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SIU-SDM HAWAIIAN CRUISE

SIU-SDM HAWAIIAN CRUISE. SIU-SDM HAWAIIAN CRUISE. CONE BEAM C T IS IT FOR THE GENERALIST’S OFFICE?. DEBRA DIXON, DMD. SDM GRADUATE 1993 SDM AEGD 1995 SDM IMPLANT FELLOW 1996 THE UNIVERSITY OF LONDON MSc DENTAL RADIOLOGY 2002 SDM DIRECTOR OF RADIOLOGY . FUR. OUR AGENDA.

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SIU-SDM HAWAIIAN CRUISE

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  1. SIU-SDM HAWAIIAN CRUISE

  2. SIU-SDM HAWAIIAN CRUISE CONE BEAM C T IS IT FOR THE GENERALIST’S OFFICE?

  3. DEBRA DIXON, DMD • SDM GRADUATE 1993 • SDM AEGD 1995 • SDM IMPLANT FELLOW 1996 • THE UNIVERSITY OF LONDON MSc DENTAL RADIOLOGY 2002 • SDM DIRECTOR OF RADIOLOGY

  4. FUR

  5. OUR AGENDA • History • Radiology • Digital Radiology • CT • Cone Beam CT • What it is and What it can do for me

  6. HISTORY • Nov 8, 1895 Wilhelm RÖntgen discovers the X-Ray • Digital radiography is more than 25 years old • 11% to 30% of dentists have converted to digital • Financial investment • Complexity of computers • Software • Hardware • Simply reluctant to switch…if everything is running smoothly, why change it? Van der Stelt 2008

  7. BASICS OF DIGITAL IMAGING • Composed of pixels (picture elements) which are characterized by 3 numbers • These numbers are stored in an image file in the computer • Image processing is possible • Brightness/Darkness • Contrast • Zoom…limited by the resolution of the system

  8. BASICS OF DIGITAL IMAGING • Image Analysis • Measurement of root length for Endo • Digital subtraction radiography

  9. BASICS OF DIGITAL IMAGING • Advantages • Immediate image with CCD sensor • Ability to manipulate the image • Integrated storage with software systems • Security of backup and off-site archiving of images • Ease of transfer by email • Security of the original image • DICOM (Digital Imaging and Communications in Medicine) format standards

  10. BASICS OF DIGITAL IMAGING • Dose Reduction? • Once promoted as a “huge advantage” to digital imaging • Why the dose reduction is not as large as often suggested • Dose per exposure • Reduction of 0% to 50% as compared with “F” speed film • Increase in the number of radiographs made • Increase in the number of retakes due to the ease of exposing additional images Van der Stelt 2008

  11. SALLY

  12. C TCOMPUTED TOMOGRAPHY

  13. C T • History • Basics of Tomography • Generations of Scanners • 1st Generation • 2nd Generation • 3rd Generation • 4th Generation • 5th Generation • Conventional data gathering versus Spiral geometry

  14. C T • History • The word Tomography can be traced to the 1920’s • Tomography = section, from the Greek tomos • Dr. Godfrey Hounsfield • Born 1919 in Nottinghamshire, England • The inventor of clinical computed tomography • First patient scanned in 1972 • Demonstrated a suspected brain lesion • Dr. Allan Cormack • Born 1924 in Johannesburg, South Africa • Developed solutions for the mathematical problems in CT Seeram, Computed Tomography, 2001

  15. C T • History • Dr. Robert Ledley • 1948 Doctorate in Dental Surgery, New York University • 1949 Master’s in theoretical physics, Columbia University • Developed the first whole-body CT scanner Seeram, Computed Tomography, 2001

  16. C T • History • Tomography • X-ray tube and film move simultaneously and in opposite directions • This keeps the object of interest in focus while blurring out the structures around it • Panoramic technique Seeram, Computed Tomography, 2001

  17. C T • History • A • 1st Generation • B • 2nd Generation • C • 3rd Generation • D • 4th Generation Seeram, Computed Tomography, 2001

  18. C T • History • 1st Generation • Minimum 4.5 to 5.5 minute whole body scan • Parallel beam, Translate & Rotate • After 1 translation, the tube and detector rotate by 1° and translate again, repeated for 180° around the patient Seeram, Computed Tomography, 2001

