The document discusses the key components of a CT scanner, including the gantry, data acquisition system (DAS), computer, and storage. It describes the detectors and data conversion process in the DAS, including scintillation and gas-filled detectors. Scintillation detectors were improved by replacing photomultiplier tubes with photo cathode assemblies, allowing for smaller size, lower cost, and not requiring separate power supplies. Common scintillation crystals mentioned include sodium iodide, bismuth germinate, cesium iodide, and cadmium tungstate. Gas-filled detectors provide similar efficiency and are constructed with large metallic chambers separated by approximately 1mm baffles. Examples of gases used include xenon

2. Dedicated to:
From:

3. PARTS OF CT:
 Gantry
 DAS
 Computer
 Storage

4. DAS (data acquizition system)
 DETECTORS
 CURRENT TO VOLTAGE CONVERTERS
 PRE AMPLIFIER
 INTEGRATOR
 ADC
 To computer world

5. DETECTORS:
1) Scintillation
2) Gas filled.

6. 1) Cyntillation:
 Early cyntillation detectors are array contained
cyntillation crystal & PMT assemblies.
Drawbacks:
 Cannot be packed very tightly together.
(Might be chance of image loss.)
 PMT require separate power supply for each one.
(require more power,Area,cost,etc).

7. Problem Over Come:
 PMT’s were replaced by Photo cathode
assembly.
Advantage:
 Smaller in size
 Cheaper in cost.
 No need of separate supply.

8.  1) Sodium iodide (Na I).
 2)Bismuth Germinate (BGO).
 3)Cesium iodide (CI).
 4)Cadmium thungstate (CdWO4).

9. 2) Gas FILLED:
 It has the same Efficiency as Scintillation crystal .
 We have to do it Air lock.
* They are constructed with large metallic
chambers,
With baffles space approximately 1mm.
* Each small chamber function as a separate
radiation detector.

10. I. XENON gas.
II. KRYPTON gas.
III. XENON KRYPTON gas.

12. Manufacturer: Toshiba
Model: Aquilion

13. Thank you