Imaging Flashcards
What is the traditional projection of a chest x-ray?
PA.
During what portion of breathing should a chest x-ray be taken?
Inspiration.
How can you tell if an x-ray way taken during an inspiration?
- Should be able to count 10 posterior
What 3 pieces of information does a chest x-ray not provide?
- Blood flow
- Ventilation
- Perfusion
Order the following in terms of radiodensity from greatest to least:
- Water
- Fat
- Bone
- Metal
- Air
Metal Bone Water Fat Air
What state of matter does the heart have a similar density to?
Fluid.
What is a silhouette sign?
- Blurring of borders
What lobe is implicated with an obliteration of the superior mediastinum?
Upper lobes
What lobe is implicated in an obliteration of the border of the right heart?
Right middle lobe.
What lobe is implicated in an obliteration of the border of the right hemi-diaphragm?
-Lower right lobe
What lobe is implicated in an obliteration of the border of the left hemi-diaphragm?
- Lower left lobe
What is the upper limit of the cardiothoracic ratio of the adult heart?
- Less than half the width of the chest at the level of diaphragm
What 3 situations can make a heart appear larger than it actually is?
- Taken during expiration
- Pregnancy
- AP projection
What 3 pathologies may cause an actual enlarged heart?
- Cardiomyopathy
- CHF
- Incompetent valves
What 4 structures are contained within the mediastinum?
- Heart
- Vessels
- Trachea
- Esophagus
What is the mediastinum bounded by anteriorly and posteriorly?
- Sternum
- Vertebral bodies
Why are the individual contents of the mediastinum indistinguishable?
- All the same radiodensity
What are the 4 bumps running down the right mediastinum in a CXR from superior in inferior?
- Superior vena cava
- Ascending Aorta
- Right atrium
- Inferior vena cava
What are the 5 bumps running down the left mediastinum in a CXR from superior to inferior?
- Left subclavian vein/ artery
- Aortic arch
- Pulmonary artery
- Left atrium
- Left ventricle
What gives the diaphragm its opacity?
Its underlying structures
Which side of the diaphragm is larger? Why?
Right side is larger due to liver.
What will push the mediastinum to the opposite side?
- Air
- Fluid
What will pull the mediastinum to the same side?
- Removal of lung
- Atelectasis
What 4 things can cause a mass in the mediastinum?
- Goiter
- Lymphoma
- Esophageal/ bronchial cancers
- Aortic aneurysms
What rib level does the dome of the diaphragm typically align with?
- The 10th rib
What 3 factors may cause an elevated diaphragm?
- Excessive fluid in peritoneal space
- Later stages of pregnancy
- Splinting after abdominal surgery
What causes a flattened diaphragm?
- Increased lung volume
What structure is contained in the left hemidiaphragm?
- The stomach
What are the costophrenic angles?
- Area where diaphragm and chest wall meet
- Usually has sharp point
What is the normal costophrenic angle?
- 30 degrees
What can obscure the costophrenic angle?
- Pleural effusion or other pathologies causing fluid to collect in the lungs
Why are lateral chest x-ray views controversial?
- Increased radiation exposure
- Limited clinical information
What 5 structures are visible on a left lateral CXR?
- Pulmonary artery
- Right ventricle
- Trachea
- Aortic arch
- Left ventricle
What are 4 diagnostic categories for a CXR?
- Lung field abnormally white
- Lung field abnormally black
- Mediastinum abnormally wide
- Heart abnormally shaped
What produces the consolidation seen on an x-ray with pneumonia?
- Fluid filling around alveoli and bronchi
What are 3 x-ray findings of pneumonia?
- Consolidation of 1 or more lobes
- Silhouette sign if lobe borders heart or diaphragm
- Opacity of bronchi/ alveoli
What is atelectasis?
Loss of volume of a portion of a lung.
What 3 factors can cause atelectasis?
- Obstruction of bronchi
- Compression
- Traction
When is atelectasis common? Why?
Common post-op due to poor inspiratory effort, and secretion retention.
Does atelectasis respond well to chest PT?
Yes.
How opacities of the collapsed lobe, and the surrounding lobes change in atelectasis?
- Darker surrounding lobes
- White collapsed lobe
To which side does the medistinum shift in atelectasis?
- Toward collapsed lobe
What changes will occur in the diaphragm due to alectasis?
- Hemidiaphragm elevated on collapsed side.
What are 4 types of pleural effusion?
- Serous fluid
- Blood
- Chyle (lymph and free fatty acids)
- Pus
What are the major findings of pleural effusion typically?
- Blunted costophrenic angles
What are 4 x-ray findings of tension pneumothorax?
- Blacker due to absence of lung vasculature
- Visceral lining of lung edge visble
- Deep costophrenic angle (sulcus sign)
- Mediastinum shifts away from collapsed lung
What will be the 6 x-ray findings in a patient with COPD?
