1. TU Delft IRI-ST Inorganic Scintillators in Medical-imaging Detectors C.W.E. van Eijk A msterdam, 9 September 2002

2. TU Delft IRI-ST Radiation in Medical Imaging Energies X-ray imaging Mammography 25 kVp, ~18 keV Radiography, chest 150 kVp Fluoroscopy 150 kVp X-ray CT 150 kVp Nuclear medicine Scintigraphy 80 - 140 keV SPECT 60 - 511 keV PET 511 keV Efficiency Inorganic scintillator Modality emission transmission

3. TU Delft IRI-ST From: Philips Medical Systems BV300 series Mobile C-arm system for full surgical and minimally-invasive procedures Interventional Radiology Fluoroscopy - Real time - Low dose ImageIntensifier

4. TU Delft IRI-ST Transjugular Intrahepatic Portosystemic Shunt (TIPS) Interventional Radiology minimally-invasive procedure

5. TU Delft IRI-ST Flat panel detector - Amorphous silicon also for radiography Columnar CsI:Tl ADC readout addressing Interventional Radiology From: Philips, Aachen Flat X-ray Detectors for Medical Imaging Dr. Michael Overdick Session 5 2k x 2k 40 x 40 cm 2

6. TU Delft IRI-ST signal depends on: –scintillator light yield –optical coupling –spectral matching –diode efficiency Photodiode From: Philips, Aachen Flat panel detector - Amorphous silicon Interventional Radiology

7. TU Delft IRI-ST pillar growth induced by evaporation technique –crack structure –focussing of light –>500 µm layers –high MTF CsI:Tl From: Philips, Aachen Interventional Radiology

8. TU Delft IRI-ST X-ray Computed Tomography X-ray source (rotating) + 1-D or 2-D position-sensitive detector (rotating) X-ray fan beam (rotating) + Ceramic scintillators + photodiodes ~ 1 k x 1 mm ~ 16 x 1 mm E. Hell et al, NIM A 454 (2000) 40-48

9. TU Delft IRI-ST 1974: 80 x 80 pixels slices of 13 mm spacing 2000: 1024 x 1024 pixels spiral scanning From: W.A. Kalender, CT, 2000, MCD Verlag X-ray Computed Tomography

10. TU Delft IRI-ST density ρZ 4 light yield dec. time afterglow wavel. max. (g/cm 3 ) (10 6 ) (phot./MeV) (μs) (% after (nm) 3/100 ms) CdWO 4 7.9 134 20,000 5 < 0.1/ 0.02 495 Bi 4 Ge 3 O 12 (BGO) 7.1 2279,000 0.3 480 CsI:Tl 4.5 38 66,000 8- > 6 >2/0.3 550 Gd 2 O 2 S:Pr,Ce,F 7.3 103 35,000 4 < 0.1/< 0.01 510 Gd 2 O 2 S:Pr (UFC) 7.3 10350,000 3 0.02/0.002 510 Y 1.34 Gd 0.60 O 3 :(Eu,Pr) 0.06 5.9 44 44,000 1000 4.9/< 0.01 610 (Hilight) Gd 3 Ga 5 O 12 :Cr,Ce 7.1 58 40,000 140 < 0.1/0.01 730 Lu 2 O 3 :Eu,Tb 9.4 211 30,000 > 1000 > 1/0.3 610 X-ray Computed Tomography Ceramic Scintillators

11. TU Delft IRI-ST From: W.A. Kalendber, CT, 2000, MCD Verlag Afterglow in scintillators 1 angle per < ms X-ray Computed Tomography

12. TU Delft IRI-ST Positron Emission Tomography Detector ring (inner diam. ~ 0.8 m) Collinearly emitted 511 keV quanta detected in coincidence Radiopharmaceutical β + emitter Detectors BGO + PMT Bi 4 Ge 3 O 1 2

13. TU Delft IRI-ST http://www.epub.org.br/cm/n01/pet/pet_hist.htm PET systems Siemens-CTI Positron Emission Tomography

14. TU Delft IRI-ST PET Detector Block A B C D 4 PMTs BGO detector block 8 x 8 columns 30 mm of 6 x 6 x 30 mm 3 Bi 4 Ge 3 O 1 2 Efficiency

15. TU Delft IRI-ST Positron Emission Tomography: 2D & 3D

16. TU Delft IRI-ST From: G. Muehllehner et al. & SCINT 2001 Increase Random coincidences ~ N 2 singles τ 3D PET Energy resolution Time resolution Positron Emission Tomography Light yield Decay time Non-proportionality

17. TU Delft IRI-ST Bi 4 Ge 3 O 12 (BGO) 7.1 11.6 / 44 9,000 300 480 Lu 2 SiO 5 :Ce (LSO) 7.4 12.3 / 34 26,000 40 420 Gd 2 SiO 5 :Ce (GSO) 6.7 15 / 26 8,000 60 440 Lu x Y 1-x AlO 3 : Ce (LuAP) 8.3 11.0 / 32 11,000 18 365 Lu 2 Si 2 O 7 :Ce (LPS) 6.2 14.5 / 29 20,000 30 380  1 /μ 511 keV light yield  (g/cm 3 ) (mm) /PE (%) (photons/MeV) (ns) (nm) Positron Emission Tomography PET Scintillators Energy resolution poor

18. TU Delft IRI-ST ΔE/E = 3.1 % photomultiplier readout Hamamatsu R1791 LaCl 3 :Ce(10%) Scintillators Energy Resolution 600700 0 200 400 600 800 1000 1200 1400 1600 LaCl 3 :Ce counts energy [keV] LaCl 3 :Ce E (keV) COUNTS E.V.D. van Loef et al Appl. Phys. Lett. 77 (2000) 1467

19. TU Delft IRI-ST PET basics: Position resolution Efficient High position resolution parallax error or radial elongation Off centre: incorrect Line of Response Remedy: Depth of Interaction measurement DOI

20. TU Delft IRI-ST PET: Depth of Interaction in HRRT PMTs LSO scintillators Light guides PMTs 7.5 x 2.1 x 2.1 mm 3 From: D.W. Townsend, C. Morel presented at SCINT 2001 K. Wienhard et al 2000 IEEE NSS/MIC CDROM 17 280 Lu 2 SiO 5 :Ce Different decay times in the two layers  Different pulse shape  DOI

21. TU Delft IRI-ST Depth of Interaction LuAP APD array Pulse shape discrimination Saoudi et al IEEE Trans Nucl Sci 46(1999)462, also 479 Seidel et al IEEE Trans Nucl Sci 46(1999)485 LSO PET: DOI Crystal Clear

22. TU Delft IRI-ST From: Klaus Wienhard MPI für Neurologische Forschung, Köln Blood flow changes under speech activation (red) Tumor (green) Multi modality PET + MRI Positron Emission Tomography

23. TU Delft IRI-ST Inorganic Scintillators in Medical-imaging Detectors Conclusion Interest in further improvement of inorganic scintillators Fundamental research Especially for PET also Mammography PET Small Animal PET Use of new light detectors APDs Silicon drift detectors C.W.E. van Eijk Inorganic scintillators in medical imaging Phys.Med.Biol. 47 (2002) R85 - R106