CT final exam study guide
What three limitations of conventional radiography lead to the invention of tomography -
answer1. superimposed anatomic structures on the two-dimensional film image
2. not quantitative
3. inferior contrast resolution
__ uses motion of the x-ray tube and the image receptor to blur out structures above
and below the anatomic structure or region of interest - answer tomography
computed tomography overcomes the limitations in detail and clarity found in
radiography and tomography by using ___- - answer image reconstruction from
projection (computers)
emission ct is different from transmission ct in that (3 ways) - answer1. it views the
function of the body instead of anatomy
2. it receives emissions from radioactive agents that have been introduced into the
patient's body
3. it uses a gamma camera/coicidence detector instead of x-ray tubes
what type of ct scanner is used to view the pateint's anatomy, uses an xray tube that
travels around the patient in gantry and pulses on and off and transmitted xrays are
detected. the computer reconstructs the data to produce cross-sectional images of the
body and image reconstructions - answertransmission ct
the current and most appropriate term for the modality discussed in this course is -
answercomputed tomography (ct
what order does the CT process - answer1. image process
2. image display, manipulation, storage, recording, and communication
3. data acquisition
an example of emission ct is - answerSPECT
the first clinically useful CT scanner was produced by - answersir dr. godfrey hounsfield
what generation has a pencil beam and a single detector - answerfirst
which type of ct has two sources (beams) - answerdual source
the different "advancements" in the methods of scanning in CT units over the years are
referred to as - answergenerations
,most ct unites used today are variation of what type of generation - answerthird
a technique in which a volume of tissue is scanned by moving the patient continuously
through the gantry of the scanner while the x-ray tube and detectors rotate continuously
for several rotations is known as - answerspiral, helical, and volume scanning
what are the 4 benefits of ct over radiography? - answer1. ability to manipulate
attentuation data
2. ability to create multi-planar recontructions (MPRs)
3. ct has increased contrast resolution
4. anatomic structures are visualized withouth superinposition
HL7 - answercommunication protocol for text
DICOM - answercommunication protocol for images
RAM - answertemporary storage for programming and operating instructions
bit - answerbinary digit
bus - answerconductors that connect CPU to other parts of the computer
CPU - answer"heart of the computer" that directs information to and from various parts
of the computer
byte - answer8 bits
HIS - answerinformation system used in hospital for all patient information, EMR,
address biling, medical records, etc.
RIS - answerinformation system used radiology department for obtaining patient
information, charging, supplies, etc.
u - answerattenuation coefficient
what are the 3 examples of an input hardware device - answer1. capiler measurement
tool in sonography
2. RIO measurement in CT
3. touch screen monitor at the control panel
what is a device that changes discrete data to continuous information - answerdigital to
analog converter
an image displayed on a monitor is known as a __ display - answersoft copy
, a device that changes continuous data to discrete data is known as - answeranalog to
digital converter
a network of computers in a hospital, building, or in a similar location is known as -
answerlocal area network (LAN)
you have an external hard drive that can hold two tera-bytes of data. how many bits
does it hold? - answer16,000,000,000,000 (8x2) tera=trillions=12
what has the best number of gray level color output for analog to digital converter -
answer3 bits (the most bits)
secondary storage refers to - answermagnetic tapes, magenetic disks, opital disks
secondary storage does not refer to - answerread only memory (ROM)
the electrical signal that leaves the detector is __ information - answeranalog
a mathematical formula that changes that data is known as an - answeralgorithm
which ct components are found inside the ct gantry (3) - answerx-ray tube, detector
array, collimators
how does bone appear on a ct image - answerit depends on the window width and level
as compared to a standard ct image, an image with smaller pixels will have -
answerincreased spatial resoluation
based on the Hounsfield scale, if the u of CSF is 3.206 and the u of fat is 0.185, what is
the number of water - answer0
if the FOV is 15cm in diameter and the matrix size is 512 x 512, what is the size of the
pixel (pixel size is measured in mm!) - answer.29mmx.29mm
(convert all numbers to mm)
(150x150)/(512x512)
the FOV is 400x400mm the matrix size is 200 x 200, and the pixel size is 2mm, what
would happen to the size of the pixel if the matrix size is increased while the FOV
remains the same - answerthe pixel will be smaller
the formula I=Ie^(-ux) i sused in ct scanning to determine - answerthe linear attenuation
