MRI for attenuation correction in PET: methods and challenges

Wagenknecht, Gudrun; Kaiser, H.; Mottaghy, Felix M.; Herzog, Hans

doi:10.1007/s10334-012-0353-4

Cited by 201 publications

(152 citation statements)

References 53 publications

Supporting

Mentioning

150

Contrasting

Order By: Relevance

“…The values for each tissue class were chosen by inspecting the corresponding CT images of the training patients. The values are comparable to those reported by other authors (Wagenknecht et al 2013).…”

Section: Discussionsupporting

confidence: 92%

Region specific optimization of continuous linear attenuation coefficients based on UTE (RESOLUTE): application to PET/MR brain imaging

et al. 2015

View full text Add to dashboard Cite

The reconstruction of PET brain data in a PET/MR hybrid scanner is challenging in the absence of transmission sources, where MR images are used for MR-based attenuation correction (MR-AC). The main challenge of MR-AC is to separate bone and air, as neither have a signal in traditional MR images, and to assign the correct linear attenuation coefficient to bone. The ultra-short echo time (UTE) MR sequence was proposed as a basis for MR-AC as this sequence shows a small signal in bone. The purpose of this study was to develop a new clinically feasible MR-AC method with patient specific continuous-valued linear attenuation coefficients in bone that provides accurate reconstructed PET image data.A total of 164 [ 18 F]FDG PET/MR patients were included in this study, of which 10 were used for training. MR-AC was based on either standard CT (reference), UTE or our method (RESOLUTE). The reconstructed PET images were evaluated in the whole brain, as well as regionally in the brain using a ROI-based analysis. Our method segments air, brain, cerebral spinal fluid, and soft tissue voxels on the unprocessed UTE TE images, and uses a mapping of R * 2 values to CT Hounsfield Units (HU) to measure the density in bone voxels.

show abstract

Section: Discussionsupporting

confidence: 92%

Region specific optimization of continuous linear attenuation coefficients based on UTE (RESOLUTE): application to PET/MR brain imaging

et al. 2015

View full text Add to dashboard Cite

show abstract

“…This is an active area of study and several methods have been developed for AC based on MR acquired information (37,38). Most commercial systems use a segmentation approach to account for PET attenuation from fat and water tissue using Dixon fat-water separated images and known AC coefficients.…”

Section: Pet Attenuation Correction (Ac)mentioning

confidence: 99%

“…AC of these hardware components is required as their presence leads to considerable attenuation of the PET signal (37). Rigid and stationary MR hardware components, such as the patient table, are corrected for by integrating CT-based attenuation templates of these parts at a fixed position in the μ-map used for AC in PET image reconstruction (38).…”

Section: Pet Attenuation Correction (Ac)mentioning

confidence: 99%

Potential of PET-MRI for imaging of non-oncologic musculoskeletal disease

Kogan

Fan

Gold

2016

Quant. Imaging Med. Surg.

View full text Add to dashboard Cite

Early detection of musculoskeletal disease leads to improved therapies and patient outcomes, and would benefit greatly from imaging at the cellular and molecular level. As it becomes clear that assessment of multiple tissues and functional processes are often necessary to study the complex pathogenesis of musculoskeletal disorders, the role of multi-modality molecular imaging becomes increasingly important.New positron emission tomography-magnetic resonance imaging (PET-MRI) systems offer to combine high-resolution MRI with simultaneous molecular information from PET to study the multifaceted processes involved in numerous musculoskeletal disorders. In this article, we aim to outline the potential clinical utility of hybrid PET-MRI to these non-oncologic musculoskeletal diseases. We summarize current applications of PET molecular imaging in osteoarthritis (OA), rheumatoid arthritis (RA), metabolic bone diseases and neuropathic peripheral pain. Advanced MRI approaches that reveal biochemical and functional information offer complementary assessment in soft tissues. Additionally, we discuss technical considerations for hybrid PET-MR imaging including MR attenuation correction, workflow, radiation dose, and quantification.

show abstract

“…This approach works directly in standard T1-dependent MR images routinely for every patient. The most difficult task in using these images is the differentiation between bone tissue and air-filled spaces, as the same intensity range appears in both those tissue types [25].…”

Section: Technological Achievements Of Pet/mr Systemsmentioning

confidence: 99%