  19. C T • History • 2nd Generation • Scan time 20 sec to 3.5 minutes • Fan beam, Translate & Rotate • Fan beam = ~30 detectors coupled to the x-ray tube and multiple pencil beams • Process is repeated for 180° Seeram, Computed Tomography, 2001

  20. C T • History • 3rd Generation • Scan time of a few seconds • Fan beam geometry that rotates continuously around the patient for 360° Seeram, Computed Tomography, 2001

  21. C T • History • 4th Generation • Scan time is very short, varies by manufacturer • A rotating fan beam within a stationary ring of detectors Seeram, Computed Tomography, 2001

  22. C T • History • 5th Generation • High-speed CT scanners • EBCT Electron Beam CT scanner • DSR • Dynamic Spatial Reconstructor • Scan time of milliseconds Seeram, Computed Tomography, 2001

  23. C T • History • A • Conventional Slice by Slice data acquisition • The x-ray tube stops between slices, the patient is repositioned for the next slice Seeram, Computed Tomography, 2001

  24. C T • History • B • Helical or spiral geometry • The latest development in CT data acquisition (as of the writing of the text in 2001) • Volume scanning • Utilizes a narrowly collimated, fan shaped x-ray beam, projected through a limited thickness slice through the body • Utilizes a linear array of detectors • Patient has to be advanced through the gantry while the x-ray tube and detectors rotate around the patient Seeram, Computed Tomography, 2001

  25. C T • Spiral Scanners • Provide improved multiplanar image reconstructions • Reduced exam time • 12 seconds versus 5 minutes for an incremental scan • Reduced radiation dose • Up to 75% of the dose delivered by an incremental scanner

  26. C T • Image is recorded and displayed as matrix of individual blocks called voxels (volume elements) • Voxel length (1 to 20 mm) is determined by the width of the x-ray beam • Analogous to the tomographic layer in film tomography • For image display, each pixel is assigned a CT number • Represents density • Also known as a Hounsfield unit • Air -1000 • Water 0 • Dense bone +1000

  27. EM

  28. CONE BEAM C T

  29. C B C T • Definition • Indications • Comparisons • CBCT versus Panoramic • CBCT versus Plain-film Tomography • CBCT versus Medical CT • Disadvantages • Currently available units • Specialized Uses • Orthodontic Analysis • Dolphin Imaging Software Program • Interpretation

  30. C B C T • Developed for Dental purposes to provide 3D volume images of the dental and craniofacial complex • Available for craniofacial imaging • Since 1999 in Europe • Since 2001 in the U.S. • Ideally suited for craniofacial imaging • The compact size of the unit • Relatively low radiation dose • Becoming the “Standard of Care” for diagnosis of the craniofacial region • Allows multiplanar viewing of the anatomical volume and overcomes the limitations of 2D radiography www.conebeam.com

  31. C B C T • Cone Beam • Utilizes a cone shaped x-ray beam • Round or rectangular • Utilizes an area detector • Acquires a full volume of images in a single rotation with no need for patient movement • Rotates 360° around the head • 360 projections • Scan time typically < 1 minute www.conebeam.com

  32. C B C T • End Result • 3-D visualization of the oral and maxillofacial complex from any plane • A stack of 360 images or exposures compiled into a volumetric dataset through a computer process known as primary reconstruction • This data volume is then converted into a patient-study by accompanying software • Can be visualized as • 2D trans-axial, multi-planar reformatted • 3D techniques such as surface reconstruction and volume rendering • A combination of 2D and 3D techniques www.conebeam.com

  33. C B C T • Indications • Evaluation of the jaw bones • Implant placement and evaluation • TMJ • Pathology • Bony & Soft tissue lesions • Periodontal assessment • Endodontic assessment • Alveolar ridge resorption • Assessment of the IAN prior to extraction of impactions • Orthodontic evaluation • Airway assessment • Need for 3D reconstructions www.conebeam.com

  34. C B C T • Evaluation of the jaw bones • Implant placement and evaluation #12-13 • a) Panoramic line and cross-section line in the axial imageof Maxilla identified • b) Slices of the area in cross-section • c) Reconstruction in a ‘panoramic-like’ layout Araki et al. Dentomaxillofac Radiol 31 (1):51, Figure 9

  35. C B C T • Evaluation of the jaw bones • a) Slice as seen from a ‘frontal’ view • b) Slice as seen from the side • c) Reconstructed maxilla and mandible Dentomaxillofac Radiol (2004) 33, 285-290

