chest x rays Flashcards
basics
- CR, radiograph, film
- quick, inexpensive, non-invasive
- mirror of health or disease (identify many abnormalities/diseases; provides info about adjacent structures)
- doesn’t provide info about blood flow, ventilation, perfusion, etc.. other studies used
things to check
- x-ray is of your pt
- what view was taken (AP, PA, lateral)
- taken on inspiration?? if so, should be able to count the 10 posterior ribs
major difference from other x-rays
- chest films traditionally taken from posterior to anterior view
- different shades of gray of structures is related to tissues attenuation of x-ray beam
decreased to increased radiodensity:
- air
- fat
- water
- bone
- metal
CXR
- silhouette sign used to locate lesions in specific lobes of the lung
- no border between tissues of 2 similar densities
ex: if water density process like pneumonia is in a lobe near the heart, the border between that lobe and heart will disappear
commonly obliterated borders & associated lobes
Loss of border of superior mediastinum= lesion in upper lobes
Loss of border of R heart=lesion at R middle lobe
Loss of border of R hemi-diaphragm=lesion at R lower lobe
Loss of border of L hemi-diaphragm=lesion at L lower lobe
loss of border of superior mediastinum
=lesion in upper lobes
Loss of border of R heart
=lesion at R middle lobe
Loss of border of R hemi-diaphragm
lesion at R lower lobe
Loss of border of L hemi-diaphragm
lesion at L lower lobe
cardiothoracic ratio
- estimate of the size of the heart
- adults: widest width should be less that half the width of the chest at the level of the diaphragm
enlarged heart due to:
- cardiomyopathy
- CHF
- incompetent valves
heart appears enlarged if:
- AP view
- image made at expiration not inspiration
- diaphragm is superiorly displaced due to pregnancy, abdominal distention, or pericardial effusion is present & surrounding fluid enlarge entire cardiac image
mediastinum
=space between lungs; bound by sternum and spine
-contains heart, vessels, trachea, esophagus
- except for air filled trachea & primary bronchi, all these structures have the same radiodensity and can’t be distinguished
- only the lateral borders outlined by air filled lungs can be identified
mediastinum contains:
heart
vessels
trachea
esophagus
mediastinal shifts
-whole structure can move to one side of another and can be permanent (removal of a lung) or temporary (pleural effusion) or atelectasis
- air or fluid in pleural space will push contents (including trachea) to the opposite side;
- lung collapse or volume loss will pull contents to the same side
Can also identify masses in this area
-goiter, lymphoma, esophageal or bronchial cancers, aortic aneurysms
diaphragm
- can see the 2 halves of this muscle bc it borders air-filled lungs
- white area is combined areas of liver, spleen, stomach, posterior lungs and the part of the diaphragm that’s next to the x-ray beam
- dome normally seen on inspiration at level of 10th rib
elevated diaphragm due to:
- excessive fluid in the peritoneal space (ascites (fluid build up) or cirrhosis of the liver)
- later stages of pregnancy
- splinting after abdominal surgery
flattened diaphragm due to:
-increased volume of the lung (emphysema, pleural effusion, or masses in the lung)
hemi-diaphragms
- highest point of each hemi–diaphragm is middle 1/3rd
- R is higher bc of liver
- L contains the stomach-often see a bubble in the funds
costophrenic angles
- seen where diaphragm and chest wall meet.
- angle is about 30 degrees
- angle is obscured on x-ray with diagnosis such as pleural effusion
routine CXR
-includes PA and lateral views
Controversy about lateral view:
- increased radiation exposure
- limited in pediatrics and frail who had difficulty raising arms
- less useful clinical info
abnormally white lungs
1: pneumonia
2: atelectasis
3: pleural effusion
pneumonia
(fluid fills in and around alveoli & bronchi producing consolidation seen on x ray)
- determine which lobe
- represents dozens of pulmonary infections.
