title: In vivo blood T(1) measurements at 1.5 T, 3 T, and 7 T.
abstract: The longitudinal relaxation time of blood is a crucial parameter for quantification of cerebral blood flow by arterial spin labeling and is one of the main determinants of the signal-to-noise ratio of the resulting perfusion maps. Whereas at low and medium magnetic field strengths (B0), its in vivo value is well established; at ultra-high field, this is still uncertain. In this study, longitudinal relaxation time of blood in the sagittal sinus was measured at 1.5 T, 3 T, and 7 T. A nonselective inversion pulse preceding a Look-Locker echo planar imaging sequence was performed to obtain the inversion recovery curve of venous blood. The results showed that longitudinal relaxation time of blood at 7 T was ∼ 2.1 s which translates to an anticipated 33% gain in the signal-to-noise ratio in arterial spin labeling experiments due to T1 relaxation alone compared with 3 T. In addition, the linear relationship between longitudinal relaxation time of blood and B0 was confirmed.
authors.affiliation: Department of Radiology, C. J. Gorter Center for High Field MRI, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: X
authors.initials: X
authors.lastname: Zhang
authors.forename: E T
authors.initials: ET
authors.lastname: Petersen
authors.forename: E
authors.initials: E
authors.lastname: Ghariq
authors.forename: J B
authors.initials: JB
authors.lastname: De Vis
authors.forename: A G
authors.initials: AG
authors.lastname: Webb
authors.forename: W M
authors.initials: WM
authors.lastname: Teeuwisse
authors.forename: J
authors.initials: J
authors.lastname: Hendrikse
authors.forename: M J P
authors.initials: MJ
authors.lastname: van Osch
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D001810:Blood Volume / Q000502:physiology*; D001811:Blood Volume Determination / Q000379:methods*; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult