TR&D Project I

Gamma-Ray Detectors and Imaging Systems

Project Leader

Lars R. Furenlid, Ph.D.

Project Summary

The overall goals of TR&D Project I are to develop the read-out electronics and software that operate the detectors developed in Core Project I and to integrate the resulting gamma-ray cameras into complete imaging systems by developing system gantries, apertures, shielded enclosures, positioning stages, calibration methods, and control software and hardware.

TR&D Project I also strives to translate its electronics and systems concepts into clinical applications, principally through collaborative research. As an example, in an ongoing project with Rush Memorial Hospital, we are providing several copies of our second-generation list-mode acquisition electronics and associated software to be used in a dedicated clinical cardiac SPECT system. Important themes include

  • Advancing the state of the art in spatial and temporal resolution in gamma-ray imaging through super-listmode front-end processing, in which all available information is recorded for each event and assembled into data packets that are transmitted to one or more back-end event buffers
  • Maximum-likelihood processing of event packets with advanced algorithms and hardware, including x86 clusters, cell processors, GPUs, and FPGAs
  • Adaptive imaging in which acquisition trajectories and system settings are automatically determined from pre-scans of the subject
  • Application-driven system designs that address the needs of the cardiovascular, cancer, and neuroimaging studies in Project V and collaborative research.

Current Projects

  • Imaging aperture
  • System design and fabrication

Imaging systems developed at the CGRI

Adaptive imaging system

  • Application: Hardware optimization for individual subjects and imaging tasks
  • Detector(s): 3 x 3 modular scintillation camera
  • System Status: Complete; first applications with simple feedback rules carried out

Dual-modality CT/SPECT

  • Application: Simultaneous imaging of anatomy and function in mice
  • Detector(s): CZT spot imager; CCD X-ray detector
  • System Status: Complete, nicely packaged, in routine use, produces excellent images. Plans in place for updating with Bazooka camera and Helical scanning mode out

FaCT (Addition of CT to FastSPECT II)

  • Application: Enhance capability by adding anatomic imaging
  • Detector(s): CMOS X-Ray Detector
  • System Status: Assembly complete and system approved by Radiation Control Office. Available for animal imaging. Mounted to FastSPECT II, but will be movable to AdaptiSPECT system


  • Application: Routine imaging of mice and rats
  • Detector(s): 24 2 x 2 modular scintillation cameras
  • System Status: Evaluation of cameras in order to decide on whether to refurbish with new acquisition electronics or retire is underway.


  • Application: Versatile animal imager
  • Detector(s): 16 3 x 3 modular scintillation cameras
  • System Status: In service following nearly year-long down time while cameras repaired by vendor


  • Application: High-resolution mouse and rat brain imaging
  • Detector(s): 20 BazookaSPECT detectors (image intensifier + fast, inexpensive CCD camera)
  • System Status: Phantom images look very good. First animal experiments underway. Revision to increase scintillator thickness and field of view planned

Gamma converter

  • Application: Conversion of current bioluminescence systems to SPECT
  • Detector(s): columnar CsI(Tl) scintillator (plus existing CCD)
  • System Status: Prototype constructed and tested

Gamma-ray microscope

  • Application: Ultrahigh-resolution imaging of small objects (e.g., cells in culture)
  • Detector(s): Single-channel Bazooka plus micro-coded aperture
  • System Status: Initial phantom and animal images obtained. Further development in the form of BazookaSPECT


  • Application: Dual-modality mouse imaging: SPECT and bioluminescence
  • Detector(s): ultrasensitive Roper CCD camera viewing scintillator
  • System Status: Prototype constructed and tested

M3R (multi-module, multi-resolution)

  • Application: Versatile, inexpensive table-top animal imager; test bed for synthetic collimator studies
  • Detector(s): 4 3 x 3 modular scintillation cameras
  • System Status: Very versatile system about to be used for adaptive imaging studies. Two cameras currently in use in ModPET system


  • Application: Compact, high-sensitivity PET system for animal imaging
  • Detector(s): 2 3 x 3 modular cameras with 25-mm CsI(Na) crystals
  • System Status: Available for animal PET imaging.

NanoSPECT (FastSPECT II with 100-µm pinholes)

  • Application: Ultrahigh-resolution imaging of implanted tumors Goal: 1 nL resolution
  • Detector(s): 16 3 x 3 modular scintillation cameras
  • System Status: See above. Aperture available. Generates very high-resolution images of mouse femurs with neuroblastoma tumors

SAMCAM (stand- alone modular camera)

  • Application: Planar imaging with 12 cm x 12 cm FOV
  • Detector(s): 3 x 3 modular scintillation camera
  • System Status: Collaborative projects with Academy of Athens, Vanderbilt University, and Marquette University. Cameras delivered systems operational


  • Application: Ultrahigh-resolution (~100 µm) SPECT at low energies (~30 keV)
  • Detector(s): 1-4 double-sided silicon-strip detectors
  • System Status: Calibration measurements complete; development of 3D reconstruction code on GPUs nearly finished

Single-channel BazookaSPECT

  • Application: Design studies and preliminary animal studies
  • Detector(s): Columnar scintillators, image intensifiers, and CCD/CMOS sensors
  • System Status: Excellent performance achieved. Disseminated to Lund and Galway. Collaborators have demonstrated tomographic acquisitions and reconstructions. New large area system for pre-tomography acquisition proving very valuable.

Spot imagers

  • Application: Sub-mm planar imaging of small objects; SPECT with animal rotation
  • Detector(s): 64 x 64 CZT hybrid array, 380-µm pixels, 25 mm x 25 mm FOV
  • System Status: Laboratory version complete and available for specialized applications

Synthetic SPECT

  • Application: Sub-mm planar imaging of small objects using focused pinhole collimator; SPECT with animal rotation
  • Detector(s): Columnar scintillators, image intensifiers, and CCD/CMOS sensors
  • System Status: Prototype constructed.
    Calibration measurements underway