Chest Radiographs Flashcards
What is a PA view and where do the X-rays travel from?
Posteroanterior
Beam travels from posterior to anterior (back to front)
What is a AP view and where do the X-rays travel from?
Anteroposterio
Beam travels from anterior to posterior (front to back)
Where do the X-rays travel from in a lateral view?
From side to side
What is the most common X-ray views?
PA
Lateral
When would you do an AP view?
If pt isn’t stable enough to travel to X-ray room (done in room)
Which view is greater, AP or PA and where is the heart when taking these images?
AP view is greater
AP: heart = futheraway from plate
PA: heart = closer to film plate
What happens to the heart in an AP view?
Enlarges
**Don’t diagnose cardiomegaly from Ap view
What determines how much of x-ray beam is absorbed?
Density of the object
What happens to the x-rays as the density of the object increases?
Fewer X-rays pass through the object –> lightens (bone)
What will Air look like on an X-ray?
Black
What does Fat look like on an X-ray?
Black
What does Water look like on an X-ray?
Gray
What do Organs, Muscle, Soft Tissues look like on an X-ray?
Gray
What does Metal and Bone look like on an X-ray?
White
What is conventional radiography?
Image recorded on film has to be developed (not done anymore)
What is computed/digital radiography?
Process of producing digital radiographic image
What is the correct positioning on the view box to view an X-ray?
R displayed on the radiograph should ALWAYS be opposite to the viewers left side
What is the correct way to view a chest radiograph?
Make sure to glance for obvious abnormalities @ all 4 corners of the image
What are the routine views for the chest?
PA
Lateral view
What is the equivalent radiation of a chest X-ray?
10 days exposure to environmental background radiation
What is the equivalent radiation for a CT scan?
3 years exposure to environmental background radiation
What are the important anatomical structures to be included in an X-ray view?
First Ribs
Costophrenic Angles
Lateral Edges of the Ribs
What should you have your patient do as you’re taking an X-ray image?
Take in a full breath volume –> diaphragm should be down @ 5 - 7 rib (so you can see the whole lung)
Describe the methodical approach to view a PA chest radiograph
Start @ the top
Follow trachea inferiorly (should be midline) –> cardiac shadow
Evaluate cardiac shape
Divide lungs into horizontal thirds and compare R/L lung fields for symmetry
Evaluate the sharply demarcated domed diaphragms
Determine location of gastric air bubble
What does a deviation of the trachea imply on a radiograph?
Mass effect –> thyroid enlargement (usually)
What is the cardiothoracic ratio in a PA view?
Transverse diameter of the cardiac shadow shouldn’t exceed 50% of the transverse diameter of thoracic cage (PA VIEW ONLY!)
Which hemidiaphragm (1/2 of the diaphragm) should be higher on a radiograph?
Right side b/c of the liver
What should the costodiaphragmatic angles look like?
Sharp
Form actue angle where diaphragm insert laterally into the walls
Where should you find the gastric air bubble?
Immediately underneath the left hemidiaphragm on an upright image
Which side is the patient usually facing when taking a lateral chest radiograph?
Left
Describe the methodical approach to viewing the lateral chest radiograph
Casually view entire image looking for obvious abnormalities
Estimate the size/shape of the cardiac shadow
Observe sternum/retrosternal/retrocardiac spaces
Observe contours of the diaphragms and costodiaphragmatic angles
Which disease can you usually get a good view on a lateral chest radiograph?
Pneumonia
When would you do a anteroposterior lordotic chest radiograph?
Routine imaging shows equivocal/ill defined lesion w/in the upper lobes that need further characterization
What is a lordotic radiograph?
Frontal AP image w/ pt leaning back
What are you looking at in a lordotic radiograph?
Apices of the lung
Displaces clavicles above thoracic inlet –> better visual evaluation of the apices of lungs
How do you get a decubitus chest radiograph?
Place pt on his/her side and take Ap image
When would you take a decubitus chest radiograph?
When standard imaging suggest pleural effusion and needs to be confirmed and quantified
Why should you take an X-ray when placing an NG tube?
Make sure you’ve got it in the stomach
When would you do CT chromatography?
Recommended when you have abnormal findings on standard x-rays that need further investigation
What is a CT scan?
Detailed 3D model of organs made from x-rays (+/-) dye
