Quantitative T2 measurement of a single voxel with arbitrary shape using pinwheel excitation and CPMG acquisition

Qin Qin, John C. Gore, Robin A. De Graaf, Mark D. Does

Research output: Contribution to journalArticle

Abstract

Objective: The aim of this study is to present a new approach for making quantitative single-voxel T2 measurements from an arbitrarily shaped region of interest (ROI), where the advantage of the signal-to-noise ratio (SNR) per unit time of the single-voxel approach over conventional imaging approach can be achieved. Materials and methods: Two-dimensional (2D) spatially selective radiofrequency (RF) pulses are proposed in this work for T2 measurements based on using interleaved spiral trajectories in excitation k-space (pinwheel excitation pulses), combined with a summed Carr-Purcell Meiboom-Gill (CPMG) echo acquisition. The technique is described and compared to standard multi-echo imaging methods, on a two-compartment water phantom and an excised brain tissue. Results: The studies show good agreement between imaging and our method. The measured improvement factors of SNR per unit time of our single-voxel approach over imaging approach are close to the predicted values. Conclusion: Measuring T2 relaxation times from a selected ROI of arbitrary shape using a single-voxel rather than an imaging approach can increase the SNR per unit time, which is critical for dynamic T2 or multi-component T2 measurements.

Original languageEnglish (US)
Pages (from-to)233-240
Number of pages8
JournalMagnetic Resonance Materials in Physics, Biology and Medicine
Volume20
Issue number5-6
DOIs
StatePublished - Dec 1 2007

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Keywords

  • Arbitrary shape localization
  • CPMG
  • Interleaved spiral trajectory in k-space
  • T measurement

ASJC Scopus subject areas

  • Biophysics
  • Radiological and Ultrasound Technology
  • Radiology Nuclear Medicine and imaging

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