Radiology Flashcards
Which unit of measurement quantifies occupational exposure to electromagnetic radiation?
a. Curie
b. Rad
c. Rem
d. Roentgen
C. Rem
A roentgen is a
unit of radiation exposure
-describe the output intensity of an x-ray machine
A radiation absorbed dose or a RAD is
the quantity of radiation received by an individual
A REM or radiation equivalent man is a
unit of occupational radiation exposure
A Curie is a
quantity of radioactive material
X-rays are a form of ___________________ that penetrate matter at the molecular level
short wavelength, high frequency ionizing radiation
In addition to providing images of internal structures, X-ray exposure can
damage cellular components (RNA, DN), create reactive oxidative species, and predispose a person to cancer
These tissues are at very high sensitivity for radiation damage:
bone marrow, intestinal epithelium, reproductive cells
These tissues are at high sensitivity for radiation damage:
optic lens, thyroid epithelium, mucus membranes
Safety precautions for radiation include
stand at least 3 feet away from the X-ray source and use lead shielding (apron, thyroid shield, goggles)
The only effective barriers against X-rays and gamma rays are
lead and concrete
A roentgen is thought of as
the total dose administered
A Rad is thought of as
the total dose received at the tissue level
A Rem can be thought of as the
“effective dose”
The yearly maximum radiation exposure for adults is
5 rem
The yearly maximum exposure for the fetus of a pregnant work is
0.5 rem or 0.05 rem/month
The features of the X-ray beam required for a radiograph depend on the following three things;
patient’s body weight and habitus
density of body part being examined
orientation of the X-ray beam relative to the patient
The three ways to limit radiation exposure include
distance
duration
shielding
The minimum safe distance from the radiation source is
six feet
Which features will be present in a normal chest X-ray?
a. domed hemidiaphragm
b. heart borders >60% of chest width
C. blunted costophrenic angles
d. left hilum slightly higher than right
A & D
Describe the ABSCDEFGHI pneumonic to systematically review chest X-rays
A= assess film quality & airway
B= bones and soft tissue
C= cardiac
D= diaphragm
E= effusion
F= fields, fissures, and foreign bodies
G= great vessels and gastric bubbles
H= Hila and mediastinum
I= impression
In a normal CXR describe what you should expect of the bones and soft tissue
bones= intact bilaterally
soft tissue= free from air and edema
In a normal CXR describe what you expect of the heart
cardiac size, shape, and aortic knob within normal limits
Hemidiaphragms are part of a normal CXR and appear
domed with the right usually higher than the left
A normal CXR should see an absence of
hilar widening or mediastinal shift
A normal chest XR has ______ costophrenic angles
clear
Describe the pneumonic for image quality of a chest XR
PIER
position
inspiration
exposure
rotation
The best image quality for a chest XR is obtained when
the film is taken with the patient in the upright position
If the chest XR is taken on expiration, the lungs will
appear cloudy and the heart will appear larger than it actually is
On chest XR, inspiration separates _______ which makes these structures easier to see on the CXR
soft tissues and vessels
If the patient has a properly exposed film, you’ll see the
thoracic vertebrae through the heart shadow as well as the pulmonary vasculature
Airway assessment includes evaluating the
trachea, carina, & mainstem bronchi
if the patient has an ETT, you should determine whether it’s placed at the correct depth
Bones should be examined for
symmetry and fractures
widened intercostal spaces may indicate lung overinflation or ipsilateral pneumothorax
Examine the soft tissues for
foreign bodies, swelling, and subcutaneous air
Determining the heart size is performed by evaluating th
cardiothoracic ratio which is the ratio of the width of the heart to the width of the thorax (both at their widest points).
In the PA view, normal cardiac size is
the width of the heart is less than 50% of the width of the thorax
In the AP view, normal cardiac size is
the width of the heart is less than 60% of the width of the thorax
A unilateral depressed or flattened hemidiaphragm is a feature of
tension pneumothorax
Bilateral flattening of the diaphragm is consistent with
COPD or chronic asthma
Blunted costophrenic angles may indicate
pleural effusions
Vessels should branch and taper from the hilum to the periphery where they appear as
nearly invisible
Interstitial pulmonary edema is characterized by
peribronchial cuffing and/or linear patterns (i.e. Kerley lines)
Enlargement of the aortic know may indicate
aortic dissection, valvular insufficiency, PDA, or severe tetralogy of Fallot
The_______ is a radiolucent region under the left hemidiaphragm. It’s a normal finding caused by gas in the fundus of the stomach.
gastric bubble
