DOI measurement with monolithic scintillation crystals: A primary performance evaluation

Abstract

We report a first assessment of image quality enhancement achieved by the implementation of depth of interaction detection with monolithic crystals. The method of interaction depth measurement is based on analogue computation of the standard deviation with an enhanced charge divider readout. This technique of depth of interaction detection was developed in order to provide fast and determination of this parameter at a reasonable increase of detector cost. The detector consists of an large-sized monolithic scintillator coupled to a position sensitive photomultiplier tube. A special design feature is the flat-topped pyramidal shape of the crystal. This reduces image compression near the edges of the scintillator. We studied the image enhancement qualitatively with a FDG filled hot spot phantom and quantitatively by displacing a single point source along a radial axis. An important uniformity improvement was observed for the reconstructed image of the hot spot phantom when depth of interaction correction was applied. A moderate improvement of the spatial resolution was observed when reconstructing the images of the point source with depth of interaction correction.

Time reconstruction study using tubes of response backprojectors in list mode algorithms, applied to a monolithic crystals based breast PET

“…Every detector block mainly consists of a pyramidal truncated LYSO monolithic scintillation crystal coupled to a position sensitive photomultiplier tube (PSPMT). With monolithic crystals, the scintillation light distribution is preserved allowing us for an accurate photon impact determination, including its depth of interaction [21]. All crystal surfaces but the one in contact with the PSPMT are black painted in order to avoid unwanted reflections.…”

Biopsy system guided by positron emission tomography in real-time

“…The first moment gives the centroid along X and Y directions of the light distribution, determining the plane impact position (X,Y). The second moment is an excellent estimator of the DOI [13] and it is calculated using the information on the light spread that reaches the entrance window of the PSPMT. Coincidences between each detector and its seven opposite detector modules are allowed, providing a transaxial FOV of 170 mm.…”

Statistical moments of scintillation light distribution analysis with dSiPMs and monolithic crystals

“…The most important centered moment is the variance, µ ′ 2,0 and µ ′ 0,2 , that are a measure for the width of the distribution which are strongly correlated with depth of interaction (DOI) [2]. Note that for symmetric distributions, µ ′ 2,0 = µ ′ 0,2 .…”