CT generations
1st generation was known as
Computerized transverse axial scanner
Second-generation scan time
10 to 90 seconds
Average time for scan in first generation
4.5 to 5 minutes Had consisted of 10 to 12 sections which required 25 to 35 min exam time
Pitch is common to what CT generation
6th and 7th
What was the third generation detector range
250 to 750
Which generation added a mask and what type of mask was it?
2nd generation and a lead mask to absorb some of the scatter
Primary difference between x-ray tube used in CT to x-ray tubes in radiography
CT -handles more heat and smaller focal spot that use a pulsed beam
Predetector collimators functions
Called collimator mask reduce scatter enhances contrast determine slice thickness
Electron beam technology differences from 1st through 4th generation
Cardiac only no moving parts live as it is happening No x-ray tube
What made third-generation different from first and second
Continual motion without stopping to translate Entire body scan 360° rotation Scan take one to two seconds
Pre-patient collimators function
Determine patient dose and adjust to slice thickness selected
Fifth generation Contrast injection synchronized with what on patients
ECG
Fifth-generation CT were called
Electron beam Tomography or cardiac Cine
Definition of pitch
Extension or contraction of the helix
Second-generation major differences from first
Fan beam so has more detectors larger rotation
Which generation is like a Polaroid camera
First generation
MDCT stands for ---- and what does it aquire
Multi detector CT Provides a motion free high,resolution images and it aquires volume data rather than slice
MSCT stands for --- and resolution is determined by ---
Multi slice and width of detector
Does the 6th Generation CT table index
No, it moves in and out with a smooth motion
1st generation translation and type of beam
Pencil been The unit translates or sweeps across patient source detector assembly returns to his starting position and entire assembly then rotates around patient moves 1° out a time
Third-generation was prone to what type of artifacts
Ring
3rd-generation had a ___ to ___type of configuration
Rotate to rotate
Advantages of 6th generation
Scan time improvements lower dose of contrast patient continually advance through bore *Only one breath hold during exam
Advantages/changes of 7th generation
Shorter scan times artifacts reduced multisection or multi slice Improved spatial resolution due to thinner slices Improve the image quality for angiography 3D multiplanar reconstruction
First generation
Single x-ray tube and pair of detectors or a line on a C-arm x-rays passed through patient and water bag before being absorbed by the detectors on the other side
What made spiral/helical CTpossible and what did it eliminate
Slip ring technology Power cables
Spiral/helical CT scan is based on what type of technology and acquisition?
Slip ring technology and volume data acquisition
7th generation is known as
Spiral/helical CT
Fourth-generation had what type of detector configuration and xray rotation
Stationary - (600 to 2000 stationary detectors) and xray rotated
Second-generation used what type of configuration
Translate and rotate
Definition of translate
Translate means rotate motion side to side
What rotated on the fourth generation
X-ray source