Validation of peneloPET simulations of the Biograph PET/CT scanner with TOF capabilities

Actas de: XXVIII Congreso Anual de la Sociedad Española de Ingeniería Biomédica (CASEIB 2010). Madrid, 24-26 de noviembre de 2010.Monte Carlo simulations are currently widely used in positron emission tomography (PET) imaging for optimizing detector design and acquisition protocols, and for developing and assessing corrections and reconstruction methods. PeneloPET is a Monte Carlo code for PET simulations with basic components of detector geometry, acquisition electronics and material and source definitions. The purpose of the present study was to validate the simulations of the Siemens Biograph PET/CT scanner with TOF capabilities performed with peneloPET. The scanner components incorporate four rings of 48 detector blocks. Each block comprises 13 × 13 matrix of 4 × 4 × 20 mm3. Results were compared with experimental data obtained in accordance with the NEMA-2007 performance measurement protocol done by Jakoby, et al.This work has been supported by MEC (FPA2007-62216), UCM (Grupos UCM, 910059), CPAN (Consolider-Ingenio 2010) CSPD-2007-00042, the RECAVA-RETIC network, ARTEMIS S2009/DPI-1802, European Regional Development, ENTEPRASE grant, PSE-300000-2009-5 and TEC2008-0675-C02-01, Ministerio de Ciencia e Innovación. Spanish Government.Publicad

PeneloPET simulations of the Biograph ToF clinical PET scanner

Proceedings of: 2011 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC). Valencia, Spain, 23-29 October 2011Monte Carlo simulations are widely used in positron emission tomography (PET) for optimizing detector design, acquisition protocols, as well as for developing and assessing corrections and reconstruction methods. PeneloPET is a Monte Carlo code for PET simulations which considers detector geometry, acquisition electronics and materials, and source definitions. PeneloPET is based on PENELOPE, a Monte Carlo code for the simulation of the transport in matter of electrons, positrons and photons, with energies up to 1 GeV. In this work we use PeneloPET to simulate the Biograph TruePoint (B-TP), Biograph TruePoint with TrueV (B-TPTV) and Biograph mCT PET/CT scanners. These configurations consist of three (B-TP) and four (B-TPTV and mCT) rings of 48 detector blocks. Each block comprises a 13 × 13 matrix of 4 × 4 × 20 mm3 LSO crystals. Simulations were adjusted to reproduce some experimental results from the actual scanners and validated by comparing their predictions to further experimental results. Sensitivity, spatial resolution, noise equivalent count (NEC) rate and scatter fraction (SF) were estimated. The simulations were then employed to estimate the optimum values of system parameters, such as energy and time coincidence windows and to assess the effect of system modifications (such as number of rings) on performance.This work was supported in part by Comunidad de Madrid (ARTEMIS S2009IDPI 1802), Spanish Ministry of Science and Innovation (ENTEPRASE Grant, PSE 300000 2009 5) and PRECISION grant IPT 300000 2010 3 and european regional funds and CPAN, Centro de Fisica de Particulas, Astroparticulas y Nuclear (CSD 2007 00042@Ingenio2010 12). This study has been (partially) funded by CDTI under the CENIT Programme (AMIT Project). Part of the calculations of this work was performed in the "Cluster de Calculo de Alta Capacidad para Tecnicas Fisicas "funded in part by UCM and in part by UE with European regional funds"Publicad

Glow curve analysis of glassy system dosimeter subjected to photon and electron irradiations

The current paper illustrates glow curve analysis of newly developed Borate glass dosimeters. A series of dosimetric properties including dose response for photons and electrons, energy response, optical fading, and precision were determined. Glow curve deconvolution based on the general order kinetics equation was applied to extract the trapping parameters. Excellent fitting was obtained with the superposition of three-second order glow peaks. The quality of fitting was monitored through the r2 value which is always in excess of 0.9998. Thermoluminescence (TL) measurements showed that the material exhibits good linear dose–response over the delivered range of absorbed dose from 0.5 to 4 Gy for photons and electrons irradiation with low energy dependence. The material exhibits large signal loss when exposed to direct sunlight and moderate signal loss when exposed to fluorescent light. Therefore, it is recommended to use the current dosimeters indoor and to avoid prolonged direct exposure to fluorescent light. This combination of properties makes the material suitable for radiation dosimetry

Evaluation of PeneloPET Simulations of Biograph PET/CT Scanners

Monte Carlo (MC) simulations are widely used in positron emission tomography (PET) for optimizing detector design, acquisition protocols, and evaluating corrections and reconstruction methods. PeneloPET is a MC code based on PENELOPE, for PET simulations which considers detector geometry, acquisition electronics and materials, and source definitions. While PeneloPET has been successfully employed and validated with small animal PET scanners, it required a proper validation with clinical PET scanners including time-of-flight (TOF) information. For this purpose, we chose the family of Biograph PET/CT scanners: the Biograph True-Point (B-TP), Biograph True-Point with TrueV (B-TPTV) and the Biograph mCT. They have similar block detectors and electronics, but a different number of rings and configuration. Some effective parameters of the simulations, such as the dead-time and the size of the reflectors in the detectors, were adjusted to reproduce the sensitivity and noise equivalent count (NEC) rate of the B-TPTV scanner. These parameters were then used to make predictions of experimental results such as sensitivity, NEC rate, spatial resolution, and scatter fraction (SF), from all the Biograph scanners and some variations of them (energy windows and additional rings of detectors). Predictions agree with the measured values for the three scanners, within 7% (sensitivity and NEC rate) and 5% (SF). The resolution obtained for the B-TPTV is slightly better (10%) than the experimental values. In conclusion, we have shown that PeneloPET is suitable for simulating and investigating clinical systems with good accuracy and short computational time, though some effort tuning of a few parameters of the scanners modeled may be needed in case that the full details of the scanners studied are not available.Comunidad de Madrid, Spanish Ministry of Science and Innovation, Human Frontier Science Program, CPAN, Innovative Medicines Initiative Joint Undertaking, 10.13039/501100004963-European Union’s Seventh Framework Programme, EFPIA companies, UCM, EU FP7-PEOPLE-2011-COFUND ProgramPeer Reviewe