Implementation of ML based positioning algorithms for scintillation cameras

Joung, Jinhun; Miyaoka, Robert S.; Kohlmyer, S.G.; Lewellen, T.K.

doi:10.1109/23.856555

Cited by 35 publications

(7 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The spatial resolution using simple COG was about 4.7 mm above the center of PMT. Since, the maximum likelihood (ML) based methods [20][21][22] and also some iterative methods which have been discussed in the [23,24], require more calibration and implementation effort, we used digital CSE method which sums PMT signals in row/column arrangement, then applies a threshold and a correction factor on the row/column signals before COG. In figure 2 (right), the line spacing is uniform regarding the PMT position, indicating image linearity along X and Y directions although, there is still shrinkage in the edges of the crystal.…”

Section: Discussionmentioning

confidence: 99%

Development and calibration of a new gamma camera detector using large square Photomultiplier Tubes

et al. 2017

View full text Add to dashboard Cite

Large area scintillation detectors applied in gamma cameras as well as Single Photon Computed Tomography (SPECT) systems, have a major role in in-vivo functional imaging. Most of the gamma detectors utilize hexagonal arrangement of Photomultiplier Tubes (PMTs). In this work we applied large square-shaped PMTs with row/column arrangement and positioning. The Use of large square PMTs reduces dead zones in the detector surface. However, the conventional center of gravity method for positioning may not introduce an acceptable result. Hence, the digital correlated signal enhancement (CSE) algorithm was optimized to obtain better linearity and spatial resolution in the developed detector. The performance of the developed detector was evaluated based on NEMA-NU1-2007 standard. The acquired images using this method showed acceptable uniformity and linearity comparing to three commercial gamma cameras. Also the intrinsic and extrinsic spatial resolutions with low-energy high-resolution (LEHR) collimator at 10 cm from surface of the detector were 3.7 mm and 7.5 mm, respectively. The energy resolution of the camera was measured 9.5%. The performance evaluation demonstrated that the developed detector maintains image quality with a reduced number of used PMTs relative to the detection area.

show abstract

Section: Discussionmentioning

confidence: 99%

Development and calibration of a new gamma camera detector using large square Photomultiplier Tubes

et al. 2017

View full text Add to dashboard Cite

show abstract

“…A 2D position of interaction is usually obtained by a simple centroid calculation based on the signal from the different PMTs [1]. However, a better spatial resolution and linearity can be obtained using a maximum-likelihood (ML) position estimation [31,32]. Normally, 2D positioning is considered sufficient, but DOI information can be useful, especially if non-parallelhole collimators are used [33,34].…”

Section: Detection Position Estimationmentioning

confidence: 99%

Advances in clinical molecular imaging instrumentation

Hutton

Erlandsson

Thielemans

2018

Clin Transl Imaging

View full text Add to dashboard Cite

In this article, we describe recent developments in the design of both single-photon emission computed tomography (SPECT) and positron emission tomography (PET) instrumentation that have led to the current range of superior performance instruments. The adoption of solid-state technology for either complete detectors [e.g., cadmium zinc telluride (CZT)] or read-out systems that replace photomultiplier tubes [avalanche photodiodes (APD) or silicon photomultipliers (SiPM)] provide the advantage of compact technology, enabling flexible system design. In SPECT, CZT is well suited to multi-radionuclide and kinetic studies. For PET, SiPM technology provides MR compatibility and superior time-of-flight resolution, resulting in improved signal-to-noise ratio. Similar SiPM technology has also been used in the construction of the first SPECT insert for clinical brain SPECT/MRI.

show abstract

“…Splines made of higher degree polynomials are smoother but more costly to evaluate. Following the approach used in [13,15,22], we have decided to use cubic splines for LRF parameterization as it ensures a smooth first derivative (important for convergence of several minimization algorithms) while still not being too computationally expensive. Besides piecewise polynomial functions, splines can also be presented as a weighted sum of basis functions called B-splines.…”

Section: Splinesmentioning

confidence: 99%

B-spline parameterization of spatial response in a monolithic scintillation camera

et al. 2016

View full text Add to dashboard Cite

A framework for parameterization of the light response functions (LRFs) in a scintillation camera is presented. It is based on approximation of the measured or simulated photosensor response with weighted sums of uniform cubic B-splines or their tensor products. The LRFs represented in this way are smooth, computationally inexpensive to evaluate and require much less computer memory than non-parametric alternatives. The parameters are found in a straightforward way by the linear least squares method. Several techniques that allow to reduce the storage and processing power requirements were developed. A software library for fitting simulated and measured light response with spline functions was developed and integrated into an open source software package ANTS2 designed for simulation and data processing for Anger camera type detectors.

show abstract

Implementation of ML based positioning algorithms for scintillation cameras

Cited by 35 publications

References 12 publications

Development and calibration of a new gamma camera detector using large square Photomultiplier Tubes

Development and calibration of a new gamma camera detector using large square Photomultiplier Tubes

Advances in clinical molecular imaging instrumentation

B-spline parameterization of spatial response in a monolithic scintillation camera

Contact Info

Product

Resources

About