Photon Counting Detectors

Transcription

1 J. Xu et l. (preseted t AAPM, 9/5/ 6 Cscded Systems Alysis of Silico-Strip Photo Coutig Systems J Xu W Zbijewski, G Gg,,JW Stym J Crrio, K Tguchi, E Fredeberg 4 JH Siewerdse, Dept.of Biomedicl Egieerig, Istitute of Biomedicl Egieerig, Uiversity of Toroto Russel H. Morg Dept. of Rdiology, 4 Phillips Wome's Helthcre, Sol, Swede Photo Coutig Detectors Advtges of Coutig Low dditive oise Spectrl iformtio Improved CNR Mteril decompositio Chllegig Chrcteristics Temporl respose (pileup) Eergy respose (spectrl resolutio) Modelig of Imgig Performce Cscded systems model Trck the distributio of ut t ech stge of the imgig chi Test gist bechtop system Oil C Iodie Philips MicroDoseSi strip PCD Phillips M. Tpiovr et l, Med Phys (985) J. Tguy et l. Med Phys () (

2 J. Xu et l. (preseted t AAPM, 9/5/ g g T g4 T5 σ6 t III8 photo (E) kvp kvp kvp kev Normlized s PDF E E E de TASMIP, J.M. Booe et l, Med Phys (99) g g T g4 T5 σ6 t III8 Photo iterctio (E) kev E PE totl C totl g g PE C E, E E, E (

3 J. Xu et l. (preseted t AAPM, 9/5/ g g T g4 T5 σ6 t III8 Iterctio Geertio of secodry ut ( = ) (electros) g E E E g E Poisso ;me= E W W Work fuctio of detector g g T g4 T5 σ6 t III8 Iterctio Secodry ut Electro cloud blur.4.5 p () p e ; g4p d g4p d M. Ludvist et l, IEEE () (

4 J. Xu et l. (preseted t AAPM, 9/5/ g g T g4 T5 σ6 t III8.4 Iterctio Secodry ut Electro cloud Collectio efficiecy.5 4 () g p ; g4p d g4p d g g T g4 T5 σ6 t III8 Iterctio Secodry ut Electro cloud Collectio efficiecy Aperture 4 () 5 (;=) (# electros) 4 (#electros) ; ; g4p d 4p d g () ( 4

5 J. Xu et l. (preseted t AAPM, 9/5/ g g T g4 T5 σ6 t III8 Iterctio Secodry ut Electro cloud Collectio efficiecy Aperture Additive oise 6 (;=) dd ; dd 6 e dd dd.5.5 (# electros) 4 E. Fredeberg, g g T g4 T5 σ6 t III8 6 (;=) t Iterctio Secodry ut Electro cloud Collectio efficiecy t (threshold) 6 4 Aperture Additive oise Thresholdig,t (# electros) ; t ; t 6 ( 5

6 J. Xu et l. (preseted t AAPM, 9/5/ g g T g4 T5 σ6 t III8 Iterctio Secodry ut Electro cloud Collectio efficiecy Aperture Additive oise Threshold Smplig 6 4,t.8 t ; t 8 ; III 8 ; b t (threshold) Imgig Performce Metrics t (threshold) 6,t orm ut F t MTF ; ; t NPS ut ; t MTF ut ; III 8 u; b DQE ut ; t u t ut MTF ; NPS ; ( 6

7 J. Xu et l. (preseted t AAPM, 9/5/ Eperimetl Prmeters X-Ry Source Detector photos s Trsltio & Rottio Tble Imgig Techiue kvp ( Al +. Cu filtrtio) - ma tube curret 5 ms pulse durtio Detector Specifictios Edge-o Si-strip detectors.5. piel size.6 thickess Model Prmeter Vlue ḡ. g T ḡ rys/ /mas W =. ev/electro σ =. T 5 σ 6 t III 8 =.5 σ dd 6 = electros vrious b =.5 Compriso of Theory d Mesuremet: Me Sigl # photos t ma: t (detector threshold) # photos kvp = t = theory mesuremet Tube curret (ma) (

8 J. Xu et l. (preseted t AAPM, 9/5/ Compriso of Theory d Mesuremet: MTF d NPS.8 kvp = t =.5 ma MTF(u).6.4 NPS ( ) ma 4 ma. theory mesuremet 5 5 Sptil Freuecy ( - ).5.5 ma ma 4 5 Sptil Freuecy ( - ) Detective Qutum Efficiecy DQE(u) kv p DQE(u) t Sptil Freuecy ( - ). kvp 4 ma Sptil Freuecy ( - ) ( 8

9 J. Xu et l. (preseted t AAPM, 9/5/ Coclusio Modelig PCD systems Imge ulity metrics Other PCD types (CdTe, CdZTe, etc.) Compriso to eergy-itegrtig systems Future Work Blur from Compto iterctios Coicidece rejectio Reductio of chrge shrig Et Etesio of model dlto: D recostructio Spectrl imgig Ackowledgmets The I STAR Lb Collbortors () Joche Ci Collbortors (Philips Helthcre) Erik Fredeberg Mts Ludvist Mgus Aslud Hk Lgemrk Mts Dielsso Fudig NIH CA R 6 ( 9