lung imaging theory 1

What can be seen

Lung nodules and tumors

 Pneumonia

 Emphysema

 Interstitial Lung Disease

 Pleural effusion

Four distinct tests

CXR, CT scan, MRI, PET scan ultrasound becoming more popular

Radiation Exposure

Background radiation = 3mSv

 CXR radiation = 0.1mSv

Indications for chest x ray

Detect alterations in lung pathology

 Determine appropriate therapy

 Evaluate therapy

 Determine position of tubes and catheters

 Follow disease progression

 Assessing the patient after an invasive procedure

Views

PA (Posterior-anterior) view, Most common and most useful

 AP (Anterior-posterior) view

 Lateral, Lateral decubitus, Apical lordotic, Oblique

Radiopaque

X-ray beam cannot pass as easily through dense objects and

appear white

 Bones, infiltrates, consolidation

Radiolucent

Air cannot stop x-ray beam and appears black

 Air filled organs or cavities like the trachea, mainstem bronchi

Chest X-Ray image

Lateral decubitus Chest X-Ray

Performed while patient is laying on their side

 More sensitive than others for detecting small pleural effusions

Apical lordotic cxr

Used to evaluate upper lung fields

 Lung tumors

 Apical TB

 Picture angle eliminates clavicles obstructing view

 Rarely used

 CT is much better

Oblique cxr

Helpful in evaluating heart size

 Can be taken right and left oblique

 Rarely used due to widespread use of echocardiography

 Patient is positioned facing the film, but rotated

Cardiac Silhouette

Checking size of heart in relation to the space it occupies in the thorax

 The size of the heart should occupy half the space of the total thorax

 When it occupies more it can be a sign of

 Congestive heart failure

Diaphragm

Look for sharp costophrenic angles

 Blunting

 pleural effusion if fluid

 May be able to see a water line

 Flattened diaphragms

 Possible COPD if approximately 90 degrees

 Look at cardiophrenic angles as well

 Left hemi-diaphragm is usually lower than the right

 Why? The liver pushes up the right hemidiaphragm