title: An indirect method for in vivo T2mapping of [1-13C] pyruvate using hyperpolarized13C CSI.
abstract: An indirect method for in vivo T2mapping of13C-labeled metabolites using T2and T2* information of water protons obtained a priori is proposed. The T2values of13C metabolites are inferred using the relationship to T2' of coexisting1H and the T2* of13C metabolites, which is measured using routine hyperpolarized13C CSI data. The concept is verified with phantom studies. Simulations were performed to evaluate the extent of T2estimation accuracy due to errors in the other measurements. Also, bias in the13C T2* estimation from the13C CSI data was studied. In vivo experiments were performed from the brains of normal rats and a rat with C6 glioma. Simulation results indicate that the proposed method provides accurate and unbiased13C T2values within typical experimental settings. The in vivo studies found that the estimated T2of [1-13C] pyruvate using the indirect method was longer in tumor than in normal tissues and gave values similar to previous reports. This method can estimate localized T2relaxation times from multiple voxels using conventional hyperpolarized13C CSI and can potentially be used with time resolved fast CSI.
authors.affiliation: Department of Electrical and Electronic Engineering, Yonsei University, Seoul, Korea.
authors.forename: Eunhae
authors.initials: E
authors.lastname: Joe
authors.affiliation: Department of Electrical and Electronic Engineering, Yonsei University, Seoul, Korea.
authors.forename: Hansol
authors.initials: H
authors.lastname: Lee
authors.affiliation: Center for Neuroscience Imaging Research, Institute for Basic Science, Sungkyunkwan University, Suwon, Korea.
authors.forename: Joonsung
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Electrical and Electronic Engineering, Yonsei University, Seoul, Korea.
authors.forename: Seungwook
authors.initials: S
authors.lastname: Yang
authors.affiliation: Department of Radiology, College of Medicine, Yonsei University, Seoul, Korea.
authors.forename: Young-Suk
authors.initials: YS
authors.lastname: Choi
authors.affiliation: Department of Radiology, College of Medicine, Yonsei University, Seoul, Korea.
authors.forename: Eunkyung
authors.initials: E
authors.lastname: Wang
authors.affiliation: Department of Radiology, College of Medicine, Yonsei University, Seoul, Korea.
authors.forename: Ho-Taek
authors.initials: HT
authors.lastname: Song
authors.affiliation: Department of Electrical and Electronic Engineering, Yonsei University, Seoul, Korea.
authors.forename: Dong-Hyun
authors.initials: DH
authors.lastname: Kim
mesh_terms: D000465:Algorithms; D000818:Animals; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001932:Brain Neoplasms / Q000378:metabolism* / Q000473:pathology; D066241:Carbon-13 Magnetic Resonance Spectroscopy / Q000379:methods*; D005260:Female; D005910:Glioma / Q000378:metabolism* / Q000473:pathology; D019289:Pyruvic Acid / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D014018:Tissue Distribution
chemical_list: D014408:Biomarkers, Tumor; D019289:Pyruvic Acid
keywords: C6 glioma; T2 relaxation time; [1-13C] pyruvate; hyperpolarized 13C; in vivo metabolic CSI