Diagnostic Imaging Exam UPDATED
ACTUAL Exam Questions and CORRECT
Answers
Conventional Radiology - CORRECT ANSWER - •Utilizes ionizing radiation from X-ray
equipment
1. Plain radiographs
2. Computed tomography
3. Contrast-enhanced radiographs/CT
X-ray - CORRECT ANSWER - A discrete bundle of electromagnetic energy
- also known as a photon
X-ray beam - CORRECT ANSWER - A swarm of photons traveling at the speed of
light
Electromagnetic radiation production (X-ray Machine) - CORRECT ANSWER - •Via
acceleration/deceleration of electrons
In an x-ray tube:
•Electrons boiled off from a hot filament accelerate toward a tungsten anode with massive
amounts of kinetic energy
•Most of the electrons collide with other
negative electrons and create heat; wasteful by-product of this
•Small fraction of these electrons encounter the highly positive nucleus and are accelerated
significantly
•Result is an x-ray photon
Radiolucent - CORRECT ANSWER - •Refers to structures that are less dense and permit
the x-ray beam to pass through them.
,•Black structures in the image
•Air/gas; water has an attenuation similar to water because soft tissue is composed of water
Radiopaque - CORRECT ANSWER - •Refers to structures that are dense and resist the
passage of x-rays
•White structures in the image, calcification deposits
(ex: bone and metal screws)
What projection do we use to check for fat pads? - CORRECT ANSWER - The lateral
projection.
•If an effusion is present, it distends the capsule, displacing the fat pads away from the bone.
This provides evidence of a significant injury.
Displaced anterior fat pad - CORRECT ANSWER - - "Sail sign"
- Abnormal
A visible posterior fat pad is ALWAYS - CORRECT ANSWER - - Abnormal
•It denotes a very large effusion—usually a considerable volume of blood in the joint.
•Make sure that you are evaluating for fractures if the fat pad is displaced (the bones do NOT tell
the whole story)
What does a visible posterior fat pad denote? - CORRECT ANSWER - A very large
effusion—usually a considerable volume of blood in the joint.
If a fat pad is displaced, make sure to - CORRECT ANSWER - Evaluate for fractures
Are all joint effusions associated with a fracture? - CORRECT ANSWER - No.
An effusion indicates that a significant injury has occurred, even if a fracture is not seen.
Whenever either fat pad is displaced but no fracture identified, the arm needs to be placed in a
, collar and cuff until orthopedic assessment a few days later. Some of these patients will have
sustained a non-displaced fracture
Absence of a visible fat pad does not exclude a - CORRECT ANSWER - Fracture
Ex: The radial neck is usually extracapsular, and a fracture of the neck may not produce a joint
effusion/hemarthrosis or displace the fat pads.
Standard practice is to obtain at least how many X-ray projections? - CORRECT
ANSWER - 2, usually at right angles to each other
At sites where fractures are known to be exceptionally difficult to detect (ie scaphoid fracture), it
is routine practice to obtain more than how many views? - CORRECT ANSWER - Two
How many X-ray views do we obtain for a scaphoid fracture? - CORRECT ANSWER -
More than 2 because this kind of fracture is exceptionally difficult to detect.
What position must a patient be in to notice the fat-fluid level in the knee? - CORRECT
ANSWER - •Can only be seen on horizontal view
•Allows for the fluid to displace the fat pad upward
Small pneumothorax on a chest X-ray when standing - CORRECT ANSWER - Usually
detectable at the apex of the lung; air rises
Small pneumothorax on CXR when supine - CORRECT ANSWER - Much lower - around
the heart, diaphragm, and at costophrenic angle; know not to look at apices since the patient was
lying down
Detection of a fracture, and the components of a complex injury, depends on adherence to three
cardinal rules: - CORRECT ANSWER - 1. Rule 1
•Always analyze all views: even if you found something abnormal in one, look at ALL of them.
