Unit 4 Week 15 Flashcards
what are the 6 parts included in the radiographic anatomy of the chest xray?
bony thorax, respiratory organs, the heart, the mediastinum, the hilum, the diaphragm
what is the difference between a radiograph of the thoracic spine and a chest x-ray?
thoracic spine = high contrast
chest x-ray = low contrast
when might a AP position be used for a chest x-ray?
PA is standard
AP used for patients who are too ill to stand
what respiratory organs are seen on a chest x-ray?
larynx, trachea, bronchi, lungs
what is the cardiothoracic ratio?
radiographic estimate of heart size
- the widest width of the heart should be less than half the width of the chest at the level of the diaphragm
what is the mediastinum?
the space between the lungs, bounded anteriorly by the sternum, posteriorly by the spine
- contains the bundle of soft tissues of the heart, the great vessels, the trachea, and the esophagus
what are the 4 main bumps found in the mediastinum on a chest x-ray?
on the right: ascending aorta, right atrium
on the left: aortic arch, pulmonary artery, left ventricle
how does the diaphragm look in a radiograph of a patient with emphysema?
diaphragm low and flat
what does free air outside of the bowel and in the peritoneal cavity signify?
the bowel has been perforated either from cancer, diverticulitis, peptic ulcer disease, or trauma
what is the goal of the chest radiographic exam?
the help establish the presence, absence or etiology of disease processes that involve the thorax and to follow their course
what are the 5 indications for chest radiography as per ACR?
- evaluate the s/s potentially related to the respiratory, cardiovascular and upper GI systems
- evaluation of extrathoracic disease that secondarily involves the chest
- follow-up of known thoracic disease processes
- monitoring patients with life-support devices
- surveillance studies as required by public law (TB or occupational lung exposures)
what are the 2 routine chest exam projections?
- erect PA
- erect left lateral
what are the steps for assessing for rotation in a radiograph?
- compare sternoclavicular joints to midline distance
- compare rib cage margin to midline distance
- sternum should be midline, superimposed over thoracic spine
- kyphosis or scoliosis may cause assymmetry
what boney observations should be looked for in a chest x-ray?
bilateral symmetry of scapula, clavicles, and ribs
bone density: fractures or erosions, calcifications, osteoporotic or osteoblastic lesion
vertebral body height and disk space
what soft tissue observations should be looked for in a chest x-ray?
overall amount of fat and muscle in the supraclavicular region, axilla, along the lateral chest walls, and the breast tissue
what observations should be looked for in a chest x-ray regarding the mediastinum?
overall size, shape, and position
what is a mediastinal shift?
the mediastinum is displaced to one side or the other, as a result of any condition that changes volume in one hemithorax, such as pleural effusion, a pneumothorax, or atelectasis
what lung observations should be looked for in a chest x-ray?
compare overall size of each lung field
equally radiolucent
any abnormal radiolucent or radiodense areas? any air brochograms?
compare R and L hila, normal caliber or enlarged?
are the lung/heart and lung/diaphragm borders clear, or does a silhouette sign exist?
follow the pleural space around the lung periphery. any calcifications, air, or fluid present?
what is a silhouette sign?
the loss of the normal radiographic order between air in the lungs and the soft tissue of either the heart or the diaphragm; localizes a lesion to a specific lobe
when are airway vessels visible on a radiograph?
if the alveoli around them fill up with fluid. the fluid then outlines the vessels and provides contrast
what causes an air bronchogram sign?
due to the air within bronchi surrounded by consolidated lung
infection (pneumonia)
blood (hemorrhage)
serous fluid (pulmonary edema)
if there is a loss of border of the superior mediastinum where is the lesion?
upper lobes
if there is a loss of border of the right heart where is the lesion?
right middle lobe
if there is a loss of border of the left heart where is the lesion?
left upper lobe or lingula
if there is a loss of border of the right hemidiaphragm where is the lesion?
right lower lobe
if there is a loss of border of the left hemidiaphragm where is the lesion?
left lower lobe
what observations should be looked for in a chest x-ray regarding the diaphragm?
normally at the 10th pair of posterior ribs
is the done of the diaphragm abnormally elevated or abnormally flattened?
are the costophrenic angles sharp and downwardly pointed?
normal gastric bubble in the left hemidiaphragm?
scan the abdominal soft tissues for abnormal calcifications, masses, or free peritoneal air
what does the chest x-ray rank first in the diagnostic investigation for all pathologies?
separate cardiac from pulmonary disease
may define the pathology sufficiently to begin treatment
may exclude some differential diagnoses, narrow the diagnostic choices, and thus direct the subsequent imaging evaluation
what are the 4 diagnostic categories assessed on the chest radiograph?
lung field is abnormally white
lung field is abnormally black
mediastinum is abnormally wide
heart is abnormally shaped
what diagnoses fall under “the lung field is abnormally white”?
pneumonia, atelectasis, pleural effusion
how does pneumonia present on a radiograph?
a water density consolidation in one or more lobes
a silhouette sign if the consolidation is in a lobe that borders the heart or diaphragm
air bronchogram signs due to fluid accumulation around the terminal airway vessels
how does atelectasis present on a radiograph?
