Motion tracking / correction in PET-MRI

All motion related topics can be found here ...

Attenuation correction in PET-MRI using WASPI

One of the biggest hurdles of PET-MR is the accurate attenuation correction especially for the bone. The standard approach is to segment an MR image volume into different tissue classes and then assign the corresponding attenuation coefficients to them. Due to the lack of signal from solid bone in normal MR sequences, accurate attenuation correction in regions within or near bone is still an open problem. Investigators have proposed atlas-based technique and ultrashort echo time (UTE) pulse sequence based segmentation technique. These approaches might not fully capture the intra- and inter-subject bone density variation, which will inevitably lead to bias in reconstructed PET images.

We investigated using the Water- And fat-Suppressed Proton projection Imaging (WASPI) sequence to obtain accurate and continuous attenuation for the bones which accounts for intra- and inter-subject bone attenuation variations. Using data acquired from a phantom, it was shown that attenuation based on WASPI sequence is more accurate and precise comparing to conventional MR attenuation correction and UTE based segmentation approaches.

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Simultaneous PET-MRI

Simultaneous Positron Emission Tomography (PET) and Magnetic Resonance (MR) imaging (PET-MR) is a novel and promising hybrid modality generating substantial interest in recent years. Individually, these two imaging modalities have complementary advantages and disadvantages in terms of sensitivity, molecular specificity, and spatial and temporal resolution. Their strengths may be integrated and provide new insights in neuroimaging through the concurrent acquisition of synergistic anatomical, functional and biochemical information