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Paolo Bosco
(INFN)
22/05/2018, 16:15
Dealing with heterogeneity is the main challenge that scientists are facing in several diseases, including Autism Spectrum Disorders (ASD). This complexity urges the implementation of dedicated analysis techniques to obtain the maximum from the interrelationship among the numerous variables that describe affected individuals, including clinical phenotypic characterization, genetic profile and...
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Pavel Nikulin
(Helmholtz-Zentrum Dresden-Rossendorf, PET Center, Institute of Radiopharmaceutical Cancer Research)
22/05/2018, 16:15
As is well known, utilization of time-of-flight (TOF) information can reduce noise and improve convergence rate in PET image reconstruction since it allows to incorporate the (Gaussian) probability density function (the ”TOF-kernel”) of the annihilation event position along the respective LOR into the image reconstruction process. In doing so, it is crucial to use the best possible estimate of...
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Mikio Suga
(Chiba University)
22/05/2018, 16:15
We are developing an add-on PET system which is an MR birdcage RF-coil integrated with DOI-PET detectors. This is expected to enable realization of a high resolution, high sensitivity and low cost PET-MRI system. In the proposed system, PET detectors are extremely close to the MR RF-coil. To reduce electromagnetic interaction between the PET detectors and the MR RF-coil, the PET detectors...
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João M. Sousa
(Uppsala University)
22/05/2018, 16:15
The performance of the Bayesian likelihood reconstruction algorithm in PET/MR brain imaging using receptor or transporter ligands has not previously been investigated. Ten patients underwent PET/MR brain scanning with the dopamine transporter ligand 11C-PE2I and images were reconstructed using a Bayesian penalized likelihood algorithm, with a regularization term of 25, 50, and 100, in addition...
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Roido Manavaki
(University of Cambridge)
22/05/2018, 16:15
1 - Instrumentation: detectors and electronics
Poster
Attenuation correction of brain MRI coils used on PET/MR systems can be prone to error emanating from artifacts in CT-based coil attenuation maps. In this study editing was applied to coil CT images to reduce the impact of metal-induced artifacts. In addition, CT-based attenuation maps were generated for the coil mirrors and four levels of smoothing were applied to the attenuation maps. A...
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Gaspar Delso
(UniversitätsSpital Zürich)
22/05/2018, 16:15
The purpose of this study was to evaluate a new, template-enhanced zero-echo-time (ZTE) attenuation correction method for PET/MR scanners. 20 subjects underwent 18F-FDG PET/CT, followed by PET/MR on a GE SIGNA PET/MR. A ZTE sequence was used to generate two attenuation maps: one with the standard segmentation-based method; and another with an enhanced version using pre-registered anatomical...
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Joshua Daniel Kaggie
(University of Cambridge)
22/05/2018, 16:15
Quantitative MRI has previously shown benefits for the assessment of ovarian cancer. Magnetic Resonance Fingerprinting (MRF) is a novel technique for quantitative MRI, which exploits the transient signals caused by the variation of MRI sequence parameters.
This proof-of-concept work demonstrates the utility of MRF in two patients, with low and high grade ovarian tumours on a 3.0 T MRI....
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Christoffer Laustsen
(MR Research Centre, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark)
22/05/2018, 16:15
Hyperpolarized (HP) 13C magnetic resonance imaging (MRI) is a promising tool for in vivo metabolic interrogation of disease states and treatment efficacy assessment. However, the method is currently limited by the lack of good quantitative measures. This is particularly true in humans where large variations in transport kinetics have been reported [1]. Here we introduce a novel model-free...
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Jarmo Teuho
(Turku PET Centre, University of Turku and Department of Medical Physics, Turku University Hospital, Turku, Finland)
22/05/2018, 16:15
We evaluated whether applying SPM12 instead of SPM8 to delineate bone, soft tissue and air for head MR-based attenuation correction (MRAC) would be feasible. The differences in bone delineation between SPM8- and SPM12-based MRAC methods were studied by visual analysis and evaluation of dice coefficients against CT-based attenuation correction (CTAC). The quantitative accuracy in PET was...
