Practical T2 quantitation for clinical applications

TLDR

Magnetic resonance relaxation times have been studied for tissue characterization, yet in vivo clinical whole‑body imaging studies have not yet established their diagnostic role due to error‑prone techniques. The study systematically evaluates clinical T2 measurement problems to achieve reliable in vivo quantitation. The authors systematically assessed T2 measurement techniques, evaluating artifact suppression and phase‑scheme effectiveness. The study shows spoiler gradients best suppress artifacts but invalidate RF phase schemes, leading to a more reliable multi‑echo T2 sequence that performs well in preliminary brain and cervix clinical tests.

Abstract

Many studies have investigated the use of magnetic resonance relaxation times for tissue characterization. A number have been performed in vivo with clinical whole-body imagers. Unfortunately, the results have yet to establish the role of quantitative tissue relaxation time measurements in clinical diagnosis. One of the major problems is that the techniques used in many of these studies are error prone, making the results inconclusive. In the present study, the problems associated with clinical T2 measurements were systematically evaluated in an attempt to obtain reliable in vivo quantitation. The authors demonstrate that spoiler gradients are the most effective technique for artifact suppression but that they render ineffective radio-frequency phase schemes such as the Meiboom-Gill modification to the Carr-Purcell sequence to compensate experimental imperfections. The present study results in a more reliable multi-echo sequence for T2 measurement. Preliminary clinical results in brain and cervix demonstrate the performance of the new technique.