Abstract
PURPOSE: To standardize T 2 -weighted images from clinical Turbo Spin Echo (TSE) scans by generating corresponding T 2 maps with the goal of removing scanner- and/or protocol-specific heterogeneity. METHODS: The T 2 map is estimated by minimizing an objective function containing a data fidelity term in a Virtual Conjugate Coils (VCC) framework, where the signal evolution model is expressed as a linear constraint. The objective function is minimized by Projected Gradient Descent (PGD). RESULTS: The algorithm achieves accuracy comparable to methods with customized sampling schemes for accelerated T 2 mapping. The results are insensitive to the tunable parameters, and the relaxed background phase prior produces better T 2 maps compared to the strict real-value enforcement. It is worth noting that the algorithm works well with challenging T 2 w-TSE data using typical clinical parameters. The observed normalized root mean square error ranges from 6.8% to 12.3% over grey and white matter, a clinically common level of quantitative map error. CONCLUSION: The novel methodological development creates an efficient algorithm that allows for T 2 map generated from TSE data with typical clinical parameters, such as high resolution, long echo train length, and low echo spacing. Reconstruction of T 2 maps from TSE data with typical clinical parameters has not been previously reported.