التفاصيل البيبلوغرافية
العنوان: |
Validation of single reference variable flip angle (SR‐VFA) dynamic T1 mapping with T2* correction using a novel rotating phantom. |
المؤلفون: |
Malmberg, Michael A., Odéen, Henrik, Hofstetter, Lorne W., Hadley, J. Rock, Parker, Dennis L. |
المصدر: |
Magnetic Resonance in Medicine; Apr2024, Vol. 91 Issue 4, p1419-1433, 15p |
مصطلحات موضوعية: |
ANGLES, AGAR, ROTATIONAL motion, SPEED |
مستخلص: |
Purpose: To validate single reference variable flip angle (SR‐VFA) dynamic T1 mapping with and without T2* correction against inversion recovery (IR) T1 measurements. Methods: A custom cylindrical phantom with three concentric compartments was filled with variably doped agar to produce a smooth spatial gradient of the T1 relaxation rate as a function of angle across each compartment. IR T1, VFA T1, and B1+ measurements were made on the phantom before rotation, and multi‐echo stack‐of‐radial dynamic images were acquired during rotation via an MRI‐compatible motor. B1+‐corrected SR‐VFA and SR‐VFA‐T2* T1 maps were computed from the sliding window reconstructed images and compared against rotationally registered IR and VFA T1 maps to determine the percentage error. Results: Both VFA and SR‐VFA‐T2* T1 maps fell within 10% of IR T1 measurements for a low rotational speed, with a mean accuracy of 2.3% ± 2.6% and 2.8% ± 2.6%, respectively. Increasing rotational speed was found to decrease the accuracy due to increasing temporal smoothing over ranges where the T1 change had a nonconstant slope. SR‐VFA T1 mapping was found to have similar accuracy as the SR‐VFA‐T2* and VFA methods at low TEs (˜<2 ms), whereas accuracy degraded strongly with later TEs. T2* correction of the SR‐VFA T1 maps was found to consistently improve accuracy and precision, especially at later TEs. Conclusion: SR‐VFA‐T2* dynamic T1 mapping was found to be accurate against reference IR T1 measurements within 10% in an agar phantom. Further validation is needed in mixed fat–water phantoms and in vivo. [ABSTRACT FROM AUTHOR] |
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قاعدة البيانات: |
Complementary Index |