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Updated: Jun 26, 2026

Magnetic Resonance Imaging Quantification of Pulmonary Perfusion using Calibrated Arterial Spin Labeling
Published on: May 31, 2011
Optimization of blood oxygenation level-dependent sensitivity in magnetic resonance imaging using intermolecular
Jianhui Zhong1, Zhong Chen, W Edmund Kwok
1Department of Radiology, University of Rochester, Rochester, New York, USA. jianhui.zhong@rochester.edu
Purpose:
To optimize timing parameters in an intermolecular double-quantum coherence (iDQC) imaging pulse sequence for overall image signal-to-noise ratio (SNR) and blood oxygenation level-dependent (BOLD) sensitivity for brain functional imaging.
Material And Methods:
Fresh human blood was measured under different oxygenation conditions, and human brain functional magnetic resonance (fMR) images in three normal volunteers were obtained, using iDQC techniques at 1.5 T. The dependence of SNR and BOLD sensitivity was measured as a function of time delays after the iDQC evolution period.
Results:
A time delay after the iDQC evolution period tau can be adjusted either to refocus the dephasing accumulated during tau, thus increasing SNR, with full rephasing occurring at delay = +/-2tau (for iDQC order n = +/-2), or to enhance BOLD effects with consequent reduced image SNR at delay = 0.
Conclusion:
Image SNR and BOLD sensitivity often impose different requirements for iDQC image sequence design and timing parameter selections. It is therefore important to select properly relevant parameters for different applications.
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