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Tim Fryer
(University of Cambridge)
22/05/2018, 16:15
Fourier rebinning combined with 2D filtered backprojection (FORE-FBP) was implemented for the GE SIGNA PET/MR. The algorithm was designed and tested for brain imaging. Spatial resolution, image uniformity and signal-to-noise ratio (SNR) were assessed for a range of maximum ring differences (ΔZ). Results were compared to those for ordered subsets expectation maximum (OSEM) and time-of-flight...
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Parisa Khateri
(Institute for Particle Physics and Astrophysics, ETH Zürich, Switzerland)
22/05/2018, 16:15
The SAFIR collaboration is developing a PET insert for a pre-clinical MRI system, aiming at excellent temporal resolution, of ~5s time frames. Image reconstruction is performed using the Software for Tomographic Image Reconstruction (STIR). An accurate system matrix is necessary for the precise reconstruction of quantitative PET data and the exact representation of the scanners geometry is a...
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Amadeo Iborra
(LaTIM, INSERM, UMR 1101, Brest, France)
22/05/2018, 16:15
We present a simple but accurate model to compute the uncertainty regions of impact coordinates measured in monolithic crystals. The proposed model considers the scintillation crystal, internal reflection, crystal coating, the presence of a surface retroreflective structure, and the pixel detector layout. This model is used to estimate the uncertainty in the LOR vertex location, and...
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Poonam Choudhary
(Buffalo Neuroimaging Analysis Center, University at Buffalo)
22/05/2018, 16:15
1 - Instrumentation: detectors and electronics
Poster
This study presents preliminary results on the feasibility of truly simultaneous PET-MRI in live mice on a conventional 9.4T MRI system retrofitted with a miniature-PET ring. Wild-type and Twitcher mice, a model of Krabbe disease, were anaesthetized and imaged longitudinally at four time points. Simultaneously acquired MRI images allowed the generation of a model-specific brain template for...
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Matteo Cencini
(Università di Pisa)
22/05/2018, 16:15
The purpose of this work is to obtain quantitative MRI maps of fat and water with a fast acquisition for musculoskeletal imaging applications. Conventional fat separation methods are based on steady-state signal models, relying either on relaxometry or chemical shift. A recent approach for parameter mapping, called magnetic resonance fingerprinting (MRF), uses transient-state acquisitions,...
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Inés Mérida
(CERMEP-Imagerie du vivant, Lyon, France)
22/05/2018, 16:15
The correction of head motion of dynamic PET in the context of PET-MR imaging can benefit from estimation either based on PET data, or on MRI data, when both modalities have been simultaneously acquired. Based on a recent method developed for a direct correction of PET list-mode data during the rebinning of PET dynamics into sinograms, this paper reports the study of the relation between...
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Paola Scifo
(Nuclear Medicine Dept., IRCCS San Raffaele Scientific Institute, Milan, Italy)
22/05/2018, 16:15
In this work we present the characterization of the physical performance of the fully integrated PET/MR whole body system SIGNA PET/MRI (GE Medical Systems), following the NEMA NU 2-2012 standards. All the measurements, except count rate performance, have been performed first in the PET-only mode, without the simultaneous MR acquisition (MR-idle), then with two different MR pulse sequences on...
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Kevin Chen
(Department of Radiology, Stanford University)
22/05/2018, 16:15
2 - Software and quantification
Poster
In this study, we aimed to generate diagnostic-quality amyloid positron emission tomography (PET) images from “low-dose” PET images, reconstructed from massively undersampled raw data, as well as simultaneously-acquired multimodal magnetic resonance imaging (MRI) contrasts used as inputs in a convolutional neural network (CNN) framework. We have shown that the synthesized images generated from...
