BACKGROUND Positron emission tomography (PET) studies using 15O-labeled CO2, O2, and CO have been used in humans to evaluate cerebral blood flow (CBF), the cerebral oxygen extraction fraction (OEF), and the cerebral metabolic rate of oxygen (CMRO2) and cerebral blood volume (CBV), respectively. In preclinical studies, however, PET studies using 15O-labeled gases are not widely performed because...

UNLABELLED The Inveon small-animal PET scanner is characterized by a large, 127-mm axial length and a 161-mm crystal ring diameter. The associated high sensitivity is obtained by using all lines of response (LORs) up to the maximum ring difference (MRD) of 79, for which the most oblique LORs form acceptance angles of 38.3 degrees with transaxial planes. The result is 2 phenomena that are normal...

SPECT imaging suffers from low spatial resolution and statistical noise. Consequently, the contrast of small structures is reduced, visual detection of defects is limited and exact quantification is difficult. To improve the contrast, it is possible to incorporate a blurring model into the iterative reconstruction process such as OSEM3D. This approach is well known to be effective, but time con...

Using iterative three-dimensional (3D) reconstruction techniques for reconstruction of positron emission tomography (PET) is not feasible on most single-processor machines due to the excessive computing time needed, especially so for the large sinogram sizes of our high-resolution research tomograph (HRRT). In our first approach to speed up reconstruction time we transform the 3D scan into the ...

conclusion osem3d may provide better image quality and higher contrast than other methods for small animal imaging with the new myocardial imaging agent, [18f] fptp. results the location and size of myocardial infarction on pet images correlated closely with that observed with ttc staining. among the four reconstruction methods, osem3d provided the best assessment of infarct size (r2 = 0.994, p...

Time-of-flight (TOF) positron emission tomography (PET) was studied and preliminarily developed in the 1980s, but the lack of a scintillator able to deliver at the same time proper time resolution and stopping power has prevented this technique from becoming widespread and commercially available. With the introduction of LSO in PET, TOF is now a feasible option. TOF reconstruction has been impl...

Institute of Neuroscience and Medicine, Forschungszentrum Jülich, Jülich, Germany To quantify CBF studies using [O]water PET an input function must be provided, e.g. by means of arterial blood sampling. An image derived input function (IDIF) gained from the dynamic PET images may be a non-invasive alternative. The time-activity curve (TAC) of the blood can be obtained from a volume of interest ...

Institute of Biophysics and Biomedical Engineering, Faculty of Sciences, University of Lisbon, Portugal The introduction of hybrid MR-PET scanners offers new perspectives to better correlate MR and PET data with respect to time and space domain. In case of brain tumor patients, dynamic susceptibility contrast (DSC)-MRI is often used to measure perfusion levels of brain, while dynamic [F]-fluoro...