Objectives
The main goal of the HYPERImage project is focused in the development of a brand new system for simultaneous whole-body high time resolution PET-MR imaging for humans.
We plan to significantly contribute with the improvement in the diagnose of several human diseases, and to help providing with a state-of-the-art technology for future applications in Biomedical and Clinical research. In order to achive this goal, the following objectives are now conducted:
Development of MR compatible detector technology with ultra-high time resolution
For concurrent acquisition of PET and MR data within an MR scanner the project will develop PET detector technology based on dedicated silicon photomultipliers (SiPM). To increase the effective sensitivity, and to reduce scan-time and the dependence of the sensitivity on the patient size, the detector will be designed to support time-of-flight measurements with extremely short coincidence time resolution (<200 ps), yielding a gain in effective sensitivity of 10 compared to standard systems, see Figure 1.2.1. This will be achieved by the development of a fast and highly sensitive SiPM technology, and a low jitter and low power signal acquisition unit. The requirement for low power consuption is essential to prepare the technology for the integrated whole body application.
HYPERImage will focus in particular on reducing the mutual interferences between the PET and the MR data measurement to a level which allows undisturbed image acquisition with both modalities at the same time.
Development of concurrent PET/MR test systems
It is the aim to develop two PET/MR test systems in order to investigate the technical and the preclinical/clinical feasibility of concurrent PET/MR. Initially, a preclinical system will be constructed, both to guide further developments towards a clinical whole body test system, and to test concurrent PET/MR under preclinical conditions. Secondly, the human whole body test system will be constructed.
Development of 4D PET/MR motion, attenuation, and functional data acquisition techniques
It is the aim to develop acquisition and data processing techniques that will enable MR monitoring of patient motion to be used to correct the PET data for the effects of this motion, and enable MR image data to be used to correct the PET data for the effects of photon attenuation. This is to ensure that quantitatively accurate PET images are obtained from the hybrid system, and to enhance the quality of the PET images by correcting for patient motion. MR acquisition sequences will be developed such that the PET correction data is acquired along with complementary functional MR data. These techniques will be evaluated in phantom studies and subsequently in pre-clinical and clinical studies.
PET/MR test and validation in preclinical studies towards cancer and cardiovascular diseases (CVD)
It is the aim of the preclinical investigations to show the technical feasibility of the PET/MR animal insert, providing with significant data in living human disease models, which will contribute to the fine tuning of the system ready for clinical validation in humans. Furthermore, it is the aim to demonstrate the MR-based motion compensation of PET with concurrent acquisition of (f)MRI, with respect to early detection, staging, and response monitoring of tumours, atherosclerosis and myocardial infarction. MR guided biopsy will be used to investigate the correlation between PET and MR images.
First clinical whole body PET/MR investigations towards breast cancer
Here, HYPERImage aims to determine the improvement in diagnostic efficacy gained with motion compensation and MR based attenuation correction from concurrent PET/MR, and compare this with conventional sequential PET/MR. The registration of (f)MRI features (e.g., spectroscopy) will be correlated with values obtained with PET, to improve the early detection, staging, and response monitoring of breast cancer. Furthermore, it is the aim to asses the advantage of concurrent imaging with dual-agent injection studies. Image guided biopsy will be applied to improve on the targeting of specific tumour regions.