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Pietro Carra
(PI)
22/05/2018, 16:15
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Maya Ottilia Dalgaard
(Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen)
22/05/2018, 16:15
AIM:
Scatter correction is applied in PET imaging to reduce signal from scattered coincidence events, thereby improving image quality and quantitative accuracy. In dynamic PET imaging, predefined time frames with the aim of reflecting tissue metabolism over time contain the net coincidence count registered within a specific time window. Short time frames are often desired to obtain precise...
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Göran Rosenqvist
(Karolinska Institute)
22/05/2018, 16:15
Background
The Mediso LFER-150 is currently the only commercially available high resolution PET/CT-system mainly dedicated for non-human primate (NHP) imaging. The gantry bore diameter of the system is 26 cm. The transaxial and axial fields of view are 15 cm and 20 cm respectively. Resolution at the center of field of view, in images reconstructed with full detector modelling, is 1 mm . These...
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Stephen Sawiak
(Wolfson Brain Imaging Centre, University of Cambridge)
22/05/2018, 16:15
Magnetic resonance fingerprinting (MRF) uses non-steady state magnetic resonance acquisitions and dictionary-based matching to measure parameters such as T1, T2, B0 and B1. Standard clinical contrasts can then be calculated from these retrospectively. Here, we implement a radial acquisition scheme for MRF and apply it to the animal brain at 9.4T to map T1 and B1 in short in vivo acquisitions...
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Catherine Scott
(UCL)
22/05/2018, 16:15
Due to the long acquisition time required for dynamic PET with pharmacokinetic (PK) modelling, the statically acquired standardised uptake value ratio (SUVR) is commonly used. However, SUVR is sensitive to blood flow changes which confound longitudinal studies. We have proposed a framework to incorporate cerebral blood flow (CBF) from arterial spin labelling (ASL) MRI into the PK modelling to...
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Carlo Mancini Terracciano
(ROMA1)
22/05/2018, 16:15
The therapy for locally advanced rectal cancers is: neoadjuvant chemo-radiotherapy (CRT) followed by radical surgery. Although the local pelvic recurrence rate is lower than 10%, this therapeutic approach is an over-treatment of the patients who completely respond (CR) to CRT. Indeed, CR could benefit from either less invasive surgery (ie, transanal endoscopic microsurgery) or “wait-and-watch”...
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Giada Fallo
(Dipartimento di Informatica, Università di Pisa)
22/05/2018, 16:15
Magnetic resonance fingerprinting (MRF) is a new quanti- tative imaging paradigm, which simultaneously acquires multiple tissue parameters in an efficient experiment. MRF can map several parameters simultaneously including T1, T2, and spin density. However, it is important to underline that specific sequences may be better suited for certain parameter ranges or sampling patterns. This work...
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Domokos Máthé
(CROmed Translational Research Centers, H-1047 Budapest, Hungary)
22/05/2018, 16:15
Sepsis-associated encephalopathy (SAE) is a frequent and devastating complication of severe acute systemic inflammation that can cause both acute and long-lasting neurological dysfunction and heavily contributes to the mortality of patients with sepsis. The knowledge of the pathophysiological processes overwhelming the brain at this early stage of sepsis is far from complete. The purpose of...
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Edwin ter Voert
(Department of Nuclear Medicine, University Hospital Zurich and University of Zurich)
22/05/2018, 16:15
In contrast to ordered subset expectation maximization (OSEM), block sequential regularized expectation maximization (BSREM) PET reconstruction algorithms can run until full convergence while controlling image quality and noise. Recent studies with BSREM and 18F-FDG PET reported higher signal-to-noise ratios and higher standardized uptake values (SUV). In this study we investigate the optimal...
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Anders Olin
(Dept. of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet, Denmark)
22/05/2018, 16:15
AIM:
We explore the feasibility of performing PET/MR scans of head and neck cancer (HNC) patients in radiation therapy (RT) treatment position using MR-compatible RT immobilization devices. We develop and test a proper workflow and scan protocol, which can be implemented for daily routine. Finally, to explore the use of multiparametric PET/MR in relation to personalized RT, we compare the...
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