Optimal Diffusion Gradient Encoding Scheme for Diffusion Tensor Imaging Based on Golden Ratio

Background The accuracy of the estimated diffusion tensor elements can be improved by using a well-chosen magnetic resonance imaging (MRI) diffusion gradient encoding scheme (DGES). Conversely, diffusion tensor imaging (DTI) is typically challenged by the subject's motion during data acquisition and results in corrupted image data. Purpose To identify a reliable DGES based on the golden ratio (GR) that can generate an arbitrary number of uniformly distributed directions to precisely estimate the DTI parameters of partially acquired datasets owing to subject motion. Study Type Prospective. Population Simulations study; three healthy volunteers. Field Strength/Sequence 3 T/DTI data were obtained using a single-shot echo planar imaging sequence. Statistical Tests A paired sample t-test and the Wilcoxon test were used, P < 0.05 was considered statistically significant. Assessment Two corrupted scenarios A and B were considered and evaluated. For the simulation study, the GR DGES and generated subsets were compared with the Jones and spiral DGESs by electric potential (EP) and condition number (CN). For the human study, the specific subsets A and B selected from scenarios A and B were used for MRI to evaluate fractional anisotropic (FA) map. Results For the simulation study, the EPs of the GR (14034.25 +/- 12957.24) DGES were significantly lower than the Jones (15112.81 +/- 13926.08) and spiral (14297.49 +/- 13232.94) DGESs. CN variations of GR (1.633 +/- 0.024) DGES were significantly lower than Jones (1.688 +/- 0.119) and spiral (4.387 +/- 2.915) DGESs. For the human study, GR (0.008 +/- 0.020) DGES performed similarly with Jones (0.008 +/- 0.022) DGES and was superior to spiral (0.022 +/- 0.054) DGES in the FA map error. Data Conclusion The GR DGES ensured that directions of the complete sets and subsets were uniform. The GR DGES had lower error propagation sensitivity, which can help image infants or patients who cannot stay still during scanning. Level of Evidence 2 Technical Efficacy Stage 1

Automated summary

The study aimed to identify a reliable diffusion gradient encoding scheme (DGES) based on the golden ratio (GR) to precisely estimate DTI parameters of partially acquired datasets due to subject motion, showing lower error propagation sensitivity compared to other encoding schemes.