W3 CT Generations PDF

The CT Imaging System W3 PART1 ILO’s On completion of this section, the student should be able to know the following: PHYSICS AND MATHEMATICAL CONCEPTS...

The CT Imaging System W3 PART1 ILO’s On completion of this section, the student should be able to know the following: PHYSICS AND MATHEMATICAL CONCEPTS 1ST GENERATION SCANNER 2ND GENERATION SCANNER 3RD GENERATION SCANNER S. Jastaniah, J. Al-Ghamdi, A. Aref (KAU), A. Musa (KKU), K. Hassan (BMC) 3/3/24 1  PHYSICAL PRINCIPLES OF CT: Ø THE PHYSICAL PRINCIPLES INVOLVE PHYSICS AND MATHEMATICAL CONCEPTS TO UNDERSTAND THE WAY THE IMAGE IS PRODUCED, AND INCLUDE THREE PROCESSES:- Ø DATA ACQUISITION Ø IMAGE RECONSTRUCTION Ø IMAGE DISPLAY, MANIPULATION, STORAGE AND RECORDING.  STEPS OF CT DATA ACQUISITIONS Ø X-RAY TUBE AND DETECTORS ARE IN PERFECT ALIGNMENT. Ø THE TUBE AND DETECTORS SCAN THE PATIENT TO COLLECT A LARGE NUMBER OF TRANSMISSION MEASUREMENTS. Ø THE BEAM IS SHAPED BY SPECIAL FILTER AS IT LEAVES THE TUBE. Ø THE BEAM IS COLLIMATED TO PASS THROUGH ONLY THE SLICE OF INTEREST. Ø THE BEAM IS ATTENUATED BY THE PATIENT AND THEN MEASURED BY THE DETECTORS.  CONTD… Ø THE DETECTORS CONVERT THE X-RAY PHOTONS INTO AN ELECTRICAL SIGNAL (ANALOG DATA). Ø THE ANALOG DATA ARE CONVERTED TO DIGITAL DATA BY ANALOG TO DIGITAL CONVERTER, (ADC). Ø THE DIGITAL DATA ARE SENT TO THE COMPUTER FOR IMAGE RECONSTRUCTION. BASIC SCHEME FOR DATA ACQUISITION:  1st generation Scanner Ø DESIGN: SINGLE X-RAY SOURCE AND SINGLE X-RAY DETECTOR CELL TO COLLECT ALL THE DATA FOR A SINGLE SLICE Ø SOURCE AND DETECTOR, RIGIDLY COUPLED Ø BEAM: PENCIL BEAM (TRANSLATED ACROSS PATIENT TO OBTAIN SET OF PARALLEL PROJECTION MEASUREMENTS AT ONE ANGLE ) http://www.youtube.com/watch?v=fNaCxhhhZTE  1st generation Scanner Ø SOURCE/DETECTOR ROTATE SLIGHTLY AND A SUBSEQUENT SET OF MEASUREMENTS ARE OBTAINED DURING A TRANSLATION PAST PATIENT Ø PROCESS IS REPEATED FOR EACH ANGLE UNTIL 180 PROJECTIONS. Ø TRANSLATION AND ROTATION PROCESS, THIS GEOMETRY IS REFERRED TO AS A TRANSLATE/ROTATE SCANNER  1st generation Scanner Ø 4.5 MINUTES FOR A SINGLE SCAN Ø RESOLUTION VERY POOR  2ND GENERATION SCANNER Ø DESIGN: MULTIPLE DETECTORS ( 30 DETECTORS ) Ø SMALL FAN BEAM Ø SOURCE AND ARRAY OF DETECTORS ARE TRANSLATED AS IN A FIRST GENERATION SYSTEM Ø MULTIPLE PROJECTIONS OBTAINED DURING EACH TRAVERSAL PAST THE PATIENT Ø THIS GENERATION :A TRANSLATE/ROTATE SCANNER https://www.youtube.com/watch?v=Ni4Hsi3GhXo  2ND GENERATION SCANNER Ø REDUCING SCAN TIME ( TWO TO THREE MINUTES ) Ø UP TO 53 DETECTORS Ø FASTER THAN 1ST ONE  3RD GENERATION SCANNER Ø DESIGN: LARGER ARRAY OF DETECTORS (300-700 DETECTORS) Ø WIDE FAN BEAM Ø TUBE AND DETECTOR ARRAY ROTATE AROUND PATIENT Ø DIFFERENT PROJECTIONS ARE