Performance results of a new DOI detector block for a high resolution PET-LSO research tomograph HRRT

To improve the spatial resolution and uniformity in modern high resolution brain PET systems over the entire field of view (FOV), it is necessary to archive the depth of interaction (DOI) information and correct for spatial resolution degradation. In this work the authors present the performance results of a high resolution LSO/GSO phoswich block detector with DOI capability. This detector design will be used in the new CTI High Resolution Research Tomograph, ECAT HRRT. The two crystal layer (19/spl times/19/spl times/7.5 mm/sup 3/) and a light guide are stacked on each other and mounted on a (2/spl times/2) PMT set, so that the corners of the phoswich are positioned over the PMT centers. The crystal phoswich is cut into a 8/spl times/8 matrix of discrete crystals. The separation of the LSO and the GSO layer by pulse shape discrimination allows discrete DOI information to be obtained. The high light output and the light guide design results in an accurate identification of the 128 single crystals per block. Flood source measurements document a very good homogeneity of events, energy centroid stability and energy resolution (14-20% FWHM) per single crystal. An intrinsic resolution of /spl sim/1.3 mm and the DOI feasibility is extracted by coincidence measurements with a single GSO crystal.

[1]  Bojan T. Turko,et al.  Initial characterization of a position-sensitive photodiode/BGO detector for PET (positron emission tomography) , 1988 .

[2]  R. Nutt,et al.  A Multicrystal Two Dimensional BGO Detector System for Positron Emission Tomography , 1986, IEEE Transactions on Nuclear Science.

[3]  Wai-Hoi Wong,et al.  Designing a Stratified Detection System for PET Cameras , 1986, IEEE Transactions on Nuclear Science.

[4]  Joel G. Rogers,et al.  A method for correcting the depth-of-interaction blurring in PET cameras , 1995, IEEE Trans. Medical Imaging.

[5]  Christer Halldin,et al.  A PET-study of [11C]FLB 457 binding to extrastriatal D2-dopamine receptors in healthy subjects and antipsychotic drug-treated patients , 1997, Psychopharmacology.

[6]  C. Melcher,et al.  Cerium-doped lutetium oxyorthosilicate: a fast, efficient new scintillator , 1991, Conference Record of the 1991 IEEE Nuclear Science Symposium and Medical Imaging Conference.

[7]  Roger Lecomte,et al.  Design of a high resolution positron emission tomograph using solid state scintillation detectors , 1988 .

[8]  William J. Jagust,et al.  The cortical topography of temporal lobe hypometabolism in early Alzheimer's disease , 1993, Brain Research.

[9]  Magnus Dahlbom,et al.  Investigation of LSO crystals for high spatial resolution positron emission tomography , 1996 .

[10]  K. Shimizu,et al.  Development of 3-D detector system for positron CT , 1988 .

[11]  K. Shimizu,et al.  High resolution block detectors for PET , 1990 .

[12]  P. Bartzakos,et al.  A depth-encoded PET detector , 1990 .

[13]  T A Yousry,et al.  Preoperative activation and intraoperative stimulation of language-related areas in patients with glioma. , 1997, Neurosurgery.

[14]  Joel S. Karp,et al.  Depth-of-interaction determination in NaI(Tl) and BGO scintillation crystals using a temperature gradient , 1987 .

[15]  Wai-Hoi Wong,et al.  A positron camera detector design with cross-coupled scintillators and quadrant sharing photomultipliers , 1992 .