RADR 211: COMPUTED TOMOGRAPHY
How many meningeal spaces are there? - Answers - 3
The central nervous system consists of 2 divisions known as: - Answers - 1. Brain
2. Spinal Cord
How many cranial nerves are there? - Answers - 12
Dendrites are processes that conduct impulses____ the neuron cell body - Answers -
away from
Which structures make up the brain stem? - Answers -
How many lobes make up the cerebrum? - Answers -
What is the name of the white matter structure that interconnects the hemispheres of
the cerebrum? - Answers -
Specialized capillary beds found in the ventricles that produce CSF are termed -
Answers -
Second generation scanners include: - Answers - - 30 or more detectors
- 40 slices in 10 minutes
Third generation scanners include: - Answers - - Bank of up to 960 detectors
- Detectors and x-ray tuberotate 360°
First generation scanners include: - Answers - - one or two detectors
- 4½-minute scan
The Gantry consists of what components? - Answers - - X-ray tube
- Detector array
- Collimator assembly
What are the Advantages of Multislice Over Single-Slice Scanners? - Answers - 1.
Shorter Acquisition Time
2. Decreased Amount of Contrast Medium
3. Improved Spatial Resolution
4. Improved Image Quality
Within the operator console, the technologist is able to: - Answers - - Establish scan
parameters (protocol)
- View/manipulate images
- Modify scan parameters (kV, pitch, FOV, slicetable indexing, andrecon algorithms)
, Current scanners can produce ____ or more slices per x-ray tube rotation. - Answers -
64
Dual-focus x-ray tube with ______________ detector array, resulting in ____ slices per
rotation - Answers - eight element, 16
Fourth generation scanners include: - Answers - - Up to 4800 or more detectors on a
fixed ring
- Only x-ray tube rotates
- Shorter scan times
What is another term for the hypophysis? - Answers -
First generation CT scanner: - Answers - pencil beam, single detector. translate/rotate
2nd generation CT scanner: - Answers - -Head and body imager
-Multiple radiaiton detectors
-Translate-rotate motion
-10 minutes for exam
3rd generation CT scanner: - Answers - Wide fan shaped beam: cover entire patient
360 degree rotate-rotate (rotation only): no translation needed
X-ray tube and detector array rotate together
Multiple detectors (500 - 800) rotating detectors
Hundreds of image projections acquired during each rotation
Scan time: as fast as ½ second per rotation.
One rotation = one slice
4th generation CT scanner: - Answers - -About 4000 stationary detectors
-Fan beam
-Only the tube rotates with short bursts of radiation
-1 minute for multiple slices
-Sub second scan time
Window Width - Answers - - Range of CT numbers displayed as shades of gray
- Controls the image contrast
What does Pitch calculate? - Answers - Calculates amount of anatomy
examinedduring particular multislice scan
What is the pitch formula? - Answers - Pitch = Couch movement (mm/sec) per 360°
rotation\ Collimation
How should a patient be prepped before a CT exam? - Answers - Informed consent
form
Clinical history
How many meningeal spaces are there? - Answers - 3
The central nervous system consists of 2 divisions known as: - Answers - 1. Brain
2. Spinal Cord
How many cranial nerves are there? - Answers - 12
Dendrites are processes that conduct impulses____ the neuron cell body - Answers -
away from
Which structures make up the brain stem? - Answers -
How many lobes make up the cerebrum? - Answers -
What is the name of the white matter structure that interconnects the hemispheres of
the cerebrum? - Answers -
Specialized capillary beds found in the ventricles that produce CSF are termed -
Answers -
Second generation scanners include: - Answers - - 30 or more detectors
- 40 slices in 10 minutes
Third generation scanners include: - Answers - - Bank of up to 960 detectors
- Detectors and x-ray tuberotate 360°
First generation scanners include: - Answers - - one or two detectors
- 4½-minute scan
The Gantry consists of what components? - Answers - - X-ray tube
- Detector array
- Collimator assembly
What are the Advantages of Multislice Over Single-Slice Scanners? - Answers - 1.
Shorter Acquisition Time
2. Decreased Amount of Contrast Medium
3. Improved Spatial Resolution
4. Improved Image Quality
Within the operator console, the technologist is able to: - Answers - - Establish scan
parameters (protocol)
- View/manipulate images
- Modify scan parameters (kV, pitch, FOV, slicetable indexing, andrecon algorithms)
, Current scanners can produce ____ or more slices per x-ray tube rotation. - Answers -
64
Dual-focus x-ray tube with ______________ detector array, resulting in ____ slices per
rotation - Answers - eight element, 16
Fourth generation scanners include: - Answers - - Up to 4800 or more detectors on a
fixed ring
- Only x-ray tube rotates
- Shorter scan times
What is another term for the hypophysis? - Answers -
First generation CT scanner: - Answers - pencil beam, single detector. translate/rotate
2nd generation CT scanner: - Answers - -Head and body imager
-Multiple radiaiton detectors
-Translate-rotate motion
-10 minutes for exam
3rd generation CT scanner: - Answers - Wide fan shaped beam: cover entire patient
360 degree rotate-rotate (rotation only): no translation needed
X-ray tube and detector array rotate together
Multiple detectors (500 - 800) rotating detectors
Hundreds of image projections acquired during each rotation
Scan time: as fast as ½ second per rotation.
One rotation = one slice
4th generation CT scanner: - Answers - -About 4000 stationary detectors
-Fan beam
-Only the tube rotates with short bursts of radiation
-1 minute for multiple slices
-Sub second scan time
Window Width - Answers - - Range of CT numbers displayed as shades of gray
- Controls the image contrast
What does Pitch calculate? - Answers - Calculates amount of anatomy
examinedduring particular multislice scan
What is the pitch formula? - Answers - Pitch = Couch movement (mm/sec) per 360°
rotation\ Collimation
How should a patient be prepped before a CT exam? - Answers - Informed consent
form
Clinical history
