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The purpose of our experimental study was to assess the accuracy and precision of CT angiography (CTA), MR angiography (MRA) and rotational digital subtraction angiography (DSA) for measuring the volume of an in vitro aneurysm model. A rigid model of the anterior cerebral circulation harbouring an anterior communicating aneurysm was connected to a pulsatile circuit. It was studied using unenhanced 3D time-of-flight MRA, contrast-enhanced CTA and rotational DSA angiography. The source images were then postprocessed on dedicated workstations to calculate the volume of the aneurysm. CTA was more accurate than MRA (P=0.0019). Rotational DSA was more accurate than CTA, although the difference did not reach statistical significance (P=0.1605), and significantly more accurate than MRA (P<0.00001). CTA was more precise than MRA (P=0.12), although this did not reach statistical significance. Rotational DSA can be part of the diagnosis, treatment planning and support endovascular treatment of intracranial aneurysms. The emerging endovascular treatment techniques which consist of using liquid polymers as implants to exclude aneurysms from arterial circulation would certainly benefit from this precise measurement of the volume of aneurysms

Multiple time-to-digital converters coupled with silicon photomultipliers allow to timestamp several light photons generated by a scintillation event. Multichannel digital silicon photomultipliers opened the possibility to estimate a gammaphoton time mark by using several photoelectrons timestamps. We studied the already-existing statistics models of photoeletron time-stamping generation, while extending the current models by adding the skipping effect. Which accounts for the inability of the system to timestamp a continuous set of photoelectrons. In addition, we proposed two multiple photoelectron timemark estimators based on the best linear unbiased and the maximum likelihood estimation methods. We calculated the Cram´er Rao lower bound for several system parameter and compared it to the proposed estimators’ performance. We concluded that under certain system configurations the proposed estimators are efficient. Moreover, we investigated the effect of the dark count rate on the timing performance. Also, we introduced a filtering method that is based on measuring the time distance between adjacent timestamps. We performed a full Monte Carlo simulation to evaluate the proposed filter efficiency. Finally, we performed a full Monte Carlo simulation to compare the timemark estimators’ performance. We concluded that the best linear unbiased estimator is as efficient as the maximum likelihood estimator. In addition, it was verified that the multichannel digital silicon photomultipliers have a stronger tolerance to dark counts in comparison current digital silicon photomultiplier architectures, Microelectronics, Electrical Engineering, Mathematics and Computer Science

We present an optimization technique utilizing order statistics with a multichannel digital silicon photomultiplier (MD-SiPM) for timing measurements. Accurate timing measurements are required by 3D rangefinding and time-of-flight positron emission tomography, to name a few applications. We have demonstrated the ability of the MD-SiPM to detect multiple photons, and we verified the advantage of detecting multiple photons assuming incoming photons follow a Gaussian distribution. We have also shown the advantage of utilizing multiple timestamps for estimating time-of-arrivals more accurately. This estimation technique can be widely available in various applications, which have a certain probability density function of incoming photons, such as a scintillator or a laser source., Microelectronics, Electrical Engineering, Mathematics and Computer Science

This thesis discusses the potential of CMOS based SiPMs, especially for TOF PET applications, in a systematic and comprehensive fashion. CMOS based SPADs are still need to be designed carefully to improve fill factor, TDCs be improved from the point of the area and power consumption, and the necessity of high voltage for SPADs be handled efficiently. Thus, this thesis also aims to design and integrate various circuits in the SiPM to realize the high integrations utilizing the biggest advantage of the CMOS technology., Microelectronics, Electrical Engineering, Mathematics and Computer Science

We present a 4 X 4 array of digital silicon photomultipliers (D-SiPMs) capable of timestamping up to 48 photons per D-SiPM and we show the advantage of generating multiple timestamps in the context of positron emission tomography (PET). The D-SiPMs have a pitch of 800 ?m and comprise 416 pixels each; the timing resolution achieved by the SiPMs is 179 ps FWHM, while each pixel has a fill factor of up to 57% and a single-photon timing resolution of 114 ps., Microelectronics, Electrical Engineering, Mathematics and Computer Science

The EndoTOFPET-US project aims to develop a multimodal detector to foster the development of new biomarkers for prostate and pancreatic tumors. The detector will consist of two main components: an external plate, and a PET extension to an endoscopic ultrasound probe. The external plate is an array of LYSO crystals read out by silicon photomultipliers (SiPM) coupled to an Application Specific Integrated Circuit (ASIC). The internal probe will be an highly integrated and miniaturized detector made of LYSO crystals read out by a fully digital SiPM featuring photosensor elements and digital readout in the same chip. The position and orientation of the two detectors will be tracked with respect to the patient to allow the fusion of the metabolic image from the PET and the anatomic image from the ultrasound probe in the time frame of the medical procedure. The fused information can guide further interventions of the organ, such as biopsy or in vivo confocal microscopy. © 2013 IOP Publishing Ltd and Sissa Medialab srl.

We present a single-photon avalanche diode (SPAD) with a wide spectral range fabricated in an advanced 180 nm CMOS process. The realized SPAD achieves 20 % photon detection probability (PDP) for wavelengths ranging from 440 nm to 820 nm at an excess bias of 4V, with 30 % PDP at wavelengths from 520 nm to 720 nm. Dark count rates (DCR) are at most 5 kHz, which is 30 Hz/?m2, at an excess bias of 4V when we measure 10 ?m diameter active area structure. Afterpulsing probability, timing jitter, and temperature effects on DCR are also presented., Microelectronics, Electrical Engineering, Mathematics and Computer Science