CAT
Computerized Axial Transverse/ Tomography
o - Hounsfield build a whole body CT SCANNER
1975
o 1971: EMI ( ____
Introduced by SIR GODFREY HOUNSFIELD
Electrical Musical Instrumentation)
FEATURES if 1ST CT > scanning motion or tube detector movements
TRANSLATE- ROTATE
1st CT
Detector & Xray source:
X-ray Beam:
Duration of Scan ( average):
Single
Pencil- shaped
25-30 mins
mins to scan one slicein 1st CT
3-5
: minute to reconstruct
1.5
1st CT SCAN
Number of Slice per rotation:
Motion of Gantry:
Scan Mode: step and shoot scanning
Power Supply: straighten twisted system cables
Characteristics:made up of ____
1
Linear and Rotary
Sodium Iodide
1st CT
___ translations with __ degree rotation in LINEAR MOTION
180
1
2nd Generation
Tube- detector movement:
Translate Rotate
2nd CT
introduced by ___ @ Georgetown University in Feb. 1974
LEDLEY
2ND CT
the machines utilizes ___ PMT. Complete a scan in only 9 TRANSLATE- ROTATE CYCLE.
30
Xray beam shaped of 2nd CT
___ secondd per slice
Narrow fan beam
20
___ translations in CT
60
No. Of detector in earlier and late version of CT
3, 53
3rd generation introduced in year
1971
3rd generation of CT with ____ shaped beam 40 to 60 deg
Fan beam
Xtube and detector of 3rd generation
Rotate rotate
Larger array of detectors (more than __) were used. Scanning time was reduced to 2 seconds
Of 3rd generation
800
Third generation had been proven by the-study of
Mathias Meyer
spiral scanning This is the most commonly used method today and takes about __ seconds to image a single slice
0.3
DISADVANTAGE: of 3rd generation
RING ARTIFACT.
Duration of scan
(average): approximately __sec ( 3rd)
5
4th generation
Year
Scan
1976
1
