Resolution properties of a prototype continuous miniature crystal element (cMiCE) scanner

Continuous miniature crystal element (cMiCE) detectors are a potentially lower cost alternative to high resolution discrete crystal PET detector designs. We report on performance characteristics of a prototype PET scanner consisting of two cMiCE detector modules. Each cMiCE detector is comprised of a 50 mm by 50 mm by 8 mm LYSO crystal coupled to a 64 channel multi-anode PMT. The cMiCE detectors use a statistics-based positioning method based upon the maximum likelihood method for event positioning. In addition, cMiCE detectors can provide some depth of interaction event positioning information. For the prototype scanner, the cMiCE detectors were positioned across from one another on a horizontal gantry with a detector spacing of 10.1 cm. Full tomographic data were collected by placing the object to be imaged on a rotating stage. Data were collected in a step and shoot fashion with 6 degree angular steps. Data were collected for point sources placed at 1, 5, 10 and 15 mm radial offset from the center of the imaging field of view. Data were binned using single slice rebinning and reconstructed using filtered back projection with a ramp filter. The average image resolutions for X (radial), Y (transverse) and Z (axial) were 1.09 mm, 0.99 mm, 1.25 mm FWHM, respectively. The initial imaging results from a prototype cMiCE imaging system demonstrate the outstanding image resolution performance than can be achieved using cMiCE detectors.