Speaker
Description
Positron Emission Tomography (PET) systems have significantly evolved in the last decade with the access to new photosensor technology such as Silicon Photomultipliers (SiPM) and novel readout electronics enabling the possibility to accurately determine the Coincidence Timing Resolution (CTR) of the two annihilation photons.
There has been a large effort into the so-called Total-Body PET (TB-PET) imaging for humans. That means, PET systems with a very large axial coverage, in one case up to 2 meters long. This development makes it possible to increase the system sensitivity a factor 40 compared to 20-25 cm axial length of conventional whole-body PET systems. TB-PET also allows clinicians to perform multi-organ imaging. The non-negligible drawback of such TB-PET endeavors is their huge cost.
An alternative to increase the effective sensitivity is to improve the timing capabilities. For instance, a CTR of 100 ps FWHM will boost this sensitivity by a factor of 16. Moreover, organ-dedicated systems exhibit higher overall performance than WB or TB-PET due to their smaller geometries. I3M has developed several organ-dedicated PET systems, recently including the capabilities to reach 240 ps CTR. In most of the systems monolithic crystal technology is used, offering determination of the depth of interaction of the annihilation event and, thus, allowing one to correct for the parallax error.
In this contribution we describe systems such as the breast dedicated MAMMI reaching 1.4 mm spatial resolution with few thousands of patients already scanned. Two new designs are ongoing, one based on two-panels PET and another on an edgeless crystal geometry. We will also describe the brain dedicated PET so-called MINDView that is also an insert, that means MR compatible. This system uses the largest volume of monolithic crystals in a clinical PET scanner. A circular prostate-dedicated PET system was developed few years ago, after the attempt of using novel geometries, and tested at the neighboring largest hospital in our region. Our last development is a heart PET system, based on crystal arrays but reaching timing resolutions below 240 ps CTR. Other novel designs will also be discussed.