OBTAINED DURING ROTATION Ø SCANNERS ROTATE 360° FOR EACH SCAN. Ø THIS GENERATION :A ROTATE /ROTATE SCANNER https://www.youtube.com/watch?v=bdf0kXn5Eeg  3RD GENERATION SCANNER Ø SHORTER SCANNING TIME (2 SEC) Ø HIGH SPATIAL RESOLUTION Ø IMAGING PROCESS IS SIGNIFICANTLY FASTER THAN 1ST OR 2ND GENERATION SYSTEMS  The CT Imaging System PART2 ILO’s On completion of this section, the student should be able to know the following: 4TH GENERATION SCANNERS: FIFTH-GENERATION SCANNER SIXTH-GENERATION CT SCANNERS SEVENTH-GENERATION CT SCANNERS MOBILE CT SCANNERS Course Instructors Dr. Saddig Jastaniah & Dr. Jamaan Al-Ghamdi 3/3/24 14  4TH GENERATION SCANNERS: Ø DESIGN: STATIONARY DETECTOR RING & ROTATING X-RAY TUBE (600 TO 4,800 DETECTORS) Ø LARGER FAN BEAM Ø ONLY THE X-RAY GENERATOR AND TUBE ROTATE AT 360 Ø SHORTER SCANNING TIME http://www.youtube.com/watch?v=AWVz3yke_bY Course Instructors Dr. Saddig Jastaniah & Dr. Jamaan Al-Ghamdi 3/3/24 16  FIFTH-GENERATION SCANNER:- Ø HIGH SPEED SCANNER, ACQUIRE SCAN DATA IN MILLISECONDS. Ø TWO SUCH SCANNERS ARE THE ELECTRON BEAM SCANNER (EBCT) AND DYNAMIC SPATIAL RECONSTRUCTION (DSR). Ø OWING TO ITS HIGH-SPEED CAPABILITIES , THE PRIMARY APPLICATION OF EBCT IS CARDIAC IMAGING. Ø THE DYNAMIC SPATIAL RECONSTRUCTION (DSR) IS A HIGHLY SPECIALIZED FIFTH GENERATION HIGH-SPEED SCANNERS CAPABLE OF PRODUCING DYNAMIC THREE-DIMENSIONAL(3D) IMAGES.  ELECTRON BEAM CT SCANNER http://www.youtube.com/watch?v=0fXWEyx2q2M EBCT VS. CONVENTIONAL CT SYSTEMS 1. THE FIFTH-GENERATION SCANNER DESIGN IS BASED ON THE ELECTRON BEAM TECHNOLOGY WHERE THERE IS NO X-RAY TUBE FOR THE PRODUCTION OF X- RAY. 2. THE DATA CAN BE ACQUIRED 10 TIMES FASTER THAN THAT WITH CONVENTIONAL CT SYSTEMS 3. THE DATA ACQUISITION GEOMETRY IS DIFFERENT FROM THAT OF OTHER GENERATIONS OF CT SCANNERS  SIXTH-GENERATION CT SCANNERS 1. THIS TYPE OF SCANNERS RESEMBLES THE THIRD X-Ray Tube GENERATION WITH THE ADDITION OF B X-Ray Tube ANOTHER SET OF TUBE AND DETECTORS A RESULTED IN TWO X-RAY TUBES AND TWO SETS OF DETECTORS 2. THE MAIN GOAL OF THIS SCANNER DESIGN IS 2 D s or et TO REDUCE SCANNING TIME WHICH IMPROVES ct ec te to De rs TEMPORAL RESOLUTION FOR IMAGING THE 1 HEART. Dual Source CT System  SEVENTH-GENERATION CT SCANNERS 1. FLAT-PANEL DIGITAL DETECTORS SUCH AS THE ONE USED IN DIGITAL RADIOGRAPHY. 2. IT PROVIDES ULTRA-HIGH SPATIAL RESOLUTION, BUT LOWER CONTRAST RESOLUTION; THUS, IT IS USED WHENEVER SHARPNESS IS NEEDED SUCH AS IN ANGIOGRAPHY. 3. THIS TYPE OF CT SCANNERS IS BEING INVESTIGATED FOR BREAST IMAGING APPLICATIONS.  MOBILE CT SCANNERS A SMALL GANTRY THAT IS USED FOR HEAD AND NECK IMAGING. A RECHARGEABLE AND WIRELESS SCANNER. IS USED IN INTENSIVE CARE UNITS (ICU), OPERATING ROOMS (OR), OR EMERGENCY ROOM (ER).