FDI quizzes
What is the definition of energy?
Ability to do work
What specific scans are for CT?
Bone, soft tissue, lung
What is the primary drawback of utilizing computed tomography (CT) imaging in the clinical setting?
CT utilizes ionizing radiation to acquire an image and therefore exposes the patient to harmful radiation.
What is the most common form of a stochastic effect?
Cancer
_____ produces an image that reflects the densities of patient's anatomy.
Computed tomography (CT)
What was the device Roentgen was using when he discovered x-rays?
Crookes tube
What color does cortical bone appear on a magnetic resonance imaging (MR)?
Dark
What modality is used for ultrasound?
Echoic
Magnetic resonance imaging (MR) uses x-ray photons to produce the images. True or false
False
The primary purpose of MRI is to produce a study of anatomic density. True or false
False
X-ray beam attenuation increases with higher-energy x-ray beams compared to lower-energy x-ray beams. True or false
False
What type of electromagnetic radiation is used to produce the images in nuclear bone scans (scintigraphy)?
Gamma rays
How is an area of increased radionucleotide uptake described in a nuclear scan?
Hot spot
What atom is most commonly used in magnetic resonance imaging (MR) to produce an image?
Hydrogen
What areas normally show increased uptake on bone scans/scintigraphy and is not considered pathologic?
Kidneys Bladder Injection site Sacroiliac joints
Which imaging modality delivers no radiation dose to the patient?
MRI, ultrasound
Can x-ray be focused by a lens?
No
Which imaging modality primarily evaluates tissue physiology?
Nuclear Medicine
An area of anatomy that is easily penetrated by x-ray photons producing a dark area on the film is called ______.
Radiolucent
What specific scans are for MRI?
T1, T2, STIR
What image sequence would have a TR of 1200 ms and TE of 120 ms?
T2
Which radiotracer is used in a bone scan?
Technetium-99m
What is the primary drawback to the use of MRI in the clinical setting?
The exam is very expensive, which may limit patient access
Which factors can attenuate the X-ray beam?
Tissue thickness tissue density atomic number
Bone attenuates more of x-ray beam than fat. True or false
True
Bone scans (scintigraphy) can detect as little as 5-10% increased bone turnover. Therefore bone scans are said to be very sensitive in detecting osteoblastic activity. However, because normal physiologic osteoblastic activity (areas of much biomechanical stress) and osteoblastic pathologies (ex. bone metastasis) but show as hot spots, this study is said to be fairly unspecific in diagnotic yield. True or false
True
Computed tomography (CT) is acquired in the axial plane as the X-ray tube spirals around the patient in the gantry. The computer can reformat the data and create sagittal, coronal, and 3-Dimensional models. True or false
True
On a computed tomography scan (CT), cortical bone appears what color?
White
Who discovered x-rays?
Wilhelm Conrad Roentgen
What modality is used for CT?
attenuation
What was the phosphor Roentgen used is early experiments with x-rays?
barium platinocyanide
What two imaging properties contribute to visibility of the x-ray image?
brightness or density
X-rays are classified as a specific type of energy termed ________ _________.
electromagnetic radiation
The number of waves passing a given point per given unit of time defines _____ and is represented by the Greek letter ________
frequency; nu
Rank these electromagnetic energies in order from most to least energetic.
gamma/ x-rays/ visible light/ microwaves
A film image with a few visible densities but great differences among them is said to have ______ ________.
high contrast
Material with a ________ object density will typically produce areas of ____________ optical density.
high, low
What modality is used for PET scans?
hot spots/cold spots
As the frequency of electromagnetic radiation decreases, wavelength will ___________.
increase
What modality is used for MRI?
intensity
Wavelength and frequency are _________ related.
inversely
What percentage of the primary x-ray beam interacting with an anatomic part actually reaches the image receptor (the film)?
less than 5%
What modality is used for x-ray
opaque/lucent
A ____________ is a small, discrete bundle of electromagnetic energy.
photon
The sound waves used in ultrasonography are produced by the __________________ effect.
piezoelectric
The x-ray beam used in diagnostic imaging can be described as being ____________.
polyenergetic
X-rays travel in straight lines True or false
true
The distance between two successive crests or troughs of a wave defines ________ and is represented the Greek letter ________
wavelength; lambda
