Unit 6 (Computed Tomography)

when was CT first introduced?

who received the Nobel Peace Prize for inventing CT and when?

_____________ demonstrated the first CT scanner in _______. He was using ______________'s mathematic formulas  that were developed in __________.

who first demonstrated that images could be created through mathematical projections and when?

the movable frame of the CT unit that contains the x-ray tube and detectors:

the part of the CT unit that delivers x-ray around the patient:

the part of the CT unit that receives the x-rays that are attenuated by the patient to acquire data to be sent to the CPU:

name seven main parts that make up the modern CT unit:

the part of the CT unit that processes data received at the detectors:

the part of the CT unit that shows post processed data:

the part of the CT units that can store massive amounts of data to be used to visualize images through various dimensions:

what is the size range of the gantry aperture in CT?

describe the first generation CT unit:

describe the second generation CT unit:

describe the third generation CT unit:

describe the fourth generation CT unit:

describe the fifth generation CT unit:

describe the sixth generation CT unit:

describe the seventh generation CT unit:

what generation CT unit does each image represent?

if you increase the pitch, what happens to the amount of tissue being scanned?

if you increase the pitch, what happens to the scan time?

if you increase the pitch, what happens to slice thickness?

smaller fields yield ___________ resolution.

give the typical scan field sizes for head & spine, small bodies, and large bodies:

what two things help determine the resolution on a helical multi section CT?

give all the versions of the name of the seventh generation CT unit:

what type of CT unit can be found at Holy Cross Hospital in Fort Lauderdale, Florida?

what type of CT unit can be found at Le Bonheur in Memphis, Tennessee?

what type of CT unit can be found at John Hopkins?

describe the shape and composition of the CT table:

with the x-ray tube, rapid sequential loading requires a design with:

give some technical aspects to the x-ray tube of a CT unit:

if taking a scan of a child or infant, would you raise or lower the kVp to reduce pt dose?

for a CT x-ray tube, ___________ exposures in a month is not uncommon. Nor is it unusual for tubes to fail after _______________.

double collimation controls:

the actual production of a CT image of a cross-sectional slice of anatomy begins with the ___________ and ends with a _______________ that represents the attenuation characteristics of the anatomy being imaged.

between the x-ray tube and the matrix of CT numbers are the (6):

give some general characteristics of the CT x-ray tube:

the high-frequency generator allows the production of an x-ray beam with ________________ energy levels, due to its ____________________.

describe the filter commonly used for a CT unit:

name the two sets of collimators used in CT:

where is the prepatient collimator located and what is its function?

where is the predetector collimator located and what is its function?

the _______________ is the physical component consisting of multiple detectors that efficiently absorbs the ______________ and accurately converts it to _______________.

name desirable traits in detectors:

name the three elements of detector dose efficiency:

what are the detectors composed of?

absorb the transmitted radiation and produce a proportional flash of light:

a solid-state device that converts the light to a proportional electrical signal:

A 64-slice CT Scanner has a detector array of ______ rows of _______ detectors.

the electrical signal produced by the detector-photodiode goes immediately to the ____________, which amplifies this weak signal, converts it to a ______________  (converts it from analog to digital data) and sends it to the _____________.

the ______________ of the measured electrical signal is critical in CT.

logarithmic conversion produces attenuation information from the:

a measure of the probability that the x-ray beam will interact with the material it is in while traveling in a straight path:

name two factors that can influence the linear attenuation coefficient:

the logarithmic data goes through ___________ before reaching the computer for image reconstruction.

give two matrix sizes common to CT:

the __________________ consists of the computer analyzing raw data sent from the ________________ and reconstructing it into a digital array of ______________ based on the image matrix.

the logarithmic data from the linear attenuation coefficient that is converted from analog to digital information by the ADC and sent to the computer:

help the massive amounts of data and calculations needed to reconstruct the image:

with a _____________________: using a computer or electronic filter, the computer analyzes all the data for one slice of the area being imaged to determine the _________________ which is then converted to a ____________.

determined for each voxel when the computer analyzes all the data for one slice of area being imaged:

begins with the x-ray tube and ends with a matrix of CT numbers:

how is the Hounsfield Unit/CT number calculated?

the CT number of water is set at:

the CT number of bone is:

the CT number of air is:

list items as they appear according to their CT number:

name some of the imaging controls that the technologist must use in CT:

name some responsibilities of the CT technologist:

be familiar with the items that the imaging controls and data storage have protocols for:

be familiar with the multiple options of post processing:

name a way to magnify in post processing:

reformatting differs from reconstruction in that:

Multiplanar reformation (MPR) is used to display:

windowing involves using WW and WL to adjust:

in CT there is a WW of _________ and a WL of ________.

in post processing, CT numbers range from:

in post processing CT numbers, pixels _____________ are black and pixels ____________ are white.

in CT post processing, decreasing WW will:

in CT post processing, increasing WL will:

name four basic things that affect image quality in CT:

an impediment of image quality that, in CT, typically results from statistical fluctuation recorded by the detectors

affects the low contrast resolving ability of the CT unit:

what type of relationship do noise and SNR have?

name four basic artifacts that affect image quality in CT:

be familiar with these artifact types:

name some routine quality control procedures:

test objects are used in quality control to monitor:

today, CT accounts for approximately ________ of the U.S. population’s radiation exposure resulting from medical procedures.

to minimize exposure to patients the ___________ should be reduced while the _________ should be increased.

what type of shielding is available and for what specific parts is this shielding mentioned?

name some technical amounts the pulsed beam CT unit uses: