A standalone Monte Carlo simulation toolkit at the micro-cell level to mimic SiPMs signals

International audienceRecently, a SiPM digitizer has been implemented in GATE version 8.2 and has been made available as open source code. A standalone version of this experimentally-validated digitizer is presented here, which allows to simulate a SiPM offline or with data not specifically generated with GATE. It is composed of a C++ class with a default implemention including several functions modeling the SiPM detection efficiency, geometry, noise properties (crosstalk, afterpulse), timing response (SPTR and micro-cell signal shape generation). All parameters can be modified by the user to match with a desired experimental or simulated setup. The SiPM class allows Mont Carlo simulation at the micro-cell scale and is based on the generation of a signal for each impinging photon (also called pulse) onto a micro-cell

A standalone Monte Carlo simulation toolkit at the micro-cell level to mimic SiPMs signals

International audienceRecently, a SiPM digitizer has been implemented in GATE version 8.2 and has been made available as open source code. A standalone version of this experimentally-validated digitizer is presented here, which allows to simulate a SiPM offline or with data not specifically generated with GATE. It is composed of a C++ class with a default implemention including several functions modeling the SiPM detection efficiency, geometry, noise properties (crosstalk, afterpulse), timing response (SPTR and micro-cell signal shape generation). All parameters can be modified by the user to match with a desired experimental or simulated setup. The SiPM class allows Mont Carlo simulation at the micro-cell scale and is based on the generation of a signal for each impinging photon (also called pulse) onto a micro-cell

First images from a CeBr 3 /LYSO:Ce Temporal Imaging portable Compton camera at 1.3 MeV

International audienceDuring nuclear decommissioning or waste management operations, there is a need for imaging the contamination field while identifying and quantifying the contaminants. Our objective is to test a Compton camera within the energy range 300 keV-2 MeV that uses both light and timing distribution of fast scintillating monolithic crystals. In this experiment we use a 5 mm thick CeBr3 scatterer plate and a 20 mm thick LYSO absorber plate. Our algorithms record for each scintillation event the full position and energy of the event including DOI, even in the thin plate and the relative timing between the detection in the two plate. Our CRT was measured at 293 ps FWHM in coincidence mode without DOI correction. This good time resolution allows for a stringent veto on real Compton event that must be recorded simultaneously in both the scatterer and the absorber plates, thus reducing background very efficiently. Acquisitions were performed with a Phillips Digital Photon Counter SiPM 3200 matrix with a delay-time correction map applied pixel by pixel. After accurate detection of gamma interaction coordinates (x,y,z) and energy in each plate, a list-mode maximum likelihood iterative reconstruction algorithm is applied to better estimate the gamma source activity distribution. Our Compton camera is a promising device for imaging high energy gamma rays, moreover, it can be also suitable for on-line monitoring due to its timing performance. The project TEMPORAL is funded by the ANDRA/PAI under the grant No. RTSCNADAA160019

Faux anévrisme après ligature d'un canal artériel opéré avec succès

Postoperative aneurysm of ductus arteriosus is a rare complication but may be lethal without treatment. It is less frequent than spontaneous aneurysm of ductus arteriosus. We report the case of 5 years-old girl who underwent a ligation of patent ductus arteriosus complicated, 6 months later, with a false aneurysm of ductus arteriosus and endocarditis of the ductus and the aortic valve. The diagnosis of the aneurysm was suspected on the anteroposterior chest X-ray which showed a left superior mediastinal opacity and confirmed by echocardiography. Through bilateral thoracotomy, an anevrismorraphy and aortic repair was carried out without problem. The postoperative course was unremarkable

Primary pericardial synovial sarcoma: A case report and literature review

Primary pericardial synovial sarcoma is extremely rare, with few published cases in the literature. We report the case of an adolescent aged 13 years with primary pericardial synovial sarcoma discovered during tamponade, confirmed by molecular biology, and for whom treatment combined radiosurgery and adjuvant chemotherapy. The particularity of the case we are reporting stems from the young age of our patient (13 years) as well as the duration of remission, which is quite long (21 months) prior to a superior mediastinal relapse compared to cases reported in the literature.\ud Learning objective: Synovial sarcoma is difficult to diagnose and has a poor prognosis. Here, a 13-year-old diagnosed with primary pericardial synovial sarcoma was treated with combined radiosurgery and adjuvant chemotherapy leading to continuous remission for 21 months. This regimen could be used to successfully manage future patients. Molecular biology is useful in the diagnosis of synovial sarcoma through the identification of t(X;18) translocation in atypical locations as in the present case