Journals
Books
Articles by keyword Пирс
New Approach to Analysis of the Strongly-Correlated Acoustic Sequences: Detection of the States of the Bees Clusters
R.R. Nigmatullin, V.A. Toboev
Algorihms for control of heterogeneity in absorbing coatings
P.A. Fedyunin, A.I., Kazmin, O.E. Kiryanov
Dynamic infocognitive model of verbal consciousness
Yu.N. Philippovich, A.Yu. Philippovich
Management method radio engineering system in conditions parametric uncertainty of model of a vector of a condition
V.A. Pogorelov - Dr.Sc. (Eng.), Associate Professor, Leading Researcher, FRPC «RNIIRS» A.S. Mit-kin - Leader of Sector, FRPC «RNIIRS»
Neuropragmatism as a justificative stategy of cognitive science
M.D. Terekhov - Post-Graduate Student, Chair of Philosophy and Methodology of Science, Philosophy Faculty, Lomonosov Moscow State University. E-mail: stereodrome@yandex.ru
On the use of Pearson distributions in the modeling of image registration parameters\' recursive estimation
A.G. Tashlinskii - Dr. Sc. (Eng.), Professor, Head of Department «Radio Engineering», Ulyanovsk State Technical University E-mail: tag@ulstu.ru I.V. Voronov - Post-graduate Student, Department «Radio Engineering», Ulyanovsk State Technical University E-mail: i.voronov@ulstu.ru
Measuring T2 relaxation time in MRI gradient echo sequences

In magnetic resonance imaging (MRI), the gradient recalled echo (GRE) sequence became a powerful tool for classification of biological tissues due its sensitivity to structural heterogeneities of mesoscopic and macroscopic scale. The atomic scale heterogeneities, determined by spin-spin interaction of protons, can be imaged in contrast of transverse relaxation time T2, obtained in spin-echo (SE) sequence. For many years, the SE sequence was the only way to measure T2 accurately because, in GRE sequence, this parameter is masked by more rapid decay of the signal due to magnetic gradients. First attempts to evaluate - even not exactly measure - T2 in GRE sequences revealed serious algorithmic problems. Recently introduced new solution to this problem - multipoint algorithm with clamping (MPC) - opens the possibility for accurate and fast measurements of T2 in GRE sequences. The present short communication presents quantitative statistical confirmation of its performance on phantoms. It is shown that MPC algorithm produces accurate measurements of T2 in GRE sequences with average discrepancies of about 2% on small magnetic heterogeneities and 8% on the large ones with Pearson coefficients in the range 0.9-0.95. Commonly accepted in practice evaluation of T2 on GRE sequences by means of monoexponential fitting (the so-called  values) gives inadequate average values with errors of about 30% and Pearson coefficient of only 0.7.