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Cone Beam CT Dr. T.J.Maal Prof. A.M. Kuijpers-Jagtman

OMF-Surgery, Nijmegen, the Netherlands


Cone Beam CT

1. Principles of CBCT ? 2. How to work with a CBCT ? 3. CBCT and OPG


Cone Beam CT

1. Principles of CBCT ? 2. How to work with a CBCT ? 3. CBCT and OPG


Cone Beam CT

1. Principles of CBCT ?

A. History B. Physical principles


Cone Beam CT

1. Principles of CBCT ?

A. History B. Physical principles


W.C. Röntgen. Ueber eine neue Art von Strahlen”. 28 december 1895


Walkhoff, Braunschweig, January 1896


Angle E.H. Double resection of the lower maxilla, Dent. Cosmos 40; 552-557, 1898


‌.cephalograms are far more accurate for treatment planning, since a cephalogram displays both the facial skeleton and the facial profile‌. Broadbent BH. A new X-ray technique and its application to orthodontia. The Angle Orthodontist 1931: 1: 45-66.


• • • • •

Yryo Paatero, Helsinki (1898 – 1971) •

• •

• •

Sydney Blackman (1898 – 1971)

1: PAATERO YV. The use of a mobile source of light in radiography. Acta radiol.1948 Mar 31;29(3):221-7. 2: PAATERO YV. The use of a mobile source of light in radiography. Acta Odontol Scand. 1949 Jun;8(3):236-43.. 3: PAATERO YV. A new tomographical method for radiographing curved outersurfaces. Acta radiol. 1949 Sep 30;32(2-3):177-84, 4: PAATERO YV. [Effect of pressure on the emulsion of dental roentgen film.]Suom Hammaslaak Toim. 1950 Mar;1:5-10. 5: PAATERO YV. Photo-pantomography; a theoretical study for combiningphotoroentgenography and pantomography. Suom Hammaslaak Toim. 1952;48(1Suppl.):21-7. 6: PAATERO YV. [Photopantomography; a projected plan for combiningphotoroentgenography and pantomography.]. Suom Hammaslaak Toim. 1952Mar;48(1):1-9. 7: PAATERO YV. [Line focus in pantomography.]. Suom Hammaslaak Toim. 1952Mar;48(1):11-3. 8: PAATERO YV. [Thickness of layer reproduced on pantomogram in relation tolocation of the object, speed of rotation, and divergence of roentgen rays.]Suom Hammaslaak Toim. 1952 Sep;48(3):113-28. 9: PAATERO YV. [Pantomographic roentgenophotography.]. Fortschr Kieferorthop.1952 Oct;13(3):115-7. 10: PAATERO YV. [Technic in pantomography of the temporomandibular joint.]. Suom Hammaslaak Toim. 1952 Dec;48(4):168-78. Undetermined Language. 11: KOSKI K, PAATERO YV. [Pantomography in the study of the growth anddevelopment of the


Allan McLeod Cormack (1924 – 1998)

A. M. Cormack Representation of a Function by Its Line Integrals, with Some Radiological ApplicationsJ. Appl. Phys. 34, 2722 (1963)

A. M. Cormack Representation of a Function by Its Line Integrals, with Some Radiological Applications. II. Appl. Phys. 35, 2908 (1964)


Allan McLeod Cormack (1924 – 1998) A. M. Cormack Representation of a Function by Its Line Integrals, with Some Radiological ApplicationsJ. Appl. Phys. 34, 2722 (1963)

A. M. Cormack Representation of a Function by Its Line Integrals, with Some Radiological Applications. II. Appl. Phys. 35, 2908 (1964)

Godfrey Hounsfield (1919 – 2004)


Smith KT, Solmon DC, Wagner SL, Hamaker C. Mathematical aspects of divergent beam radiography. Proc Natl Acad Sci USA. 1978 May; 75(5):2055-2058.


Arai Y, Tammisalo E, Iwai K, Hashimoto K, Shinoda K. Development of a compact computed tomographic apparatus for dental use. Dentomaxillofac Radiol. 1999 Jul;28(4):245-8.


Arai Y, Tammisalo E, Iwai K, Hashimoto K, Shinoda K. Development of a compact computed tomographic apparatus for dental use. Dentomaxillofac Radiol. 1999 Jul;28(4):245-8.


Cone Beam CT Basic Course 1. Principles of CBCT ?

A. History B. Physical principles


Cone Beam CT Basic Course 1. Principles of CBCT ?

A. History B. Physical principles


Computed Tomography (CT)

Cone Beam Computed Tomography (CBCT)

Smith KT, Solmon DC, Wagner SL, Hamaker C. Mathematical aspects of divergent beam radiography. Proc Natl Acad Sci USA. 1978 May; 75(5):2055-2058.


Conventional Multi-Slice CT  ‘fan-beam’  Rotates quickly around the

patient  Patient moves through gantry


X-ray source

Demetrios Halazonetis


Detectors

X-ray source

Demetrios Halazonetis


Computed Tomography (CT)

Cone Beam Computed Tomography (CBCT)

Smith KT, Solmon DC, Wagner SL, Hamaker C. Mathematical aspects of divergent beam radiography. Proc Natl Acad Sci USA. 1978 May; 75(5):2055-2058.