- lobe, entire lung, 1 or both
x-ray findings:
- consolidation
- silhouette sign is pneumonia in a lobe that borders the heart or diaphragm
atelectasis
=loss of volume of a portion of a lung, not a disease
results from:
- obstruction in the bronchi (foreign object, mucous plug, cancer)
- compression (pleural effusions, enlarged heart)
- traction (scarring, fibrosis, adhesions)
- responds well to chest PT
- tx depends on cause of collapse
- common post-op due to poor inspiratory effort bc of pain; secretion retention may cause obstruction
atelectasis x-ray
- increased whiteness of collapsed lung-no air
- lobes next to collapse lobe may appear darker
- mediastinum shifts TOWARD collapsed lobe due to lost volume in lobe
- hemidiaphragm will elevate on collapsed side
pleural effusion
=excess fluid in pleural cavity due to infection, heart failure, liver failure, cancer, PE, TB, or trauma
4 types of fluid can collect
-fluid is withdrawn from pleural space and analyzed
types of pleural fluid
1: serous fluid (hydrothorax)
2: blood (hemothorax)
3: chyle= fluid filled with lymph & free fatty acids (chlothorax)
4: pus (pyothorax or empyema)
x-ray findings of pleural effusion
-blunting of costophrenic angle
diagnostic categories for CXR
1: lung field is abnormally white
2: lung field is abnormally black
3: mediastinum is abnormally wide
4: heart is abnormally shaped
abnormally black lungs
1: pneumothorax
- tension
- non-tension
2: COPD
pneumothorax
air in pleural cavity; occurs spontaneously, following penetrating chest wound, barotraumas (in scuba divers); chronic lung pathologies or due to medical procedure
- most are unilateral
- tension or non-tension
tension pneumothorax
- potentially fatal
- air collects in pleural space with each breath, can’t escape
- pressure builds causing shift of mediastinum AWAY from affected lung
- compression of intrathoracic vessels occurs and L sided venous return is obstructed.
non-tension pneumothorax
- less severe
- no accumulation of air, etc
- treated with O2 and monitoring
tension pneumothorax x-ray
- appears blacker due to absence of lung vasculature
- visceral pleural line on lung edge is visible
- deep sulcus sign present at costophrenic angle
- mediastinal shift AWAY due to positive pressure in affected lung
COPD
=group of diseases with airflow obstruction
- emphysema=enlargement of airspaces distal to terminal bronchioles with destruction of alveolar walls
- chronic bronchitis= inflammation of airway walls with increased mucus; walls thicken & result in narrowing of vessels & restricted airflow
- can have both; both due to smoking
COPD film
- blacker lung fields
- bullae (pockets of trapped air)
- increased vertical height of lungs-flattening or scalloping of diaphragm
- narrowed mediastinum with narrowed cardiac image
- airspace below the heart
- increased retrosternal airspace on lateral view
widened mediastinum
aortic dissection
aortic dissection
=tear in inner layer of aorta allows column of blood to separate inner and middle layers
-if it ruptures through the outer aortic wall, dissection is usually fatal
-common site of dissection: ascending aorta; most are preceded by aortic aneurysm
Symptom: severe chest pain
Dx confirmed with CT angiography, MR angiography or transesophageal echocardiography
aortic dissection film
- widened mediastinum
- obliteration of normal shape of aortic arch
- downward slant of main stem bronchus
- tracheal deviation due to aortic compression
enlarged heat
CHF
heart valve disease
mitral valve stenosis
CHF
- due to inability of heart to pump out enough blood
- caused by CAD, MI, cardiomyopathy (things that weaken the heart) or disease that increase O2 demand beyond what the heart can deliver (HTN, valve disease, thyroid disease, kidney disease, diabetes, heart defects)
- R or L heart failure
L sided heart failure
-failure of L side causes congestion in pulmonary vessels; fluid backs up into pulmonary veins and lungs , resulting in pulmonary edema
R sided heart failure
leads to congestion of systemic capillaries and causes dependednt peripheral pitting edema, ascites and hepatomegaly
CHF film
- enlarged heart width
- pleural effusion
- bat wing pattern- fluid replaces air in lower lobe producing white areas. bilateral dark areas are in the shape of wings (decreased costophrenic angles)
heart valve disease
- stenosis or insufficiency
- congenital, disease, age-related change, enlarged heart
symptoms: depend on severity- SOB, CHF
- susceptible to endocarditis so on prophylactic antibiotics
mitral valve stenosis
- straightening or bulging of L heart border
- double line density on R heart border due to enlarged LA projecting through RA
- prominence of upper lobe veins
cardiac US
-non invasive US used since 1960s
Provides info about: abnormal patterns of BF, CO & EF -valvular function -thickness & movement of heart wall -presence & severity of CAD -state of pericardium
types of US
1: Trans thoracic echo (TTE)-standard
2: Transesophageal echo (TEE)
3: stress echocardiography
4: doppler echo
5: 3D echo
trans thoracic echo (TTE) US
-transducer placed on chest wall and pictures taken through it
transesophageal echo (TEE) US
- transducer passed into esophagus-allows for clearer pictures
- disadvantage is it requires fasting and sedation
stress echocardiography US
-done pre and post treadmill or bike exercise with ECG monitoring
purpose=compare BF at rest and under stress
-sometimes use drugs to stress heard instead of exercise
doppler echo US
- uses doppler principle to measure velocity and direction of BF in the heart
- evaluates valve function, abnormal communication between R and L heart, leaky valves, measures CO
3D echo US
more precise measurements
nuclear medicine
Ventilation/Perfusion scan of the lungs
V/Q scans
- measures both airflow and blood flow in lungs
- typically done to detect PE in pulmonary artery
- evaluates lung function in advanced disease (COPD)
- used pre and post lung lobectomy surgery to determine performance
Performing V/Q scans
V: pt inhales radioactive Xenon gas and pictures are taken to determine which lobes of lungs the gas has reached
Q: radioisotope is injected through IV and photoes taken
- study evaluates 2 sets of images and matching lung segment to lung segment
- PE diagnosed in segment of lung that has normal airflow but decreased BF
- criteria used for dx of PE based on number of mismatches
nuclear perfusion studies of the heart
- use radioisotopes together with stress tests to evaluate coronary arteries
- nuclear stress tests or cardiolite stress tests
- radioisotope tracer specific for heart muscle cells is given via IV
- HR increased by exercise or drugs; pictures taken at rest, after exercise and at rest a few hours later
- evaluate all walls of heart
- used to look for obstruction in coronary arteries
possible outcomes of nuclear perfusion test
- unobstructed flow-normal
- normal perfusion at rest but decreased during exercise -reversible defect
- decreased perfusion at rest and exercise-complete block of 1 or more coronary arteries: blocks at all times. -non-reversible defect- area of heart is permanently damaged
- combo of reversible and non reversible - common in pts with CAD; blockages can be of different degrees of severity in different arteries
MUGA scan
=multigated acquisition
- evaluates the ventricles= nuclear ventriculography
- isotope injected, images take from end diastolic volume (heart filled) to end systolic volume (blood ejected)
- more accurate than echocardiogram, still non-invasive
angiography
=study of blood vessels; can be done in any organ
- looking for obstructions or aneurysms
- iodine based contrast delivered via catheter threaded through femoral vein up into heart, viewed through fluoroscopy
coronary angiography
contrast to L heart to evaluate coronary arteries
part of cardiac catheterization procedures (balloon angioplasty, stent placement)
invasive, risky
pulmonary angiography
contrast to R heart into pulmonary artery to diagnose PE
aortic angiography via L heart catheterization used to assess aortic regurgitation, coarctation, patent ductus aretiosus and dissection
invasive, risky
ventriculography
used to visualize motion of ventricle wall, ventricular flow and calculate EJ
invasive, risky
CT pulmonary angiography
contrast injected into peripheral vein (if suspect PE)
vessels appear white, obstructions appear darker
more effective than V/Q for emboli
MRA
=magnetic resonance angiography
=pulse sequence to generate signal from flowing blood
-non invasive
-high cost
pulmonary function tests
FEV1= forced expiratory volume in 1 sec FVC= forced vital capacity FEV1/FVC= ratio FEF25-75: forced expiratory flow in med range of forced expiration PEF: peak expiratory flow rate
FEV1
forced expiratory volume in 1 second
normal: 80%
obstructive:
65-80% =mild
50-65%= moderate
<50%=severe
restrictive:
normal or low
FVC
forced vital capacity
normal: 80%
obstructive: normal or low
restrictive: low
FEV1/FVC
normal: >70-80%
obstructive: <70%
restrictive: normal or high
FEF25-75
normal: >80%
obstructive: <50%
restrictive: normal
lung biopsy
catheter inserted through bronchoscope to take piece of lung
sputum tests
note color, consistency and smell
label with name and date
sputum descriptors
color: clear, white, yellow, brown, greenish brown, green (infection)
consistency: thin- pt less sick
- moderately thick- sicker
- thick-sick
smell:
- none
- foul- more ill
