1. Part No...., Module No....Lesson No
Module title
CT Scanner
Presented by:
Dr M A Oghabian
Medical Physics Department,
Tehran University of Medical Sciences
Part …: (Add part number and title)
Module…: (Add module number and title)
Lesson …: (Add session number and title)
Learning objectives: Upon completion of this lesson, the students will be able to: …
. (Add a list of what the students are expected to learn or be able to do upon completion of the session)
Activity: (Add the method used for presenting or conducting the lesson – lecture, demonstration, exercise, laboratory exercise, case study, simulation, etc.)
Duration: (Add presentation time or duration of the session – hrs)
Materials and equipment needed: (List materials and equipment needed to conduct the session, if appropriate)
References: (List the references for the session)
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

2. Part No...., Module No....Lesson No
Module title
Computed Tomography
CT uses a rotating x-ray tube, with the beam in the form of a thin slice (about mm)
The “image” is a simple array of x-ray intensity (Projections), and many hundreds of these are used to make the CT image, which is a “slice” through the patient
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

3. Part No...., Module No....Lesson No
Module title
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

4. First generation CT Scanner (Rotate/Translate Pencil beam)
Part No...., Module No....Lesson No
Module title
First generation CT Scanner (Rotate/Translate Pencil beam)
180 translational movement
180 Rotary movement
160 parallel rays across a 24 cm FOV
Each 2 slices=4.5 min.
Processing time=1.5min.
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

5. Part No...., Module No....Lesson No
Module title
Second generation CT scanners Rotate/Translate Narrow fan beam~10 degree
Narrow fan beam~10 degree
Linear array of 30 detectors
6 linear movement
6 rotary movement
Scan time~ 18 Sec.
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

6. Third generation CT Scanners (Rotate/Rotate , Wide fan beam)
Part No...., Module No....Lesson No
Module title
Third generation CT Scanners (Rotate/Rotate , Wide fan beam)
Wide fan beam
More than 800 detectors
No translational motion
Scan time ~ 0.5 Sec.
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

7. 4th Generation CT Scanners Rotate/Stationary
Part No...., Module No....Lesson No
Module title
4th Generation CT Scanners Rotate/Stationary
Fan beam geometry
More than 4800 detectors
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

8. Electron Beam Computed Tomography (EBCT)
Part No...., Module No....Lesson No
Module title
- x-ray source is not x-ray tube but a focused, steered, microwave-accelerated EB incident on a tungsten target.
- It has no moving parts .
- Target covers one-half of the imaging circle; detector array covers the other half.
- Images in less than 50ms.
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

9. Part No...., Module No....Lesson No
EBCT(CONT’D)
Module title
There are 4 targets and 4 detector arrays resulting in 4 contiguous images simultaneously.
The detector array may consists of two separate rings
Each solid -state detector consists of a luminescent crystal and cadmium tungstate coupled with silicon photodiodes.
Heat dissipation is no problem in EBCT.
Developed for fast imaging.
Used for cardiac imaging
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

10. Part No...., Module No....Lesson No
Module title
A look inside a rotate/rotate CT
Detector Array
and Collimator
X-Ray
Tube
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

11. Part No...., Module No....Lesson No
Module title
Helical Scanning:
Continuous Gantry Rotation
Continuous Table Movement
Continuous Data Acquisition
One set of detectors
Beam collimation = slice thickness
Helical scanning goes by several different names, depending on which company that you happen to be talking to. <describe>
Essentially they all describe the same concept, which a continuous movement of the table, coupled with continuous acquisition.
In single slice spiral scanners, the X-ray tube emits a beam as it rotates around the patient. On the other side of the patient, opposite the tube, a set of detectors rotates in synchrony with the tube movement, registering the radiation that has passed thru the patient.
In a single detector unit, the tube may emit a beam that is approx 5mm thick,and the detector unit is collimated to register that 5mm beam, leading to the creation of a single 5 mm thick image.
Challenges:
Tube cooling, and patient comfort – breathhold difficult.
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

12. Part No...., Module No....Lesson No
Module title
Comparison of data acquisition for axial and helical technologies.
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

13. Part No...., Module No....Lesson No
Module title
Reciprocating rotation (A) versus fast continuous rotation using slip-ring technology (B)
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

14. A Look Inside a Slip Ring CT
Part No...., Module No....Lesson No
Module title
A Look Inside a Slip Ring CT
Note:
how most
of the
electronics is
placed on
the rotating
gantry
X-Ray
Tube
Detector
Array
Slip Ring
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

15. Part No...., Module No....Lesson No
Module title
(A) Pitch = (B) Pitch = 2
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

16. Part No...., Module No....Lesson No
Module title
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

17. Part No...., Module No....Lesson No
Module title
Comparison of the accuracy of 3D reconstruction for conventional (A) and spiral/helical (B) CT scanning.
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

18. More New CT Features: Multislice Scanning
Part No...., Module No....Lesson No
Module title
More New CT Features: Multislice Scanning
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

19. Part No...., Module No....Lesson No
Module title
Multislice CT, where up to 64 variable thickness slices can be collected simultaneously
CT fluoroscopy, where the patient is stationary, but the tube continues to rotate
3-dimensional CT and CT endoscopy
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

