Attenuation Correction Synthesis for Hybrid PET-MR Scanners: Application to Brain Studies

• Published in: IEEE transactions on medical imaging Vol. 33; no. 12; pp. 2332 - 2341
• Main Authors: Burgos, Ninon, Cardoso, M. Jorge, Thielemans, Kris, Modat, Marc, Pedemonte, Stefano, Dickson, John, Barnes, Anna, Ahmed, Rebekah, Mahoney, Colin J., Schott, Jonathan M., Duncan, John S., Atkinson, David, Arridge, Simon R., Hutton, Brian F., Ourselin, Sebastien
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.12.2014; The Institute of Electrical and Electronics Engineers, Inc. (IEEE); Institute of Electrical and Electronics Engineers
• Subjects: Accuracy; Algorithms; Attenuation; Attenuation correction; Bones; Brain - anatomy & histology; Brain - diagnostic imaging; Computed tomography; Computer Science; Humans; image synthesis; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Medical Imaging; Multimodal Imaging - methods; Neuroimaging - methods; Positron emission; Positron emission tomography; positron emission tomography/magnetic resonance (PET/MR); Positron-Emission Tomography - methods; Scanners; Synthesis; Tomography; biomedical MRI; magnetic resonance imaging; multi-atlas information propagation scheme; biomedical equipment; patient-specific attenuation map; attenuation correction improvement; synthetic attenuation map generation; visual databases; segmentation method; simplified atlas-based method; MRI image; CT synthesis; MRI-derived patient morphology matching; Accuracy; Image synthesis; Databases; Computed tomography; database of MRI-CT pair matching; Attenuation; Bones; positron emission tomography/magnetic resonance (PET/MR); data acquisition; local image similarity measure; positron emission tomography data quantification; Attenuation correction; medical image processing; brain study application; hybrid PET-MR scanner; image reconstruction; computed tomography image; brain; image matching; 0; computerised tomography; attenuation correction synthesis; synthetic CT image generation; ultrashort-echo-time MRI sequence; positron emission tomography; neurophysiology; PET-CT acquisition system; PET reconstruction accuracy
• ISSN: 0278-0062; 1558-254X
• DOI: 10.1109/TMI.2014.2340135

Attenuation correction is an essential requirement for quantification of positron emission tomography (PET) data. In PET/CT acquisition systems, attenuation maps are derived from computed tomography (CT) images. However, in hybrid PET/MR scanners, magnetic resonance imaging (MRI) images do not directly provide a patient-specific attenuation map. The aim of the proposed work is to improve attenuation correction for PET/MR scanners by generating synthetic CTs and attenuation maps. The synthetic images are generated through a multi-atlas information propagation scheme, locally matching the MRI-derived patient's morphology to a database of MRI/CT pairs, using a local image similarity measure. Results show significant improvements in CT synthesis and PET reconstruction accuracy when compared to a segmentation method using an ultrashort-echo-time MRI sequence and to a simplified atlas-based method.