  36. C B C T • Evaluation of the jaw bones www.ddsgadget.com e-ssentialnetworks.com

  37. PANORAMIC Provides a distorted (unequal magnification) and magnified image Image layer view only Structures are superimposed CBCT Provides an undistorted image Cross-sectional (bucco-lingual), axial, coronal, sagittal, and panoramic views Structures can be separated C B C T versusPANORAMIC www.conebeam.com

  38. PLAIN-FILM TOMOGRAPHY Provides an undistorted image, but there is magnification Provides direct cross-sectional, sagittal, and coronal views Scan time may be short, but chair time can be lengthy CBCT Provides an undistorted, 1:1 image Provides reconstructed views Scan time 10-40 second range, dependent on the region being imaged and the desired quality Provides an indication of bone quality C B C TversusPLAIN-FILM TOMOGRAPHY www.conebeam.com

  39. Med CT Conventional linear fan beam Single row or a series (4, 8, 12, 32, 64) of solid state detectors Provides a set of consecutive slices of the patient CBCT Cone beam Square 2 dimensional array of detectors Provides a volume of data C B C TversusMedical C T www.osseonews.com www.conebeam.com

  40. Med CT Greater contrast resolution More discrimination between different tissue types (i.e. bone, teeth, and soft tissue) CBCT Equipment Cost 3-5x less than MDCT Lighter & Smaller No special electrical No floor strengthening No special cooling Ease of operation Dedicated to dental Patient sits or stands Both jaws can be imaged at the same time Lower radiation burden C B C TversusMedical C T www.conebeam.com

  41. C B C T • Disadvantages • Noise from radiation scatter • Streak artifacts from metal restorations • Algorithms and filters try to correct for noise & artifacts • Image degradation from patient movement • Head stabilizing devices • Cost • Range from $150,000 to 300,000 • Training • For maximum benefit • For interpretation of the volume of data & images • Within the purview of the dentist • Outside the purview of the dentist Howerton et. al.

  42. C B C T • Currently available units • 3D Accuitomo FPD XYZ Slice View Tomograph • J. Morita USA, Irvine, CA • 3D X-ray CT Scanner Alphard Series • Asahi, Kyoto, Japan • Quolis Alphard Alphard-3030-Cone-Beam • Belmont Equipment, Somerset, NJ • CB MercuRay • Hitachi Medical Systems America, Twinsburg, Ohio • Galileos 3D • Sirona Dental Systems, Charlotte, NC • i-CAT • Imaging Sciences International, Hatfield, PA Howerton et. al.

  43. C B C T • Currently available units • Iluma Ultra Cone Beam CT Scanner • Carestream, Rochester, NY • NewTom 3G and VG • AFP Imaging, Elmsford, NY • Picasso • E-woo Technology, Houston • PreXion 3D • TeraRecon, San Mateo, CA • ProMax 3D • Planmeca USA, Roselle, IL • Scanora 3D • Soredex, Tuusula, Finland Howerton et. al.

  44. C B C T Inside Dentistry 1:90-93, 2007, Dental Economics August 2007, Dental Town August 2007

  45. C B C T • All Cone Beam Units are not created equal! • Volume Size • Geometric resolution • Contrast resolution • Slice thickness • Radiation dose • Ease of use • Image Capture

  46. C B C T Farman AG, Levato CM, Scarfe WC. A primer on cone beam CT. Inside Dentistry 1:90-93, 2007

  47. C B C T • The i-CAT CT scanner • Low dose settings for children • Landscape View • Full resolution and detail obtained for smaller fields of view • Portrait View • Captures Extended Field of View data • Ceph data in 8.5 seconds www.imagingsciences.com

  48. C B C T • i-CAT • Typical reconstruction time • Less than 30 seconds www.imagingsciences.com

  49. C B C T • i-CAT • Measurement • Labeling • Hounsfield units • Density www.imagingsciences.com

  50. C B C T • NewTom VG • Features a single 8"x10" Field Of View, • Most utilized by implantologists and maxillo-facial surgeons. • Small focal spot = high quality images • Volume of data captured kept to a minimum • Short reconstruction times (3 minutes) • Low dose • up to 20 - 50 times less radiation than conventional CT • Adjusts dose to size and age of patient • Unique “pulse” system • Activates the x-ray source only when needed—delivering less than 4 seconds of total exposure for a full scan. www.afpimaging.com/newtom

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