- Poster presentation
- Open Access
Comparing the accuracy and precision of SMART1Map, SASHA and MOLLI
© Stainsby and Slavin; licensee BioMed Central Ltd. 2014
- Published: 16 January 2014
- High Heart Rate
- Relaxation Curve
- Saturation Recovery
- Heart Imaging
- Measure Delay Time
A phantom containing 22 samples of different T1s (200-1600 ms) and T1/T2 ratios (1.1 - 20.4) was imaged at 1.5T with MOLLI, SASHA, and SMART1Map using identical scan parameters. Scans were repeated 10 times each with simulated heart rates of 60 and 100 bpm. For SMART1Map and SASHA, T1 values were derived by curve fitting to A-B*exp[-TS/T1]. For MOLLI, A-B*exp[-TI/T1*] and the "Look-Locker correction" T1=(B/A-1)T1* were used. Reference T1s were determined with conventional single-point IR-spin echo.
The sampling strategy of MOLLI yields low variability for long T1s and a high reproducibility, however the Look-Locker approach leads to high variability at short T1s and a low accuracy. The reduced accuracy of SASHA at longer T1s and higher heart rates is likely due to the limited distribution of sample times relative to the relaxation curve. This will pose a challenge for applying SASHA in systole (e.g., for right heart imaging), at higher heart rates, for non-contrast imaging, and at 3T, all of which further compress the range of sample times. Because SMART1Map has the unique ability to precisely measure delay times greater than one cardiac cycle, it provides the best combination of true T1 accuracy, high T1 repeatability and low T1 variability.
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