Transverse relaxometry with transmit field-constrained stimulated echo compensation
| Autor: | Reza Basiri, Robert Marc Lebel, Paolo Federico |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Adult
Male Relaxometry Field (physics) Biophysics 030218 nuclear medicine & medical imaging Compensation (engineering) 03 medical and health sciences 0302 clinical medicine Image Interpretation Computer-Assisted Calibration Humans Radiology Nuclear Medicine and imaging Computer Simulation Exponential decay Physics Brain Mapping Radiological and Ultrasound Technology Phantoms Imaging Echo (computing) Brain Reproducibility of Results Models Theoretical Image Enhancement Magnetic Resonance Imaging Healthy Volunteers Exponential function Transverse plane Female Algorithm Algorithms |
| Zdroj: | Magma (New York, N.Y.). 32(6) |
| ISSN: | 1352-8661 |
| Popis: | Purely exponential decay is rarely observed in conventional mono-exponential T2 mapping due to transmit field inhomogeneity and calibration errors, which collectively introduce stimulated and indirect echo pathways. Stimulated echo correction (SEC) requires an additional fit parameter for the transmit field, resulting in greater uncertainty in T2 relative to mono-exponential fitting. The aim of this study was to develop an accurate and precise method for T2 mapping using SEC. The proposed method, called two-step SEC (tSEC), leverages spatial correlations in the transmit field to reduce the number of fully independent fitting parameters from three to two. The method involves a two-pass fit: the first pass involves a fast but standard SEC fit. The initially estimated transmit field is smoothed and provided as a fixed input to the second pass. Simulations and in vivo experiments demonstrated up to 38% and 27% decreases in relative T2 variance with tSEC relative to SEC. Average T2 values were unchanged between tSEC and SEC fits. The proposed method uses the same input data as SEC and exponential fits, so it is applicable to existing data. The proposed method generates reliable and reproducible quantitative T2 maps and should be considered for future relaxometry studies. |
| Databáze: | OpenAIRE |
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