20. Clinical Benefits Of Multi-Slice
Part No...., Module No....Lesson No
Module title
Clinical Benefits Of Multi-Slice
Multi-phase Organ Studies
Liver – Pancreas Arterial, Renal Nephrogram
Arterial Phase Scanning
Hypervascular Tumors
CT Angiography
Multi-Plane Reconstructions, Contrast Enhancement
New CT Applications
CT fluoroscopy
CT Colonography
Cardiac: morphology, function
Advanced Lung Analysis
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

21. Part No...., Module No....Lesson No
Module title
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

22. Part No...., Module No....Lesson No
Module title
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

23. Part No...., Module No....Lesson No
Module title
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

24. Part No...., Module No....Lesson No
Module title
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

25. Detector Configurations
Part No...., Module No....Lesson No
Module title
Detector Configurations
X-ray Tube Focal Spot
X-ray Beam Collimator a
4 x 1.25 mm Detector Configuration
16-row Mosaic Detector
Flex Connector A
Flex Connector B
Diode
FET Switching Array
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources 6

26. Detector Configurations
Part No...., Module No....Lesson No
Module title
Detector Configurations
X-ray Tube Focal Spot
X-ray Beam Collimator
4 x 2.5 mm Detector Configuration
16-row Mosaic Detector
Flex Connector A
Flex Connector B
Diode
FET Switching Array
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources 6

27. Detector Configurations
Part No...., Module No....Lesson No
Module title
Detector Configurations
X-ray Tube Focal Spot
X-ray Beam Collimator
4 x 3.75 mm Detector Configuration
16-row Mosaic Detector
Flex Connector A
Flex Connector B
Diode
FET Switching Array
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

28. Detector Configurations
Part No...., Module No....Lesson No
Module title
Detector Configurations
X-ray Tube Focal Spot
X-ray Beam Collimator
4 x 5.0 mm Detector Configuration
16-row Mosaic Detector
Flex Connector A
Flex Connector B
Diode
FET Switching Array
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources 6

29. Multi slice CT collimation
Part No...., Module No....Lesson No
Module title
Multi slice CT collimation
5mm
2,5mm
1mm
0,5mm
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

30. Part No...., Module No....Lesson No
Module title
Speed: Single vs. 4 Slice
Chest
Coverage
Thickness
Time (s) mA
Abdomen/Pelvis
Scan Time (s)
Tube Load (mAs)
Single Slice
235 mm
5 mm 31
240
255 mm 34
300 65
17,720
235 mm
5 mm 8
240
255 mm 9
300 17
4,725
4 slice
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

31. Part No...., Module No....Lesson No
MULTISLICE SPIRAL CT
Part No...., Module No....Lesson No
Module title
Introduced at the 1998.
They are based multiple detector. rows ranging between 8, 16, 24, 32 and 64 depending on the manufacturer.
The overall goal is to improve the volume coverage speed performance.
Complete x-ray tube/detector array rotation in less than 1s.
Partial scan images can be obtained in approximately 100ms.
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

32. MULTISLICE IMAGING(CONT’D)
Part No...., Module No....Lesson No
MULTISLICE IMAGING(CONT’D)
Module title
ADVANTAGES
Improved spatial resolution this advantage improved MPR,3D images.
Reduction of radiation exposure.
Motion artifacts are greatly reduced.
Patient breathhold is much less demanding.
Imaging larger z-axis volume in less time is possible with MI.
Less contrast medium required.
Because of imaging speed, coronary artery is comparable with EBCT.
Improved accuracy in needle placement CT fluoroscopy.
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

33. Part No...., Module No....Lesson No
Module title
CT Fluoroscopy
Real Time Guidance
Great Image Quality
Low Risk
Faster Procedures
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

34. REAL-TIME CT FLUOLOROSCOPY
Part No...., Module No....Lesson No
REAL-TIME CT FLUOLOROSCOPY
Module title
CT fluoroscopy acquire dynamic images in real time.
Fast continuous imaging, fast image reconstruction & continuous image display.
Patient movement is low during Tube rotation.
Fast image Reconstruction algorithm is required.
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

35. Part No...., Module No....Lesson No
CT ANGIOGRAPHY (CTA)
Module title
CTA allows maximum visualization of the pulmonary artery and its segmental braches.
CTA requires low kVp and MA, for example 90Kvp/100mA.
CTA employs MIP and MPR to maximum advantage.
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

36. Part No...., Module No....Lesson No
Module title
3D Stereo Imaging
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

37. Part No...., Module No....Lesson No
Module title
Enhanced 3D
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

38. Part No...., Module No....Lesson No
Module title
CT Endoscopy
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

39. CT VIRTUAL REALITY IAMAGING
Part No...., Module No....Lesson No
CT VIRTUAL REALITY IAMAGING
Module title
The use of virtual reality is the creation the inner views of tubular structures.
Offers both endoluminal and extra luminal information.
It reduces complication (eg. infection and perforation).
Four requirements:
data acquisition
image processing
3D rendering
image display and analysis.
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources