Evaluation of a Combined Array-Planar Crystal for Gamma-ray Scintillation Imagers

Transcription

1 Evaluation of a Combined Array-Planar Crystal for Gamma-ray Scintillation Imagers R.Pani 1, R.Scafè 2, R.Pellegrini 1, A.Soluri 3, N.Burgio 2, C.Ciavola 2, M.N.Cinti 1, L.Indovina 1, G.De Vincentis 1, F.Garibaldi 4, F.Cusanno 4, G.M.Urciuoli 4 and E.Cisbani 4 1 Department of Experimental Medicine, University of Rome "La Sapienza", Rome, Italy 2 ENEA, C.R. Casaccia, Rome, Italy 3 Institute of Biomedical Technologies, CNR, Rome, Italy 4 Laboratory of Physics, ISS, Rome, Italy

2 R697 ( 8 inch ) Hamamatsu PSPMT Family ( crossed wire anode) R3292 ( 5 inch ) R2486 ( 3 inch ) R59 ( 1 inch )

3 SPEM Single Photon Emission Mammography A new scintigraphic technique based upon a small FOV dedicated gamma camera The main advantages of this detection system with respect to Anger camera are the compactness and the light weight SPEM detection system SPEM detection head

4 SPEM Single Photon Emission Mammography SPEM detection system allows to perform scintigrafic breast projection as Rx mammography Uncompressed Breast Compressed Breast Cranio Caudal projection

5 Spatial resolution in PSM From: J.A.Sorenson and M.E.Phelps Physics in Nuclesr Medicine Grune & Strattom ANGER CAMERA 1-15 cm Object collimator distance OCD (cm )

6 Spatial resolution in SPEM Moderate compression 3 cm SPEM

7 PSM (Prone Scinti Mammography) by using commercially available Gamma Camera Proper positioning in PSM Prone scintimammography is the only useful view allowed for a patient

8 SPEM Single Photon Emission Mammography 99m Tc Sestamibi scintimammography: Right Breast Carcinoma 13 mm sized a b a: SPEM Camera scan clearly shows the lesion as an inhomogeneous area of increase uptake of tracer (arrow) b: The same breast imaged by commercially available Anger Camera showing the lesion as a small hot spot (arrow)

9 99m Tc Sestamibi Scintimammography a b Right Breast Carcinoma 7 mm sized c d RCC uncompressed RCC compressed a and b SPEM Camera imaging with breast uncompressed (a) and mildly compressed: into the red circle the lesion is shown as an area of increased uptake of tracer c: The same breast imaged by commercially available Anger Camera: no pathological uptake is shown d: The corresponding X-Ray mammography- the lesion is surrounded by a red circle

10 2 x 2 PSPMT Hamamatsu R 59-C8 With flanges 2 x 2 PSPMT Hamamatsu R 76-C8 25 mm Flangeless 3 mm dead zone 2 mm

11 Diagram of Multi-PSPMT camera (All dimensions in mm). External dimension 27.7 ±.5 25 ±.5 22 photocathode 18 anode Flanges (2 mm) Overall dead zone 5.7 mm Scintillation light distribution

12 Read-out electronics and acquisition system Camera base PSDD PC Σx, Πx, Σy, Πy Quad ADC FAST 774 FAST Intf box PC FAST MP card

13 CsI(Na) planar crystal 55 x 55 x 3 mm 3 2 mm quartz CsI(Tl) crystal array 3 x 3 x 3 mm 3 pixel size 3 mm quartz 2 x 2 PSPMT Hamamtsu R59-C8 Flood filed irradiation 14 kev 13

14 1 mm quartz PSPMT R59-C8 Hamamatsu CsI(Tl) crystal array 3 x 3 x 3 mm 3 Flood filed irradiation 14 kev 3 mm quartz 5 mm quartz

15 Multi PSPMT Spatial Resolution CsI(Tl) crystal array 3x3x3 mm 3 / 3 mm quartz 1 cm Counts FWHM 2.5 mm resolution [mm FWHM] position [pixel] CsI(Na) planar crystal / 2 mm quartz position [mm]

16 6 counts per channel (a.u.) x 2 PSPMT R59-C8 FWHM=21% flood spot CsI(Na) planar crystal 14 kev irradiation Channels Counts per channel CsI(Tl) crystal array 3 x 3 x 3 mm 3 / 3 mm quartz FWHM=29% Counts per channel Channels Channels Channels 16

17 SCHEMA CAPC

18 COMBINED ARRAY- PLANAR CRYSTAL CsI(Na) CAPC 3 x 3 mm 2 /.25 mm dead zone

19 2 x 2 PSPMT Hamamtsu R76-C8 Individual PSPMT Energy Response from Flood Field Irradiation at 14 kev Counts Channels

20 R59-C8 PSPMT Crystal array / 3 mm quartz CAPC Flood Field Irradiation R59-C8 R76-C8 Counts CsI(Tl) CsI(Na) CsI(Na) Channe Channels Counts 45 Channels Counts Channels

21 Counts FWHM=25% R76 without flanges Multi PSPMT- CsI(Na) CAPC Energy Resolution Counts R59 with flanges Channels FWHM=22% Counts FWHM=22% Canali Channels kev spot irradiation Channels

22 2 x 2 PSPMT Hamamatsu 76-C8 CAPC CsI(Na) Spot irradiation Counts Position (pixels)

23 Counts Counts CsI(Na) CAPC Spatial Resolution 14 kev spot irradiation 5 mm FWHM 2.7 mm FWHM mm Position(Pixels) FWHM mm R76-C8 R59-C8 5 mm Position(Pixels)