Self-gated Radial MRI for Respiratory Motion Compensation on Hybrid PET/MR Systems

Nagoya, Japan
Medical image computing and computer-assisted intervention : MICCAI ... International Conference on Medical Image Computing and Computer-Assisted Intervention 01/2013; 16(Pt 3):17-24. DOI: 10.1007/978-3-642-40760-4_3
Source: PubMed


Accurate localization and uptake quantification of lesions in the chest and abdomen using PET imaging is challenging due to the respiratory motion during the exam. The advent of hybrid PET/MR systems offers new ways to compensate for respiratory motion without exposing the patient to additional radiation. The use of self-gated reconstructions of a 3D radial stack-of-stars GRE acquisition is proposed to derive a high-resolution MRI motion model. The self-gating signal is used to perform respiratory binning of the simultaneously acquired PET raw data. Matching mu-maps are generated for every bin, and post-reconstruction registration is performed in order to obtain a motion-compensated PET volume from the individual gates. The proposed method is demonstrated in-vivo for three clinical patients. Motion-corrected reconstructions are compared against ungated and gated PET reconstructions. In all cases, motion-induced blurring of lesions in the liver and lung was substantially reduced, without compromising SNR as it is the case for gated reconstructions.

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    • "Such motion model is usually formed by registering 3-D images acquired at different breathing states. To apply a cyclic model, a 1-D surrogate signal of the true motion is used to represent the current breathing state and retrieve the corresponding motion [1] [2] [3]. A common limitation of cyclic model is the assumption that respiratory motions are repeatable, i.e. the respiratory motion follows the same path from cycle to cycle. "
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