can see 10 posterior ribs above the diaphragm
Heart size is always evaluated on
Full inspiration chest film
Expiration film is used for
Lung increases in density because less air volume
Radiolucency of lung is the ratio of
Air to soft tissue in the lung
Know if diaphragm is being pushed up or paralyzed
Inspiration expiration film
If pushed up from below, the diaphragm will
Still move with breathing
If phrenic nerve is damaged
Paradoxal motion of the diaphragm with paralysis
Inhale = diaphragm goes Exhale. = diaphragm goes
Up
Down
Pneumothorax is difficult to see because it is both air density. Easier to see on inspiration or expiration
Expiration since the lung increases in density on expiration film which provides more contrast to the air in the pleural space
Air-trapping is the opposite of ___ in mechanics
Atelectasis
When we inhale, bronchi
Dilate
When we exhale, bronchi
Passively return to neutral
If obstructed on both inspiration and expiration air is absorbed distal to the obstruction
Atelectasis
If obstructed on expiration
Air-trapping
Lung expands and becomes more radiolucent
Increase air volume compared to soft tissue
Air-trapping
FFD inverse square log
From 40 inches (80 kvp and 50 mAs) to 72 inches - need 200 mAs
The shorter the FFD, the more of the ___ is used
Cone of the beam
As we back up the FFD, we use more of the __ of the beam
Center
Gives us the shortest OFD to the heart
PA position
Greater than 10 cm and kVp greater than 60
Grid rule
Grid is used
To reduce scatter
If using a grid (12:1 is best for us - absorbs at least 70% of the beam) must increase mAs by
4x
If patient is less than ___ we don’t need a grid for chest x-ray
26cm
Lateral cervical air gap acts as a grid therefore
We don’t need it
72 inch lateral cervical is same technique as a
40 inch with grid
Film identification
Facility name and address Patient name and age (DOB) Patient gneder Film date Film number is optional
Left lateral. Chest film time
The time you use on PA go up two time stations for the lateral
Chest obliques are done as
Anterior obliques
Gold standard for chest imaging is
CT
RAO observes
Left lung
Time station for oblique
1 time station up from PA
Patient postition
Visualize anatomy
Center anatomy on the cassette
Put CR to center of cassette
Way to clarify a lesion
Heels 18 inches out, lean back
Rotates bone aroudn apex of lung
Collimate
Apical lordotic
Recumbant AP view for non-ambulatory patients
40 inch
Frontal view with patient in a lateral decubitus
Beam parallel to floor
Cassette perpendicular to the floor and beam
Done to observe pleural fluid or pleural air (pneumothorax)
Done to observe pleural fluid or pleural air
Decubitus series
If suspect left pleural effusion
Do left decubitis view
The lung on the side down is
Dpeendent in a decubitus view
Fluroscopy is useless for
Chest
Vascular contrast evaluation of pulmonary vessels
Pulmonary angiography
Gold standard for heart imaging
US
Ventilation and perfusion scans - tells you where air is going and where blood is going
Nuclear medicine
Good for mediastinum and chest walls, not best for lungs
MRI
Advanced chest imaging
Decubitus series PA full inspiration Fluoroscopy Bronchography Pulmonary angiography Tomography US Nuclear medicine MRI
Contains anterior, middle, and porition of superior anatomical divisions
Anterior mediastinum
Posterior to the line to 1cm behind vertebral body
Middle mediastinum
Spine
Posterior mediastinum
Midline structure
As passes the transverse arch of aorta (aortic knkob) deviates tot he right slightly
Divides at the carina into left and right mainstem bronchi
Trachea
Carina
Infants
Teens
Adults
T4
T5
T6
Origination of the hilus (unilateral structures)
1 mainstem bronchi 1 pulmonary artery 2 pulmonary veins Vagus nerve (Recurrent laryngeal nerve) Phrenic nerve Lymph nodes
Mainstem bronchi
Left = longer and more horizontally oriented, less obtuse
Right = shorter and more vertically oriented
Pulmonary artery L vs R
L = arches up over the top of L mainstem bronchus R = passes in front of R mainstem bronchus
Contributes to majority of hilar denisty
L is higher than R
Pulmonary veins
Add density to the area but not visible as individual structures
Vagus nerve runs directly____ to the hilus
Posterior
Vaguse nerve on left
Gives recurrent laryngeal nerve that curves under arch of aorta at the hilus
Can be compressed by hilar tumors
Peter jennings - unexplained hoarseness
Vagus nerve on right
Recurrent laryngeal branches earlier on the R
hilar tumor does NOT compress recurrent laryngeal nerve but DOES compress the superior vena cava = SVC syndrome
Phrenic nerve runs ___ to the hilus
Anterior
Hilar tumors can compress the phrenic nerves
Extensive lymphatic system in the chest
Lymph nodes
Rt peritracheal nodes very common in sarcoidosis
Not normally visible as individual structures - can be seen individually with a distinct shape with pathology
Lymphadenopathy
LAN
Enlarged due to inflammatory, neoplastic, benign lymphoid hyperplasia
Infectious inflammatory LAN
TB, fungal (histo, coccidio)
Non-infectious inflammatory LAN
Sarcoidosis
Silicosis
Neoplastic LAN primary
Lymphoma - HL, NHL
Neoplastic LAN secondary
Metastasis
Benign lymphoid hyperplasia
Castleman’s
Calcification lymph nodes
End-stage granulomatous disease
Fibrotic, scarred, calcified
TB, fungal, pneumoconiosis
Medullary lymphatic drainage (big orange)
Lymph re-absorbed into hilar, subcarinal, peratracheal
Cortical lymphatic drainage big orange
Lymph travels in pleura - subpleural lymphatics - over surface of lung
When a hilus is abnormal =
Enlargement
Unilateral hilar enlargement
Bronchus or lymph nodes
Bilateral hilar enlargement
Blood vessels (arteries/veins) with pulmonary hypertension OR lymph nodes