Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
22 Cards in this Set
- Front
- Back
|
How is CT helped by image reconstuction?
|
CT overcomes limitations in detail and clarity by using image reconstruction
|
|
|
When was the idea of image reconstruction first introduced?
and By whom? |
1917
mathematician Radon |
|
|
Definition of Image Reconstruction.
|
Image Reconstruction from projections is the process of producing an image of a two dimensional distribution from estimates of its line integrals along a finite number of lines of known locations.
|
|
|
Who applied reconstruction techniques to produce the first clinically useful CT scanner for brain imaging?
and In what year? |
Hounsfield
1967 |
|
|
What is Emission CT?
|
It is where the radiation source is inside the patient.
(Ex. nuclear medicine) |
|
|
What is Transmission CT?
|
It is where the radiation source is outside the patient.
(Ex. Xray imaging) |
|
|
What 3 steps are involved in the formation of CT images by a CT scanner?
|
1. Data Acquisition
2. Image Reconstruction 3. Image display, Manipulation, Recording and Commuication |
|
|
What is Data Acquisition?
|
Data Acquisition refers to the collection of xray transmission measuremnts from the patient.
|
|
|
What are Reconstuction Algorithms?
|
Reconstuction Algorithms are the special mathematical techniques used by the computer to recontruct the CT image.
|
|
|
What is the best device for the diplay of gray-scale imagery?
|
The Cathode Ray Tube
|
|
|
What does Communications refer to in CT?
|
Communications refer to the electronic transmission of text data and images from the CT scanner to other devices. (Ex. printers, workstations, throughout the facility)
|
|
|
How does the CT Scan work?
|
When xrays pass through the patient, they are attenuated and measured by the detectors. The detector converts the xray photons into electric/analog signals, which are converted in to digital (numeric) data. With the digital data the computer reconstructs the image.
|
|
|
Who developed the first whole body CT scanner?
and In what year? |
Robert Ledley
1974 |
|
|
What is an Electron Beam CT?
|
Electron Beam CT was first used for cardiac imaging in the mid-1980's. It has no moving parts. It is capable of acquiring multislice images very rapidly.
|
|
|
What are the terms used to describe a volume of tissue being scanned by moving the patient continuously through the gantry and where the detectors rotate continuously.
|
Spiral and Helical CT
|
|
|
What is meant by "Multislice CT Scanner"?
|
Multislice scanning refers to the use of multiple detectors to produce more than 2 slices per rotation.
|
|
|
What does the term "efficacy" refer to?
and What are the terms that mean the same? |
Efficacy indicates that the therapeutic effect of a given intervention (ex. intake of a medicine, an operation, or a public health measure) is acceptable.
Efficacy is synonymous with effectiveness, efficiency and performance |
|
|
What are used to measure radiation dose?
|
Ionization chambers
Thermoluminescent dosimeters |
|
|
What are Dose descriptors?
|
Dose descriptors included the single scan dose profile, multiple scan dose profle, CT dose index, multiple scan average dose, and isodose curves.
|
|
|
What are the advantages of CT Fluoroscopy?
|
1. Fast continuous scanning
2. Fast image reconstruction 3. Continuous image display |
|
|
3D imaging uses large volumes of digital data. What 2 classes of techiques are available for 3D transformation?
|
Surface and Volume-based techniques
|
|
|
What are the 4 essential elements to produce a quality CT Angio?
|
1. Patient Prep
2. Selection of acquisition parameers 3. Contrast injection 4. Post-processing techniques |