Cone beam CT  Cone shaped x-rays  Rotates slowly around the patient  Patient should not move during scan  High resolution, less flexible geometry


X-ray Source

X-rays

Detector


µ1

µ2

µ3

µ4

µ5

A0

Auit = A0.e-µ1.d.e-µ2.d.e-µ3.d.e-µ4.d.e-µ5.d = A0.e-(µ1. µ2. µ3. µ4. µ5).d  (µ1+µ2+µ3+µ4+µ5) = - (1/d).log (Aout / A0)

 (µ1+µ2+µ3+µ4+µ5) = factor.log(detector val)  (µ1+µ2+µ3+µ4+µ5) = attenuatie


µ1

A0

µ2

µ3

Attenuatie

µ4

µ5

Aout

Aout is the value measured at a detector element.


X-ray Source

X-rays

Detector


X-ray Source

X-rays

Detector


Not all photons have the same energy

ď‚Ą

The variation in energy is called the x-ray spectrum spectrum 35 30 relatief aantal

ď‚Ą

25 20 15 10 5 0 -5 0

20

40

60

80

E (keV)

100

120

140


Effects of lower Kv’s  No absolute Hounsfield Units

Can be overcome by  Filtration of the beam

 Higher Kv / Mas

B. Titulaer


X-ray Source

X-ray Source

Detector

X-rays

Detector


Aliasing artefact

Reconstruction with 166 images

Reconstruction with 599 images

Miet Loubele; ‘Geometrical and dosimetrical aspects of low-dose CT in dentomaxillofacial radiology’, 2008


Beam hardening artefact

Phantom

Dental Implants


Truncated view artefact


X-ray Source

X-rays

Detector


Detector

X-ray Source


Different scan protocols Extended Height, 20+20 Secs Total Height = 22cm

Scan time = 40 sec Approximate Dose = 136uSv

Dose in multiples of OPG = 9


Different scanprotocols Full 13cm, 40Sec, 0.25Voxel HiRes Approximate Dose = 133uSv Dose in multiples of OPG = 9 Full 13cm, 20Sec, 0.25Voxel HiRes Full 13cm, 20 Sec, 0.4 Voxel Full 13cm, 20 Sec, 0.3 Voxel iDent/DenX Full 13cm, 20 Sec

8 cm

Approximate Dose = 68uSv Dose in multiples of OPG = 5 Full 13cm, 10 Sec, 0.4 Voxel Full 13cm, 10 Sec, 0.3 Voxel Approximate Dose = 36uSv

Dose in multiples of OPG = 2

5 cm


Different scanprotocols Mand 6cm, 40 Sec, 0.4 Voxel Mand 6cm, 40Sec, 0.25Voxel HiRes Approximate Dose = 61uSv Dose in multiples of OPG = 4

Mand 6cm, 20 Sec, 0.4 Voxel Mand 6cm, 20 Sec, 0.3 Voxel Approximate Dose = 32uSv

1 cm

Dose in multiples of OPG = 2 5 cm Mand 6cm, 10 Sec, 0.4 Voxel

Mand 6cm, 10 Sec, 0.3 Voxel Approximate Dose = 17uSv Dose in multiples of OPG = 1


Relative low x-ray system  Lower Kv/Mas  Relatvie low radiation dose  X-ray filtration options are limited • No absolute Hounsfield units • Relative large amount of noise

 No detector collimation  Movement artefacts  Low contrast in soft tissues


Multi-slice CT

Cone Beam CT

+ very fast acquisition time + fast acquisition time + available in every hospital + patient is scanned sitting + high qualitly images + available in private practice - Suppine scanposition - Radiation dose - Long waiting list

- Low contrast in soft tissues


Multi-slice CT

Cone Beam CT


Radiation Dose CBCT Unit

Protocol

Effectieve Dosis

Equilivant OPG´s

Equilevant days of background radiation

% Anual Background radiation

CB Mercuray

12-in/9-in/6 in FOV

477/289/169

74/45/26

48/29/17

13/8/4.7

Galileos

Default/maximum

29/54

5/9

3/5.5

0.8/1.5

i-Cat

12-in/9-in

135/69

21/11

13.5/7

3.7/1.9

Iluma

High/Low

331/61

53/10

33.5/6.2

9.2/1.7

Newtom 3G

12-in/9-in

45/37

7/6

4.5/3.5

1.2/1.0

PreXion 3D

Standard/high resolution

69/160

11/25

7/16

1.9/4.4

ProMax 3D

Small/large

157/210

25/33

16/21.5

4.4/5.8

Ludlow et al. 2003, 2006, 2007 Farman et al. 2008


Cone Beam CT Basic Course 1. Principles of CBCT ? 2. How to work with a CBCT ? 3. CBCT Anatomy Crash Course 4. Hands on CBCT - Exercises


Cone Beam CT Basic Course 1. Principles of CBCT ? 2. How to work with a CBCT ? 3. CBCT Anatomy Crash Course 4. Hands on CBCT - Exercises


Specific CBCT viewing programs


Specific CBCT viewing programs


Osirix


Osirix


Specific CBCT viewing programs


Implantology

Nobel Guide Casus History: 4-1-2007: Sinus lift PLAN: place implants


Implantology

68


Implantology


Implantology


Implantology


Implantology


Specifieke programma’s


Specific CBCT viewing programs


Implantology view

Orthodontic view

MPR view

TMJ view


Orthodontic View


Evaluation of the airways


MPR View


MPR View


MPR View


MPR View – measuring


MPR View – HU Statistics


MPR View - Explorer


MPR View - Line


Implantology view


TMJ view


Cone Beam CT Basic Course 1. Principles of CBCT ? 2. How to work with a CBCT ? 3. CBCT and OPG


Cone Beam CT Basic Course 1. Principles of CBCT ? 2. How to work with a CBCT ? 3. CBCT and OPG


Mandible


111


125


Heavy Traum → CT


Maxilla


Thomas Maal Introduction to CBCT(2)  
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