title: Dependence of transverse relaxation time T2 of biologic tissues on the interpulse delay time in Carr-Purcell-Meiboom-Gill (CPMG) measurements.
abstract: To determine the transverse relaxation time (T2) of biological tissues in nuclear magnetic resonance measurements, the Carr-Purcell-Meiboom-Gill (CPMG) method has been recommended to avoid the effect of external magnetic field inhomogeneity on T2 values. However, a dependence of T2 on the interpulse delay time (IPDT) in the CPMG measurements has been shown for biological tissues. The present study examined the dependence of the T2 on IPDT for muscle, lung (passively collapsed or degassed), and brain tissues. It was found that the CPMG T2 of the lung was strongly dependent upon the IPDT, in contrast to muscle and brain tissues. The IPDT dependence of the CPMG T2 for lung tissue, which was lessened by degassing, was affected by the magnetic field inhomogeneity due to air-tissue interfaces, but not by the spin-locking effect, since the T2 measured by the Carr-Purcell-Freeman-Hill (CPFH) method did not show this dependence. These results should aid in the evaluation of T2 values for biological tissues measured under various conditions and by different techniques.
authors.affiliation: Department of Internal Medicine, Tokai University School of Medicine, Kanagawa, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Shioya
authors.forename: D
authors.initials: D
authors.lastname: Kurita
authors.forename: M
authors.initials: M
authors.lastname: Haida
authors.forename: M
authors.initials: M
authors.lastname: Fukuzaki
authors.forename: T
authors.initials: T
authors.lastname: Tanigaki
authors.forename: T
authors.initials: T
authors.lastname: Kutsuzawa
authors.forename: Y
authors.initials: Y
authors.lastname: Ohta
mesh_terms: D000818:Animals; D001921:Brain / Q000033:anatomy & histology*; D008168:Lung / Q000033:anatomy & histology*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D018482:Muscle, Skeletal / Q000033:anatomy & histology*; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors