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[Dynamic contrast-enhanced T(1) measuring MRI using variable flip angle SPGR]
Yoshiyuki Ishimori1, Hirohiko Kimura, Tsuyoshi Matsuda
1Radiological Center, Fukui Medical University Hospital.
Abstract:
We modified the multi-phase spoiled gradient recalled echo (SPGR) pulse sequence using the double-echo MR technique for estimation of T(1) during the first pass of contrast agent, and examined its precision. In the first half of the pulse sequence, the flip angle was varied systematically to calculate static T(1) values. It was necessary to choose optimal flip angles to minimize the calculation error of static T(1) values. In the latter half of this sequence, changes in absolute T(1) were calculated using differences in signal intensities before and after the injection of contrast agent. The optimal flip angle was 20 degrees for precise conversion to T(1) values under the short TR (33.3 ms) condition. Double echo MR data were used to minimize the T(2)* effect. The present method appears to be useful for quantitative estimation of dynamic contrast-enhanced MRI.
Insights
This study introduces a modified multi-phase spoiled gradient recalled echo (SPGR) sequence for precise T(1) estimation during contrast agent first pass. The optimized method enhances quantitative dynamic contrast-enhanced MRI accuracy.
Area of Science:
- Magnetic Resonance Imaging (MRI)
- Biomedical Engineering
- Radiology
Context:
- Dynamic contrast-enhanced MRI (DCE-MRI) is crucial for assessing tissue perfusion and vascularity.
- Accurate T(1) quantification is essential for reliable DCE-MRI analysis.
- Existing methods may face challenges with precision and speed.
Purpose:
- To develop and validate a modified multi-phase spoiled gradient recalled echo (SPGR) pulse sequence for precise T(1) estimation.
- To optimize flip angles for accurate static T(1) calculation.
- To assess the utility of the double-echo MR technique for minimizing T(2)* effects in dynamic T(1) mapping.
Summary:
- A novel double-echo MR technique was integrated into a multi-phase SPGR sequence.
- Systematic variation of flip angles allowed for precise static T(1) value calculation, with an optimal angle of 20 degrees identified.
- Absolute T(1) changes were determined by signal intensity differences before and after contrast agent injection, utilizing double echo data to mitigate T(2)* influences.
Impact:
- The developed method offers a precise and quantitative approach for estimating T(1) during the first pass of contrast agents.
- This advancement holds potential for improving the accuracy and reliability of dynamic contrast-enhanced MRI.
- Facilitates more robust assessment of physiological parameters in various clinical applications.
