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8 Cards in this Set
- Front
- Back
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What is Gated CT?
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Gated Ct is a technique in which the heartbeat is synchronized with the scan views using information from the ECG, in an attempt to reduce motion.
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How much faster is EBCT than conventional CT? What was the main reason it was developed?
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Up to 10 times faster, Short acquisitions of 0.1 seconds or less are obtainable with EBCT
For imaging of the heart |
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What is the overall goal of EBCT?
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To produce high-resolution images of moving organs that are free of artifact caused by motion.
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What are the design differences in conventional CT from EBCT?
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1. There is no xray beam used in EBCT, it is based on electron beam
2.There is no mechanical motion in EBCT 3. The acquisition geometry is significantly different than Conventional CT |
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What is the basic configuration of EBCT?
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At one end there is an 130kV electron gun, the beam is focused at a specific angle by an electromagnetic coil to strike one of the four adjacent tungsten target rings, those stationary rings span an arc of 210 degress, the electron beam is steered along the rings, when the electro beam collides with the targets, xrays are produced, collimators shape the xrays into a fan beam, the solid state detector array made up of luminecent crystal and cadmium tungstate consists of 2 rings, one holds 864 detectors the other 432.
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What the modes of operation that the EBCT can operate in?
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Single Slice (SS)-where one of the four tungsten targets rings using collimation will yield 1.5mm-10mm scan widths
Multislice (MS)-uses all four tungsten target rings along with 2 detector arrays to generate2,4,6 or 8 scans with the patient immobilized. |
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What are the 4 types of acquisition protocols that the EBCT can use?
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1. Movie mode
2. Flow mode 3. Step-volume scanning mode (SVS)- similar to conventional CT "step and shoot" image/delay/movement/image 4. Continuous volume scanning mode (CVS)-almost identical to spiral/helical CT where the patient moves continuously thoughout the scan. |
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What is MSAD, CTDI?
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Multiple Scan Average Dose
Computed Tomography Dose Index |
