Cardiac and Pneumonia Flashcards
what is the normal cardiothoracic ratio of an adult
<50%
cardiothoracic ratio
the size of the heart compared to the size of the thorax
extracardiac causes of cardiac enlargement
- AP radiograph
- inadequate inspiration
- chest wall deformities
- rotation
- pericardial effusion
three causes of inadequate inspiration on CXR
obesity
pregnancy
ascites
two chest wall deformities that might cause cardiac enlargement on CXR
straight back syndrome
pectus excavatum
why will an AP radiograph make the heart appear enlarged
a combination of magnification, rotation, and poor inspiration
three indicators of cardiomegaly on AP radiograph
left heart border touching or almost touch left lateral chest wall = heart enlarged
heart appears significantly enlarged = heart probably enlarged
heart appears borderline enlarged = probably normal size
how would cardiomegaly be identified on a lateral CXR
note the space posterior to the heart and anterior to the spine at the level of the diaphragm
if the cardiac silhouette extends posteriorly over the spine = cardiomegaly
why would the heart look larger on expiration than inspiration
the diaphragm moves up and compresses the heart
how does normal cardiothoracic ratio differe between adults and children
a normal pediatric cardiothoracic ratio can be up to 65%
what are two considerations when examining cardiothoracic ratio in pediatrics
infants dont take deep inspiration
lobulated thymus can overlap portions of the heart
what happens to the heart during congestive heart failure/pulmonary edema
heart enlarges
what sign will be visable on CXR during left ventricular failure
interstitium widening followed by alveolar and pleural filling
fluid will back up into the pulmonary veins and lungs
what are the radiological signs of heart failure
fluid in lung fissures
kerley B lines
prominent upper lobe pulmonary arteries
fluild in the lung interstitium
large heart
pleural effusion
signs of heart failure in chronological order
heart enlargement
kerly B line
Kerly A line
fluid in lung fissures
fluid in the interstitium (batwing)
four signs of pulmonary interstitial edema
thickening of the interlobular septa
peribronchial cuffing
fluid in lung fissures
pleural effusions
Kerly B lines
short (1-2) cm long very thin and horizontal lines four at or near the costophrenic angle
kerly A lines
extend from the hila for up to 6cm and dont reach to lung periphery
pattern of pulmonary interstitial edema
thickening of the interlobular septa (kerly A and B)
peribronchial cuffing
fluid in fissures
pleural effusions
pulmonary alveolar edema
how will this look on CXR
elevated venous pressure pushes fluid from the interstitium into the alveoli
fluffy indistinct patchy “batwing” airspace densities that are usually centrally located, more likely in the lower than upper lung
what is the main way to determine if pulmonary edema is cardiogenic in nature
enlarged heart
kerly B lines
pneumonia
consolidation of lung produced by inflammatory exudate, commonly caused by infection
is pneumonia airspace, interstitial, or both?
which is most likely
it can be either one, or both
airspace
what does pneumonia look in CXR
denser than normal lung
may see air bronchogram
how will interstitial look different than airspace pneumonia
interstitial pneumonia are have more interstitial markings, spread to adjacent airways
airspace wil appear fluffly, homogenous, and indistinct
lobar pneumonia
cause
four indicators on CXR
pneumococcal pneumonia (s pneumoniae)
- classically fills most or all of a lobe or lung
- may have a sharp border
- almost always produce a silhoutte sign with heart, aorta, diaphragm
- almost always have air bronchogram
segmental pneumonia (bronchopneumonia)
cause
5 indicators on CXR
staph aureus or pseudomonas aeruginosa
- involved several segments
- margins tend to be fluffy or indistinct
- produce exudate the fill bronchi
- NO AIR BRONCHOGRAM
- may see atelectasis
interstitial pneumonia
causes
two indicators on CXR
viral pneumonia, mycoplasm pneumoniae, pneumocystis
- involve airway walls and alveolar septa
- fine, reticular pattern in the lungs spreading to alveoli (patchy confluent airspace disease)
pneumocystis pneumonia
perihilar, reticular, institial pneumonia or airspace disease
may mimic pulmonary edema
no hilar adenopathy or pleural effusion
found in AIDS patients
round pneumonia
causes
two identifiers on CXR
haemophilus influenzae, streptococcus, pneumococcus
mostly in kids
usually the posterior, lower lobes
four causes of cavitary pneumonia
straph, strep, klebsiella, coccidomycosis, tuberculosis
four indicators of cavitary pneumonia from primary TB
cavitation is rare
upper more likely than lower lobes
hilar adenopathy
large, often unilateral pleural effusions
three indicators of cavitary pneumonia from post primary TB
cavitation is common (thin walls with smooth margins)
no air fluid level
apical or posterior segments of the upper lobes that may be bilateral
two indicators of miliary tuberculosis
small nodules 1mm in size that can grow to 2-3mm
clear rapidly once treated
three indicators of aspiration pneumonia
almonst alwats occurs in the dependent portions of the lung
right side more likely that left
acute looks like airspace disease
what will aspiration pneumonia caused by anaerobic organisms
lower lobe airspace disease the cavitates
- superior vena cava
- right atria
- inferior vena cava
- aortic arch
- left pulmonary trunk
- left pulmonary artery
- left atrium
- left ventricle
- cardiophrenic angle
cardiomegaly
kerly B
kerly b an kerly a
pulmonary interstitial edema
pulmonary alveolar edema
T/F air bronchogram is specific to pneumonai
false
lobar pneumonia
right middle lobar pneumonia
right middle lobar pneumonia
right middle lober pneumonia
segmental pneumonia
segmental pneumonia
interstitial pneumonia
interstitial pneumonia
interstitial pneumonia
pneumocystic pneumonia
round pneumonia
round pneumonia
round pneumonia
round pneumonia
round pneumonia
round pneumonia
cavitary TB
miliary TB
aspiration pneumonia