coefficient
What three limitations of conventional radiography lead to the invention of tomography -
answer1. superimposed anatomic structures on the two-dimensional film image
2. not quantitative
3. inferior contrast resolution
__ uses motion of the x-ray tube and the image receptor to blur out structures above
and below the anatomic structure or region of interest - answer tomography
computed tomography overcomes the limitations in detail and clarity found in
radiography and tomography by using ___- - answer image reconstruction from
projection (computers)
emission ct is different from transmission ct in that (3 ways) - answer1. it views the
function of the body instead of anatomy
2. it receives emissions from radioactive agents that have been introduced into the
patient's body
3. it uses a gamma camera/coicidence detector instead of x-ray tubes
what type of ct scanner is used to view the pateint's anatomy, uses an xray tube that
travels around the patient in gantry and pulses on and off and transmitted xrays are
detected. the computer reconstructs the data to produce cross-sectional images of the
body and image reconstructions - answertransmission ct
the current and most appropriate term for the modality discussed in this course is -
answercomputed tomography (ct
what order does the CT process - answer1. image process
2. image display, manipulation, storage, recording, and communication
3. data acquisition
an example of emission ct is - answerSPECT
the first clinically useful CT scanner was produced by - answersir dr. godfrey hounsfield
what generation has a pencil beam and a single detector - answerfirst
which type of ct has two sources (beams) - answerdual source
the different "advancements" in the methods of scanning in CT units over the years are
referred to as - answergenerations
,most ct unites used today are variation of what type of generation - answerthird
a technique in which a volume of tissue is scanned by moving the patient continuously
through the gantry of the scanner while the x-ray tube and detectors rotate continuously
for several rotations is known as - answerspiral, helical, and volume scanning
what are the 4 benefits of ct over radiography? - answer1. ability to manipulate
attentuation data
2. ability to create multi-planar recontructions (MPRs)
3. ct has increased contrast resolution
4. anatomic structures are visualized withouth superinposition
HL7 - answercommunication protocol for text
DICOM - answercommunication protocol for images
RAM - answertemporary storage for programming and operating instructions
bit - answerbinary digit
bus - answerconductors that connect CPU to other parts of the computer
CPU - answer"heart of the computer" that directs information to and from various parts
of the computer
byte - answer8 bits
HIS - answerinformation system used in hospital for all patient information, EMR,
address biling, medical records, etc.
RIS - answerinformation system used radiology department for obtaining patient
information, charging, supplies, etc.
u - answerattenuation coefficient
what are the 3 examples of an input hardware device - answer1. capiler measurement
tool in sonography
2. RIO measurement in CT
3. touch screen monitor at the control panel
what is a device that changes discrete data to continuous information - answerdigital to
analog converter
an image displayed on a monitor is known as a __ display - answersoft copy
, a device that changes continuous data to discrete data is known as - answeranalog to
digital converter
a network of computers in a hospital, building, or in a similar location is known as -
answerlocal area network (LAN)
you have an external hard drive that can hold two tera-bytes of data. how many bits
does it hold? - answer16,000,000,000,000 (8x2) tera=trillions=12
what has the best number of gray level color output for analog to digital converter -
answer3 bits (the most bits)
secondary storage refers to - answermagnetic tapes, magenetic disks, opital disks
secondary storage does not refer to - answerread only memory (ROM)
the electrical signal that leaves the detector is __ information - answeranalog
a mathematical formula that changes that data is known as an - answeralgorithm
which ct components are found inside the ct gantry (3) - answerx-ray tube, detector
array, collimators
how does bone appear on a ct image - answerit depends on the window width and level
as compared to a standard ct image, an image with smaller pixels will have -
answerincreased spatial resoluation
based on the Hounsfield scale, if the u of CSF is 3.206 and the u of fat is 0.185, what is
the number of water - answer0
if the FOV is 15cm in diameter and the matrix size is 512 x 512, what is the size of the
pixel (pixel size is measured in mm!) - answer.29mmx.29mm
(convert all numbers to mm)
(150x150)/(512x512)
the FOV is 400x400mm the matrix size is 200 x 200, and the pixel size is 2mm, what
would happen to the size of the pixel if the matrix size is increased while the FOV
remains the same - answerthe pixel will be smaller
the formula I=Ie^(-ux) i sused in ct scanning to determine - answerthe linear attenuation
coefficient