- Bullae/ pockets of trapped air
- Increased vertical height of lungs
- Falltened/ scalloping of diaphragm
- Narrowed mediastinum
- Airspace present below heart
- Increased retrosternal space in lateral view
What is an aortic dissection?
- Tear in inner layer of aorta: inner column of blood separates inner and middle layers
Where does an aortic dissection usually occur, and what is it preceded by?
- Ascending aorta
- Aortic aneurysm
How is an aortic dissection typically diagnosed? (3 methods, None of which are x-ray)
- Ct angiography
- MR angiography
- Transesophageal echocardiography
What are the 4 x-ray findings of an aortic dissection?
- Widened mediastinum
- Obliteration of normal shape of aortic arch
- Downward slant of left main stem bronchus
- Tracheal deviation to right due to aortic compression
How does an aortic dissection appear on a CT angiography?
- Aorta has dual chamber appearance
What are the 3 x-ray findings of a patient with CHF?
- Enlarged heart width
- Pleural effusion (obscured costophrenic angles)
- Bat wing pattern
Describe a bat wing pattern.
- Fluid replaced air in lower lobes
- Upper lobes become especially dark in the shape of bat wings
What are the 3 radiographic findings in mitral valve stenosis?
- Straightening/ buldging of left heart border
- Double line density on right heart due to left atrium aligning with right atrium
- Upper lobe veins become very prominent
What 7 findings can ultrasound help provide information about that chest x-rays cannot?
- Blood flow
- Cardiac output
- Ejection fractions
- Valvular function
- Thickness/ movement of heart wall
- Presence/ severity of CAD
- State of pericardium
What are the 5 types of cardiac ultrasound?
- Trans thoracic echo (TTE)
- Transesophageal echo (TEE)
- Stress echocardiography
- Doppler echo
- 3D echo
Where is the transducer placed in a TTE?
- Chest wall
Where is the transducer placed in a TEE?
- Passed into esophagus
What is an advantage and a disadvantage of an TEE over a TTE?
- Clearer pictures
- Patient must fast/ be sedated
What is the purpose of a stress echocardiography?
- Compares blood flow at rest and under stress
- Compares pre and post exercise (bike or treadmill)
What is the purpose of a doppler echo?
- Measures velocity and direction of blood flow in the heart
What 4 functions does a doppler echo measure?
- Valve function
- Abnormal communication between left and right heart
- Leaky valves
- CO
What is the purpose of a 3D echo?
More precise measurements
What a commonly used nuclear medicine scan?
V/Q scan
What 3 pathologies are typically measured in a V/Q scan?
- PE
- Lung function in COPD
- Pre/post lung lobectomy to determine performance
How is the V measured in a V/Q scan?
- Patient inhales radioactive xenon gas`
How is the Q measured in a V/Q scan?
- Radioisotope injected through IV
How is a PE diagnosed using a V/Q scan?
- Normal ventilation with abnormal perfusion
Describe the 5 step process of a nuclear perfusion study of the coronary arteries.
- Radioisotope tracer given via IV
- HR increased by exercise or drugs
- Photos taken at rest, after exercise and a few hours later
- Assess obstruction of coronary arteries
What are the 4 possible outcomes of the nuclear perfusion test, and what are their implications?
- Unobstructed flow: NORMAL
- Normal at rest; Decreased during exercise: REVERSIBLE
- Decreased at rest and with exercise: Block of one or more coronary arteries: NON-REVERSIBLE. Permanent damage to heart tissue
- Reversible and non-reversible aspects
What does a MUGA scan evaluate?
- The function of the ventricles
What is a MUGA scan?
- Multigated acquisition
How is a MUGA scan carried out?
- Isotope injected
- Images taken from EDV to ESV
In what type of patients are MUGA scans often carried out?
- Chemo patients to montior impact on heart
What is being evaluated in angiograms?
The presence of obstructions or aneurysms
What is the 2 step process of a normal angiogram?
- Iodine based contrast delivered to heart
- Image viewed through fluoroscopy
How is the contrast injected into the heart in an angiogram?
- Catheter threaded through femoral vein into heart
Which side of the heart is the contrast injected into in a coronary angiography?
- Left heart
Which side of the heart is the contrast injected into in a pulmonary angiography to assess the presence of PE?
- Right heart
What is ventriculography?
Angiography that visualizes motion of the ventricular walls
Which types of angiography studies are free from risk?
None. All are invasive and have risk
What is a more effective imaging technique for PE than a V/Q scan?
- Computed tomography pulmonary angiography
What is the non-invasive form of angiography?
Magnetic resonance angiography
What is a bronchoscopy?
- Visualization of proximal airways through bronchoscope inserted into trachea from mouth
What is often collected using a bronchoscopy?
Lung tissue for biopsy
What 4 characteristics are measured in a sputum test?
- Color
- Consistency
- Smell
- Pathogens