increased whiteness of the collapsed lobe because it is no longer filled with air
lobes adjacent to the collapsed lobe may appear hyperinflated (darker) to compensate
the mediastinum will shift towards the collapsed lobe due to the loss of volume
the hemidiaphragm will elevate on the collapsed side
how does pleural effusion present on a radiograph?
blunting of the normally sharp costophrenic angles as fluid accumulates in the costophrenic sulcus
blunting of the posterior costophrenic angle seen on the upright lateral radiograph
what diagnoses fall under “the lung field is abnormally black”?
pneumothorax, COPD
what are the two types of pneumothorax?
tension: air accumulates with each breath but can’t escape; mediastinum shift away from the collapsed lung
non-tension: no ongoing accumulation of air, no pressure on the mediastinum
how does COPD present on a radiograph?
radiolucency
ballae
increased vertical height
flat diaphragm
narrowed mediastinum
airspace below the heart
hyperinflation
barrel chest; increased thoracic AP diameter
what diagnoses fall under “the mediastinum is abnormally wide”?
aortic dissection, mediastinal lyphadenopathy
how does aortic dissection present on a radiograph?
widened mediastinum
obliteration of the normal shape of the aortic arch
downward slant of the left mainstem bronchus due to aortic compression
tracheal deviation to the right due to aortic compression
how does mediastinal lymphadenopathy present on a radiograph?
enlargement of the lymph nodes located within the mediastinum
what diagnoses fall under “the heart is abnormally shaped”?
CHF, heart valve disease
left side failure leads to:
congestion of pulmonary vasculature
fluid then backs up into pulmonary veins and lungs
resulting in pulmonary edema
right side failure leads to:
congestion of systemic capillaries
results in dependent peripheral pitting edema
ascites
hepatomegaly
how does CHF present on a radiograph?
cardiomegaly
vascular redistribution (blood vessels in the upper lobes become larger than in the lower lobes)
Kerley B lines (small horizontal white lines that extend to the pleura, caused by fluid accumulated in the interlobular septa as a result of pulmonary edema)
peribronchial cuffing (bronchi seen head on are surrounded by fluid - a sign of pulmonary edema)
pleural effusion
bat-wing or butterfly pattern (the replacement of lower lobe airspace with fluid produces white ling fields, leaving the air-filled upper lobes dark; the bilateral dark areas resemble wings)
what are the two types of problems that affect the heart valves?
stenosis
insufficiency or incompetence
how does mitral valve stenosis present on a radiograph?
straightening or bulging of the left heart border at the atrial appendage where it is normally concave
double line density on the right heart border representing the enlarged left atrium
what is echocardiology? what is it used for?
-non-invasive ultrasound test
-provides specific information on abnormalities in the pattern of blood flow, cardiac output, ejection fractions, function of the valves, thickness and motion of the heart wall and the state of the pericardium
what is the difference between transthoracic (TTE) and transesophageal (TEE) echocardiography?
TTE - standard method: the transducer is placed on the chest and images are taken through the chest wall
TEE - alternative method: the transducer is placed on an endoscope that is inserted into the esophagus
what is a stress echocardiography? what is the primary purpose?
- performed before and after exercise on a treadmill or stationary bike.
- to compare blood flow to heart muscle at rest and again under stress to assess ischemia due to coronary artery disease
what is doppler echocardiography? what does it assess?
- uses doppler principle to measure the velocity and direction of the blood flow within the heart
- assessment of valve function, abnormal communication between the left and right sides of the heart, any leaking at the valves and calculation of cardiac output
what is the implication of the V/Q scan?
to assess the likelihood of pulmonary embolism when contrast or radiation exposure is contraindication
what is nuclear imaging of the heart used for?
to show BF of the heart = assesses coronary artery disease
what are the four possible results of a nuclear stress test?
normal perfusion
reversible defect
nonreversible defect
combination
what is considered normal perfusion?
normal perfusion during rest and exercise means no obstruction of the coronary arteries
what is considered reversible defect?
normal perfusion a rest but decreased perfusion with exercise means some degree of blockage on one or more arteries
what is considered nonreversible defect?
decreased perfusion during both rest and exercise means a complete blockage of one or more arteries
what is considered combination?
combination of reversible and non-reversible defects is common in patients with coronary artery disease, since different degrees of blockages will be present in different arteries
what is CTPA?
computed tomography pulmonary angiography
-alternative to ventilation and perfusion scanning. it is currently the standard of care for the diagnosis of acute pulmonary embolism
what is conventional coronary angiography?
an invasive procedure in which the patient is injected through the femoral or radial artery with a catheter that delivers contrast to the left heart and is imaged by fluoroscopy to visualize the location and severity of blockage
what is cardiac MRI used for?
“gold standard” in assessing blockages by looking at both the structure and function of the heart
successful is studying the aorta, its branches, and renal arteries
the mainstay for cardiac imaging, inexpensive, non-invasive, first order study of heart function
echocardiography
the standard of care for diagnosis of acute pulmonary emboli
computed tomography pulmonary angiography
an invasive procedure performed with contrast and fluoroscopy.
conventional coronary angiography
is a rapidly expanding field and has the benefits of assessing both cardiac structure and function, non-invasively. currently is complementary to echocardiology and nuclear medicine studies
magnetic resonance angiography/ cardiac MRI