2. Rule 2
ACTUAL Exam Questions and CORRECT
Answers
Conventional Radiology - CORRECT ANSWER - •Utilizes ionizing radiation from X-ray
equipment
1. Plain radiographs
2. Computed tomography
3. Contrast-enhanced radiographs/CT
X-ray - CORRECT ANSWER - A discrete bundle of electromagnetic energy
- also known as a photon
X-ray beam - CORRECT ANSWER - A swarm of photons traveling at the speed of
light
Electromagnetic radiation production (X-ray Machine) - CORRECT ANSWER - •Via
acceleration/deceleration of electrons
In an x-ray tube:
•Electrons boiled off from a hot filament accelerate toward a tungsten anode with massive
amounts of kinetic energy
•Most of the electrons collide with other
negative electrons and create heat; wasteful by-product of this
•Small fraction of these electrons encounter the highly positive nucleus and are accelerated
significantly
•Result is an x-ray photon
Radiolucent - CORRECT ANSWER - •Refers to structures that are less dense and permit
the x-ray beam to pass through them.
,•Black structures in the image
•Air/gas; water has an attenuation similar to water because soft tissue is composed of water
Radiopaque - CORRECT ANSWER - •Refers to structures that are dense and resist the
passage of x-rays
•White structures in the image, calcification deposits
(ex: bone and metal screws)
What projection do we use to check for fat pads? - CORRECT ANSWER - The lateral
projection.
•If an effusion is present, it distends the capsule, displacing the fat pads away from the bone.
This provides evidence of a significant injury.
Displaced anterior fat pad - CORRECT ANSWER - - "Sail sign"
- Abnormal
A visible posterior fat pad is ALWAYS - CORRECT ANSWER - - Abnormal
•It denotes a very large effusion—usually a considerable volume of blood in the joint.
•Make sure that you are evaluating for fractures if the fat pad is displaced (the bones do NOT tell
the whole story)
What does a visible posterior fat pad denote? - CORRECT ANSWER - A very large
effusion—usually a considerable volume of blood in the joint.
If a fat pad is displaced, make sure to - CORRECT ANSWER - Evaluate for fractures
Are all joint effusions associated with a fracture? - CORRECT ANSWER - No.
An effusion indicates that a significant injury has occurred, even if a fracture is not seen.
Whenever either fat pad is displaced but no fracture identified, the arm needs to be placed in a
, collar and cuff until orthopedic assessment a few days later. Some of these patients will have
sustained a non-displaced fracture
Absence of a visible fat pad does not exclude a - CORRECT ANSWER - Fracture
Ex: The radial neck is usually extracapsular, and a fracture of the neck may not produce a joint
effusion/hemarthrosis or displace the fat pads.
Standard practice is to obtain at least how many X-ray projections? - CORRECT
ANSWER - 2, usually at right angles to each other
At sites where fractures are known to be exceptionally difficult to detect (ie scaphoid fracture), it
is routine practice to obtain more than how many views? - CORRECT ANSWER - Two
How many X-ray views do we obtain for a scaphoid fracture? - CORRECT ANSWER -
More than 2 because this kind of fracture is exceptionally difficult to detect.
What position must a patient be in to notice the fat-fluid level in the knee? - CORRECT
ANSWER - •Can only be seen on horizontal view
•Allows for the fluid to displace the fat pad upward
Small pneumothorax on a chest X-ray when standing - CORRECT ANSWER - Usually
detectable at the apex of the lung; air rises
Small pneumothorax on CXR when supine - CORRECT ANSWER - Much lower - around
the heart, diaphragm, and at costophrenic angle; know not to look at apices since the patient was
lying down
Detection of a fracture, and the components of a complex injury, depends on adherence to three
cardinal rules: - CORRECT ANSWER - 1. Rule 1
•Always analyze all views: even if you found something abnormal in one, look at ALL of them.
2. Rule 2
