Novel method for rapid, simultaneous <i>T</i>₁, <i>T^*</i>₂, and proton density quantification

TLDR

The authors introduce QRAPTEST, an imaging technique that rapidly measures T1, T2*, and proton density in a single sequence. QRAPTEST uses a twin‑echo saturation‑recovery turbo‑field echo sequence with B1‑inhomogeneity estimation, validated against established techniques, and demonstrated whole‑brain quantification at 1.5 mm³ resolution in under eight minutes. The method produces high‑resolution, large‑volume images in 5–10 min, with accuracy that can be tuned to anticipated values. Published in Magn Reson Med 57:528–537, 2007 © Wiley‑Liss, Inc.

Abstract

Abstract An imaging method called “quantification of relaxation times and proton density by twin‐echo saturation‐recovery turbo‐field echo” (QRAPTEST) is presented as a means of quickly determining the longitudinal T 1 and transverse T relaxation time and proton density (PD) within a single sequence. The method also includes an estimation of the B 1 field inhomogeneity. High‐resolution images covering large volumes can be achieved within clinically acceptable times of 5–10 min. The range of accuracy for determining T 1 , T , and PD values is flexible and can be optimized relative to any anticipated values. We validated the experimental results against existing methods, and provide a clinical example in which quantification of the whole brain using 1.5 mm 3 voxels was achieved in less than 8 min. Magn Reson Med 57:528–537, 2007. © 2007 Wiley‐Liss, Inc.