Respiratory: The Chest Xray Flashcards
How does an xray work?
Xrays are passed through the body and absorbed to different degrees by different tissues - dense tissues appear white
What are the types of projection and when are they used?
PA projection normally used - involves pt standing and bean travels from posterior to anterior
AP projection used if the pt cant stand - important to know because AP magnifies the heart so cant comment on heart size
What does a chest xray need to include?
1st rib, lateral margin of ribs and costophrenic angle
How can you see if the xray is rotated?
Look at the medial ends of the clavicles, should be able to see the spinous process between. Ignore if slightly rotated
How would you assess lung volumes on an xray?
Xray should be taken when pt inspires and holds breath. If there is hyperinflation the diaphragm will be flattened
What is penetration and how do you assess it?
Penetration is the degree to which the xrays have passed through the body.
The penetration is accurate is adequate if the vertebrae are just visible through the heart and the complete left hemidiaphragm is visible
What are you looking for when assessing the costophrenic angles?
They should be sharp and pointy
If they are rounded it shows there is pleural effusion
What is the systematic ABC approach of evaluating a chest xray?
Begin by checking pt demographics, checking projection and adequacy (RIP rotation, inspiration, penetration)
A - airway, look for deviated trachea
B - breathing, lungs
C - circulation, heart and aortic knuckle
D - diaphragm and dem bones, look at costophrenic angles and for any fractures, bubbles of gas
What are the causes of mediastinal shift away from the affected side?
Tension pneumothorax
Massive pleural effusion
What are the causes of mediastinal shift towards the affected side?
Fibrosis
Lung collapse
What are some causes of a lobar collapse?
Blockage of the lumen by aspirated foreign material, mucous plugging
Bronchogenic carcinoma or compression by adjacent mass
What could a space occupying lesion be?
Malignancy - primary or metastasis
A benign mass
Inflammation
How to calculate the cardiac index?
Heart should be less than 50% the width of the thoracic cavity - can only be measure on a PA image
